Discussion:
[PATCH v7 00/15] i2c-octeon and i2c-thunderx drivers
(too old to reply)
Jan Glauber
2016-04-25 14:34:05 UTC
Permalink
Hi Wolfram,

v7 implements the changes from your review plus some comments from David.
I've moved the flush writeq patch before the HLC patch, because it is
already needed there and seems quite trivial and I've added a new patch
to disable the SMBUS QUICK support as discussed.

This series for the Octeon i2c driver is an attempt to upstream some
bug fixes and features that accumulated for some time.

On top of the Octeon changes a i2c driver for the ThunderX SOC is
added which uses the same functional block as the Octeon driver.

Patches are on top of next-20160422 and were tested on OCTEON, OCTEON-78
and ThunderX.

Changes to v6:
- Fixed read_int kerneldoc
- Removed udelay after write-int in recovery
- Killed retries in recovery, use EAGAIN
- Disable SMBUS QUICK and remove unneeded length check
- Spell out enable/disable
- Switch to wait_event_timeout
- Removed superfluous status check in HLC write
- Optimize wait-queue also for HLC
- Use readq/writeq instead of __raw_* in some places
- Add STAT_IDLE to status check (valid after a write)

Changes to v5:
- Switch to i2c recovery framework
- Clean-up register access, introduce new helper functions
- Fixed ready bit check in combined write
- Fixed IFLG clear in hlc_enable
- Removed complicated last phase logic, not needed when we send
START for every message part

Changes to v4:
- Splitted the High-Level Controller patch into several patches
- Reworded some commit messages

Changes to v3:
- Added more functionality flags for SMBUS
- Removed both module parameters
- Make xfer return also other errors than EGAIN
- Return EPROTO on invalid SMBUS block length
- Use devm_ioremap_resource
- Added rename-only patch
- Removed kerneldoc patch from series
- Improved defines

Changes to v2:
- Split clenaup patch into several patches
- Strictly moved functional changes to later patches
- Fixed do-while checkpatch errors
- Moved defines to the patches that use them
- Use BIT_ULL macro
- Split ThunderX patch into 2 patches

Changes to v1:
- Fixed compile error on x86_64
- Disabled thunderx driver on MIPS
- Re-ordered some thunderx probe functions for readability
- Fix missing of_irq.h and i2c-smbus.h includes
- Use IS_ENABLED for CONFIG options

Jan

-------------------------------------------------



David Daney (3):
i2c: octeon: Enable High-Level Controller
i2c: octeon: Add support for cn78xx chips
i2c: octeon: Add workaround for broken irqs on CN3860

Jan Glauber (10):
i2c: octeon: Improve error status checking
i2c: octeon: Use i2c recovery framework
i2c: octeon: Remove I2C_FUNC_SMBUS_QUICK support
dt-bindings: i2c: Add Octeon cn78xx TWSI
i2c: octeon: Move read function before write
i2c: octeon: Rename driver to prepare for split
i2c: octeon: Split the driver into two parts
i2c: thunderx: Add i2c driver for ThunderX SOC
i2c: octeon,thunderx: Move register offsets to struct
i2c: thunderx: Add smbus alert support

Peter Swain (2):
i2c: octeon: Add flush writeq helper function
i2c: octeon: Improve performance if interrupt is early

.../devicetree/bindings/i2c/i2c-octeon.txt | 6 +
drivers/i2c/busses/Kconfig | 10 +
drivers/i2c/busses/Makefile | 3 +
drivers/i2c/busses/i2c-cavium.c | 799 +++++++++++++++++++++
drivers/i2c/busses/i2c-cavium.h | 214 ++++++
drivers/i2c/busses/i2c-octeon-core.c | 288 ++++++++
drivers/i2c/busses/i2c-octeon.c | 606 ----------------
drivers/i2c/busses/i2c-thunderx-core.c | 306 ++++++++
8 files changed, 1626 insertions(+), 606 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-cavium.c
create mode 100644 drivers/i2c/busses/i2c-cavium.h
create mode 100644 drivers/i2c/busses/i2c-octeon-core.c
delete mode 100644 drivers/i2c/busses/i2c-octeon.c
create mode 100644 drivers/i2c/busses/i2c-thunderx-core.c
--
1.9.1
Jan Glauber
2016-04-25 14:34:10 UTC
Permalink
SMBUS QUICK never worked for the read case, because EINVAL was returned
for a zero length message. The hardware does not support SMBUS QUICK
messages so disable the support and remove the zero length check.

Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 0f536a1..ad563cf 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -459,9 +459,6 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
int i, result, length = *rlength;
bool final_read = false;

- if (length < 1)
- return -EINVAL;
-
octeon_i2c_data_write(i2c, (target << 1) | 1);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);

@@ -597,7 +594,7 @@ static struct i2c_bus_recovery_info octeon_i2c_recovery_info = {

static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
}
--
1.9.1
David Daney
2016-04-25 22:43:22 UTC
Permalink
Post by Jan Glauber
SMBUS QUICK never worked for the read case, because EINVAL was returned
for a zero length message. The hardware does not support SMBUS QUICK
messages so disable the support and remove the zero length check.
I see better now and I think we need to drop this patch. It looks like
the driver supports only SMBUS_QUICK_WRITE which can be used for
scanning devices. The driver probably works with 'i2cdetect -q'. This
will regress if I apply the patch.
It seems it can't do SMBUS_QUICK_READ thus the extra check in the code.
I2C_FUNC_SMBUS_QUICK should have been split up in READ and WRITE to
support this scenario.
Are my assumptions correct?
I think you may be reading too much into the intent of the code.

I don't know that anyone has ever run "i2cdetect -q" on these buses, I
know that I haven't. Since I2C is inherently unprobable, we specify the
presence of all devices from the device tree passed by system firmware.
Runtime scanning for devices is not necessary.

That said, it is not a big deal one way or the other with respect to
this patch. If someone verifies that "i2cdetect -q" does something
sensible, then there is probably no harm in dropping this patch.
Post by Jan Glauber
---
drivers/i2c/busses/i2c-octeon.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 0f536a1..ad563cf 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -459,9 +459,6 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
int i, result, length = *rlength;
bool final_read = false;
- if (length < 1)
- return -EINVAL;
-
octeon_i2c_data_write(i2c, (target << 1) | 1);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
@@ -597,7 +594,7 @@ static struct i2c_bus_recovery_info octeon_i2c_recovery_info = {
static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
}
--
1.9.1
Jan Glauber
2016-04-26 06:13:57 UTC
Permalink
Post by Jan Glauber
SMBUS QUICK never worked for the read case, because EINVAL was returned
for a zero length message. The hardware does not support SMBUS QUICK
messages so disable the support and remove the zero length check.
I see better now and I think we need to drop this patch. It looks like
the driver supports only SMBUS_QUICK_WRITE which can be used for
scanning devices. The driver probably works with 'i2cdetect -q'. This
will regress if I apply the patch.
It seems it can't do SMBUS_QUICK_READ thus the extra check in the code.
I2C_FUNC_SMBUS_QUICK should have been split up in READ and WRITE to
support this scenario.
Are my assumptions correct?
Yes, I thought briefly about splitting SMBUS_QUICK into read-write
variants too. To me the question is if this feature is still used on modern
devices or if this is more a relict of the past. I don't know enough
about SMBUS to answer that.

Also, the ThunderX documentation does not mention that it is supported.
The read case would be forbidden by the documentation (that was probably
the reason for adding the read EINVAL). The write case is kind of a grey
area, it might or might not work.

I'll see what i2cdetect does.

Thanks,
Jan
Post by Jan Glauber
---
drivers/i2c/busses/i2c-octeon.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 0f536a1..ad563cf 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -459,9 +459,6 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
int i, result, length = *rlength;
bool final_read = false;
- if (length < 1)
- return -EINVAL;
-
octeon_i2c_data_write(i2c, (target << 1) | 1);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
@@ -597,7 +594,7 @@ static struct i2c_bus_recovery_info octeon_i2c_recovery_info = {
static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
}
--
1.9.1
Jan Glauber
2016-04-26 06:43:08 UTC
Permalink
Post by Jan Glauber
Post by Jan Glauber
SMBUS QUICK never worked for the read case, because EINVAL was returned
for a zero length message. The hardware does not support SMBUS QUICK
messages so disable the support and remove the zero length check.
I see better now and I think we need to drop this patch. It looks like
the driver supports only SMBUS_QUICK_WRITE which can be used for
scanning devices. The driver probably works with 'i2cdetect -q'. This
will regress if I apply the patch.
It seems it can't do SMBUS_QUICK_READ thus the extra check in the code.
I2C_FUNC_SMBUS_QUICK should have been split up in READ and WRITE to
support this scenario.
Are my assumptions correct?
Yes, I thought briefly about splitting SMBUS_QUICK into read-write
variants too. To me the question is if this feature is still used on modern
devices or if this is more a relict of the past. I don't know enough
about SMBUS to answer that.
Also, the ThunderX documentation does not mention that it is supported.
The read case would be forbidden by the documentation (that was probably
the reason for adding the read EINVAL). The write case is kind of a grey
area, it might or might not work.
I'll see what i2cdetect does.
Checking on ThunderX:

[***@localhost linux-aarch64]# i2cdetect -q 0
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-0 using quick write commands.
I will probe address range 0x03-0x77.
Continue? [Y/n]
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
30: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
40: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
60: 60 61 62 63 64 65 66 67 UU 69 6a 6b 6c 6d 6e 6f
70: 70 71 72 73 74 75 76 77

Address 68 is the only device (rtc clock, module loaded).

Do all these other numbers make sense (although there are no
devices)?

--Jan
Jan Glauber
2016-04-26 12:35:10 UTC
Permalink
Post by Jan Glauber
Post by Jan Glauber
Yes, I thought briefly about splitting SMBUS_QUICK into read-write
variants too. To me the question is if this feature is still used on modern
devices or if this is more a relict of the past. I don't know enough
about SMBUS to answer that.
Well, note that there are zero-length messages in I2C allowed as well.
Not only in SMBUS. I mainly use the term SMBUS_QUICK because it covers
both cases.
...
Post by Jan Glauber
Do all these other numbers make sense (although there are no
devices)?
It makes sense in a way that it shows SMBUS_QUICK_WRITE is broken :) It
1) remove SMBUS_QUICK as you did in this patch 2) move the length check
so it doesn't only check read messages but also write messages. That is
to prevent handling custom setup I2C messages with a length of 0 (which
is legal). I'd suggest to return -EOPNOTSUPP in this case.
OK, I'll do that. Should I rebase the remaining patches or would you
like to review them first ? :)

Thanks,
Jan
Thanks,
Wolfram
Jan Glauber
2016-04-25 14:34:19 UTC
Permalink
Add compatible string for Cavium Octeon cn78XX SOCs TWSI.

Cc: Rob Herring <robh+***@kernel.org>
Cc: Pawel Moll <***@arm.com>
Cc: Mark Rutland <***@arm.com>
Cc: Ian Campbell <ijc+***@hellion.org.uk>
Cc: Kumar Gala <***@codeaurora.org>

Signed-off-by: Jan Glauber <***@cavium.com>
Acked-by: David Daney <***@caviumnetworks.com>
---
Documentation/devicetree/bindings/i2c/i2c-octeon.txt | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-octeon.txt b/Documentation/devicetree/bindings/i2c/i2c-octeon.txt
index dced82e..872d485 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-octeon.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-octeon.txt
@@ -4,6 +4,12 @@

Compatibility with all cn3XXX, cn5XXX and cn6XXX SOCs.

+ or
+
+ compatible: "cavium,octeon-7890-twsi"
+
+ Compatibility with cn78XX SOCs.
+
- reg: The base address of the TWSI/I2C bus controller register bank.

- #address-cells: Must be <1>.
--
1.9.1
Jan Glauber
2016-04-25 14:34:26 UTC
Permalink
Move common functionality into a separate file in preparation of the
re-use from the ThunderX i2c driver.

Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/Makefile | 3 +-
drivers/i2c/busses/i2c-cavium.c | 799 +++++++++++++++++++++++++++++
drivers/i2c/busses/i2c-cavium.h | 197 +++++++
drivers/i2c/busses/i2c-octeon-core.c | 963 +----------------------------------
4 files changed, 999 insertions(+), 963 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-cavium.c
create mode 100644 drivers/i2c/busses/i2c-cavium.h

diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 3405286..282f781 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -91,7 +91,8 @@ obj-$(CONFIG_I2C_UNIPHIER) += i2c-uniphier.o
obj-$(CONFIG_I2C_UNIPHIER_F) += i2c-uniphier-f.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
obj-$(CONFIG_I2C_WMT) += i2c-wmt.o
-obj-$(CONFIG_I2C_OCTEON) += i2c-octeon-core.o
+i2c-octeon-objs := i2c-cavium.o i2c-octeon-core.o
+obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
obj-$(CONFIG_I2C_XLR) += i2c-xlr.o
obj-$(CONFIG_I2C_XLP9XX) += i2c-xlp9xx.o
diff --git a/drivers/i2c/busses/i2c-cavium.c b/drivers/i2c/busses/i2c-cavium.c
new file mode 100644
index 0000000..ac37ae1
--- /dev/null
+++ b/drivers/i2c/busses/i2c-cavium.c
@@ -0,0 +1,799 @@
+/*
+ * (C) Copyright 2009-2010
+ * Nokia Siemens Networks, ***@nsn.com
+ *
+ * Portions Copyright (C) 2010 - 2016 Cavium, Inc.
+ *
+ * This file contains the shared part of the driver for the i2c adapter in
+ * Cavium Networks' OCTEON processors and ThunderX SOCs.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "i2c-cavium.h"
+
+/* interrupt service routine */
+irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
+{
+ struct octeon_i2c *i2c = dev_id;
+
+ i2c->int_disable(i2c);
+ wake_up(&i2c->queue);
+
+ return IRQ_HANDLED;
+}
+
+static bool octeon_i2c_test_iflg(struct octeon_i2c *i2c)
+{
+ return (octeon_i2c_ctl_read(i2c) & TWSI_CTL_IFLG);
+}
+
+static bool octeon_i2c_test_ready(struct octeon_i2c *i2c, bool *first)
+{
+ if (octeon_i2c_test_iflg(i2c))
+ return true;
+
+ if (*first) {
+ *first = false;
+ return false;
+ }
+
+ /*
+ * IRQ has signaled an event but IFLG hasn't changed.
+ * Sleep and retry once.
+ */
+ usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+ return octeon_i2c_test_iflg(i2c);
+}
+
+/**
+ * octeon_i2c_wait - wait for the IFLG to be set
+ * @i2c: The struct octeon_i2c
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_wait(struct octeon_i2c *i2c)
+{
+ long time_left;
+ bool first = 1;
+
+ /*
+ * Some chip revisions don't assert the irq in the interrupt
+ * controller. So we must poll for the IFLG change.
+ */
+ if (i2c->broken_irq_mode) {
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_test_iflg(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ udelay(50);
+
+ return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
+ }
+
+ i2c->int_enable(i2c);
+ time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
+ i2c->adap.timeout);
+ i2c->int_disable(i2c);
+
+ if (i2c->broken_irq_check && !time_left &&
+ octeon_i2c_test_iflg(i2c)) {
+ dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
+ }
+
+ if (!time_left)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c)
+{
+ return (__raw_readq(i2c->twsi_base + SW_TWSI) & SW_TWSI_V) == 0;
+}
+
+static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c, bool *first)
+{
+ /* check if valid bit is cleared */
+ if (octeon_i2c_hlc_test_valid(i2c))
+ return true;
+
+ if (*first) {
+ *first = false;
+ return false;
+ }
+
+ /*
+ * IRQ has signaled an event but valid bit isn't cleared.
+ * Sleep and retry once.
+ */
+ usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+ return octeon_i2c_hlc_test_valid(i2c);
+}
+
+static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
+{
+ /* clear ST/TS events, listen for neither */
+ octeon_i2c_write_int(i2c, TWSI_INT_ST_INT | TWSI_INT_TS_INT);
+}
+
+/*
+ * Cleanup low-level state & enable high-level controller.
+ */
+static void octeon_i2c_hlc_enable(struct octeon_i2c *i2c)
+{
+ int try = 0;
+ u64 val;
+
+ if (i2c->hlc_enabled)
+ return;
+ i2c->hlc_enabled = true;
+
+ while (1) {
+ val = octeon_i2c_ctl_read(i2c);
+ if (!(val & (TWSI_CTL_STA | TWSI_CTL_STP)))
+ break;
+
+ /* clear IFLG event */
+ if (val & TWSI_CTL_IFLG)
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+
+ if (try++ > 100) {
+ pr_err("%s: giving up\n", __func__);
+ break;
+ }
+
+ /* spin until any start/stop has finished */
+ udelay(10);
+ }
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_CE | TWSI_CTL_AAK | TWSI_CTL_ENAB);
+}
+
+static void octeon_i2c_hlc_disable(struct octeon_i2c *i2c)
+{
+ if (!i2c->hlc_enabled)
+ return;
+
+ i2c->hlc_enabled = false;
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+}
+
+/**
+ * octeon_i2c_hlc_wait - wait for an HLC operation to complete
+ * @i2c: The struct octeon_i2c
+ *
+ * Returns 0 on success, otherwise -ETIMEDOUT.
+ */
+static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
+{
+ bool first = 1;
+ int time_left;
+
+ /*
+ * Some cn38xx boards don't assert the irq in the interrupt
+ * controller. So we must poll for the valid bit change.
+ */
+ if (i2c->broken_irq_mode) {
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_hlc_test_valid(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ udelay(50);
+
+ return octeon_i2c_hlc_test_valid(i2c) ? 0 : -ETIMEDOUT;
+ }
+
+ i2c->hlc_int_enable(i2c);
+ time_left = wait_event_timeout(i2c->queue,
+ octeon_i2c_hlc_test_ready(i2c, &first),
+ i2c->adap.timeout);
+ i2c->hlc_int_disable(i2c);
+ if (!time_left)
+ octeon_i2c_hlc_int_clear(i2c);
+
+ if (i2c->broken_irq_check && !time_left &&
+ octeon_i2c_hlc_test_valid(i2c)) {
+ dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
+ }
+
+ if (!time_left)
+ return -ETIMEDOUT;
+ return 0;
+}
+
+static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
+{
+ u8 stat = octeon_i2c_stat_read(i2c);
+
+ switch (stat) {
+ /* Everything is fine */
+ case STAT_IDLE:
+ case STAT_AD2W_ACK:
+ case STAT_RXADDR_ACK:
+ case STAT_TXADDR_ACK:
+ case STAT_TXDATA_ACK:
+ return 0;
+
+ /* ACK allowed on pre-terminal bytes only */
+ case STAT_RXDATA_ACK:
+ if (!final_read)
+ return 0;
+ return -EIO;
+
+ /* NAK allowed on terminal byte only */
+ case STAT_RXDATA_NAK:
+ if (final_read)
+ return 0;
+ return -EIO;
+
+ /* Arbitration lost */
+ case STAT_LOST_ARB_38:
+ case STAT_LOST_ARB_68:
+ case STAT_LOST_ARB_78:
+ case STAT_LOST_ARB_B0:
+ return -EAGAIN;
+
+ /* Being addressed as slave, should back off & listen */
+ case STAT_SLAVE_60:
+ case STAT_SLAVE_70:
+ case STAT_GENDATA_ACK:
+ case STAT_GENDATA_NAK:
+ return -EOPNOTSUPP;
+
+ /* Core busy as slave */
+ case STAT_SLAVE_80:
+ case STAT_SLAVE_88:
+ case STAT_SLAVE_A0:
+ case STAT_SLAVE_A8:
+ case STAT_SLAVE_LOST:
+ case STAT_SLAVE_NAK:
+ case STAT_SLAVE_ACK:
+ return -EOPNOTSUPP;
+
+ case STAT_TXDATA_NAK:
+ return -EIO;
+ case STAT_TXADDR_NAK:
+ case STAT_RXADDR_NAK:
+ case STAT_AD2W_NAK:
+ return -ENXIO;
+ default:
+ dev_err(i2c->dev, "unhandled state: %d\n", stat);
+ return -EIO;
+ }
+}
+
+static int octeon_i2c_recovery(struct octeon_i2c *i2c)
+{
+ int ret;
+
+ ret = i2c_recover_bus(&i2c->adap);
+ if (ret)
+ /* recover failed, try hardware re-init */
+ ret = octeon_i2c_init_lowlevel(i2c);
+ return ret;
+}
+
+/**
+ * octeon_i2c_start - send START to the bus
+ * @i2c: The struct octeon_i2c
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_start(struct octeon_i2c *i2c)
+{
+ int ret;
+ u8 stat;
+
+ octeon_i2c_hlc_disable(i2c);
+
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
+ ret = octeon_i2c_wait(i2c);
+ if (ret)
+ goto error;
+
+ stat = octeon_i2c_stat_read(i2c);
+ if (stat == STAT_START || stat == STAT_REP_START)
+ /* START successful, bail out */
+ return 0;
+
+error:
+ /* START failed, try to recover */
+ ret = octeon_i2c_recovery(i2c);
+ return (ret) ? ret : -EAGAIN;
+}
+
+/* send STOP to the bus */
+static void octeon_i2c_stop(struct octeon_i2c *i2c)
+{
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STP);
+}
+
+/**
+ * octeon_i2c_read - receive data from the bus via low-level controller
+ * @i2c: The struct octeon_i2c
+ * @target: Target address
+ * @data: Pointer to the location to store the data
+ * @rlength: Length of the data
+ * @recv_len: flag for length byte
+ *
+ * The address is sent over the bus, then the data is read.
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
+ u8 *data, u16 *rlength, bool recv_len)
+{
+ int i, result, length = *rlength;
+ bool final_read = false;
+
+ octeon_i2c_data_write(i2c, (target << 1) | 1);
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+
+ result = octeon_i2c_wait(i2c);
+ if (result)
+ return result;
+
+ /* address OK ? */
+ result = octeon_i2c_check_status(i2c, false);
+ if (result)
+ return result;
+
+ for (i = 0; i < length; i++) {
+ /* for the last byte TWSI_CTL_AAK must not be set */
+ if (i + 1 == length)
+ final_read = true;
+
+ /* clear iflg to allow next event */
+ if (final_read)
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+ else
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_AAK);
+
+ result = octeon_i2c_wait(i2c);
+ if (result)
+ return result;
+
+ data[i] = octeon_i2c_data_read(i2c);
+ if (recv_len && i == 0) {
+ if (data[i] > I2C_SMBUS_BLOCK_MAX + 1) {
+ dev_err(i2c->dev,
+ "%s: read len > I2C_SMBUS_BLOCK_MAX %d\n",
+ __func__, data[i]);
+ return -EPROTO;
+ }
+ length += data[i];
+ }
+
+ result = octeon_i2c_check_status(i2c, final_read);
+ if (result)
+ return result;
+ }
+ *rlength = length;
+ return 0;
+}
+
+/**
+ * octeon_i2c_write - send data to the bus via low-level controller
+ * @i2c: The struct octeon_i2c
+ * @target: Target address
+ * @data: Pointer to the data to be sent
+ * @length: Length of the data
+ *
+ * The address is sent over the bus, then the data.
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
+ const u8 *data, int length)
+{
+ int i, result;
+
+ octeon_i2c_data_write(i2c, target << 1);
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+
+ result = octeon_i2c_wait(i2c);
+ if (result)
+ return result;
+
+ for (i = 0; i < length; i++) {
+ result = octeon_i2c_check_status(i2c, false);
+ if (result)
+ return result;
+
+ octeon_i2c_data_write(i2c, data[i]);
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+
+ result = octeon_i2c_wait(i2c);
+ if (result)
+ return result;
+ }
+
+ return 0;
+}
+
+/* high-level-controller pure read of up to 8 bytes */
+static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ int i, j, ret = 0;
+ u64 cmd;
+
+ octeon_i2c_hlc_enable(i2c);
+ octeon_i2c_hlc_int_clear(i2c);
+
+ cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10;
+ else
+ cmd |= SW_TWSI_OP_7;
+
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+
+ for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
+ msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
+
+ if (msgs[0].len > 4) {
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+ for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
+ msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
+ }
+
+err:
+ return ret;
+}
+
+/* high-level-controller pure write of up to 8 bytes */
+static int octeon_i2c_hlc_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ int i, j, ret = 0;
+ u64 cmd;
+
+ octeon_i2c_hlc_enable(i2c);
+ octeon_i2c_hlc_int_clear(i2c);
+
+ cmd = SW_TWSI_V | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10;
+ else
+ cmd |= SW_TWSI_OP_7;
+
+ for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
+ cmd |= (u64)msgs[0].buf[j] << (8 * i);
+
+ if (msgs[0].len > 4) {
+ u64 ext = 0;
+
+ for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
+ ext |= (u64) msgs[0].buf[j] << (8 * i);
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+ }
+
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+
+ ret = octeon_i2c_check_status(i2c, false);
+
+err:
+ return ret;
+}
+
+/* high-level-controller composite write+read, msg0=addr, msg1=data */
+static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ int i, j, ret = 0;
+ u64 cmd;
+
+ octeon_i2c_hlc_enable(i2c);
+
+ cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64)(msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10_IA;
+ else
+ cmd |= SW_TWSI_OP_7_IA;
+
+ if (msgs[0].len == 2) {
+ u64 ext = 0;
+
+ cmd |= SW_TWSI_EIA;
+ ext = (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+ cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+ } else
+ cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+
+ octeon_i2c_hlc_int_clear(i2c);
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+
+ for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
+ msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
+
+ if (msgs[1].len > 4) {
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+ for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
+ msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
+ }
+
+err:
+ return ret;
+}
+
+/* high-level-controller composite write+write, m[0]len<=2, m[1]len<=8 */
+static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ bool set_ext = false;
+ int i, j, ret = 0;
+ u64 cmd, ext = 0;
+
+ octeon_i2c_hlc_enable(i2c);
+
+ cmd = SW_TWSI_V | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64) (msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10_IA;
+ else
+ cmd |= SW_TWSI_OP_7_IA;
+
+ if (msgs[0].len == 2) {
+ cmd |= SW_TWSI_EIA;
+ ext |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+ set_ext = true;
+ cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
+ } else
+ cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+
+ for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
+ cmd |= (u64) msgs[1].buf[j] << (8 * i);
+
+ if (msgs[1].len > 4) {
+ for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
+ ext |= (u64)msgs[1].buf[j] << (8 * i);
+ set_ext = true;
+ }
+ if (set_ext)
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+
+ octeon_i2c_hlc_int_clear(i2c);
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+
+ ret = octeon_i2c_check_status(i2c, false);
+
+err:
+ return ret;
+}
+
+/**
+ * octeon_i2c_xfer - The driver's master_xfer function
+ * @adap: Pointer to the i2c_adapter structure
+ * @msgs: Pointer to the messages to be processed
+ * @num: Length of the MSGS array
+ *
+ * Returns the number of messages processed, or a negative errno on failure.
+ */
+int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+ int i, ret = 0;
+
+ if (num == 1) {
+ if (msgs[0].len > 0 && msgs[0].len <= 8) {
+ if (msgs[0].flags & I2C_M_RD)
+ ret = octeon_i2c_hlc_read(i2c, msgs);
+ else
+ ret = octeon_i2c_hlc_write(i2c, msgs);
+ goto out;
+ }
+ } else if (num == 2) {
+ if ((msgs[0].flags & I2C_M_RD) == 0 &&
+ (msgs[1].flags & I2C_M_RECV_LEN) == 0 &&
+ msgs[0].len > 0 && msgs[0].len <= 2 &&
+ msgs[1].len > 0 && msgs[1].len <= 8 &&
+ msgs[0].addr == msgs[1].addr) {
+ if (msgs[1].flags & I2C_M_RD)
+ ret = octeon_i2c_hlc_comp_read(i2c, msgs);
+ else
+ ret = octeon_i2c_hlc_comp_write(i2c, msgs);
+ goto out;
+ }
+ }
+
+ for (i = 0; ret == 0 && i < num; i++) {
+ struct i2c_msg *pmsg = &msgs[i];
+
+ ret = octeon_i2c_start(i2c);
+ if (ret)
+ return ret;
+
+ if (pmsg->flags & I2C_M_RD)
+ ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
+ &pmsg->len, pmsg->flags & I2C_M_RECV_LEN);
+ else
+ ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
+ pmsg->len);
+ }
+ octeon_i2c_stop(i2c);
+out:
+ return (ret != 0) ? ret : num;
+}
+
+/* calculate and set clock divisors */
+void octeon_i2c_set_clock(struct octeon_i2c *i2c)
+{
+ int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff;
+ int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = 1000000;
+
+ for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) {
+ /*
+ * An mdiv value of less than 2 seems to not work well
+ * with ds1337 RTCs, so we constrain it to larger values.
+ */
+ for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) {
+ /*
+ * For given ndiv and mdiv values check the
+ * two closest thp values.
+ */
+ tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10;
+ tclk *= (1 << ndiv_idx);
+ thp_base = (i2c->sys_freq / (tclk * 2)) - 1;
+
+ for (inc = 0; inc <= 1; inc++) {
+ thp_idx = thp_base + inc;
+ if (thp_idx < 5 || thp_idx > 0xff)
+ continue;
+
+ foscl = i2c->sys_freq / (2 * (thp_idx + 1));
+ foscl = foscl / (1 << ndiv_idx);
+ foscl = foscl / (mdiv_idx + 1) / 10;
+ diff = abs(foscl - i2c->twsi_freq);
+ if (diff < delta_hz) {
+ delta_hz = diff;
+ thp = thp_idx;
+ mdiv = mdiv_idx;
+ ndiv = ndiv_idx;
+ }
+ }
+ }
+ }
+ octeon_i2c_reg_write(i2c, SW_TWSI_OP_TWSI_CLK, thp);
+ octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
+}
+
+int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
+{
+ u8 status = 0;
+ int tries;
+
+ /* reset controller */
+ octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_RST, 0);
+
+ for (tries = 10; tries && status != STAT_IDLE; tries--) {
+ udelay(1);
+ status = octeon_i2c_stat_read(i2c);
+ if (status == STAT_IDLE)
+ break;
+ }
+
+ if (status != STAT_IDLE) {
+ dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n",
+ __func__, status);
+ return -EIO;
+ }
+
+ /* toggle twice to force both teardowns */
+ octeon_i2c_hlc_enable(i2c);
+ octeon_i2c_hlc_disable(i2c);
+ return 0;
+}
+
+static int octeon_i2c_get_scl(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+ u64 state;
+
+ state = octeon_i2c_read_int(i2c);
+ return state & TWSI_INT_SCL;
+}
+
+static void octeon_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+ octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
+}
+
+static int octeon_i2c_get_sda(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+ u64 state;
+
+ state = octeon_i2c_read_int(i2c);
+ return state & TWSI_INT_SDA;
+}
+
+static void octeon_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+ /*
+ * The stop resets the state machine, does not _transmit_ STOP unless
+ * engine was active.
+ */
+ octeon_i2c_stop(i2c);
+
+ octeon_i2c_hlc_disable(i2c);
+ octeon_i2c_write_int(i2c, 0);
+}
+
+static void octeon_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+ octeon_i2c_write_int(i2c, 0);
+}
+
+struct i2c_bus_recovery_info octeon_i2c_recovery_info = {
+ .recover_bus = i2c_generic_scl_recovery,
+ .get_scl = octeon_i2c_get_scl,
+ .set_scl = octeon_i2c_set_scl,
+ .get_sda = octeon_i2c_get_sda,
+ .prepare_recovery = octeon_i2c_prepare_recovery,
+ .unprepare_recovery = octeon_i2c_unprepare_recovery,
+};
diff --git a/drivers/i2c/busses/i2c-cavium.h b/drivers/i2c/busses/i2c-cavium.h
new file mode 100644
index 0000000..81c6a81
--- /dev/null
+++ b/drivers/i2c/busses/i2c-cavium.h
@@ -0,0 +1,197 @@
+#include <linux/atomic.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+
+/* Register offsets */
+#define SW_TWSI 0x00
+#define TWSI_INT 0x10
+#define SW_TWSI_EXT 0x18
+
+/* Controller command patterns */
+#define SW_TWSI_V BIT_ULL(63) /* Valid bit */
+#define SW_TWSI_EIA BIT_ULL(61) /* Extended internal address */
+#define SW_TWSI_R BIT_ULL(56) /* Result or read bit */
+#define SW_TWSI_SOVR BIT_ULL(55) /* Size override */
+#define SW_TWSI_SIZE_SHIFT 52
+#define SW_TWSI_ADDR_SHIFT 40
+#define SW_TWSI_IA_SHIFT 32 /* Internal address */
+
+/* Controller opcode word (bits 60:57) */
+#define SW_TWSI_OP_SHIFT 57
+#define SW_TWSI_OP_7 (0ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_7_IA (1ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_10 (2ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_10_IA (3ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_TWSI_CLK (4ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_EOP (6ULL << SW_TWSI_OP_SHIFT) /* Extended opcode */
+
+/* Controller extended opcode word (bits 34:32) */
+#define SW_TWSI_EOP_SHIFT 32
+#define SW_TWSI_EOP_TWSI_DATA (SW_TWSI_OP_EOP | 1ULL << SW_TWSI_EOP_SHIFT)
+#define SW_TWSI_EOP_TWSI_CTL (SW_TWSI_OP_EOP | 2ULL << SW_TWSI_EOP_SHIFT)
+#define SW_TWSI_EOP_TWSI_CLKCTL (SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
+#define SW_TWSI_EOP_TWSI_STAT (SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
+#define SW_TWSI_EOP_TWSI_RST (SW_TWSI_OP_EOP | 7ULL << SW_TWSI_EOP_SHIFT)
+
+/* Controller command and status bits */
+#define TWSI_CTL_CE 0x80 /* High level controller enable */
+#define TWSI_CTL_ENAB 0x40 /* Bus enable */
+#define TWSI_CTL_STA 0x20 /* Master-mode start, HW clears when done */
+#define TWSI_CTL_STP 0x10 /* Master-mode stop, HW clears when done */
+#define TWSI_CTL_IFLG 0x08 /* HW event, SW writes 0 to ACK */
+#define TWSI_CTL_AAK 0x04 /* Assert ACK */
+
+/* Status values */
+#define STAT_ERROR 0x00
+#define STAT_START 0x08
+#define STAT_REP_START 0x10
+#define STAT_TXADDR_ACK 0x18
+#define STAT_TXADDR_NAK 0x20
+#define STAT_TXDATA_ACK 0x28
+#define STAT_TXDATA_NAK 0x30
+#define STAT_LOST_ARB_38 0x38
+#define STAT_RXADDR_ACK 0x40
+#define STAT_RXADDR_NAK 0x48
+#define STAT_RXDATA_ACK 0x50
+#define STAT_RXDATA_NAK 0x58
+#define STAT_SLAVE_60 0x60
+#define STAT_LOST_ARB_68 0x68
+#define STAT_SLAVE_70 0x70
+#define STAT_LOST_ARB_78 0x78
+#define STAT_SLAVE_80 0x80
+#define STAT_SLAVE_88 0x88
+#define STAT_GENDATA_ACK 0x90
+#define STAT_GENDATA_NAK 0x98
+#define STAT_SLAVE_A0 0xA0
+#define STAT_SLAVE_A8 0xA8
+#define STAT_LOST_ARB_B0 0xB0
+#define STAT_SLAVE_LOST 0xB8
+#define STAT_SLAVE_NAK 0xC0
+#define STAT_SLAVE_ACK 0xC8
+#define STAT_AD2W_ACK 0xD0
+#define STAT_AD2W_NAK 0xD8
+#define STAT_IDLE 0xF8
+
+/* TWSI_INT values */
+#define TWSI_INT_ST_INT BIT_ULL(0)
+#define TWSI_INT_TS_INT BIT_ULL(1)
+#define TWSI_INT_CORE_INT BIT_ULL(2)
+#define TWSI_INT_ST_EN BIT_ULL(4)
+#define TWSI_INT_TS_EN BIT_ULL(5)
+#define TWSI_INT_CORE_EN BIT_ULL(6)
+#define TWSI_INT_SDA_OVR BIT_ULL(8)
+#define TWSI_INT_SCL_OVR BIT_ULL(9)
+#define TWSI_INT_SDA BIT_ULL(10)
+#define TWSI_INT_SCL BIT_ULL(11)
+
+#define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */
+
+struct octeon_i2c {
+ wait_queue_head_t queue;
+ struct i2c_adapter adap;
+ int irq;
+ int hlc_irq; /* For cn7890 only */
+ u32 twsi_freq;
+ int sys_freq;
+ void __iomem *twsi_base;
+ struct device *dev;
+ bool hlc_enabled;
+ bool broken_irq_mode;
+ bool broken_irq_check;
+ void (*int_enable)(struct octeon_i2c *);
+ void (*int_disable)(struct octeon_i2c *);
+ void (*hlc_int_enable)(struct octeon_i2c *);
+ void (*hlc_int_disable)(struct octeon_i2c *);
+ atomic_t int_enable_cnt;
+ atomic_t hlc_int_enable_cnt;
+};
+
+static inline void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
+{
+ __raw_writeq(val, addr);
+ __raw_readq(addr); /* wait for write to land */
+}
+
+/**
+ * octeon_i2c_reg_write - write an I2C core register
+ * @i2c: The struct octeon_i2c
+ * @eop_reg: Register selector
+ * @data: Value to be written
+ *
+ * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
+ */
+static inline void octeon_i2c_reg_write(struct octeon_i2c *i2c, u64 eop_reg, u8 data)
+{
+ u64 tmp;
+
+ __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI);
+ do {
+ tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
+ } while ((tmp & SW_TWSI_V) != 0);
+}
+
+#define octeon_i2c_ctl_write(i2c, val) \
+ octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL, val)
+#define octeon_i2c_data_write(i2c, val) \
+ octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_DATA, val)
+
+/**
+ * octeon_i2c_reg_read - read lower bits of an I2C core register
+ * @i2c: The struct octeon_i2c
+ * @eop_reg: Register selector
+ *
+ * Returns the data.
+ *
+ * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
+ */
+static inline u8 octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg)
+{
+ u64 tmp;
+
+ __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI);
+ do {
+ tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
+ } while ((tmp & SW_TWSI_V) != 0);
+
+ return tmp & 0xFF;
+}
+
+#define octeon_i2c_ctl_read(i2c) \
+ octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_CTL)
+#define octeon_i2c_data_read(i2c) \
+ octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_DATA)
+#define octeon_i2c_stat_read(i2c) \
+ octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT)
+
+/**
+ * octeon_i2c_read_int - read the TWSI_INT register
+ * @i2c: The struct octeon_i2c
+ *
+ * Returns the value of the register.
+ */
+static inline u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
+{
+ return __raw_readq(i2c->twsi_base + TWSI_INT);
+}
+
+/**
+ * octeon_i2c_write_int - write the TWSI_INT register
+ * @i2c: The struct octeon_i2c
+ * @data: Value to be written
+ */
+static inline void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
+{
+ octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT);
+}
+
+/* Prototypes */
+irqreturn_t octeon_i2c_isr(int irq, void *dev_id);
+int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
+int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c);
+void octeon_i2c_set_clock(struct octeon_i2c *i2c);
+extern struct i2c_bus_recovery_info octeon_i2c_recovery_info;
diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index 2bc32b9..fec4306 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -24,192 +24,10 @@
#include <linux/of.h>

#include <asm/octeon/octeon.h>
+#include "i2c-cavium.h"

#define DRV_NAME "i2c-octeon"

-/* Register offsets */
-#define SW_TWSI 0x00
-#define TWSI_INT 0x10
-#define SW_TWSI_EXT 0x18
-
-/* Controller command patterns */
-#define SW_TWSI_V BIT_ULL(63) /* Valid bit */
-#define SW_TWSI_EIA BIT_ULL(61) /* Extended internal address */
-#define SW_TWSI_R BIT_ULL(56) /* Result or read bit */
-#define SW_TWSI_SOVR BIT_ULL(55) /* Size override */
-#define SW_TWSI_SIZE_SHIFT 52
-#define SW_TWSI_ADDR_SHIFT 40
-#define SW_TWSI_IA_SHIFT 32 /* Internal address */
-
-/* Controller opcode word (bits 60:57) */
-#define SW_TWSI_OP_SHIFT 57
-#define SW_TWSI_OP_7 (0ULL << SW_TWSI_OP_SHIFT)
-#define SW_TWSI_OP_7_IA (1ULL << SW_TWSI_OP_SHIFT)
-#define SW_TWSI_OP_10 (2ULL << SW_TWSI_OP_SHIFT)
-#define SW_TWSI_OP_10_IA (3ULL << SW_TWSI_OP_SHIFT)
-#define SW_TWSI_OP_TWSI_CLK (4ULL << SW_TWSI_OP_SHIFT)
-#define SW_TWSI_OP_EOP (6ULL << SW_TWSI_OP_SHIFT) /* Extended opcode */
-
-/* Controller extended opcode word (bits 34:32) */
-#define SW_TWSI_EOP_SHIFT 32
-#define SW_TWSI_EOP_TWSI_DATA (SW_TWSI_OP_EOP | 1ULL << SW_TWSI_EOP_SHIFT)
-#define SW_TWSI_EOP_TWSI_CTL (SW_TWSI_OP_EOP | 2ULL << SW_TWSI_EOP_SHIFT)
-#define SW_TWSI_EOP_TWSI_CLKCTL (SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
-#define SW_TWSI_EOP_TWSI_STAT (SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
-#define SW_TWSI_EOP_TWSI_RST (SW_TWSI_OP_EOP | 7ULL << SW_TWSI_EOP_SHIFT)
-
-/* Controller command and status bits */
-#define TWSI_CTL_CE 0x80 /* High level controller enable */
-#define TWSI_CTL_ENAB 0x40 /* Bus enable */
-#define TWSI_CTL_STA 0x20 /* Master-mode start, HW clears when done */
-#define TWSI_CTL_STP 0x10 /* Master-mode stop, HW clears when done */
-#define TWSI_CTL_IFLG 0x08 /* HW event, SW writes 0 to ACK */
-#define TWSI_CTL_AAK 0x04 /* Assert ACK */
-
-/* Status values */
-#define STAT_ERROR 0x00
-#define STAT_START 0x08
-#define STAT_REP_START 0x10
-#define STAT_TXADDR_ACK 0x18
-#define STAT_TXADDR_NAK 0x20
-#define STAT_TXDATA_ACK 0x28
-#define STAT_TXDATA_NAK 0x30
-#define STAT_LOST_ARB_38 0x38
-#define STAT_RXADDR_ACK 0x40
-#define STAT_RXADDR_NAK 0x48
-#define STAT_RXDATA_ACK 0x50
-#define STAT_RXDATA_NAK 0x58
-#define STAT_SLAVE_60 0x60
-#define STAT_LOST_ARB_68 0x68
-#define STAT_SLAVE_70 0x70
-#define STAT_LOST_ARB_78 0x78
-#define STAT_SLAVE_80 0x80
-#define STAT_SLAVE_88 0x88
-#define STAT_GENDATA_ACK 0x90
-#define STAT_GENDATA_NAK 0x98
-#define STAT_SLAVE_A0 0xA0
-#define STAT_SLAVE_A8 0xA8
-#define STAT_LOST_ARB_B0 0xB0
-#define STAT_SLAVE_LOST 0xB8
-#define STAT_SLAVE_NAK 0xC0
-#define STAT_SLAVE_ACK 0xC8
-#define STAT_AD2W_ACK 0xD0
-#define STAT_AD2W_NAK 0xD8
-#define STAT_IDLE 0xF8
-
-/* TWSI_INT values */
-#define TWSI_INT_ST_INT BIT_ULL(0)
-#define TWSI_INT_TS_INT BIT_ULL(1)
-#define TWSI_INT_CORE_INT BIT_ULL(2)
-#define TWSI_INT_ST_EN BIT_ULL(4)
-#define TWSI_INT_TS_EN BIT_ULL(5)
-#define TWSI_INT_CORE_EN BIT_ULL(6)
-#define TWSI_INT_SDA_OVR BIT_ULL(8)
-#define TWSI_INT_SCL_OVR BIT_ULL(9)
-#define TWSI_INT_SDA BIT_ULL(10)
-#define TWSI_INT_SCL BIT_ULL(11)
-
-#define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */
-
-struct octeon_i2c {
- wait_queue_head_t queue;
- struct i2c_adapter adap;
- int irq;
- int hlc_irq; /* For cn7890 only */
- u32 twsi_freq;
- int sys_freq;
- void __iomem *twsi_base;
- struct device *dev;
- bool hlc_enabled;
- bool broken_irq_mode;
- bool broken_irq_check;
- void (*int_enable)(struct octeon_i2c *);
- void (*int_disable)(struct octeon_i2c *);
- void (*hlc_int_enable)(struct octeon_i2c *);
- void (*hlc_int_disable)(struct octeon_i2c *);
- atomic_t int_enable_cnt;
- atomic_t hlc_int_enable_cnt;
-};
-
-static void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
-{
- __raw_writeq(val, addr);
- __raw_readq(addr); /* wait for write to land */
-}
-
-/**
- * octeon_i2c_reg_write - write an I2C core register
- * @i2c: The struct octeon_i2c
- * @eop_reg: Register selector
- * @data: Value to be written
- *
- * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
- */
-static void octeon_i2c_reg_write(struct octeon_i2c *i2c, u64 eop_reg, u8 data)
-{
- u64 tmp;
-
- __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI);
- do {
- tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
- } while ((tmp & SW_TWSI_V) != 0);
-}
-
-#define octeon_i2c_ctl_write(i2c, val) \
- octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL, val)
-#define octeon_i2c_data_write(i2c, val) \
- octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_DATA, val)
-
-/**
- * octeon_i2c_reg_read - read lower bits of an I2C core register
- * @i2c: The struct octeon_i2c
- * @eop_reg: Register selector
- *
- * Returns the data.
- *
- * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
- */
-static u8 octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg)
-{
- u64 tmp;
-
- __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI);
- do {
- tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
- } while ((tmp & SW_TWSI_V) != 0);
-
- return tmp & 0xFF;
-}
-
-#define octeon_i2c_ctl_read(i2c) \
- octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_CTL)
-#define octeon_i2c_data_read(i2c) \
- octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_DATA)
-#define octeon_i2c_stat_read(i2c) \
- octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT)
-
-
-/**
- * octeon_i2c_read_int - read the TWSI_INT register
- * @i2c: The struct octeon_i2c
- *
- * Returns the value of the register.
- */
-static u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
-{
- return __raw_readq(i2c->twsi_base + TWSI_INT);
-}
-
-/**
- * octeon_i2c_write_int - write the TWSI_INT register
- * @i2c: The struct octeon_i2c
- * @data: Value to be written
- */
-static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
-{
- octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT);
-}
-
/**
* octeon_i2c_int_enable - enable the CORE interrupt
* @i2c: The struct octeon_i2c
@@ -281,58 +99,6 @@ static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c)
__octeon_i2c_irq_disable(&i2c->hlc_int_enable_cnt, i2c->hlc_irq);
}

-/*
- * Cleanup low-level state & enable high-level controller.
- */
-static void octeon_i2c_hlc_enable(struct octeon_i2c *i2c)
-{
- int try = 0;
- u64 val;
-
- if (i2c->hlc_enabled)
- return;
- i2c->hlc_enabled = true;
-
- while (1) {
- val = octeon_i2c_ctl_read(i2c);
- if (!(val & (TWSI_CTL_STA | TWSI_CTL_STP)))
- break;
-
- /* clear IFLG event */
- if (val & TWSI_CTL_IFLG)
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
-
- if (try++ > 100) {
- pr_err("%s: giving up\n", __func__);
- break;
- }
-
- /* spin until any start/stop has finished */
- udelay(10);
- }
- octeon_i2c_ctl_write(i2c, TWSI_CTL_CE | TWSI_CTL_AAK | TWSI_CTL_ENAB);
-}
-
-static void octeon_i2c_hlc_disable(struct octeon_i2c *i2c)
-{
- if (!i2c->hlc_enabled)
- return;
-
- i2c->hlc_enabled = false;
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
-}
-
-/* interrupt service routine */
-static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
-{
- struct octeon_i2c *i2c = dev_id;
-
- i2c->int_disable(i2c);
- wake_up(&i2c->queue);
-
- return IRQ_HANDLED;
-}
-
/* HLC interrupt service routine */
static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
{
@@ -344,738 +110,11 @@ static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
return IRQ_HANDLED;
}

-static bool octeon_i2c_test_iflg(struct octeon_i2c *i2c)
-{
- return (octeon_i2c_ctl_read(i2c) & TWSI_CTL_IFLG);
-}
-
-static bool octeon_i2c_test_ready(struct octeon_i2c *i2c, bool *first)
-{
- if (octeon_i2c_test_iflg(i2c))
- return true;
-
- if (*first) {
- *first = false;
- return false;
- }
-
- /*
- * IRQ has signaled an event but IFLG hasn't changed.
- * Sleep and retry once.
- */
- usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
- return octeon_i2c_test_iflg(i2c);
-}
-
-/**
- * octeon_i2c_wait - wait for the IFLG to be set
- * @i2c: The struct octeon_i2c
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_wait(struct octeon_i2c *i2c)
-{
- long time_left;
- bool first = 1;
-
- /*
- * Some chip revisions don't assert the irq in the interrupt
- * controller. So we must poll for the IFLG change.
- */
- if (i2c->broken_irq_mode) {
- u64 end = get_jiffies_64() + i2c->adap.timeout;
-
- while (!octeon_i2c_test_iflg(i2c) &&
- time_before64(get_jiffies_64(), end))
- udelay(50);
-
- return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
- }
-
- i2c->int_enable(i2c);
- time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
- i2c->adap.timeout);
- i2c->int_disable(i2c);
-
- if (i2c->broken_irq_check && !time_left &&
- octeon_i2c_test_iflg(i2c)) {
- dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
- i2c->broken_irq_mode = true;
- return 0;
- }
-
- if (!time_left)
- return -ETIMEDOUT;
-
- return 0;
-}
-
-static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
-{
- u8 stat = octeon_i2c_stat_read(i2c);
-
- switch (stat) {
- /* Everything is fine */
- case STAT_IDLE:
- case STAT_AD2W_ACK:
- case STAT_RXADDR_ACK:
- case STAT_TXADDR_ACK:
- case STAT_TXDATA_ACK:
- return 0;
-
- /* ACK allowed on pre-terminal bytes only */
- case STAT_RXDATA_ACK:
- if (!final_read)
- return 0;
- return -EIO;
-
- /* NAK allowed on terminal byte only */
- case STAT_RXDATA_NAK:
- if (final_read)
- return 0;
- return -EIO;
-
- /* Arbitration lost */
- case STAT_LOST_ARB_38:
- case STAT_LOST_ARB_68:
- case STAT_LOST_ARB_78:
- case STAT_LOST_ARB_B0:
- return -EAGAIN;
-
- /* Being addressed as slave, should back off & listen */
- case STAT_SLAVE_60:
- case STAT_SLAVE_70:
- case STAT_GENDATA_ACK:
- case STAT_GENDATA_NAK:
- return -EOPNOTSUPP;
-
- /* Core busy as slave */
- case STAT_SLAVE_80:
- case STAT_SLAVE_88:
- case STAT_SLAVE_A0:
- case STAT_SLAVE_A8:
- case STAT_SLAVE_LOST:
- case STAT_SLAVE_NAK:
- case STAT_SLAVE_ACK:
- return -EOPNOTSUPP;
-
- case STAT_TXDATA_NAK:
- return -EIO;
- case STAT_TXADDR_NAK:
- case STAT_RXADDR_NAK:
- case STAT_AD2W_NAK:
- return -ENXIO;
- default:
- dev_err(i2c->dev, "unhandled state: %d\n", stat);
- return -EIO;
- }
-}
-
-static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c)
-{
- return (__raw_readq(i2c->twsi_base + SW_TWSI) & SW_TWSI_V) == 0;
-}
-
-static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c, bool *first)
-{
- /* check if valid bit is cleared */
- if (octeon_i2c_hlc_test_valid(i2c))
- return true;
-
- if (*first) {
- *first = false;
- return false;
- }
-
- /*
- * IRQ has signaled an event but valid bit isn't cleared.
- * Sleep and retry once.
- */
- usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
- return octeon_i2c_hlc_test_valid(i2c);
-}
-
static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
{
octeon_i2c_write_int(i2c, TWSI_INT_ST_EN);
}

-static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
-{
- /* clear ST/TS events, listen for neither */
- octeon_i2c_write_int(i2c, TWSI_INT_ST_INT | TWSI_INT_TS_INT);
-}
-
-/**
- * octeon_i2c_hlc_wait - wait for an HLC operation to complete
- * @i2c: The struct octeon_i2c
- *
- * Returns 0 on success, otherwise -ETIMEDOUT.
- */
-static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
-{
- bool first = 1;
- int time_left;
-
- /*
- * Some cn38xx boards don't assert the irq in the interrupt
- * controller. So we must poll for the valid bit change.
- */
- if (i2c->broken_irq_mode) {
- u64 end = get_jiffies_64() + i2c->adap.timeout;
-
- while (!octeon_i2c_hlc_test_valid(i2c) &&
- time_before64(get_jiffies_64(), end))
- udelay(50);
-
- return octeon_i2c_hlc_test_valid(i2c) ? 0 : -ETIMEDOUT;
- }
-
- i2c->hlc_int_enable(i2c);
- time_left = wait_event_timeout(i2c->queue,
- octeon_i2c_hlc_test_ready(i2c, &first),
- i2c->adap.timeout);
- i2c->hlc_int_disable(i2c);
- if (!time_left)
- octeon_i2c_hlc_int_clear(i2c);
-
- if (i2c->broken_irq_check && !time_left &&
- octeon_i2c_hlc_test_valid(i2c)) {
- dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
- i2c->broken_irq_mode = true;
- return 0;
- }
-
- if (!time_left)
- return -ETIMEDOUT;
- return 0;
-}
-
-/* high-level-controller pure read of up to 8 bytes */
-static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
- int i, j, ret = 0;
- u64 cmd;
-
- octeon_i2c_hlc_enable(i2c);
- octeon_i2c_hlc_int_clear(i2c);
-
- cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
- /* SIZE */
- cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
- /* A */
- cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
-
- if (msgs[0].flags & I2C_M_TEN)
- cmd |= SW_TWSI_OP_10;
- else
- cmd |= SW_TWSI_OP_7;
-
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
- ret = octeon_i2c_hlc_wait(i2c);
- if (ret)
- goto err;
-
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
- if ((cmd & SW_TWSI_R) == 0)
- return -EAGAIN;
-
- for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
- msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
-
- if (msgs[0].len > 4) {
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
- for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
- msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
- }
-
-err:
- return ret;
-}
-
-/* high-level-controller pure write of up to 8 bytes */
-static int octeon_i2c_hlc_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
- int i, j, ret = 0;
- u64 cmd;
-
- octeon_i2c_hlc_enable(i2c);
- octeon_i2c_hlc_int_clear(i2c);
-
- cmd = SW_TWSI_V | SW_TWSI_SOVR;
- /* SIZE */
- cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
- /* A */
- cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
-
- if (msgs[0].flags & I2C_M_TEN)
- cmd |= SW_TWSI_OP_10;
- else
- cmd |= SW_TWSI_OP_7;
-
- for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
- cmd |= (u64)msgs[0].buf[j] << (8 * i);
-
- if (msgs[0].len > 4) {
- u64 ext = 0;
-
- for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
- ext |= (u64) msgs[0].buf[j] << (8 * i);
- octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
- }
-
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
- ret = octeon_i2c_hlc_wait(i2c);
- if (ret)
- goto err;
-
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
- if ((cmd & SW_TWSI_R) == 0)
- return -EAGAIN;
-
- ret = octeon_i2c_check_status(i2c, false);
-
-err:
- return ret;
-}
-
-/* high-level-controller composite write+read, msg0=addr, msg1=data */
-static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
- int i, j, ret = 0;
- u64 cmd;
-
- octeon_i2c_hlc_enable(i2c);
-
- cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
- /* SIZE */
- cmd |= (u64)(msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
- /* A */
- cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
-
- if (msgs[0].flags & I2C_M_TEN)
- cmd |= SW_TWSI_OP_10_IA;
- else
- cmd |= SW_TWSI_OP_7_IA;
-
- if (msgs[0].len == 2) {
- u64 ext = 0;
-
- cmd |= SW_TWSI_EIA;
- ext = (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
- cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
- octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
- } else
- cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
-
- octeon_i2c_hlc_int_clear(i2c);
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
-
- ret = octeon_i2c_hlc_wait(i2c);
- if (ret)
- goto err;
-
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
- if ((cmd & SW_TWSI_R) == 0)
- return -EAGAIN;
-
- for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
- msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
-
- if (msgs[1].len > 4) {
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
- for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
- msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
- }
-
-err:
- return ret;
-}
-
-/* high-level-controller composite write+write, m[0]len<=2, m[1]len<=8 */
-static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
- bool set_ext = false;
- int i, j, ret = 0;
- u64 cmd, ext = 0;
-
- octeon_i2c_hlc_enable(i2c);
-
- cmd = SW_TWSI_V | SW_TWSI_SOVR;
- /* SIZE */
- cmd |= (u64) (msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
- /* A */
- cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
-
- if (msgs[0].flags & I2C_M_TEN)
- cmd |= SW_TWSI_OP_10_IA;
- else
- cmd |= SW_TWSI_OP_7_IA;
-
- if (msgs[0].len == 2) {
- cmd |= SW_TWSI_EIA;
- ext |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
- set_ext = true;
- cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
- } else
- cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
-
- for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
- cmd |= (u64) msgs[1].buf[j] << (8 * i);
-
- if (msgs[1].len > 4) {
- for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
- ext |= (u64)msgs[1].buf[j] << (8 * i);
- set_ext = true;
- }
- if (set_ext)
- octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
-
- octeon_i2c_hlc_int_clear(i2c);
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
-
- ret = octeon_i2c_hlc_wait(i2c);
- if (ret)
- goto err;
-
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
- if ((cmd & SW_TWSI_R) == 0)
- return -EAGAIN;
-
- ret = octeon_i2c_check_status(i2c, false);
-
-err:
- return ret;
-}
-
-/* calculate and set clock divisors */
-static void octeon_i2c_set_clock(struct octeon_i2c *i2c)
-{
- int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff;
- int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = 1000000;
-
- for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) {
- /*
- * An mdiv value of less than 2 seems to not work well
- * with ds1337 RTCs, so we constrain it to larger values.
- */
- for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) {
- /*
- * For given ndiv and mdiv values check the
- * two closest thp values.
- */
- tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10;
- tclk *= (1 << ndiv_idx);
- thp_base = (i2c->sys_freq / (tclk * 2)) - 1;
-
- for (inc = 0; inc <= 1; inc++) {
- thp_idx = thp_base + inc;
- if (thp_idx < 5 || thp_idx > 0xff)
- continue;
-
- foscl = i2c->sys_freq / (2 * (thp_idx + 1));
- foscl = foscl / (1 << ndiv_idx);
- foscl = foscl / (mdiv_idx + 1) / 10;
- diff = abs(foscl - i2c->twsi_freq);
- if (diff < delta_hz) {
- delta_hz = diff;
- thp = thp_idx;
- mdiv = mdiv_idx;
- ndiv = ndiv_idx;
- }
- }
- }
- }
- octeon_i2c_reg_write(i2c, SW_TWSI_OP_TWSI_CLK, thp);
- octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
-}
-
-static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
-{
- u8 status = 0;
- int tries;
-
- /* reset controller */
- octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_RST, 0);
-
- for (tries = 10; tries && status != STAT_IDLE; tries--) {
- udelay(1);
- status = octeon_i2c_stat_read(i2c);
- if (status == STAT_IDLE)
- break;
- }
-
- if (status != STAT_IDLE) {
- dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n",
- __func__, status);
- return -EIO;
- }
-
- /* toggle twice to force both teardowns */
- octeon_i2c_hlc_enable(i2c);
- octeon_i2c_hlc_disable(i2c);
- return 0;
-}
-
-static int octeon_i2c_recovery(struct octeon_i2c *i2c)
-{
- int ret;
-
- ret = i2c_recover_bus(&i2c->adap);
- if (ret)
- /* recover failed, try hardware re-init */
- ret = octeon_i2c_init_lowlevel(i2c);
- return ret;
-}
-
-/**
- * octeon_i2c_start - send START to the bus
- * @i2c: The struct octeon_i2c
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_start(struct octeon_i2c *i2c)
-{
- int ret;
- u8 stat;
-
- octeon_i2c_hlc_disable(i2c);
-
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
- ret = octeon_i2c_wait(i2c);
- if (ret)
- goto error;
-
- stat = octeon_i2c_stat_read(i2c);
- if (stat == STAT_START || stat == STAT_REP_START)
- /* START successful, bail out */
- return 0;
-
-error:
- /* START failed, try to recover */
- ret = octeon_i2c_recovery(i2c);
- return (ret) ? ret : -EAGAIN;
-}
-
-/* send STOP to the bus */
-static void octeon_i2c_stop(struct octeon_i2c *i2c)
-{
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STP);
-}
-
-/**
- * octeon_i2c_read - receive data from the bus via low-level controller
- * @i2c: The struct octeon_i2c
- * @target: Target address
- * @data: Pointer to the location to store the data
- * @rlength: Length of the data
- * @recv_len: flag for length byte
- *
- * The address is sent over the bus, then the data is read.
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
- u8 *data, u16 *rlength, bool recv_len)
-{
- int i, result, length = *rlength;
- bool final_read = false;
-
- octeon_i2c_data_write(i2c, (target << 1) | 1);
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
-
- result = octeon_i2c_wait(i2c);
- if (result)
- return result;
-
- /* address OK ? */
- result = octeon_i2c_check_status(i2c, false);
- if (result)
- return result;
-
- for (i = 0; i < length; i++) {
- /* for the last byte TWSI_CTL_AAK must not be set */
- if (i + 1 == length)
- final_read = true;
-
- /* clear iflg to allow next event */
- if (final_read)
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
- else
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_AAK);
-
- result = octeon_i2c_wait(i2c);
- if (result)
- return result;
-
- data[i] = octeon_i2c_data_read(i2c);
- if (recv_len && i == 0) {
- if (data[i] > I2C_SMBUS_BLOCK_MAX + 1) {
- dev_err(i2c->dev,
- "%s: read len > I2C_SMBUS_BLOCK_MAX %d\n",
- __func__, data[i]);
- return -EPROTO;
- }
- length += data[i];
- }
-
- result = octeon_i2c_check_status(i2c, final_read);
- if (result)
- return result;
- }
- *rlength = length;
- return 0;
-}
-
-/**
- * octeon_i2c_write - send data to the bus via low-level controller
- * @i2c: The struct octeon_i2c
- * @target: Target address
- * @data: Pointer to the data to be sent
- * @length: Length of the data
- *
- * The address is sent over the bus, then the data.
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
- const u8 *data, int length)
-{
- int i, result;
-
- octeon_i2c_data_write(i2c, target << 1);
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
-
- result = octeon_i2c_wait(i2c);
- if (result)
- return result;
-
- for (i = 0; i < length; i++) {
- result = octeon_i2c_check_status(i2c, false);
- if (result)
- return result;
-
- octeon_i2c_data_write(i2c, data[i]);
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
-
- result = octeon_i2c_wait(i2c);
- if (result)
- return result;
- }
-
- return 0;
-}
-
-/**
- * octeon_i2c_xfer - The driver's master_xfer function
- * @adap: Pointer to the i2c_adapter structure
- * @msgs: Pointer to the messages to be processed
- * @num: Length of the MSGS array
- *
- * Returns the number of messages processed, or a negative errno on failure.
- */
-static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
- int num)
-{
- struct octeon_i2c *i2c = i2c_get_adapdata(adap);
- int i, ret = 0;
-
- if (num == 1) {
- if (msgs[0].len > 0 && msgs[0].len <= 8) {
- if (msgs[0].flags & I2C_M_RD)
- ret = octeon_i2c_hlc_read(i2c, msgs);
- else
- ret = octeon_i2c_hlc_write(i2c, msgs);
- goto out;
- }
- } else if (num == 2) {
- if ((msgs[0].flags & I2C_M_RD) == 0 &&
- (msgs[1].flags & I2C_M_RECV_LEN) == 0 &&
- msgs[0].len > 0 && msgs[0].len <= 2 &&
- msgs[1].len > 0 && msgs[1].len <= 8 &&
- msgs[0].addr == msgs[1].addr) {
- if (msgs[1].flags & I2C_M_RD)
- ret = octeon_i2c_hlc_comp_read(i2c, msgs);
- else
- ret = octeon_i2c_hlc_comp_write(i2c, msgs);
- goto out;
- }
- }
-
- for (i = 0; ret == 0 && i < num; i++) {
- struct i2c_msg *pmsg = &msgs[i];
-
- ret = octeon_i2c_start(i2c);
- if (ret)
- return ret;
-
- if (pmsg->flags & I2C_M_RD)
- ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
- &pmsg->len, pmsg->flags & I2C_M_RECV_LEN);
- else
- ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
- pmsg->len);
- }
- octeon_i2c_stop(i2c);
-out:
- return (ret != 0) ? ret : num;
-}
-
-static int octeon_i2c_get_scl(struct i2c_adapter *adap)
-{
- struct octeon_i2c *i2c = i2c_get_adapdata(adap);
- u64 state;
-
- state = octeon_i2c_read_int(i2c);
- return state & TWSI_INT_SCL;
-}
-
-static void octeon_i2c_set_scl(struct i2c_adapter *adap, int val)
-{
- struct octeon_i2c *i2c = i2c_get_adapdata(adap);
-
- octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
-}
-
-static int octeon_i2c_get_sda(struct i2c_adapter *adap)
-{
- struct octeon_i2c *i2c = i2c_get_adapdata(adap);
- u64 state;
-
- state = octeon_i2c_read_int(i2c);
- return state & TWSI_INT_SDA;
-}
-
-static void octeon_i2c_prepare_recovery(struct i2c_adapter *adap)
-{
- struct octeon_i2c *i2c = i2c_get_adapdata(adap);
-
- /*
- * The stop resets the state machine, does not _transmit_ STOP unless
- * engine was active.
- */
- octeon_i2c_stop(i2c);
-
- octeon_i2c_hlc_disable(i2c);
- octeon_i2c_write_int(i2c, 0);
-}
-
-static void octeon_i2c_unprepare_recovery(struct i2c_adapter *adap)
-{
- struct octeon_i2c *i2c = i2c_get_adapdata(adap);
-
- octeon_i2c_write_int(i2c, 0);
-}
-
-static struct i2c_bus_recovery_info octeon_i2c_recovery_info = {
- .recover_bus = i2c_generic_scl_recovery,
- .get_scl = octeon_i2c_get_scl,
- .set_scl = octeon_i2c_set_scl,
- .get_sda = octeon_i2c_get_sda,
- .prepare_recovery = octeon_i2c_prepare_recovery,
- .unprepare_recovery = octeon_i2c_unprepare_recovery,
-};
-
static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
--
1.9.1
Jan Glauber
2016-04-25 14:35:11 UTC
Permalink
This is an intermediate commit in preparation of the driver split.
The module rename in this commit will be reverted in the next patch,
this is just done to make the series bisectible.

Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/Makefile | 2 +-
drivers/i2c/busses/{i2c-octeon.c => i2c-octeon-core.c} | 0
2 files changed, 1 insertion(+), 1 deletion(-)
rename drivers/i2c/busses/{i2c-octeon.c => i2c-octeon-core.c} (100%)

diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 37f2819..3405286 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -91,7 +91,7 @@ obj-$(CONFIG_I2C_UNIPHIER) += i2c-uniphier.o
obj-$(CONFIG_I2C_UNIPHIER_F) += i2c-uniphier-f.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
obj-$(CONFIG_I2C_WMT) += i2c-wmt.o
-obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
+obj-$(CONFIG_I2C_OCTEON) += i2c-octeon-core.o
obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
obj-$(CONFIG_I2C_XLR) += i2c-xlr.o
obj-$(CONFIG_I2C_XLP9XX) += i2c-xlp9xx.o
diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon-core.c
similarity index 100%
rename from drivers/i2c/busses/i2c-octeon.c
rename to drivers/i2c/busses/i2c-octeon-core.c
--
1.9.1
Jan Glauber
2016-04-25 14:35:50 UTC
Permalink
The ThunderX SOC uses the same i2c block as the Octeon SOC.
The main difference is that on ThunderX the device is a PCI device
so device probing is done via PCI, interrupts are MSIX and the
clock is taken from device tree.

Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/Kconfig | 10 ++
drivers/i2c/busses/Makefile | 2 +
drivers/i2c/busses/i2c-cavium.h | 16 +-
drivers/i2c/busses/i2c-thunderx-core.c | 267 +++++++++++++++++++++++++++++++++
4 files changed, 292 insertions(+), 3 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-thunderx-core.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index faa8e68..92d23de 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -953,6 +953,16 @@ config I2C_OCTEON
This driver can also be built as a module. If so, the module
will be called i2c-octeon.

+config I2C_THUNDERX
+ tristate "Cavium ThunderX I2C bus support"
+ depends on 64BIT && PCI && !CAVIUM_OCTEON_SOC
+ help
+ Say yes if you want to support the I2C serial bus on Cavium
+ ThunderX SOC.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-thunderx.
+
config I2C_XILINX
tristate "Xilinx I2C Controller"
depends on HAS_IOMEM
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 282f781..a32ff14 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -93,6 +93,8 @@ obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
obj-$(CONFIG_I2C_WMT) += i2c-wmt.o
i2c-octeon-objs := i2c-cavium.o i2c-octeon-core.o
obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
+i2c-thunderx-objs := i2c-cavium.o i2c-thunderx-core.o
+obj-$(CONFIG_I2C_THUNDERX) += i2c-thunderx.o
obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
obj-$(CONFIG_I2C_XLR) += i2c-xlr.o
obj-$(CONFIG_I2C_XLP9XX) += i2c-xlp9xx.o
diff --git a/drivers/i2c/busses/i2c-cavium.h b/drivers/i2c/busses/i2c-cavium.h
index 81c6a81..33c7e1f 100644
--- a/drivers/i2c/busses/i2c-cavium.h
+++ b/drivers/i2c/busses/i2c-cavium.h
@@ -8,9 +8,15 @@
#include <linux/pci.h>

/* Register offsets */
-#define SW_TWSI 0x00
-#define TWSI_INT 0x10
-#define SW_TWSI_EXT 0x18
+#if IS_ENABLED(CONFIG_I2C_THUNDERX)
+ #define SW_TWSI 0x1000
+ #define TWSI_INT 0x1010
+ #define SW_TWSI_EXT 0x1018
+#else
+ #define SW_TWSI 0x00
+ #define TWSI_INT 0x10
+ #define SW_TWSI_EXT 0x18
+#endif

/* Controller command patterns */
#define SW_TWSI_V BIT_ULL(63) /* Valid bit */
@@ -94,6 +100,7 @@
struct octeon_i2c {
wait_queue_head_t queue;
struct i2c_adapter adap;
+ struct clk *clk;
int irq;
int hlc_irq; /* For cn7890 only */
u32 twsi_freq;
@@ -109,6 +116,9 @@ struct octeon_i2c {
void (*hlc_int_disable)(struct octeon_i2c *);
atomic_t int_enable_cnt;
atomic_t hlc_int_enable_cnt;
+#if IS_ENABLED(CONFIG_I2C_THUNDERX)
+ struct msix_entry i2c_msix;
+#endif
};

static inline void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
diff --git a/drivers/i2c/busses/i2c-thunderx-core.c b/drivers/i2c/busses/i2c-thunderx-core.c
new file mode 100644
index 0000000..656b405
--- /dev/null
+++ b/drivers/i2c/busses/i2c-thunderx-core.c
@@ -0,0 +1,267 @@
+/*
+ * Cavium ThunderX i2c driver.
+ *
+ * Copyright (C) 2015,2016 Cavium Inc.
+ * Authors: Fred Martin <***@caviumnetworks.com>
+ * Jan Glauber <***@cavium.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include "i2c-cavium.h"
+
+#define DRV_NAME "i2c-thunderx"
+
+#define PCI_CFG_REG_BAR_NUM 0
+#define PCI_DEVICE_ID_THUNDER_TWSI 0xa012
+
+#define TWSI_DFL_RATE 100000
+#define SYS_FREQ_DEFAULT 800000000
+
+#define TWSI_INT_ENA_W1C 0x1028
+#define TWSI_INT_ENA_W1S 0x1030
+
+/*
+ * Enable the CORE interrupt.
+ * The interrupt will be asserted when there is non-STAT_IDLE state in the
+ * SW_TWSI_EOP_TWSI_STAT register.
+ */
+static void thunder_i2c_int_enable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
+ i2c->twsi_base + TWSI_INT_ENA_W1S);
+}
+
+/*
+ * Disable the CORE interrupt.
+ */
+static void thunder_i2c_int_disable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
+ i2c->twsi_base + TWSI_INT_ENA_W1C);
+}
+
+static void thunder_i2c_hlc_int_enable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
+ i2c->twsi_base + TWSI_INT_ENA_W1S);
+}
+
+static void thunder_i2c_hlc_int_disable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
+ i2c->twsi_base + TWSI_INT_ENA_W1C);
+}
+
+static u32 thunderx_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
+ I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
+}
+
+static const struct i2c_algorithm thunderx_i2c_algo = {
+ .master_xfer = octeon_i2c_xfer,
+ .functionality = thunderx_i2c_functionality,
+};
+
+static struct i2c_adapter thunderx_i2c_ops = {
+ .owner = THIS_MODULE,
+ .name = "ThunderX adapter",
+ .algo = &thunderx_i2c_algo,
+};
+
+static void thunder_i2c_clock_enable(struct device *dev, struct octeon_i2c *i2c)
+{
+ int ret;
+
+ i2c->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(i2c->clk)) {
+ i2c->clk = NULL;
+ goto skip;
+ }
+
+ ret = clk_prepare_enable(i2c->clk);
+ if (ret)
+ goto skip;
+ i2c->sys_freq = clk_get_rate(i2c->clk);
+
+skip:
+ if (!i2c->sys_freq)
+ i2c->sys_freq = SYS_FREQ_DEFAULT;
+
+ dev_info(dev, "Set system clock to %u\n", i2c->sys_freq);
+}
+
+static void thunder_i2c_clock_disable(struct device *dev, struct clk *clk)
+{
+ if (!clk)
+ return;
+ clk_disable_unprepare(clk);
+ devm_clk_put(dev, clk);
+}
+
+static void thunder_i2c_set_name(struct pci_dev *pdev, struct octeon_i2c *i2c,
+ char *name)
+{
+ u8 i2c_bus_id, soc_node;
+ resource_size_t start;
+
+ start = pci_resource_start(pdev, PCI_CFG_REG_BAR_NUM);
+ soc_node = (start >> 44) & 0x3;
+ i2c_bus_id = (start >> 24) & 0x7;
+ snprintf(name, 10, "i2c%d", soc_node * 6 + i2c_bus_id);
+
+ snprintf(i2c->adap.name, sizeof(i2c->adap.name), "thunderx-i2c-%d.%d",
+ soc_node, i2c_bus_id);
+}
+
+static int thunder_i2c_probe_pci(struct pci_dev *pdev,
+ const struct pci_device_id *ent)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = NULL;
+ struct octeon_i2c *i2c;
+ char i2c_name[10];
+ int ret = 0;
+
+ i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
+ if (!i2c)
+ return -ENOMEM;
+
+ i2c->dev = dev;
+ pci_set_drvdata(pdev, i2c);
+ ret = pci_enable_device(pdev);
+ if (ret) {
+ dev_err(dev, "Failed to enable PCI device\n");
+ goto out_free_i2c;
+ }
+
+ ret = pci_request_regions(pdev, DRV_NAME);
+ if (ret) {
+ dev_err(dev, "PCI request regions failed 0x%x\n", ret);
+ goto out_disable_device;
+ }
+
+ i2c->twsi_base = pci_ioremap_bar(pdev, PCI_CFG_REG_BAR_NUM);
+ if (!i2c->twsi_base) {
+ dev_err(dev, "Cannot map CSR memory space\n");
+ ret = -EINVAL;
+ goto out_release_regions;
+ }
+
+ thunder_i2c_clock_enable(dev, i2c);
+
+ thunder_i2c_set_name(pdev, i2c, i2c_name);
+ node = of_find_node_by_name(NULL, i2c_name);
+ if (!node || of_property_read_u32(node, "clock-frequency",
+ &i2c->twsi_freq))
+ i2c->twsi_freq = TWSI_DFL_RATE;
+
+ init_waitqueue_head(&i2c->queue);
+
+ i2c->int_enable = thunder_i2c_int_enable;
+ i2c->int_disable = thunder_i2c_int_disable;
+ i2c->hlc_int_enable = thunder_i2c_hlc_int_enable;
+ i2c->hlc_int_disable = thunder_i2c_hlc_int_disable;
+
+ ret = pci_enable_msix(pdev, &i2c->i2c_msix, 1);
+ if (ret) {
+ dev_err(dev, "Unable to enable MSI-X\n");
+ goto out_unmap;
+ }
+
+ ret = devm_request_irq(dev, i2c->i2c_msix.vector, octeon_i2c_isr, 0,
+ DRV_NAME, i2c);
+ if (ret < 0) {
+ dev_err(dev, "Failed to attach i2c interrupt\n");
+ goto out_msix;
+ }
+
+ ret = octeon_i2c_init_lowlevel(i2c);
+ if (ret) {
+ dev_err(dev, "Init low level failed\n");
+ goto out_msix;
+ }
+
+ octeon_i2c_set_clock(i2c);
+
+ i2c->adap = thunderx_i2c_ops;
+ i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+ i2c->adap.timeout = msecs_to_jiffies(5);
+ i2c->adap.retries = 5;
+ i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
+ i2c->adap.dev.parent = dev;
+ i2c->adap.dev.of_node = pdev->dev.of_node;
+ i2c_set_adapdata(&i2c->adap, i2c);
+
+ ret = i2c_add_adapter(&i2c->adap);
+ if (ret < 0) {
+ dev_err(dev, "Failed to add i2c adapter\n");
+ goto out_irq;
+ }
+
+ dev_info(i2c->dev, "probed\n");
+ return 0;
+
+out_irq:
+ devm_free_irq(dev, i2c->i2c_msix.vector, i2c);
+out_msix:
+ pci_disable_msix(pdev);
+out_unmap:
+ iounmap(i2c->twsi_base);
+ thunder_i2c_clock_disable(dev, i2c->clk);
+out_release_regions:
+ pci_release_regions(pdev);
+out_disable_device:
+ pci_disable_device(pdev);
+out_free_i2c:
+ pci_set_drvdata(pdev, NULL);
+ devm_kfree(dev, i2c);
+ return ret;
+}
+
+static void thunder_i2c_remove_pci(struct pci_dev *pdev)
+{
+ struct octeon_i2c *i2c = pci_get_drvdata(pdev);
+ struct device *dev;
+
+ if (!i2c)
+ return;
+
+ dev = i2c->dev;
+ thunder_i2c_clock_disable(dev, i2c->clk);
+ i2c_del_adapter(&i2c->adap);
+ devm_free_irq(dev, i2c->i2c_msix.vector, i2c);
+ pci_disable_msix(pdev);
+ iounmap(i2c->twsi_base);
+ pci_release_regions(pdev);
+ pci_disable_device(pdev);
+ pci_set_drvdata(pdev, NULL);
+ devm_kfree(dev, i2c);
+}
+
+static const struct pci_device_id thunder_i2c_pci_id_table[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_THUNDER_TWSI) },
+ { 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, thunder_i2c_pci_id_table);
+
+static struct pci_driver thunder_i2c_pci_driver = {
+ .name = DRV_NAME,
+ .id_table = thunder_i2c_pci_id_table,
+ .probe = thunder_i2c_probe_pci,
+ .remove = thunder_i2c_remove_pci,
+};
+
+module_pci_driver(thunder_i2c_pci_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Fred Martin <***@caviumnetworks.com>");
+MODULE_DESCRIPTION("I2C-Bus adapter for Cavium ThunderX SOC");
--
1.9.1
Jan Glauber
2016-04-25 14:35:58 UTC
Permalink
The register offsets are different between Octeon and ThunderX so move
them into the algorithm struct and get rid of the define.

Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-cavium.c | 28 +++++++++++++--------------
drivers/i2c/busses/i2c-cavium.h | 35 +++++++++++++++++-----------------
drivers/i2c/busses/i2c-octeon-core.c | 4 ++++
drivers/i2c/busses/i2c-thunderx-core.c | 4 ++++
4 files changed, 40 insertions(+), 31 deletions(-)

diff --git a/drivers/i2c/busses/i2c-cavium.c b/drivers/i2c/busses/i2c-cavium.c
index ac37ae1..6ac9d63 100644
--- a/drivers/i2c/busses/i2c-cavium.c
+++ b/drivers/i2c/busses/i2c-cavium.c
@@ -99,7 +99,7 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)

static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c)
{
- return (__raw_readq(i2c->twsi_base + SW_TWSI) & SW_TWSI_V) == 0;
+ return (__raw_readq(i2c->twsi_base + SW_TWSI(i2c)) & SW_TWSI_V) == 0;
}

static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c, bool *first)
@@ -443,12 +443,12 @@ static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
else
cmd |= SW_TWSI_OP_7;

- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));
ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;

- cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return -EAGAIN;

@@ -456,7 +456,7 @@ static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;

if (msgs[0].len > 4) {
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT(i2c));
for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
}
@@ -493,15 +493,15 @@ static int octeon_i2c_hlc_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)

for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
ext |= (u64) msgs[0].buf[j] << (8 * i);
- octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT(i2c));
}

- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));
ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;

- cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return -EAGAIN;

@@ -536,18 +536,18 @@ static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs
cmd |= SW_TWSI_EIA;
ext = (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
- octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT(i2c));
} else
cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;

octeon_i2c_hlc_int_clear(i2c);
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));

ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;

- cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return -EAGAIN;

@@ -555,7 +555,7 @@ static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs
msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;

if (msgs[1].len > 4) {
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT(i2c));
for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
}
@@ -601,16 +601,16 @@ static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msg
set_ext = true;
}
if (set_ext)
- octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT(i2c));

octeon_i2c_hlc_int_clear(i2c);
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));

ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;

- cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return -EAGAIN;

diff --git a/drivers/i2c/busses/i2c-cavium.h b/drivers/i2c/busses/i2c-cavium.h
index 33c7e1f..ad57b03 100644
--- a/drivers/i2c/busses/i2c-cavium.h
+++ b/drivers/i2c/busses/i2c-cavium.h
@@ -7,17 +7,6 @@
#include <linux/kernel.h>
#include <linux/pci.h>

-/* Register offsets */
-#if IS_ENABLED(CONFIG_I2C_THUNDERX)
- #define SW_TWSI 0x1000
- #define TWSI_INT 0x1010
- #define SW_TWSI_EXT 0x1018
-#else
- #define SW_TWSI 0x00
- #define TWSI_INT 0x10
- #define SW_TWSI_EXT 0x18
-#endif
-
/* Controller command patterns */
#define SW_TWSI_V BIT_ULL(63) /* Valid bit */
#define SW_TWSI_EIA BIT_ULL(61) /* Extended internal address */
@@ -97,9 +86,21 @@

#define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */

+/* Register offsets */
+struct octeon_i2c_reg_offset {
+ unsigned int sw_twsi;
+ unsigned int twsi_int;
+ unsigned int sw_twsi_ext;
+};
+
+#define SW_TWSI(x) (x->roff.sw_twsi)
+#define TWSI_INT(x) (x->roff.twsi_int)
+#define SW_TWSI_EXT(x) (x->roff.sw_twsi_ext)
+
struct octeon_i2c {
wait_queue_head_t queue;
struct i2c_adapter adap;
+ struct octeon_i2c_reg_offset roff;
struct clk *clk;
int irq;
int hlc_irq; /* For cn7890 only */
@@ -139,9 +140,9 @@ static inline void octeon_i2c_reg_write(struct octeon_i2c *i2c, u64 eop_reg, u8
{
u64 tmp;

- __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI);
+ __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI(i2c));
do {
- tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
+ tmp = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
} while ((tmp & SW_TWSI_V) != 0);
}

@@ -163,9 +164,9 @@ static inline u8 octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg)
{
u64 tmp;

- __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI);
+ __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI(i2c));
do {
- tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
+ tmp = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
} while ((tmp & SW_TWSI_V) != 0);

return tmp & 0xFF;
@@ -186,7 +187,7 @@ static inline u8 octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg)
*/
static inline u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
{
- return __raw_readq(i2c->twsi_base + TWSI_INT);
+ return __raw_readq(i2c->twsi_base + TWSI_INT(i2c));
}

/**
@@ -196,7 +197,7 @@ static inline u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
*/
static inline void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
{
- octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT);
+ octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT(i2c));
}

/* Prototypes */
diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index fec4306..038007d 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -163,6 +163,10 @@ static int octeon_i2c_probe(struct platform_device *pdev)
}
i2c->dev = &pdev->dev;

+ i2c->roff.sw_twsi = 0x00;
+ i2c->roff.twsi_int = 0x10;
+ i2c->roff.sw_twsi_ext = 0x18;
+
res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
i2c->twsi_base = devm_ioremap_resource(&pdev->dev, res_mem);
if (IS_ERR(i2c->twsi_base)) {
diff --git a/drivers/i2c/busses/i2c-thunderx-core.c b/drivers/i2c/busses/i2c-thunderx-core.c
index 656b405..8fcd26c 100644
--- a/drivers/i2c/busses/i2c-thunderx-core.c
+++ b/drivers/i2c/busses/i2c-thunderx-core.c
@@ -134,6 +134,10 @@ static int thunder_i2c_probe_pci(struct pci_dev *pdev,
if (!i2c)
return -ENOMEM;

+ i2c->roff.sw_twsi = 0x1000;
+ i2c->roff.twsi_int = 0x1010;
+ i2c->roff.sw_twsi_ext = 0x1018;
+
i2c->dev = dev;
pci_set_drvdata(pdev, i2c);
ret = pci_enable_device(pdev);
--
1.9.1
Jan Glauber
2016-04-25 14:36:12 UTC
Permalink
Add smbus alert interrupt support.

Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-cavium.h | 6 ++++++
drivers/i2c/busses/i2c-thunderx-core.c | 35 ++++++++++++++++++++++++++++++++++
2 files changed, 41 insertions(+)

diff --git a/drivers/i2c/busses/i2c-cavium.h b/drivers/i2c/busses/i2c-cavium.h
index ad57b03..749dffc 100644
--- a/drivers/i2c/busses/i2c-cavium.h
+++ b/drivers/i2c/busses/i2c-cavium.h
@@ -3,6 +3,7 @@
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/pci.h>
@@ -120,6 +121,11 @@ struct octeon_i2c {
#if IS_ENABLED(CONFIG_I2C_THUNDERX)
struct msix_entry i2c_msix;
#endif
+
+#if IS_ENABLED(CONFIG_I2C_SMBUS)
+ struct i2c_smbus_alert_setup alert_data;
+ struct i2c_client *ara;
+#endif
};

static inline void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
diff --git a/drivers/i2c/busses/i2c-thunderx-core.c b/drivers/i2c/busses/i2c-thunderx-core.c
index 8fcd26c..e1a111d 100644
--- a/drivers/i2c/busses/i2c-thunderx-core.c
+++ b/drivers/i2c/busses/i2c-thunderx-core.c
@@ -9,9 +9,11 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/of_irq.h>
#include <linux/pci.h>

#include "i2c-cavium.h"
@@ -106,6 +108,35 @@ static void thunder_i2c_clock_disable(struct device *dev, struct clk *clk)
devm_clk_put(dev, clk);
}

+static int thunder_i2c_smbus_setup(struct octeon_i2c *i2c,
+ struct device_node *node)
+{
+#if IS_ENABLED(CONFIG_I2C_SMBUS)
+ u32 type;
+
+ i2c->alert_data.irq = irq_of_parse_and_map(node, 0);
+ if (!i2c->alert_data.irq)
+ return -EINVAL;
+
+ type = irqd_get_trigger_type(irq_get_irq_data(i2c->alert_data.irq));
+ i2c->alert_data.alert_edge_triggered =
+ (type & IRQ_TYPE_LEVEL_MASK) ? 1 : 0;
+
+ i2c->ara = i2c_setup_smbus_alert(&i2c->adap, &i2c->alert_data);
+ if (!i2c->ara)
+ return -ENODEV;
+#endif
+ return 0;
+}
+
+static void thunder_i2c_smbus_remove(struct octeon_i2c *i2c)
+{
+#if IS_ENABLED(CONFIG_I2C_SMBUS)
+ if (i2c->ara)
+ i2c_unregister_device(i2c->ara);
+#endif
+}
+
static void thunder_i2c_set_name(struct pci_dev *pdev, struct octeon_i2c *i2c,
char *name)
{
@@ -210,6 +241,9 @@ static int thunder_i2c_probe_pci(struct pci_dev *pdev,
goto out_irq;
}

+ ret = thunder_i2c_smbus_setup(i2c, node);
+ if (ret < 0)
+ dev_info(dev, "Failed to setup smbus alert\n");
dev_info(i2c->dev, "probed\n");
return 0;

@@ -240,6 +274,7 @@ static void thunder_i2c_remove_pci(struct pci_dev *pdev)

dev = i2c->dev;
thunder_i2c_clock_disable(dev, i2c->clk);
+ thunder_i2c_smbus_remove(i2c);
i2c_del_adapter(&i2c->adap);
devm_free_irq(dev, i2c->i2c_msix.vector, i2c);
pci_disable_msix(pdev);
--
1.9.1
Jan Glauber
2016-04-25 14:36:26 UTC
Permalink
From: Peter Swain <***@cavium.com>

There is a race between the TWSI interrupt and the condition
that is required before proceeding:

Low-level: interrupt flag bit must be set
High-level controller: valid bit must be clear

If the interrupt comes too early and the condition is not met
the wait will time out, and the transfer is aborted leading
to very poor performance.

To avoid this race retry for the condition ~80 ┬Ás later.
The retry is avoided on the very first invocation of
wait_event_timeout() (which tests the condition before entering
the wait and is therefore always wrong in this case).

EEPROM reads on 100kHz i2c now measure ~5.2kB/s, about 1/2 what's
achievable, and much better than the worst-case 100 bytes/sec before.

While at it remove the debug print from the low-level wait function.

Signed-off-by: Peter Swain <***@cavium.com>
Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 55 ++++++++++++++++++++++++++++++++++-------
1 file changed, 46 insertions(+), 9 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 76fa479..3144fe9 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -109,6 +109,8 @@
#define TWSI_INT_SDA BIT_ULL(10)
#define TWSI_INT_SCL BIT_ULL(11)

+#define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */
+
struct octeon_i2c {
wait_queue_head_t queue;
struct i2c_adapter adap;
@@ -340,11 +342,29 @@ static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
return IRQ_HANDLED;
}

-static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
+static bool octeon_i2c_test_iflg(struct octeon_i2c *i2c)
{
return (octeon_i2c_ctl_read(i2c) & TWSI_CTL_IFLG);
}

+static bool octeon_i2c_test_ready(struct octeon_i2c *i2c, bool *first)
+{
+ if (octeon_i2c_test_iflg(i2c))
+ return true;
+
+ if (*first) {
+ *first = false;
+ return false;
+ }
+
+ /*
+ * IRQ has signaled an event but IFLG hasn't changed.
+ * Sleep and retry once.
+ */
+ usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+ return octeon_i2c_test_iflg(i2c);
+}
+
/**
* octeon_i2c_wait - wait for the IFLG to be set
* @i2c: The struct octeon_i2c
@@ -354,15 +374,14 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
static int octeon_i2c_wait(struct octeon_i2c *i2c)
{
long time_left;
+ bool first = 1;

i2c->int_enable(i2c);
- time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
+ time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
i2c->adap.timeout);
i2c->int_disable(i2c);
- if (!time_left) {
- dev_dbg(i2c->dev, "%s: timeout\n", __func__);
+ if (!time_left)
return -ETIMEDOUT;
- }

return 0;
}
@@ -428,11 +447,28 @@ static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
}
}

-static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c)
+static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c)
+{
+ return (__raw_readq(i2c->twsi_base + SW_TWSI) & SW_TWSI_V) == 0;
+}
+
+static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c, bool *first)
{
- u64 val = __raw_readq(i2c->twsi_base + SW_TWSI);
+ /* check if valid bit is cleared */
+ if (octeon_i2c_hlc_test_valid(i2c))
+ return true;

- return (val & SW_TWSI_V) == 0;
+ if (*first) {
+ *first = false;
+ return false;
+ }
+
+ /*
+ * IRQ has signaled an event but valid bit isn't cleared.
+ * Sleep and retry once.
+ */
+ usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+ return octeon_i2c_hlc_test_valid(i2c);
}

static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
@@ -454,11 +490,12 @@ static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
*/
static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
{
+ bool first = 1;
int time_left;

i2c->hlc_int_enable(i2c);
time_left = wait_event_timeout(i2c->queue,
- octeon_i2c_hlc_test_ready(i2c),
+ octeon_i2c_hlc_test_ready(i2c, &first),
i2c->adap.timeout);
i2c->hlc_int_disable(i2c);
if (!time_left) {
--
1.9.1
Jan Glauber
2016-04-25 14:36:39 UTC
Permalink
From: David Daney <***@cavium.com>

cn78xx has a different interrupt architecture, so we have to manage
the interrupts differently.

Signed-off-by: David Daney <***@caviumnetworks.com>
Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 131 ++++++++++++++++++++++++++++++++++++----
1 file changed, 120 insertions(+), 11 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 9520f78..76fa479 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -11,6 +11,7 @@
* warranty of any kind, whether express or implied.
*/

+#include <linux/atomic.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
@@ -112,11 +113,18 @@ struct octeon_i2c {
wait_queue_head_t queue;
struct i2c_adapter adap;
int irq;
+ int hlc_irq; /* For cn7890 only */
u32 twsi_freq;
int sys_freq;
void __iomem *twsi_base;
struct device *dev;
bool hlc_enabled;
+ void (*int_enable)(struct octeon_i2c *);
+ void (*int_disable)(struct octeon_i2c *);
+ void (*hlc_int_enable)(struct octeon_i2c *);
+ void (*hlc_int_disable)(struct octeon_i2c *);
+ atomic_t int_enable_cnt;
+ atomic_t hlc_int_enable_cnt;
};

static void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
@@ -217,6 +225,58 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
octeon_i2c_write_int(i2c, 0);
}

+/**
+ * octeon_i2c_int_enable78 - enable the CORE interrupt
+ * @i2c: The struct octeon_i2c
+ *
+ * The interrupt will be asserted when there is non-STAT_IDLE state in the
+ * SW_TWSI_EOP_TWSI_STAT register.
+ */
+static void octeon_i2c_int_enable78(struct octeon_i2c *i2c)
+{
+ atomic_inc_return(&i2c->int_enable_cnt);
+ enable_irq(i2c->irq);
+}
+
+static void __octeon_i2c_irq_disable(atomic_t *cnt, int irq)
+{
+ int count;
+
+ /*
+ * The interrupt can be disabled in two places, but we only
+ * want to make the disable_irq_nosync() call once, so keep
+ * track with the atomic variable.
+ */
+ count = atomic_dec_if_positive(cnt);
+ if (count >= 0)
+ disable_irq_nosync(irq);
+}
+
+/* disable the CORE interrupt */
+static void octeon_i2c_int_disable78(struct octeon_i2c *i2c)
+{
+ __octeon_i2c_irq_disable(&i2c->int_enable_cnt, i2c->irq);
+}
+
+/**
+ * octeon_i2c_hlc_int_enable78 - enable the ST interrupt
+ * @i2c: The struct octeon_i2c
+ *
+ * The interrupt will be asserted when there is non-STAT_IDLE state in
+ * the SW_TWSI_EOP_TWSI_STAT register.
+ */
+static void octeon_i2c_hlc_int_enable78(struct octeon_i2c *i2c)
+{
+ atomic_inc_return(&i2c->hlc_int_enable_cnt);
+ enable_irq(i2c->hlc_irq);
+}
+
+/* disable the ST interrupt */
+static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c)
+{
+ __octeon_i2c_irq_disable(&i2c->hlc_int_enable_cnt, i2c->hlc_irq);
+}
+
/*
* Cleanup low-level state & enable high-level controller.
*/
@@ -263,7 +323,18 @@ static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
{
struct octeon_i2c *i2c = dev_id;

- octeon_i2c_int_disable(i2c);
+ i2c->int_disable(i2c);
+ wake_up(&i2c->queue);
+
+ return IRQ_HANDLED;
+}
+
+/* HLC interrupt service routine */
+static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
+{
+ struct octeon_i2c *i2c = dev_id;
+
+ i2c->hlc_int_disable(i2c);
wake_up(&i2c->queue);

return IRQ_HANDLED;
@@ -284,10 +355,10 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
{
long time_left;

- octeon_i2c_int_enable(i2c);
+ i2c->int_enable(i2c);
time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
i2c->adap.timeout);
- octeon_i2c_int_disable(i2c);
+ i2c->int_disable(i2c);
if (!time_left) {
dev_dbg(i2c->dev, "%s: timeout\n", __func__);
return -ETIMEDOUT;
@@ -385,11 +456,11 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
{
int time_left;

- octeon_i2c_hlc_int_enable(i2c);
+ i2c->hlc_int_enable(i2c);
time_left = wait_event_timeout(i2c->queue,
octeon_i2c_hlc_test_ready(i2c),
i2c->adap.timeout);
- octeon_i2c_int_disable(i2c);
+ i2c->hlc_int_disable(i2c);
if (!time_left) {
octeon_i2c_hlc_int_clear(i2c);
return -ETIMEDOUT;
@@ -942,14 +1013,26 @@ static struct i2c_adapter octeon_i2c_ops = {
static int octeon_i2c_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
+ int irq, result = 0, hlc_irq = 0;
struct resource *res_mem;
struct octeon_i2c *i2c;
- int irq, result = 0;
-
- /* All adaptors have an irq. */
- irq = platform_get_irq(pdev, 0);
- if (irq < 0)
- return irq;
+ bool cn78xx_style;
+
+ cn78xx_style = of_device_is_compatible(node, "cavium,octeon-7890-twsi");
+ if (cn78xx_style) {
+ hlc_irq = platform_get_irq(pdev, 0);
+ if (hlc_irq < 0)
+ return hlc_irq;
+
+ irq = platform_get_irq(pdev, 2);
+ if (irq < 0)
+ return irq;
+ } else {
+ /* All adaptors have an irq. */
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+ }

i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
if (!i2c) {
@@ -984,6 +1067,31 @@ static int octeon_i2c_probe(struct platform_device *pdev)

i2c->irq = irq;

+ if (cn78xx_style) {
+ i2c->hlc_irq = hlc_irq;
+
+ i2c->int_enable = octeon_i2c_int_enable78;
+ i2c->int_disable = octeon_i2c_int_disable78;
+ i2c->hlc_int_enable = octeon_i2c_hlc_int_enable78;
+ i2c->hlc_int_disable = octeon_i2c_hlc_int_disable78;
+
+ irq_set_status_flags(i2c->irq, IRQ_NOAUTOEN);
+ irq_set_status_flags(i2c->hlc_irq, IRQ_NOAUTOEN);
+
+ result = devm_request_irq(&pdev->dev, i2c->hlc_irq,
+ octeon_i2c_hlc_isr78, 0,
+ DRV_NAME, i2c);
+ if (result < 0) {
+ dev_err(i2c->dev, "failed to attach interrupt\n");
+ goto out;
+ }
+ } else {
+ i2c->int_enable = octeon_i2c_int_enable;
+ i2c->int_disable = octeon_i2c_int_disable;
+ i2c->hlc_int_enable = octeon_i2c_hlc_int_enable;
+ i2c->hlc_int_disable = octeon_i2c_int_disable;
+ }
+
result = devm_request_irq(&pdev->dev, i2c->irq,
octeon_i2c_isr, 0, DRV_NAME, i2c);
if (result < 0) {
@@ -1030,6 +1138,7 @@ static int octeon_i2c_remove(struct platform_device *pdev)

static const struct of_device_id octeon_i2c_match[] = {
{ .compatible = "cavium,octeon-3860-twsi", },
+ { .compatible = "cavium,octeon-7890-twsi", },
{},
};
MODULE_DEVICE_TABLE(of, octeon_i2c_match);
--
1.9.1
Jan Glauber
2016-04-25 14:36:51 UTC
Permalink
Just sorting the functions to be consistent with the other
read/write variants.

Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 78 ++++++++++++++++++++---------------------
1 file changed, 39 insertions(+), 39 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 009cc33..2bc32b9 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -864,45 +864,6 @@ static void octeon_i2c_stop(struct octeon_i2c *i2c)
}

/**
- * octeon_i2c_write - send data to the bus via low-level controller
- * @i2c: The struct octeon_i2c
- * @target: Target address
- * @data: Pointer to the data to be sent
- * @length: Length of the data
- *
- * The address is sent over the bus, then the data.
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
- const u8 *data, int length)
-{
- int i, result;
-
- octeon_i2c_data_write(i2c, target << 1);
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
-
- result = octeon_i2c_wait(i2c);
- if (result)
- return result;
-
- for (i = 0; i < length; i++) {
- result = octeon_i2c_check_status(i2c, false);
- if (result)
- return result;
-
- octeon_i2c_data_write(i2c, data[i]);
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
-
- result = octeon_i2c_wait(i2c);
- if (result)
- return result;
- }
-
- return 0;
-}
-
-/**
* octeon_i2c_read - receive data from the bus via low-level controller
* @i2c: The struct octeon_i2c
* @target: Target address
@@ -967,6 +928,45 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
}

/**
+ * octeon_i2c_write - send data to the bus via low-level controller
+ * @i2c: The struct octeon_i2c
+ * @target: Target address
+ * @data: Pointer to the data to be sent
+ * @length: Length of the data
+ *
+ * The address is sent over the bus, then the data.
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
+ const u8 *data, int length)
+{
+ int i, result;
+
+ octeon_i2c_data_write(i2c, target << 1);
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+
+ result = octeon_i2c_wait(i2c);
+ if (result)
+ return result;
+
+ for (i = 0; i < length; i++) {
+ result = octeon_i2c_check_status(i2c, false);
+ if (result)
+ return result;
+
+ octeon_i2c_data_write(i2c, data[i]);
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+
+ result = octeon_i2c_wait(i2c);
+ if (result)
+ return result;
+ }
+
+ return 0;
+}
+
+/**
* octeon_i2c_xfer - The driver's master_xfer function
* @adap: Pointer to the i2c_adapter structure
* @msgs: Pointer to the messages to be processed
--
1.9.1
Jan Glauber
2016-04-25 14:37:15 UTC
Permalink
From: David Daney <***@cavium.com>

CN3860 does not interrupt the CPU when the i2c status changes. If
we get a timeout, and see the status has in fact changed, we know we
have this problem, and drop back to polling.

Signed-off-by: David Daney <***@caviumnetworks.com>
Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 53 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 51 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 3144fe9..009cc33 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -121,6 +121,8 @@ struct octeon_i2c {
void __iomem *twsi_base;
struct device *dev;
bool hlc_enabled;
+ bool broken_irq_mode;
+ bool broken_irq_check;
void (*int_enable)(struct octeon_i2c *);
void (*int_disable)(struct octeon_i2c *);
void (*hlc_int_enable)(struct octeon_i2c *);
@@ -376,10 +378,32 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
long time_left;
bool first = 1;

+ /*
+ * Some chip revisions don't assert the irq in the interrupt
+ * controller. So we must poll for the IFLG change.
+ */
+ if (i2c->broken_irq_mode) {
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_test_iflg(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ udelay(50);
+
+ return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
+ }
+
i2c->int_enable(i2c);
time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
i2c->adap.timeout);
i2c->int_disable(i2c);
+
+ if (i2c->broken_irq_check && !time_left &&
+ octeon_i2c_test_iflg(i2c)) {
+ dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
+ }
+
if (!time_left)
return -ETIMEDOUT;

@@ -493,15 +517,37 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
bool first = 1;
int time_left;

+ /*
+ * Some cn38xx boards don't assert the irq in the interrupt
+ * controller. So we must poll for the valid bit change.
+ */
+ if (i2c->broken_irq_mode) {
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_hlc_test_valid(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ udelay(50);
+
+ return octeon_i2c_hlc_test_valid(i2c) ? 0 : -ETIMEDOUT;
+ }
+
i2c->hlc_int_enable(i2c);
time_left = wait_event_timeout(i2c->queue,
octeon_i2c_hlc_test_ready(i2c, &first),
i2c->adap.timeout);
i2c->hlc_int_disable(i2c);
- if (!time_left) {
+ if (!time_left)
octeon_i2c_hlc_int_clear(i2c);
- return -ETIMEDOUT;
+
+ if (i2c->broken_irq_check && !time_left &&
+ octeon_i2c_hlc_test_valid(i2c)) {
+ dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
}
+
+ if (!time_left)
+ return -ETIMEDOUT;
return 0;
}

@@ -1136,6 +1182,9 @@ static int octeon_i2c_probe(struct platform_device *pdev)
goto out;
}

+ if (OCTEON_IS_MODEL(OCTEON_CN38XX))
+ i2c->broken_irq_check = true;
+
result = octeon_i2c_init_lowlevel(i2c);
if (result) {
dev_err(i2c->dev, "init low level failed\n");
--
1.9.1
Jan Glauber
2016-04-27 09:38:00 UTC
Permalink
Post by Jan Glauber
CN3860 does not interrupt the CPU when the i2c status changes. If
we get a timeout, and see the status has in fact changed, we know we
have this problem, and drop back to polling.
CHECKPATCH
CHECK: usleep_range is preferred over udelay; see Documentation/timers/timers-howto.txt
+ udelay(50);
CHECK: usleep_range is preferred over udelay; see Documentation/timers/timers-howto.txt
+ udelay(50);
Yes, makes sense.
SMATCH
drivers/i2c/busses/i2c-octeon.c:544 octeon_i2c_hlc_wait() warn: inconsistent indenting
This is true as well.
OK, I'll reply with an updated patch.
Jan Glauber
2016-04-25 14:37:59 UTC
Permalink
From: David Daney <***@caviumnetworks.com>

Use High-Level Controller (HLC) when possible. The HLC can read/write
up to 8 bytes and is completely optional. The most important difference
of the HLC is that it only requires one interrupt for a transfer
(up to 8 bytes) where the low-level read/write requires 2 interrupts
plus one interrupt per transferred byte. Since the interrupts are costly
using the HLC improves the performance. Also, the HLC provides improved
error handling.

Signed-off-by: David Daney <***@caviumnetworks.com>
Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 345 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 335 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 60a02b2..9520f78 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -29,13 +29,23 @@
/* Register offsets */
#define SW_TWSI 0x00
#define TWSI_INT 0x10
+#define SW_TWSI_EXT 0x18

/* Controller command patterns */
#define SW_TWSI_V BIT_ULL(63) /* Valid bit */
+#define SW_TWSI_EIA BIT_ULL(61) /* Extended internal address */
#define SW_TWSI_R BIT_ULL(56) /* Result or read bit */
+#define SW_TWSI_SOVR BIT_ULL(55) /* Size override */
+#define SW_TWSI_SIZE_SHIFT 52
+#define SW_TWSI_ADDR_SHIFT 40
+#define SW_TWSI_IA_SHIFT 32 /* Internal address */

/* Controller opcode word (bits 60:57) */
#define SW_TWSI_OP_SHIFT 57
+#define SW_TWSI_OP_7 (0ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_7_IA (1ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_10 (2ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_10_IA (3ULL << SW_TWSI_OP_SHIFT)
#define SW_TWSI_OP_TWSI_CLK (4ULL << SW_TWSI_OP_SHIFT)
#define SW_TWSI_OP_EOP (6ULL << SW_TWSI_OP_SHIFT) /* Extended opcode */

@@ -48,7 +58,7 @@
#define SW_TWSI_EOP_TWSI_RST (SW_TWSI_OP_EOP | 7ULL << SW_TWSI_EOP_SHIFT)

/* Controller command and status bits */
-#define TWSI_CTL_CE 0x80
+#define TWSI_CTL_CE 0x80 /* High level controller enable */
#define TWSI_CTL_ENAB 0x40 /* Bus enable */
#define TWSI_CTL_STA 0x20 /* Master-mode start, HW clears when done */
#define TWSI_CTL_STP 0x10 /* Master-mode stop, HW clears when done */
@@ -87,6 +97,11 @@
#define STAT_IDLE 0xF8

/* TWSI_INT values */
+#define TWSI_INT_ST_INT BIT_ULL(0)
+#define TWSI_INT_TS_INT BIT_ULL(1)
+#define TWSI_INT_CORE_INT BIT_ULL(2)
+#define TWSI_INT_ST_EN BIT_ULL(4)
+#define TWSI_INT_TS_EN BIT_ULL(5)
#define TWSI_INT_CORE_EN BIT_ULL(6)
#define TWSI_INT_SDA_OVR BIT_ULL(8)
#define TWSI_INT_SCL_OVR BIT_ULL(9)
@@ -101,6 +116,7 @@ struct octeon_i2c {
int sys_freq;
void __iomem *twsi_base;
struct device *dev;
+ bool hlc_enabled;
};

static void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
@@ -201,6 +217,47 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
octeon_i2c_write_int(i2c, 0);
}

+/*
+ * Cleanup low-level state & enable high-level controller.
+ */
+static void octeon_i2c_hlc_enable(struct octeon_i2c *i2c)
+{
+ int try = 0;
+ u64 val;
+
+ if (i2c->hlc_enabled)
+ return;
+ i2c->hlc_enabled = true;
+
+ while (1) {
+ val = octeon_i2c_ctl_read(i2c);
+ if (!(val & (TWSI_CTL_STA | TWSI_CTL_STP)))
+ break;
+
+ /* clear IFLG event */
+ if (val & TWSI_CTL_IFLG)
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+
+ if (try++ > 100) {
+ pr_err("%s: giving up\n", __func__);
+ break;
+ }
+
+ /* spin until any start/stop has finished */
+ udelay(10);
+ }
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_CE | TWSI_CTL_AAK | TWSI_CTL_ENAB);
+}
+
+static void octeon_i2c_hlc_disable(struct octeon_i2c *i2c)
+{
+ if (!i2c->hlc_enabled)
+ return;
+
+ i2c->hlc_enabled = false;
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+}
+
/* interrupt service routine */
static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
{
@@ -300,6 +357,243 @@ static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
}
}

+static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c)
+{
+ u64 val = __raw_readq(i2c->twsi_base + SW_TWSI);
+
+ return (val & SW_TWSI_V) == 0;
+}
+
+static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_write_int(i2c, TWSI_INT_ST_EN);
+}
+
+static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
+{
+ /* clear ST/TS events, listen for neither */
+ octeon_i2c_write_int(i2c, TWSI_INT_ST_INT | TWSI_INT_TS_INT);
+}
+
+/**
+ * octeon_i2c_hlc_wait - wait for an HLC operation to complete
+ * @i2c: The struct octeon_i2c
+ *
+ * Returns 0 on success, otherwise -ETIMEDOUT.
+ */
+static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
+{
+ int time_left;
+
+ octeon_i2c_hlc_int_enable(i2c);
+ time_left = wait_event_timeout(i2c->queue,
+ octeon_i2c_hlc_test_ready(i2c),
+ i2c->adap.timeout);
+ octeon_i2c_int_disable(i2c);
+ if (!time_left) {
+ octeon_i2c_hlc_int_clear(i2c);
+ return -ETIMEDOUT;
+ }
+ return 0;
+}
+
+/* high-level-controller pure read of up to 8 bytes */
+static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ int i, j, ret = 0;
+ u64 cmd;
+
+ octeon_i2c_hlc_enable(i2c);
+ octeon_i2c_hlc_int_clear(i2c);
+
+ cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10;
+ else
+ cmd |= SW_TWSI_OP_7;
+
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+
+ for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
+ msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
+
+ if (msgs[0].len > 4) {
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+ for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
+ msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
+ }
+
+err:
+ return ret;
+}
+
+/* high-level-controller pure write of up to 8 bytes */
+static int octeon_i2c_hlc_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ int i, j, ret = 0;
+ u64 cmd;
+
+ octeon_i2c_hlc_enable(i2c);
+ octeon_i2c_hlc_int_clear(i2c);
+
+ cmd = SW_TWSI_V | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10;
+ else
+ cmd |= SW_TWSI_OP_7;
+
+ for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
+ cmd |= (u64)msgs[0].buf[j] << (8 * i);
+
+ if (msgs[0].len > 4) {
+ u64 ext = 0;
+
+ for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
+ ext |= (u64) msgs[0].buf[j] << (8 * i);
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+ }
+
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+
+ ret = octeon_i2c_check_status(i2c, false);
+
+err:
+ return ret;
+}
+
+/* high-level-controller composite write+read, msg0=addr, msg1=data */
+static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ int i, j, ret = 0;
+ u64 cmd;
+
+ octeon_i2c_hlc_enable(i2c);
+
+ cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64)(msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10_IA;
+ else
+ cmd |= SW_TWSI_OP_7_IA;
+
+ if (msgs[0].len == 2) {
+ u64 ext = 0;
+
+ cmd |= SW_TWSI_EIA;
+ ext = (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+ cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+ } else
+ cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+
+ octeon_i2c_hlc_int_clear(i2c);
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+
+ for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
+ msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
+
+ if (msgs[1].len > 4) {
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+ for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
+ msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
+ }
+
+err:
+ return ret;
+}
+
+/* high-level-controller composite write+write, m[0]len<=2, m[1]len<=8 */
+static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ bool set_ext = false;
+ int i, j, ret = 0;
+ u64 cmd, ext = 0;
+
+ octeon_i2c_hlc_enable(i2c);
+
+ cmd = SW_TWSI_V | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64) (msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10_IA;
+ else
+ cmd |= SW_TWSI_OP_7_IA;
+
+ if (msgs[0].len == 2) {
+ cmd |= SW_TWSI_EIA;
+ ext |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+ set_ext = true;
+ cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
+ } else
+ cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+
+ for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
+ cmd |= (u64) msgs[1].buf[j] << (8 * i);
+
+ if (msgs[1].len > 4) {
+ for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
+ ext |= (u64)msgs[1].buf[j] << (8 * i);
+ set_ext = true;
+ }
+ if (set_ext)
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+
+ octeon_i2c_hlc_int_clear(i2c);
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+
+ ret = octeon_i2c_check_status(i2c, false);
+
+err:
+ return ret;
+}
+
/* calculate and set clock divisors */
static void octeon_i2c_set_clock(struct octeon_i2c *i2c)
{
@@ -344,23 +638,29 @@ static void octeon_i2c_set_clock(struct octeon_i2c *i2c)

static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
{
- u8 status;
+ u8 status = 0;
int tries;

- /* disable high level controller, enable bus access */
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
-
/* reset controller */
octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_RST, 0);

- for (tries = 10; tries; tries--) {
+ for (tries = 10; tries && status != STAT_IDLE; tries--) {
udelay(1);
status = octeon_i2c_stat_read(i2c);
if (status == STAT_IDLE)
- return 0;
+ break;
}
- dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n", __func__, status);
- return -EIO;
+
+ if (status != STAT_IDLE) {
+ dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n",
+ __func__, status);
+ return -EIO;
+ }
+
+ /* toggle twice to force both teardowns */
+ octeon_i2c_hlc_enable(i2c);
+ octeon_i2c_hlc_disable(i2c);
+ return 0;
}

static int octeon_i2c_recovery(struct octeon_i2c *i2c)
@@ -385,6 +685,8 @@ static int octeon_i2c_start(struct octeon_i2c *i2c)
int ret;
u8 stat;

+ octeon_i2c_hlc_disable(i2c);
+
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
ret = octeon_i2c_wait(i2c);
if (ret)
@@ -524,6 +826,28 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
struct octeon_i2c *i2c = i2c_get_adapdata(adap);
int i, ret = 0;

+ if (num == 1) {
+ if (msgs[0].len > 0 && msgs[0].len <= 8) {
+ if (msgs[0].flags & I2C_M_RD)
+ ret = octeon_i2c_hlc_read(i2c, msgs);
+ else
+ ret = octeon_i2c_hlc_write(i2c, msgs);
+ goto out;
+ }
+ } else if (num == 2) {
+ if ((msgs[0].flags & I2C_M_RD) == 0 &&
+ (msgs[1].flags & I2C_M_RECV_LEN) == 0 &&
+ msgs[0].len > 0 && msgs[0].len <= 2 &&
+ msgs[1].len > 0 && msgs[1].len <= 8 &&
+ msgs[0].addr == msgs[1].addr) {
+ if (msgs[1].flags & I2C_M_RD)
+ ret = octeon_i2c_hlc_comp_read(i2c, msgs);
+ else
+ ret = octeon_i2c_hlc_comp_write(i2c, msgs);
+ goto out;
+ }
+ }
+
for (i = 0; ret == 0 && i < num; i++) {
struct i2c_msg *pmsg = &msgs[i];

@@ -539,7 +863,7 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
pmsg->len);
}
octeon_i2c_stop(i2c);
-
+out:
return (ret != 0) ? ret : num;
}

@@ -578,6 +902,7 @@ static void octeon_i2c_prepare_recovery(struct i2c_adapter *adap)
*/
octeon_i2c_stop(i2c);

+ octeon_i2c_hlc_disable(i2c);
octeon_i2c_write_int(i2c, 0);
}
--
1.9.1
Jan Glauber
2016-04-26 05:51:47 UTC
Permalink
Post by Jan Glauber
Use High-Level Controller (HLC) when possible. The HLC can read/write
up to 8 bytes and is completely optional. The most important difference
of the HLC is that it only requires one interrupt for a transfer
(up to 8 bytes) where the low-level read/write requires 2 interrupts
plus one interrupt per transferred byte. Since the interrupts are costly
using the HLC improves the performance. Also, the HLC provides improved
error handling.
Applied to for-next, thanks!
I thought checkpatch is always strict, but seriously, I didn't know that
option. Thanks for fixing that!

Jan
total: 0 errors, 0 warnings, 18 checks, 427 lines checked
CHECK: No space is necessary after a cast
+ ext |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
I fixed all 14 of those.
CHECK: braces {} should be used on all arms of this statement
+ if (msgs[0].len == 2) {
[...]
+ } else
[...]
and 2 of those.
Jan Glauber
2016-04-25 14:39:12 UTC
Permalink
From: Peter Swain <***@cavium.com>

Add helper function that reads back a value after writing to
make sure the write is finished and use it in octeon_i2c_write_int().

Signed-off-by: Peter Swain <***@cavium.com>
Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index ad563cf..60a02b2 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -103,6 +103,12 @@ struct octeon_i2c {
struct device *dev;
};

+static void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
+{
+ __raw_writeq(val, addr);
+ __raw_readq(addr); /* wait for write to land */
+}
+
/**
* octeon_i2c_reg_write - write an I2C core register
* @i2c: The struct octeon_i2c
@@ -173,8 +179,7 @@ static u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
*/
static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
{
- __raw_writeq(data, i2c->twsi_base + TWSI_INT);
- __raw_readq(i2c->twsi_base + TWSI_INT);
+ octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT);
}

/**
--
1.9.1
Jan Glauber
2016-04-25 14:39:40 UTC
Permalink
Switch to the i2c bus recovery framework using generic SCL recovery.
If this fails try to reset the hardware. The recovery is triggered
during START on timeout of the interrupt or failure to reach
the START / repeated-START condition.

The START function is moved to xfer and while at it remove the
xfer debug message (i2c core already provides a debug message
for this).

Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 160 ++++++++++++++++++++++++----------------
1 file changed, 97 insertions(+), 63 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 471d06e..0f536a1 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -90,6 +90,8 @@
#define TWSI_INT_CORE_EN BIT_ULL(6)
#define TWSI_INT_SDA_OVR BIT_ULL(8)
#define TWSI_INT_SCL_OVR BIT_ULL(9)
+#define TWSI_INT_SDA BIT_ULL(10)
+#define TWSI_INT_SCL BIT_ULL(11)

struct octeon_i2c {
wait_queue_head_t queue;
@@ -152,6 +154,18 @@ static u8 octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg)
#define octeon_i2c_stat_read(i2c) \
octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT)

+
+/**
+ * octeon_i2c_read_int - read the TWSI_INT register
+ * @i2c: The struct octeon_i2c
+ *
+ * Returns the value of the register.
+ */
+static u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
+{
+ return __raw_readq(i2c->twsi_base + TWSI_INT);
+}
+
/**
* octeon_i2c_write_int - write the TWSI_INT register
* @i2c: The struct octeon_i2c
@@ -182,33 +196,6 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
octeon_i2c_write_int(i2c, 0);
}

-/**
- * octeon_i2c_unblock - unblock the bus
- * @i2c: The struct octeon_i2c
- *
- * If there was a reset while a device was driving 0 to bus, bus is blocked.
- * We toggle it free manually by some clock cycles and send a stop.
- */
-static void octeon_i2c_unblock(struct octeon_i2c *i2c)
-{
- int i;
-
- dev_dbg(i2c->dev, "%s\n", __func__);
-
- for (i = 0; i < 9; i++) {
- octeon_i2c_write_int(i2c, 0);
- udelay(5);
- octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
- udelay(5);
- }
- /* hand-crank a STOP */
- octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR | TWSI_INT_SCL_OVR);
- udelay(5);
- octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR);
- udelay(5);
- octeon_i2c_write_int(i2c, 0);
-}
-
/* interrupt service routine */
static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
{
@@ -371,6 +358,17 @@ static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
return -EIO;
}

+static int octeon_i2c_recovery(struct octeon_i2c *i2c)
+{
+ int ret;
+
+ ret = i2c_recover_bus(&i2c->adap);
+ if (ret)
+ /* recover failed, try hardware re-init */
+ ret = octeon_i2c_init_lowlevel(i2c);
+ return ret;
+}
+
/**
* octeon_i2c_start - send START to the bus
* @i2c: The struct octeon_i2c
@@ -379,34 +377,23 @@ static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
*/
static int octeon_i2c_start(struct octeon_i2c *i2c)
{
- int result;
- u8 data;
+ int ret;
+ u8 stat;

octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
+ ret = octeon_i2c_wait(i2c);
+ if (ret)
+ goto error;

- result = octeon_i2c_wait(i2c);
- if (result) {
- if (octeon_i2c_stat_read(i2c) == STAT_IDLE) {
- /*
- * Controller refused to send start flag May
- * be a client is holding SDA low - let's try
- * to free it.
- */
- octeon_i2c_unblock(i2c);
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
- result = octeon_i2c_wait(i2c);
- }
- if (result)
- return result;
- }
-
- data = octeon_i2c_stat_read(i2c);
- if ((data != STAT_START) && (data != STAT_REP_START)) {
- dev_err(i2c->dev, "%s: bad status (0x%x)\n", __func__, data);
- return -EIO;
- }
+ stat = octeon_i2c_stat_read(i2c);
+ if (stat == STAT_START || stat == STAT_REP_START)
+ /* START successful, bail out */
+ return 0;

- return 0;
+error:
+ /* START failed, try to recover */
+ ret = octeon_i2c_recovery(i2c);
+ return (ret) ? ret : -EAGAIN;
}

/* send STOP to the bus */
@@ -431,10 +418,6 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
{
int i, result;

- result = octeon_i2c_start(i2c);
- if (result)
- return result;
-
octeon_i2c_data_write(i2c, target << 1);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);

@@ -479,10 +462,6 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
if (length < 1)
return -EINVAL;

- result = octeon_i2c_start(i2c);
- if (result)
- return result;
-
octeon_i2c_data_write(i2c, (target << 1) | 1);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);

@@ -546,10 +525,10 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
for (i = 0; ret == 0 && i < num; i++) {
struct i2c_msg *pmsg = &msgs[i];

- dev_dbg(i2c->dev,
- "Doing %s %d byte(s) to/from 0x%02x - %d of %d messages\n",
- pmsg->flags & I2C_M_RD ? "read" : "write",
- pmsg->len, pmsg->addr, i + 1, num);
+ ret = octeon_i2c_start(i2c);
+ if (ret)
+ return ret;
+
if (pmsg->flags & I2C_M_RD)
ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
&pmsg->len, pmsg->flags & I2C_M_RECV_LEN);
@@ -562,6 +541,60 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
return (ret != 0) ? ret : num;
}

+static int octeon_i2c_get_scl(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+ u64 state;
+
+ state = octeon_i2c_read_int(i2c);
+ return state & TWSI_INT_SCL;
+}
+
+static void octeon_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+ octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
+}
+
+static int octeon_i2c_get_sda(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+ u64 state;
+
+ state = octeon_i2c_read_int(i2c);
+ return state & TWSI_INT_SDA;
+}
+
+static void octeon_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+ /*
+ * The stop resets the state machine, does not _transmit_ STOP unless
+ * engine was active.
+ */
+ octeon_i2c_stop(i2c);
+
+ octeon_i2c_write_int(i2c, 0);
+}
+
+static void octeon_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+ octeon_i2c_write_int(i2c, 0);
+}
+
+static struct i2c_bus_recovery_info octeon_i2c_recovery_info = {
+ .recover_bus = i2c_generic_scl_recovery,
+ .get_scl = octeon_i2c_get_scl,
+ .set_scl = octeon_i2c_set_scl,
+ .get_sda = octeon_i2c_get_sda,
+ .prepare_recovery = octeon_i2c_prepare_recovery,
+ .unprepare_recovery = octeon_i2c_unprepare_recovery,
+};
+
static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
@@ -642,6 +675,7 @@ static int octeon_i2c_probe(struct platform_device *pdev)
i2c->adap = octeon_i2c_ops;
i2c->adap.timeout = msecs_to_jiffies(2);
i2c->adap.retries = 5;
+ i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
i2c->adap.dev.parent = &pdev->dev;
i2c->adap.dev.of_node = node;
i2c_set_adapdata(&i2c->adap, i2c);
--
1.9.1
Jan Glauber
2016-04-25 14:39:58 UTC
Permalink
Introduce a function that checks for valid status codes depending
on the phase of a transmit or receive. Also add all existing status
codes and improve error handling for various states.

The Octeon TWSI has an "assert acknowledge" bit (TWSI_CTL_AAK) that
is required to be set in master receive mode until the last byte is
requested. The state check needs to consider if this bit was set.

Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 129 +++++++++++++++++++++++++++++++++-------
1 file changed, 106 insertions(+), 23 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 4275007..471d06e 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -55,13 +55,35 @@
#define TWSI_CTL_IFLG 0x08 /* HW event, SW writes 0 to ACK */
#define TWSI_CTL_AAK 0x04 /* Assert ACK */

-/* Some status values */
+/* Status values */
+#define STAT_ERROR 0x00
#define STAT_START 0x08
-#define STAT_RSTART 0x10
+#define STAT_REP_START 0x10
#define STAT_TXADDR_ACK 0x18
+#define STAT_TXADDR_NAK 0x20
#define STAT_TXDATA_ACK 0x28
+#define STAT_TXDATA_NAK 0x30
+#define STAT_LOST_ARB_38 0x38
#define STAT_RXADDR_ACK 0x40
+#define STAT_RXADDR_NAK 0x48
#define STAT_RXDATA_ACK 0x50
+#define STAT_RXDATA_NAK 0x58
+#define STAT_SLAVE_60 0x60
+#define STAT_LOST_ARB_68 0x68
+#define STAT_SLAVE_70 0x70
+#define STAT_LOST_ARB_78 0x78
+#define STAT_SLAVE_80 0x80
+#define STAT_SLAVE_88 0x88
+#define STAT_GENDATA_ACK 0x90
+#define STAT_GENDATA_NAK 0x98
+#define STAT_SLAVE_A0 0xA0
+#define STAT_SLAVE_A8 0xA8
+#define STAT_LOST_ARB_B0 0xB0
+#define STAT_SLAVE_LOST 0xB8
+#define STAT_SLAVE_NAK 0xC0
+#define STAT_SLAVE_ACK 0xC8
+#define STAT_AD2W_ACK 0xD0
+#define STAT_AD2W_NAK 0xD8
#define STAT_IDLE 0xF8

/* TWSI_INT values */
@@ -225,6 +247,67 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
return 0;
}

+static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
+{
+ u8 stat = octeon_i2c_stat_read(i2c);
+
+ switch (stat) {
+ /* Everything is fine */
+ case STAT_IDLE:
+ case STAT_AD2W_ACK:
+ case STAT_RXADDR_ACK:
+ case STAT_TXADDR_ACK:
+ case STAT_TXDATA_ACK:
+ return 0;
+
+ /* ACK allowed on pre-terminal bytes only */
+ case STAT_RXDATA_ACK:
+ if (!final_read)
+ return 0;
+ return -EIO;
+
+ /* NAK allowed on terminal byte only */
+ case STAT_RXDATA_NAK:
+ if (final_read)
+ return 0;
+ return -EIO;
+
+ /* Arbitration lost */
+ case STAT_LOST_ARB_38:
+ case STAT_LOST_ARB_68:
+ case STAT_LOST_ARB_78:
+ case STAT_LOST_ARB_B0:
+ return -EAGAIN;
+
+ /* Being addressed as slave, should back off & listen */
+ case STAT_SLAVE_60:
+ case STAT_SLAVE_70:
+ case STAT_GENDATA_ACK:
+ case STAT_GENDATA_NAK:
+ return -EOPNOTSUPP;
+
+ /* Core busy as slave */
+ case STAT_SLAVE_80:
+ case STAT_SLAVE_88:
+ case STAT_SLAVE_A0:
+ case STAT_SLAVE_A8:
+ case STAT_SLAVE_LOST:
+ case STAT_SLAVE_NAK:
+ case STAT_SLAVE_ACK:
+ return -EOPNOTSUPP;
+
+ case STAT_TXDATA_NAK:
+ return -EIO;
+ case STAT_TXADDR_NAK:
+ case STAT_RXADDR_NAK:
+ case STAT_AD2W_NAK:
+ return -ENXIO;
+ default:
+ dev_err(i2c->dev, "unhandled state: %d\n", stat);
+ return -EIO;
+ }
+}
+
/* calculate and set clock divisors */
static void octeon_i2c_set_clock(struct octeon_i2c *i2c)
{
@@ -318,7 +401,7 @@ static int octeon_i2c_start(struct octeon_i2c *i2c)
}

data = octeon_i2c_stat_read(i2c);
- if ((data != STAT_START) && (data != STAT_RSTART)) {
+ if ((data != STAT_START) && (data != STAT_REP_START)) {
dev_err(i2c->dev, "%s: bad status (0x%x)\n", __func__, data);
return -EIO;
}
@@ -347,7 +430,6 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
const u8 *data, int length)
{
int i, result;
- u8 tmp;

result = octeon_i2c_start(i2c);
if (result)
@@ -361,14 +443,9 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
return result;

for (i = 0; i < length; i++) {
- tmp = octeon_i2c_stat_read(i2c);
-
- if ((tmp != STAT_TXADDR_ACK) && (tmp != STAT_TXDATA_ACK)) {
- dev_err(i2c->dev,
- "%s: bad status before write (0x%x)\n",
- __func__, tmp);
- return -EIO;
- }
+ result = octeon_i2c_check_status(i2c, false);
+ if (result)
+ return result;

octeon_i2c_data_write(i2c, data[i]);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
@@ -397,7 +474,7 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
u8 *data, u16 *rlength, bool recv_len)
{
int i, result, length = *rlength;
- u8 tmp;
+ bool final_read = false;

if (length < 1)
return -EINVAL;
@@ -413,19 +490,21 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
if (result)
return result;

+ /* address OK ? */
+ result = octeon_i2c_check_status(i2c, false);
+ if (result)
+ return result;
+
for (i = 0; i < length; i++) {
- tmp = octeon_i2c_stat_read(i2c);
- if ((tmp != STAT_RXDATA_ACK) && (tmp != STAT_RXADDR_ACK)) {
- dev_err(i2c->dev,
- "%s: bad status before read (0x%x)\n",
- __func__, tmp);
- return -EIO;
- }
+ /* for the last byte TWSI_CTL_AAK must not be set */
+ if (i + 1 == length)
+ final_read = true;

- if (i + 1 < length)
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_AAK);
- else
+ /* clear iflg to allow next event */
+ if (final_read)
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+ else
+ octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_AAK);

result = octeon_i2c_wait(i2c);
if (result)
@@ -441,6 +520,10 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
}
length += data[i];
}
+
+ result = octeon_i2c_check_status(i2c, final_read);
+ if (result)
+ return result;
}
*rlength = length;
return 0;
--
1.9.1
Jan Glauber
2016-04-27 09:45:16 UTC
Permalink
From: David Daney <***@cavium.com>

CN3860 does not interrupt the CPU when the i2c status changes. If
we get a timeout, and see the status has in fact changed, we know we
have this problem, and drop back to polling.

Signed-off-by: David Daney <***@caviumnetworks.com>
Signed-off-by: Jan Glauber <***@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 53 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 51 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 3144fe9..5b32a02 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -121,6 +121,8 @@ struct octeon_i2c {
void __iomem *twsi_base;
struct device *dev;
bool hlc_enabled;
+ bool broken_irq_mode;
+ bool broken_irq_check;
void (*int_enable)(struct octeon_i2c *);
void (*int_disable)(struct octeon_i2c *);
void (*hlc_int_enable)(struct octeon_i2c *);
@@ -376,10 +378,32 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
long time_left;
bool first = 1;

+ /*
+ * Some chip revisions don't assert the irq in the interrupt
+ * controller. So we must poll for the IFLG change.
+ */
+ if (i2c->broken_irq_mode) {
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_test_iflg(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ usleep_range(I2C_OCTEON_EVENT_WAIT / 2, I2C_OCTEON_EVENT_WAIT);
+
+ return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
+ }
+
i2c->int_enable(i2c);
time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
i2c->adap.timeout);
i2c->int_disable(i2c);
+
+ if (i2c->broken_irq_check && !time_left &&
+ octeon_i2c_test_iflg(i2c)) {
+ dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
+ }
+
if (!time_left)
return -ETIMEDOUT;

@@ -493,15 +517,37 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
bool first = 1;
int time_left;

+ /*
+ * Some cn38xx boards don't assert the irq in the interrupt
+ * controller. So we must poll for the valid bit change.
+ */
+ if (i2c->broken_irq_mode) {
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_hlc_test_valid(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ usleep_range(I2C_OCTEON_EVENT_WAIT / 2, I2C_OCTEON_EVENT_WAIT);
+
+ return octeon_i2c_hlc_test_valid(i2c) ? 0 : -ETIMEDOUT;
+ }
+
i2c->hlc_int_enable(i2c);
time_left = wait_event_timeout(i2c->queue,
octeon_i2c_hlc_test_ready(i2c, &first),
i2c->adap.timeout);
i2c->hlc_int_disable(i2c);
- if (!time_left) {
+ if (!time_left)
octeon_i2c_hlc_int_clear(i2c);
- return -ETIMEDOUT;
+
+ if (i2c->broken_irq_check && !time_left &&
+ octeon_i2c_hlc_test_valid(i2c)) {
+ dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
}
+
+ if (!time_left)
+ return -ETIMEDOUT;
return 0;
}

@@ -1136,6 +1182,9 @@ static int octeon_i2c_probe(struct platform_device *pdev)
goto out;
}

+ if (OCTEON_IS_MODEL(OCTEON_CN38XX))
+ i2c->broken_irq_check = true;
+
result = octeon_i2c_init_lowlevel(i2c);
if (result) {
dev_err(i2c->dev, "init low level failed\n");
--
1.9.1
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