[PATCH v3 00/14] i2c-octeon and i2c-thunderx drivers

[PATCH v3 00/14] i2c-octeon and i2c-thunderx drivers

[Jan Glauber]

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 #1-3 are cleanups.
Patches #4-11 are forward-ports of Octeon features and bugfixes.
Patch #12 prepares for the driver split
Patches #13-14 add the ThunderX driver.

Patches are on top of 4.5-rc7 and were tested on OCTEON, OCTEON-78
and ThunderX.

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 (5):
  i2c-octeon: Cleanup resource allocation code
  i2c-octeon: Support I2C_M_RECV_LEN
  i2c-octeon: Enable high-level controller and improve on bus contention
  i2c-octeon: Add support for cn78XX chips
  i2c-octeon: Add workaround for broken irqs on CN3860

Jan Glauber (6):
  i2c-octeon: Cleanup kerneldoc comments
  i2c-octeon: Cleanup i2c-octeon driver
  dt-bindings: i2c: Add Octeon cn78xx TWSI
  i2c-octeon: Split the driver into two parts
  i2c-thunderx: Add i2c driver for ThunderX SOC
  i2c-thunderx: Add smbus support

Peter Swain (3):
  i2c-octeon: Make adapter timeout tunable
  i2c-octeon: Flush TWSI writes with readback
  i2c-octeon: Faster operation when IFLG signals late

 .../devicetree/bindings/i2c/i2c-octeon.txt         |   6 +
 drivers/i2c/busses/Kconfig                         |  10 +
 drivers/i2c/busses/Makefile                        |   3 +
 drivers/i2c/busses/i2c-cavium.c                    | 828 +++++++++++++++++++++
 drivers/i2c/busses/i2c-cavium.h                    | 203 +++++
 drivers/i2c/busses/i2c-octeon-core.c               | 304 ++++++++
 drivers/i2c/busses/i2c-octeon.c                    | 633 ----------------
 drivers/i2c/busses/i2c-thunderx-core.c             | 301 ++++++++
 8 files changed, 1655 insertions(+), 633 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

[PATCH v3 01/14] i2c-octeon: Cleanup kerneldoc comments

[Jan Glauber]

Remove point after parameter description and replace kerneldoc
by a comment if it has no additional no value.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/i2c/busses/i2c-octeon.c | 89 ++++++++++++++++++-----------------------
 1 file changed, 39 insertions(+), 50 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 32914ab..4a08418 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -73,10 +73,10 @@ struct octeon_i2c {
 };
 
 /**
- * octeon_i2c_write_sw - write an I2C core register.
- * @i2c: The struct octeon_i2c.
- * @eop_reg: Register selector.
- * @data: Value to be written.
+ * octeon_i2c_write_sw - 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.
  */
@@ -93,9 +93,9 @@ static void octeon_i2c_write_sw(struct octeon_i2c *i2c,
 }
 
 /**
- * octeon_i2c_read_sw - write an I2C core register.
- * @i2c: The struct octeon_i2c.
- * @eop_reg: Register selector.
+ * octeon_i2c_read_sw - write an I2C core register
+ * @i2c: The struct octeon_i2c
+ * @eop_reg: Register selector
  *
  * Returns the data.
  *
@@ -115,8 +115,8 @@ static u8 octeon_i2c_read_sw(struct octeon_i2c *i2c, u64 eop_reg)
 
 /**
  * octeon_i2c_write_int - write the TWSI_INT register
- * @i2c: The struct octeon_i2c.
- * @data: Value to be written.
+ * @i2c: The struct octeon_i2c
+ * @data: Value to be written
  */
 static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
 {
@@ -125,8 +125,8 @@ static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
 }
 
 /**
- * octeon_i2c_int_enable - enable the TS interrupt.
- * @i2c: The struct octeon_i2c.
+ * octeon_i2c_int_enable - 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.
@@ -136,22 +136,18 @@ static void octeon_i2c_int_enable(struct octeon_i2c *i2c)
 	octeon_i2c_write_int(i2c, 0x40);
 }
 
-/**
- * octeon_i2c_int_disable - disable the TS interrupt.
- * @i2c: The struct octeon_i2c.
- */
+/* disable the CORE interrupt */
 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.
+ * 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.
+ * 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)
 {
@@ -171,11 +167,7 @@ static void octeon_i2c_unblock(struct octeon_i2c *i2c)
 	octeon_i2c_write_int(i2c, 0x0);
 }
 
-/**
- * octeon_i2c_isr - the interrupt service routine.
- * @int: The irq, unused.
- * @dev_id: Our struct octeon_i2c.
- */
+/* interrupt service routine */
 static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
 {
 	struct octeon_i2c *i2c = dev_id;
@@ -193,8 +185,8 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
 }
 
 /**
- * octeon_i2c_wait - wait for the IFLG to be set.
- * @i2c: The struct octeon_i2c.
+ * octeon_i2c_wait - wait for the IFLG to be set
+ * @i2c: The struct octeon_i2c
  *
  * Returns 0 on success, otherwise a negative errno.
  */
@@ -219,8 +211,8 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 }
 
 /**
- * octeon_i2c_start - send START to the bus.
- * @i2c: The struct octeon_i2c.
+ * octeon_i2c_start - send START to the bus
+ * @i2c: The struct octeon_i2c
  *
  * Returns 0 on success, otherwise a negative errno.
  */
@@ -260,8 +252,8 @@ static int octeon_i2c_start(struct octeon_i2c *i2c)
 }
 
 /**
- * octeon_i2c_stop - send STOP to the bus.
- * @i2c: The struct octeon_i2c.
+ * octeon_i2c_stop - send STOP to the bus
+ * @i2c: The struct octeon_i2c
  *
  * Returns 0 on success, otherwise a negative errno.
  */
@@ -282,11 +274,11 @@ static int octeon_i2c_stop(struct octeon_i2c *i2c)
 }
 
 /**
- * octeon_i2c_write - send data to the bus.
- * @i2c: The struct octeon_i2c.
- * @target: Target address.
- * @data: Pointer to the data to be sent.
- * @length: Length of the data.
+ * 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.
  *
@@ -330,11 +322,11 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
 }
 
 /**
- * octeon_i2c_read - receive data from the bus.
- * @i2c: The struct octeon_i2c.
- * @target: Target address.
- * @data: Pointer to the location to store the datae .
- * @length: Length of the data.
+ * 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
+ * @length: Length of the data
  *
  * The address is sent over the bus, then the data is read.
  *
@@ -386,13 +378,12 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 }
 
 /**
- * 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.
+ * 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.
+ * 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,
@@ -438,9 +429,7 @@ static struct i2c_adapter octeon_i2c_ops = {
 	.timeout = HZ / 50,
 };
 
-/**
- * octeon_i2c_setclock - Calculate and set clock divisors.
- */
+/* calculate and set clock divisors */
 static int octeon_i2c_setclock(struct octeon_i2c *i2c)
 {
 	int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff;
-- 
1.9.1

Re: [PATCH v3 01/14] i2c-octeon: Cleanup kerneldoc comments

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 268 bytes --]

On Mon, Mar 07, 2016 at 04:10:44PM +0100, Jan Glauber wrote:
> Remove point after parameter description and replace kerneldoc
> by a comment if it has no additional no value.
> 
> Signed-off-by: Jan Glauber <jglauber@cavium.com>

Applied to for-next, thanks!


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

[PATCH v3 02/14] i2c-octeon: Cleanup i2c-octeon driver

[Jan Glauber]

Cleanup only without functional change.

- Removed DRV_VERSION
- use BIT_ULL macro
- use defines instead of plain values
- rename waitqueue return value to time_left
- prefix TWSI_INT defines
- sort local variables by length
- fix indentation and whitespace errors
- make function return void if the result is not used
  (octeon_i2c_stop, octeon_i2c_setclock)
- update Copyright

Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/i2c/busses/i2c-octeon.c | 176 ++++++++++++++++++----------------------
 1 file changed, 77 insertions(+), 99 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 4a08418..03dd3d9 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -2,7 +2,7 @@
  * (C) Copyright 2009-2010
  * Nokia Siemens Networks, michael.lawnick.ext@nsn.com
  *
- * Portions Copyright (C) 2010, 2011 Cavium Networks, Inc.
+ * Portions Copyright (C) 2010 - 2016 Cavium, Inc.
  *
  * This is a driver for the i2c adapter in Cavium Networks' OCTEON processors.
  *
@@ -26,39 +26,41 @@
 
 #define DRV_NAME "i2c-octeon"
 
-/* The previous out-of-tree version was implicitly version 1.0. */
-#define DRV_VERSION	"2.0"
-
-/* register offsets */
-#define SW_TWSI	 0x00
-#define TWSI_INT 0x10
+/* Register offsets */
+#define SW_TWSI			0x00
+#define TWSI_INT		0x10
 
 /* Controller command patterns */
-#define SW_TWSI_V               0x8000000000000000ull
-#define SW_TWSI_EOP_TWSI_DATA   0x0C00000100000000ull
-#define SW_TWSI_EOP_TWSI_CTL    0x0C00000200000000ull
-#define SW_TWSI_EOP_TWSI_CLKCTL 0x0C00000300000000ull
-#define SW_TWSI_EOP_TWSI_STAT   0x0C00000300000000ull
-#define SW_TWSI_EOP_TWSI_RST    0x0C00000700000000ull
-#define SW_TWSI_OP_TWSI_CLK     0x0800000000000000ull
-#define SW_TWSI_R               0x0100000000000000ull
+#define SW_TWSI_V		BIT_ULL(63)
+#define SW_TWSI_OP_TWSI_CLK	BIT_ULL(59)
+#define SW_TWSI_R		BIT_ULL(56)
+#define SW_TWSI_EOP_TWSI_DATA	0x0C00000100000000ULL
+#define SW_TWSI_EOP_TWSI_CTL	0x0C00000200000000ULL
+#define SW_TWSI_EOP_TWSI_CLKCTL	0x0C00000300000000ULL
+#define SW_TWSI_EOP_TWSI_STAT	0x0C00000300000000ULL
+#define SW_TWSI_EOP_TWSI_RST	0x0C00000700000000ULL
 
 /* Controller command and status bits */
-#define TWSI_CTL_CE   0x80
-#define TWSI_CTL_ENAB 0x40
-#define TWSI_CTL_STA  0x20
-#define TWSI_CTL_STP  0x10
-#define TWSI_CTL_IFLG 0x08
-#define TWSI_CTL_AAK  0x04
+#define TWSI_CTL_CE		0x80
+#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 */
 
 /* Some status values */
-#define STAT_START      0x08
-#define STAT_RSTART     0x10
-#define STAT_TXADDR_ACK 0x18
-#define STAT_TXDATA_ACK 0x28
-#define STAT_RXADDR_ACK 0x40
-#define STAT_RXDATA_ACK 0x50
-#define STAT_IDLE       0xF8
+#define STAT_START		0x08
+#define STAT_RSTART		0x10
+#define STAT_TXADDR_ACK		0x18
+#define STAT_TXDATA_ACK		0x28
+#define STAT_RXADDR_ACK		0x40
+#define STAT_RXDATA_ACK		0x50
+#define STAT_IDLE		0xF8
+
+/* TWSI_INT values */
+#define TWSI_INT_CORE_EN	BIT_ULL(6)
+#define TWSI_INT_SDA_OVR	BIT_ULL(8)
+#define TWSI_INT_SCL_OVR	BIT_ULL(9)
 
 struct octeon_i2c {
 	wait_queue_head_t queue;
@@ -80,9 +82,7 @@ struct octeon_i2c {
  *
  * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
  */
-static void octeon_i2c_write_sw(struct octeon_i2c *i2c,
-				u64 eop_reg,
-				u8 data)
+static void octeon_i2c_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u8 data)
 {
 	u64 tmp;
 
@@ -93,7 +93,7 @@ static void octeon_i2c_write_sw(struct octeon_i2c *i2c,
 }
 
 /**
- * octeon_i2c_read_sw - write an I2C core register
+ * octeon_i2c_read_sw - read lower bits of an I2C core register
  * @i2c: The struct octeon_i2c
  * @eop_reg: Register selector
  *
@@ -133,12 +133,13 @@ static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
  */
 static void octeon_i2c_int_enable(struct octeon_i2c *i2c)
 {
-	octeon_i2c_write_int(i2c, 0x40);
+	octeon_i2c_write_int(i2c, TWSI_INT_CORE_EN);
 }
 
 /* disable the CORE interrupt */
 static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
 {
+	/* clear TS/ST/IFLG events */
 	octeon_i2c_write_int(i2c, 0);
 }
 
@@ -154,17 +155,19 @@ 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, 0x0);
+		octeon_i2c_write_int(i2c, 0);
 		udelay(5);
-		octeon_i2c_write_int(i2c, 0x200);
+		octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
 		udelay(5);
 	}
-	octeon_i2c_write_int(i2c, 0x300);
+	/* hand-crank a STOP */
+	octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR | TWSI_INT_SCL_OVR);
 	udelay(5);
-	octeon_i2c_write_int(i2c, 0x100);
+	octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR);
 	udelay(5);
-	octeon_i2c_write_int(i2c, 0x0);
+	octeon_i2c_write_int(i2c, 0);
 }
 
 /* interrupt service routine */
@@ -192,17 +195,13 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
  */
 static int octeon_i2c_wait(struct octeon_i2c *i2c)
 {
-	long result;
+	long time_left;
 
 	octeon_i2c_int_enable(i2c);
-
-	result = wait_event_timeout(i2c->queue,
-					octeon_i2c_test_iflg(i2c),
-					i2c->adap.timeout);
-
+	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
+				       i2c->adap.timeout);
 	octeon_i2c_int_disable(i2c);
-
-	if (result == 0) {
+	if (!time_left) {
 		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
 		return -ETIMEDOUT;
 	}
@@ -218,11 +217,11 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
  */
 static int octeon_i2c_start(struct octeon_i2c *i2c)
 {
-	u8 data;
 	int result;
+	u8 data;
 
 	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
-				TWSI_CTL_ENAB | TWSI_CTL_STA);
+			    TWSI_CTL_ENAB | TWSI_CTL_STA);
 
 	result = octeon_i2c_wait(i2c);
 	if (result) {
@@ -235,7 +234,6 @@ static int octeon_i2c_start(struct octeon_i2c *i2c)
 			octeon_i2c_unblock(i2c);
 			octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
 					    TWSI_CTL_ENAB | TWSI_CTL_STA);
-
 			result = octeon_i2c_wait(i2c);
 		}
 		if (result)
@@ -251,13 +249,8 @@ static int octeon_i2c_start(struct octeon_i2c *i2c)
 	return 0;
 }
 
-/**
- * octeon_i2c_stop - send STOP to the bus
- * @i2c: The struct octeon_i2c
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_stop(struct octeon_i2c *i2c)
+/* send STOP to the bus */
+static void octeon_i2c_stop(struct octeon_i2c *i2c)
 {
 	u8 data;
 
@@ -266,11 +259,8 @@ static int octeon_i2c_stop(struct octeon_i2c *i2c)
 
 	data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
 
-	if (data != STAT_IDLE) {
+	if (data != STAT_IDLE)
 		dev_err(i2c->dev, "%s: bad status(0x%x)\n", __func__, data);
-		return -EIO;
-	}
-	return 0;
 }
 
 /**
@@ -303,6 +293,7 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
 
 	for (i = 0; i < length; i++) {
 		tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+
 		if ((tmp != STAT_TXADDR_ACK) && (tmp != STAT_TXDATA_ACK)) {
 			dev_err(i2c->dev,
 				"%s: bad status before write (0x%x)\n",
@@ -345,7 +336,7 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 	if (result)
 		return result;
 
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, (target<<1) | 1);
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, (target << 1) | 1);
 	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
 
 	result = octeon_i2c_wait(i2c);
@@ -354,6 +345,7 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 
 	for (i = 0; i < length; i++) {
 		tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+
 		if ((tmp != STAT_RXDATA_ACK) && (tmp != STAT_RXADDR_ACK)) {
 			dev_err(i2c->dev,
 				"%s: bad status before read (0x%x)\n",
@@ -361,12 +353,12 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 			return -EIO;
 		}
 
-		if (i+1 < length)
+		if (i + 1 < length)
 			octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
-						TWSI_CTL_ENAB | TWSI_CTL_AAK);
+					    TWSI_CTL_ENAB | TWSI_CTL_AAK);
 		else
 			octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
-						TWSI_CTL_ENAB);
+					    TWSI_CTL_ENAB);
 
 		result = octeon_i2c_wait(i2c);
 		if (result)
@@ -385,31 +377,29 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
  *
  * 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,
+static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 			   int num)
 {
-	struct i2c_msg *pmsg;
-	int i;
-	int ret = 0;
 	struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+	int i, ret = 0;
 
 	for (i = 0; ret == 0 && i < num; i++) {
-		pmsg = &msgs[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);
 		if (pmsg->flags & I2C_M_RD)
 			ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
-						pmsg->len);
+					      pmsg->len);
 		else
 			ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
-						pmsg->len);
+					       pmsg->len);
 	}
 	octeon_i2c_stop(i2c);
 
-	return (ret != 0) ? ret : num;
+	return ret ? -EAGAIN : num;
 }
 
 static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
@@ -430,7 +420,7 @@ static struct i2c_adapter octeon_i2c_ops = {
 };
 
 /* calculate and set clock divisors */
-static int octeon_i2c_setclock(struct octeon_i2c *i2c)
+static void octeon_i2c_setclock(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;
@@ -438,8 +428,7 @@ static int octeon_i2c_setclock(struct octeon_i2c *i2c)
 	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.
+		 * with ds1337 RTCs, so we constrain it to larger values.
 		 */
 		for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) {
 			/*
@@ -449,6 +438,7 @@ static int octeon_i2c_setclock(struct octeon_i2c *i2c)
 			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)
@@ -469,8 +459,6 @@ static int octeon_i2c_setclock(struct octeon_i2c *i2c)
 	}
 	octeon_i2c_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp);
 	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
-
-	return 0;
 }
 
 static int octeon_i2c_initlowlevel(struct octeon_i2c *i2c)
@@ -496,9 +484,10 @@ static int octeon_i2c_initlowlevel(struct octeon_i2c *i2c)
 
 static int octeon_i2c_probe(struct platform_device *pdev)
 {
-	int irq, result = 0;
-	struct octeon_i2c *i2c;
+	struct device_node *node = pdev->dev.of_node;
 	struct resource *res_mem;
+	struct octeon_i2c *i2c;
+	int irq, result = 0;
 
 	/* All adaptors have an irq.  */
 	irq = platform_get_irq(pdev, 0);
@@ -507,7 +496,6 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 
 	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
 	if (!i2c) {
-		dev_err(&pdev->dev, "kzalloc failed\n");
 		result = -ENOMEM;
 		goto out;
 	}
@@ -528,10 +516,8 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 	 * "clock-frequency".  Try the official one first and then
 	 * fall back if it doesn't exist.
 	 */
-	if (of_property_read_u32(pdev->dev.of_node,
-				 "clock-frequency", &i2c->twsi_freq) &&
-	    of_property_read_u32(pdev->dev.of_node,
-				 "clock-rate", &i2c->twsi_freq)) {
+	if (of_property_read_u32(node, "clock-frequency", &i2c->twsi_freq) &&
+	    of_property_read_u32(node, "clock-rate", &i2c->twsi_freq)) {
 		dev_err(i2c->dev,
 			"no I2C 'clock-rate' or 'clock-frequency' property\n");
 		result = -ENXIO;
@@ -541,7 +527,7 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 	i2c->sys_freq = octeon_get_io_clock_rate();
 
 	if (!devm_request_mem_region(&pdev->dev, i2c->twsi_phys, i2c->regsize,
-				      res_mem->name)) {
+				     res_mem->name)) {
 		dev_err(i2c->dev, "request_mem_region failed\n");
 		goto out;
 	}
@@ -564,15 +550,11 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 		goto  out;
 	}
 
-	result = octeon_i2c_setclock(i2c);
-	if (result) {
-		dev_err(i2c->dev, "clock init failed\n");
-		goto  out;
-	}
+	octeon_i2c_setclock(i2c);
 
 	i2c->adap = octeon_i2c_ops;
 	i2c->adap.dev.parent = &pdev->dev;
-	i2c->adap.dev.of_node = pdev->dev.of_node;
+	i2c->adap.dev.of_node = node;
 	i2c_set_adapdata(&i2c->adap, i2c);
 	platform_set_drvdata(pdev, i2c);
 
@@ -581,8 +563,7 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 		dev_err(i2c->dev, "failed to add adapter\n");
 		goto out;
 	}
-	dev_info(i2c->dev, "version %s\n", DRV_VERSION);
-
+	dev_info(i2c->dev, "probed\n");
 	return 0;
 
 out:
@@ -597,10 +578,8 @@ static int octeon_i2c_remove(struct platform_device *pdev)
 	return 0;
 };
 
-static struct of_device_id octeon_i2c_match[] = {
-	{
-		.compatible = "cavium,octeon-3860-twsi",
-	},
+static const struct of_device_id octeon_i2c_match[] = {
+	{	.compatible = "cavium,octeon-3860-twsi",	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, octeon_i2c_match);
@@ -619,4 +598,3 @@ module_platform_driver(octeon_i2c_driver);
 MODULE_AUTHOR("Michael Lawnick <michael.lawnick.ext@nsn.com>");
 MODULE_DESCRIPTION("I2C-Bus adapter for Cavium OCTEON processors");
 MODULE_LICENSE("GPL");
-MODULE_VERSION(DRV_VERSION);
-- 
1.9.1

Re: [PATCH v3 02/14] i2c-octeon: Cleanup i2c-octeon driver

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 1271 bytes --]

On Mon, Mar 07, 2016 at 04:10:45PM +0100, Jan Glauber wrote:
> Cleanup only without functional change.

I like most of the changes, but there are still some functional changes
left.

> -static int octeon_i2c_stop(struct octeon_i2c *i2c)
> +/* send STOP to the bus */
> +static void octeon_i2c_stop(struct octeon_i2c *i2c)
>  {
>  	u8 data;
>  
> @@ -266,11 +259,8 @@ static int octeon_i2c_stop(struct octeon_i2c *i2c)
>  
>  	data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
>  
> -	if (data != STAT_IDLE) {
> +	if (data != STAT_IDLE)
>  		dev_err(i2c->dev, "%s: bad status(0x%x)\n", __func__, data);
> -		return -EIO;
> -	}
> -	return 0;

Why this change? I don't know what SW_TWSI_EOP_TWSI_STAT tells, but this
is surely not a cleanup.

>  	octeon_i2c_stop(i2c);
>  
> -	return (ret != 0) ? ret : num;
> +	return ret ? -EAGAIN : num;

This is also not a cleanup and looks wrong. -EAGAIN is for lost
arbitration only.

>  
> -static struct of_device_id octeon_i2c_match[] = {
> -	{
> -		.compatible = "cavium,octeon-3860-twsi",
> -	},
> +static const struct of_device_id octeon_i2c_match[] = {
> +	{	.compatible = "cavium,octeon-3860-twsi",	},

Nit: I'd prefer no tabs within the curly braces.

Thanks,

   Wolfram


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Re: [PATCH v3 02/14] i2c-octeon: Cleanup i2c-octeon driver

[Jan Glauber]

On Sat, Mar 12, 2016 at 04:35:00PM +0100, Wolfram Sang wrote:
> On Mon, Mar 07, 2016 at 04:10:45PM +0100, Jan Glauber wrote:
> > Cleanup only without functional change.
> 
> I like most of the changes, but there are still some functional changes
> left.
> 
> > -static int octeon_i2c_stop(struct octeon_i2c *i2c)
> > +/* send STOP to the bus */
> > +static void octeon_i2c_stop(struct octeon_i2c *i2c)
> >  {
> >  	u8 data;
> >  
> > @@ -266,11 +259,8 @@ static int octeon_i2c_stop(struct octeon_i2c *i2c)
> >  
> >  	data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
> >  
> > -	if (data != STAT_IDLE) {
> > +	if (data != STAT_IDLE)
> >  		dev_err(i2c->dev, "%s: bad status(0x%x)\n", __func__, data);
> > -		return -EIO;
> > -	}
> > -	return 0;
> 
> Why this change? I don't know what SW_TWSI_EOP_TWSI_STAT tells, but this
> is surely not a cleanup.

It is no functional change because the return value of
octeon_i2c_stop() was ignored anyway. That said, the whole read-back of
the status and the dev_err looks like debug code to me and is removed
in a later patch anyway. I'll incoporate this in the cleanup,
so octeon_i2c_stop() will only do the write.

> >  	octeon_i2c_stop(i2c);
> >  
> > -	return (ret != 0) ? ret : num;
> > +	return ret ? -EAGAIN : num;
> 
> This is also not a cleanup and looks wrong. -EAGAIN is for lost
> arbitration only.

I agree, this looks like an over-simplification and drops
the EINVAL/ETIMEDOUT/EIO errors. I'll drop that completely.

> >  
> > -static struct of_device_id octeon_i2c_match[] = {
> > -	{
> > -		.compatible = "cavium,octeon-3860-twsi",
> > -	},
> > +static const struct of_device_id octeon_i2c_match[] = {
> > +	{	.compatible = "cavium,octeon-3860-twsi",	},
> 
> Nit: I'd prefer no tabs within the curly braces.

Agreed.

thanks, Jan

> Thanks,
> 
>    Wolfram
> 

[PATCH v3 03/14] i2c-octeon: Cleanup resource allocation code

[Jan Glauber]

From: David Daney <david.daney@cavium.com>

Use resource start and size directly.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/i2c/busses/i2c-octeon.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 03dd3d9..519e328 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -68,9 +68,7 @@ struct octeon_i2c {
 	int irq;
 	u32 twsi_freq;
 	int sys_freq;
-	resource_size_t twsi_phys;
 	void __iomem *twsi_base;
-	resource_size_t regsize;
 	struct device *dev;
 };
 
@@ -508,8 +506,6 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 		result = -ENXIO;
 		goto out;
 	}
-	i2c->twsi_phys = res_mem->start;
-	i2c->regsize = resource_size(res_mem);
 
 	/*
 	 * "clock-rate" is a legacy binding, the official binding is
@@ -526,12 +522,13 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 
 	i2c->sys_freq = octeon_get_io_clock_rate();
 
-	if (!devm_request_mem_region(&pdev->dev, i2c->twsi_phys, i2c->regsize,
-				     res_mem->name)) {
+	if (!devm_request_mem_region(&pdev->dev, res_mem->start,
+				     resource_size(res_mem), res_mem->name)) {
 		dev_err(i2c->dev, "request_mem_region failed\n");
 		goto out;
 	}
-	i2c->twsi_base = devm_ioremap(&pdev->dev, i2c->twsi_phys, i2c->regsize);
+	i2c->twsi_base = devm_ioremap(&pdev->dev, res_mem->start,
+				      resource_size(res_mem));
 
 	init_waitqueue_head(&i2c->queue);
 
-- 
1.9.1

Re: [PATCH v3 03/14] i2c-octeon: Cleanup resource allocation code

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 319 bytes --]

On Mon, Mar 07, 2016 at 04:10:46PM +0100, Jan Glauber wrote:
> From: David Daney <david.daney@cavium.com>
> 
> Use resource start and size directly.
> 
> Signed-off-by: David Daney <david.daney@cavium.com>
> Signed-off-by: Jan Glauber <jglauber@cavium.com>

What about converting to devm_ioremap_resource()?


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Re: [PATCH v3 03/14] i2c-octeon: Cleanup resource allocation code

[Jan Glauber]

On Sat, Mar 12, 2016 at 04:37:15PM +0100, Wolfram Sang wrote:
> On Mon, Mar 07, 2016 at 04:10:46PM +0100, Jan Glauber wrote:
> > From: David Daney <david.daney@cavium.com>
> > 
> > Use resource start and size directly.
> > 
> > Signed-off-by: David Daney <david.daney@cavium.com>
> > Signed-off-by: Jan Glauber <jglauber@cavium.com>
> 
> What about converting to devm_ioremap_resource()?
> 

Nice. I'll use that.

[PATCH v3 04/14] i2c-octeon: Support I2C_M_RECV_LEN

[Jan Glauber]

From: David Daney <david.daney@cavium.com>

If I2C_M_RECV_LEN is set consider the length byte.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/i2c/busses/i2c-octeon.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 519e328..6041cd7 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -315,16 +315,17 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
  * @i2c: The struct octeon_i2c
  * @target: Target address
  * @data: Pointer to the location to store the data
- * @length: Length of 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, int length)
+			   u8 *data, u16 *rlength, bool recv_len)
 {
-	int i, result;
+	int i, result, length = *rlength;
 	u8 tmp;
 
 	if (length < 1)
@@ -363,7 +364,17 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 			return result;
 
 		data[i] = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_DATA);
+		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 -EIO;
+			}
+			length += data[i];
+		}
 	}
+	*rlength = length;
 	return 0;
 }
 
@@ -390,7 +401,7 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 			 pmsg->len, pmsg->addr, i + 1, num);
 		if (pmsg->flags & I2C_M_RD)
 			ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
-					      pmsg->len);
+					      &pmsg->len, pmsg->flags & I2C_M_RECV_LEN);
 		else
 			ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
 					       pmsg->len);
-- 
1.9.1

Re: [PATCH v3 04/14] i2c-octeon: Support I2C_M_RECV_LEN

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 684 bytes --]

On Mon, Mar 07, 2016 at 04:10:47PM +0100, Jan Glauber wrote:
> From: David Daney <david.daney@cavium.com>
> 
> If I2C_M_RECV_LEN is set consider the length byte.
> 
> Signed-off-by: David Daney <ddaney@caviumnetworks.com>
> Signed-off-by: Jan Glauber <jglauber@cavium.com>

You also might want to set "| I2C_FUNC_SMBUS_READ_BLOCK_DATA |
I2C_FUNC_SMBUS_BLOCK_PROC_CALL" in your functionality?

> +		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 -EIO;

According to Documentation/i2c/fault-codes this should be -EPROTO.


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[PATCH v3 05/14] i2c-octeon: Make adapter timeout tunable

[Jan Glauber]

From: Peter Swain <pswain@cavium.com>

Make the i2c adapter timeout a module parameter to allow upper-level
target device drivers to retry with their own logic before their own
timeouts abort operations.

For example, at24 eeprom driver retries for 25ms when -EAGAIN
indicates that an eeprom has gone unresponsive while committing
a newly written page (5ms on typical devices).

Signed-off-by: Peter Swain <pswain@cavium.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/i2c/busses/i2c-octeon.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 6041cd7..ef1720f 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -72,6 +72,10 @@ struct octeon_i2c {
 	struct device *dev;
 };
 
+static int timeout = 2;
+module_param(timeout, int, 0444);
+MODULE_PARM_DESC(timeout, "Low-level device timeout (ms)");
+
 /**
  * octeon_i2c_write_sw - write an I2C core register
  * @i2c: The struct octeon_i2c
@@ -425,7 +429,6 @@ static struct i2c_adapter octeon_i2c_ops = {
 	.owner = THIS_MODULE,
 	.name = "OCTEON adapter",
 	.algo = &octeon_i2c_algo,
-	.timeout = HZ / 50,
 };
 
 /* calculate and set clock divisors */
@@ -561,6 +564,8 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 	octeon_i2c_setclock(i2c);
 
 	i2c->adap = octeon_i2c_ops;
+	i2c->adap.timeout = msecs_to_jiffies(timeout);
+	i2c->adap.retries = 10;
 	i2c->adap.dev.parent = &pdev->dev;
 	i2c->adap.dev.of_node = node;
 	i2c_set_adapdata(&i2c->adap, i2c);
-- 
1.9.1

Re: [PATCH v3 05/14] i2c-octeon: Make adapter timeout tunable

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 643 bytes --]

On Mon, Mar 07, 2016 at 04:10:48PM +0100, Jan Glauber wrote:
> From: Peter Swain <pswain@cavium.com>
> 
> Make the i2c adapter timeout a module parameter to allow upper-level
> target device drivers to retry with their own logic before their own
> timeouts abort operations.
> 
> For example, at24 eeprom driver retries for 25ms when -EAGAIN
> indicates that an eeprom has gone unresponsive while committing
> a newly written page (5ms on typical devices).
> 
> Signed-off-by: Peter Swain <pswain@cavium.com>
> Signed-off-by: Jan Glauber <jglauber@cavium.com>

i2c-dev has IOCTLs for timeout and retries. Can't you use those?


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Re: [PATCH v3 05/14] i2c-octeon: Make adapter timeout tunable

[Jan Glauber]

On Sat, Mar 12, 2016 at 04:46:12PM +0100, Wolfram Sang wrote:
> On Mon, Mar 07, 2016 at 04:10:48PM +0100, Jan Glauber wrote:
> > From: Peter Swain <pswain@cavium.com>
> > 
> > Make the i2c adapter timeout a module parameter to allow upper-level
> > target device drivers to retry with their own logic before their own
> > timeouts abort operations.
> > 
> > For example, at24 eeprom driver retries for 25ms when -EAGAIN
> > indicates that an eeprom has gone unresponsive while committing
> > a newly written page (5ms on typical devices).
> > 
> > Signed-off-by: Peter Swain <pswain@cavium.com>
> > Signed-off-by: Jan Glauber <jglauber@cavium.com>
> 
> i2c-dev has IOCTLs for timeout and retries. Can't you use those?
> 

Yes, with these IOCTLs we don't need to add a module parameter
so I'll drop that.

Re: [PATCH v3 05/14] i2c-octeon: Make adapter timeout tunable

[Swain, Peter]

Agreed, this timeout modparam can go, it serves no purpose which can't be achieved with existing ioctl.

It was introduced during debug to reduce spurious error count while hunting an issue finally resolved by the 80uS IFLG re-poll. But the same effect is achieved by (for example) the at24 driver's retry at 25mS timeout. The issue there is not timeout _within_ command, but failure to respect a 25mS post-write recovery time before next access to the at24, and the existing at24-level retry works well (though delaying the presentation of the next at24 transaction _within_ the at24 driver would have lead to less bus-level churn).
Leaving this adapter tuning out affects nothing but the (normally invisible) adapter-level retry count, which is better addressed within the target device's code, like at24 does. Default is ioctl-tweakable, so users wanting fine tuning have a mechanism.

-pete

________________________________________
From: Jan Glauber <jan.glauber@caviumnetworks.com>
Sent: Monday, March 14, 2016 5:45 AM
To: Wolfram Sang
Cc: linux-kernel@vger.kernel.org; linux-i2c@vger.kernel.org; Daney, David; Peter Swain
Subject: Re: [PATCH v3 05/14] i2c-octeon: Make adapter timeout tunable

On Sat, Mar 12, 2016 at 04:46:12PM +0100, Wolfram Sang wrote:
> On Mon, Mar 07, 2016 at 04:10:48PM +0100, Jan Glauber wrote:
> > From: Peter Swain <pswain@cavium.com>
> >
> > Make the i2c adapter timeout a module parameter to allow upper-level
> > target device drivers to retry with their own logic before their own
> > timeouts abort operations.
> >
> > For example, at24 eeprom driver retries for 25ms when -EAGAIN
> > indicates that an eeprom has gone unresponsive while committing
> > a newly written page (5ms on typical devices).
> >
> > Signed-off-by: Peter Swain <pswain@cavium.com>
> > Signed-off-by: Jan Glauber <jglauber@cavium.com>
>
> i2c-dev has IOCTLs for timeout and retries. Can't you use those?
>

Yes, with these IOCTLs we don't need to add a module parameter
so I'll drop that.

[PATCH v3 06/14] i2c-octeon: Enable high-level controller and improve on bus contention

[Jan Glauber]

From: David Daney <david.daney@cavium.com>

Use High Level Controller when possible.

Extend octeon_i2c_write_sw() to expose the full 32bit data field.
Extend octeon_i2c_read_sw() to provide 8bit & 64bit versions, allowing
verification that the correct SW_TWSI sub-register is being read, unlike
the naked __raw_readq().

i2c-octeon was reacting badly to bus contention: when in
direct-access mode (for transfers > 8 bytes, which cannot use the
high-level controller) some !ACK or arbitration-loss states were
not causing the current transfer to be aborted, and the bus released.

There's one place in i2c protocol that !ACK is an acceptable
response: in the final byte of a read cycle.  In this case the
destination is not saying that the transfer failed, just that it
doesn't want more data.

This enables correct behavior of ACK on final byte of non-final read
msgs too.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/i2c/busses/i2c-octeon.c | 781 ++++++++++++++++++++++++++++++++--------
 1 file changed, 625 insertions(+), 156 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index ef1720f..8762473 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -29,11 +29,21 @@
 /* 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)
+#define SW_TWSI_EIA		BIT_ULL(61)
 #define SW_TWSI_OP_TWSI_CLK	BIT_ULL(59)
+#define SW_TWSI_OP_7		(0ULL << 57)
+#define SW_TWSI_OP_7_IA		BIT_ULL(57)
+#define SW_TWSI_OP_10		(2ULL << 57)
+#define SW_TWSI_OP_10_IA	(3ULL << 57)
 #define SW_TWSI_R		BIT_ULL(56)
+#define SW_TWSI_SOVR		BIT_ULL(55)
+#define SW_TWSI_SIZE_SHIFT	52
+#define SW_TWSI_A_SHIFT		40
+#define SW_TWSI_IA_SHIFT	32
 #define SW_TWSI_EOP_TWSI_DATA	0x0C00000100000000ULL
 #define SW_TWSI_EOP_TWSI_CTL	0x0C00000200000000ULL
 #define SW_TWSI_EOP_TWSI_CLKCTL	0x0C00000300000000ULL
@@ -41,7 +51,7 @@
 #define SW_TWSI_EOP_TWSI_RST	0x0C00000700000000ULL
 
 /* 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 */
@@ -49,18 +59,47 @@
 #define TWSI_CTL_AAK		0x04	/* Assert ACK */
 
 /* Some status values */
+#define STAT_ERROR		0x00
 #define STAT_START		0x08
 #define STAT_RSTART		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)
 
 struct octeon_i2c {
 	wait_queue_head_t queue;
@@ -70,8 +109,11 @@ struct octeon_i2c {
 	int sys_freq;
 	void __iomem *twsi_base;
 	struct device *dev;
+	bool hlc_enabled;
 };
 
+static int reset_how;
+
 static int timeout = 2;
 module_param(timeout, int, 0444);
 MODULE_PARM_DESC(timeout, "Low-level device timeout (ms)");
@@ -84,7 +126,7 @@ MODULE_PARM_DESC(timeout, "Low-level device timeout (ms)");
  *
  * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
  */
-static void octeon_i2c_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u8 data)
+static void octeon_i2c_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u32 data)
 {
 	u64 tmp;
 
@@ -95,7 +137,7 @@ static void octeon_i2c_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u8 data)
 }
 
 /**
- * octeon_i2c_read_sw - read lower bits of an I2C core register
+ * octeon_i2c_read_sw64 - read an I2C core register
  * @i2c: The struct octeon_i2c
  * @eop_reg: Register selector
  *
@@ -103,7 +145,7 @@ static void octeon_i2c_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u8 data)
  *
  * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
  */
-static u8 octeon_i2c_read_sw(struct octeon_i2c *i2c, u64 eop_reg)
+static u64 octeon_i2c_read_sw64(struct octeon_i2c *i2c, u64 eop_reg)
 {
 	u64 tmp;
 
@@ -112,7 +154,21 @@ static u8 octeon_i2c_read_sw(struct octeon_i2c *i2c, u64 eop_reg)
 		tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
 	} while ((tmp & SW_TWSI_V) != 0);
 
-	return tmp & 0xFF;
+	return tmp;
+}
+
+/**
+ * octeon_i2c_read_sw - 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_read_sw(struct octeon_i2c *i2c, u64 eop_reg)
+{
+	return octeon_i2c_read_sw64(i2c, eop_reg) & 0xFF;
 }
 
 /**
@@ -145,6 +201,15 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
 	octeon_i2c_write_int(i2c, 0);
 }
 
+static void octeon_i2c_disable_hlc(struct octeon_i2c *i2c)
+{
+	if (!i2c->hlc_enabled)
+		return;
+
+	i2c->hlc_enabled = false;
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+}
+
 /**
  * octeon_i2c_unblock - unblock the bus
  * @i2c: The struct octeon_i2c
@@ -154,13 +219,18 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
  */
 static void octeon_i2c_unblock(struct octeon_i2c *i2c)
 {
-	int i;
+	int state, i;
 
+	octeon_i2c_disable_hlc(i2c);
 	dev_dbg(i2c->dev, "%s\n", __func__);
 
+	/* cycle 8+1 clocks with SDA high */
 	for (i = 0; i < 9; i++) {
 		octeon_i2c_write_int(i2c, 0);
 		udelay(5);
+		state = __raw_readq(i2c->twsi_base + TWSI_INT);
+		if (state & (TWSI_INT_SDA | TWSI_INT_SCL))
+			break;
 		octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
 		udelay(5);
 	}
@@ -183,10 +253,14 @@ static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static u64 octeon_i2c_read_ctl(struct octeon_i2c *i2c)
+{
+	return octeon_i2c_read_sw64(i2c, SW_TWSI_EOP_TWSI_CTL);
+}
 
 static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
 {
-	return (octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_CTL) & TWSI_CTL_IFLG) != 0;
+	return (octeon_i2c_read_ctl(i2c) & TWSI_CTL_IFLG) != 0;
 }
 
 /**
@@ -211,106 +285,495 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 	return 0;
 }
 
-/**
- * octeon_i2c_start - send START to the bus
- * @i2c: The struct octeon_i2c
+/*
+ * Cleanup low-level state & enable high-level.
  *
- * Returns 0 on success, otherwise a negative errno.
+ * Returns -EAGAIN if low-level state could not be cleaned
  */
-static int octeon_i2c_start(struct octeon_i2c *i2c)
+static int octeon_i2c_enable_hlc(struct octeon_i2c *i2c)
 {
-	int result;
-	u8 data;
+	int try = 0, ret = 0;
+	u64 val;
+
+	if (i2c->hlc_enabled)
+		return 0;
+	i2c->hlc_enabled = true;
+
+	while (1) {
+		val = octeon_i2c_read_ctl(i2c) & (TWSI_CTL_STA | TWSI_CTL_STP);
+		if (!val)
+			break;
+
+		/* clear IFLG event */
+		if (val & TWSI_CTL_IFLG)
+			octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+		if (try++ > 100) {
+			pr_err("%s: giving up\n", __func__);
+			ret = -EAGAIN;
+			break;
+		}
+
+		/* spin until any start/stop has finished */
+		udelay(10);
+	}
 
 	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
-			    TWSI_CTL_ENAB | TWSI_CTL_STA);
+			    TWSI_CTL_CE | TWSI_CTL_AAK | TWSI_CTL_ENAB);
+	return ret;
+}
 
-	result = octeon_i2c_wait(i2c);
-	if (result) {
-		if (octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT) == 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_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
-					    TWSI_CTL_ENAB | TWSI_CTL_STA);
-			result = octeon_i2c_wait(i2c);
-		}
-		if (result)
-			return result;
-	}
+static int octeon_i2c_lost_arb(u8 code, int final_read)
+{
+	switch (code) {
+	/* 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 -EIO;
 
-	data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
-	if ((data != STAT_START) && (data != STAT_RSTART)) {
-		dev_err(i2c->dev, "%s: bad status (0x%x)\n", __func__, data);
+	/* 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 -EIO;
-	}
 
+	/* ACK allowed on pre-terminal bytes only */
+	case STAT_RXDATA_ACK:
+		if (!final_read)
+			return 0;
+		return -EAGAIN;
+
+	/* NAK allowed on terminal byte only */
+	case STAT_RXDATA_NAK:
+		if (final_read)
+			return 0;
+		return -EAGAIN;
+	case STAT_TXDATA_NAK:
+	case STAT_TXADDR_NAK:
+	case STAT_RXADDR_NAK:
+	case STAT_AD2W_NAK:
+		return -EAGAIN;
+	}
 	return 0;
 }
 
+static int check_arb(struct octeon_i2c *i2c, int final_read)
+{
+	return octeon_i2c_lost_arb(octeon_i2c_read_sw(i2c,
+			SW_TWSI_EOP_TWSI_STAT),	final_read);
+}
+
 /* send STOP to the bus */
 static void octeon_i2c_stop(struct octeon_i2c *i2c)
 {
-	u8 data;
-
 	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
 			    TWSI_CTL_ENAB | TWSI_CTL_STP);
+}
+
+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;
+}
 
-	data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
+{
+	octeon_i2c_write_int(i2c, TWSI_INT_ST_EN);
+}
 
-	if (data != STAT_IDLE)
-		dev_err(i2c->dev, "%s: bad status(0x%x)\n", __func__, data);
+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_write - send data to the bus via low-level controller
+ * octeon_i2c_hlc_wait - wait for an HLC operation to complete
  * @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)
+static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
 {
-	int i, result;
-	u8 tmp;
+	int result;
 
-	result = octeon_i2c_start(i2c);
-	if (result)
+	octeon_i2c_hlc_int_enable(i2c);
+	result = wait_event_interruptible_timeout(i2c->queue,
+						  octeon_i2c_hlc_test_ready(i2c),
+						  i2c->adap.timeout);
+	octeon_i2c_int_disable(i2c);
+	if (!result)
+		octeon_i2c_hlc_int_clear(i2c);
+	if (result < 0) {
+		dev_dbg(i2c->dev, "%s: wait interrupted\n", __func__);
 		return result;
+	} else if (!result) {
+		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
+		return -ETIMEDOUT;
+	}
+	return 0;
+}
 
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, target << 1);
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+/* high-level-controller pure read of up to 8 bytes */
+static int octeon_i2c_simple_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	int i, j, ret = 0;
+	u64 cmd;
+
+	octeon_i2c_enable_hlc(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_A_SHIFT;
+
+	if (msgs[0].flags & I2C_M_TEN)
+		cmd |= SW_TWSI_OP_10;
+	else
+		cmd |= SW_TWSI_OP_7;
+
+	octeon_i2c_hlc_int_clear(i2c);
+	__raw_writeq(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;
+	}
 
-	result = octeon_i2c_wait(i2c);
-	if (result)
-		return result;
+err:
+	return ret;
+}
 
-	for (i = 0; i < length; i++) {
-		tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+/* high-level-controller pure write of up to 8 bytes */
+static int octeon_i2c_simple_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	int i, j, ret = 0;
+	u64 cmd;
+
+	octeon_i2c_enable_hlc(i2c);
+	octeon_i2c_hlc_int_clear(i2c);
+
+	ret = check_arb(i2c, false);
+	if (ret)
+		goto err;
+
+	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_A_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);
+		__raw_writeq(ext, i2c->twsi_base + SW_TWSI_EXT);
+	}
+
+	__raw_writeq(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;
 
-		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;
+	ret = check_arb(i2c, false);
+
+err:
+	return ret;
+}
+
+/* high-level-controller composite write+read, msg0=addr, msg1=data */
+static int octeon_i2c_ia_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	int i, j, ret = 0;
+	u64 cmd;
+
+	octeon_i2c_enable_hlc(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_A_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;
+		__raw_writeq(ext, i2c->twsi_base + SW_TWSI_EXT);
+	} else
+		cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+
+	octeon_i2c_hlc_int_clear(i2c);
+	__raw_writeq(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_ia_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	bool set_ext = false;
+	int i, j, ret = 0;
+	u64 cmd, ext = 0;
+
+	octeon_i2c_enable_hlc(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_A_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)
+		__raw_writeq(ext, i2c->twsi_base + SW_TWSI_EXT);
+
+	octeon_i2c_hlc_int_clear(i2c);
+	__raw_writeq(cmd, i2c->twsi_base + SW_TWSI);
+
+	ret = octeon_i2c_hlc_wait(i2c);
+	if (ret)
+		goto err;
+
+	cmd = octeon_i2c_read_sw64(i2c, SW_TWSI_EOP_TWSI_STAT);
+	if ((cmd & SW_TWSI_R) == 0)
+		return -EAGAIN;
+	ret = octeon_i2c_lost_arb(cmd, false);
+
+err:
+	return ret;
+}
+
+/* calculate and set clock divisors */
+static void octeon_i2c_setclock(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_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp);
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
+}
 
-		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, data[i]);
-		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+static int octeon_i2c_initlowlevel(struct octeon_i2c *i2c)
+{
+	u8 status = 0;
+	int tries;
 
-		result = octeon_i2c_wait(i2c);
-		if (result)
-			return result;
+	/* reset controller */
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_RST, 0);
+
+	for (tries = 10; tries && status != STAT_IDLE; tries--) {
+		udelay(1);
+		status = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
 	}
 
+	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_enable_hlc(i2c);
+	octeon_i2c_disable_hlc(i2c);
+	return 0;
+}
+
+/*
+ * TWSI state seems stuck. Not sure if it's TWSI-engine state or something
+ * else on bus. The initial _stop() is always harmless, it just resets state
+ * machine, does not _transmit_ STOP unless engine was active.
+ */
+static int start_unstick(struct octeon_i2c *i2c)
+{
+	octeon_i2c_stop(i2c);
+
+	/*
+	 * Response is escalated over successive calls,
+	 * as EAGAIN provokes retries from i2c/core.
+	 */
+	switch (reset_how++ % 4) {
+	case 0:
+		/* just the stop above */
+		break;
+	case 1:
+		/*
+		 * Controller refused to send start flag. May be a
+		 * client is holding SDA low? Let's try to free it.
+		 */
+		octeon_i2c_unblock(i2c);
+		break;
+	case 2:
+		/* re-init our TWSI hardware */
+		octeon_i2c_initlowlevel(i2c);
+		break;
+	default:
+		/* retry in caller */
+		reset_how = 0;
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+/**
+ * octeon_i2c_start - send START to the bus
+ * @i2c: The struct octeon_i2c
+ * @first: first msg in combined operation?
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_start(struct octeon_i2c *i2c, int first)
+{
+	int result;
+	u8 data;
+
+	octeon_i2c_disable_hlc(i2c);
+
+	while (1) {
+		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+				    TWSI_CTL_ENAB | TWSI_CTL_STA);
+
+		result = octeon_i2c_wait(i2c);
+		data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+
+		switch (data) {
+		case STAT_START:
+		case STAT_RSTART:
+			if (!first)
+				return -EAGAIN;
+			reset_how = 0;
+			return 0;
+		case STAT_RXADDR_ACK:
+			if (first)
+				return -EAGAIN;
+			return start_unstick(i2c);
+		/*
+		 * case STAT_IDLE:
+		 * case STAT_ERROR:
+		 */
+		default:
+			if (!first)
+				return -EAGAIN;
+			start_unstick(i2c);
+		}
+	}
 	return 0;
 }
 
@@ -320,54 +783,51 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
  * @target: Target address
  * @data: Pointer to the location to store the data
  * @rlength: Length of the data
+ * @phase: which phase of a combined operation.
  * @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)
+static int octeon_i2c_read(struct octeon_i2c *i2c, int target, u8 *data,
+			   u16 *rlength, bool first, bool last, bool recv_len)
 {
+	u8 ctl = TWSI_CTL_ENAB | TWSI_CTL_AAK;
 	int i, result, length = *rlength;
 	u8 tmp;
 
 	if (length < 1)
 		return -EINVAL;
 
-	result = octeon_i2c_start(i2c);
+	result = octeon_i2c_start(i2c, first);
 	if (result)
 		return result;
 
 	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, (target << 1) | 1);
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
-
-	result = octeon_i2c_wait(i2c);
-	if (result)
-		return result;
 
-	for (i = 0; i < length; i++) {
+	for (i = 0; i < length; ) {
 		tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+		result = octeon_i2c_lost_arb(tmp, !(ctl & TWSI_CTL_AAK));
+		if (result)
+			return result;
 
-		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;
+		switch (tmp) {
+		case STAT_RXDATA_ACK:
+		case STAT_RXDATA_NAK:
+			data[i++] = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_DATA);
 		}
 
-		if (i + 1 < length)
-			octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
-					    TWSI_CTL_ENAB | TWSI_CTL_AAK);
-		else
-			octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
-					    TWSI_CTL_ENAB);
 
+		/* NAK last recv'd byte, as a no-more-please */
+		if (last && i == length - 1)
+			ctl &= ~TWSI_CTL_AAK;
+
+		/* clr iflg to allow next event */
+		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, ctl);
 		result = octeon_i2c_wait(i2c);
 		if (result)
 			return result;
-
-		data[i] = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_DATA);
 		if (recv_len && i == 0) {
 			if (data[i] > I2C_SMBUS_BLOCK_MAX + 1) {
 				dev_err(i2c->dev,
@@ -383,6 +843,53 @@ 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
+ * @last: is last msg in combined operation?
+ *
+ * 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 first, int last)
+{
+	int i, result;
+
+	result = octeon_i2c_start(i2c, first);
+	if (result)
+		return result;
+
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, target << 1);
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+	result = octeon_i2c_wait(i2c);
+	if (result)
+		return result;
+
+	for (i = 0; i < length; i++) {
+		result = check_arb(i2c, false);
+		if (result)
+			return result;
+
+		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, data[i]);
+		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+		result = octeon_i2c_wait(i2c);
+		if (result)
+			return result;
+		result = check_arb(i2c, false);
+		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
@@ -396,8 +903,31 @@ 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_simple_read(i2c, msgs);
+			else
+				ret = octeon_i2c_simple_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_ia_read(i2c, msgs);
+			else
+				ret = octeon_i2c_ia_write(i2c, msgs);
+			goto out;
+		}
+	}
+
 	for (i = 0; ret == 0 && i < num; i++) {
 		struct i2c_msg *pmsg = &msgs[i];
+		bool last = (i == (num - 1));
 
 		dev_dbg(i2c->dev,
 			"Doing %s %d byte(s) to/from 0x%02x - %d of %d messages\n",
@@ -405,13 +935,15 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 			 pmsg->len, pmsg->addr, i + 1, num);
 		if (pmsg->flags & I2C_M_RD)
 			ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
-					      &pmsg->len, pmsg->flags & I2C_M_RECV_LEN);
+					      &pmsg->len, !i, last,
+					      pmsg->flags & I2C_M_RECV_LEN);
 		else
 			ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
-					       pmsg->len);
+					       pmsg->len, !i, last);
 	}
 	octeon_i2c_stop(i2c);
 
+out:
 	return ret ? -EAGAIN : num;
 }
 
@@ -431,69 +963,6 @@ static struct i2c_adapter octeon_i2c_ops = {
 	.algo = &octeon_i2c_algo,
 };
 
-/* calculate and set clock divisors */
-static void octeon_i2c_setclock(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_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp);
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
-}
-
-static int octeon_i2c_initlowlevel(struct octeon_i2c *i2c)
-{
-	u8 status;
-	int tries;
-
-	/* disable high level controller, enable bus access */
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
-
-	/* reset controller */
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_RST, 0);
-
-	for (tries = 10; tries; tries--) {
-		udelay(1);
-		status = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
-		if (status == STAT_IDLE)
-			return 0;
-	}
-	dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n", __func__, status);
-	return -EIO;
-}
-
 static int octeon_i2c_probe(struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
-- 
1.9.1

[PATCH v3 07/14] dt-bindings: i2c: Add Octeon cn78xx TWSI

[Jan Glauber]

Add compatible string for Cavium Octeon cn78XX SOCs TWSI.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Acked-by: David Daney <ddaney@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

[PATCH v3 08/14] i2c-octeon: Add support for cn78XX chips

[Jan Glauber]

From: David Daney <david.daney@cavium.com>

cn78XX has a different interrupt architecture, so we have to manage
the interrupts differently.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/i2c/busses/i2c-octeon.c | 149 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 133 insertions(+), 16 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 8762473..b76ccd5 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>
@@ -105,11 +106,18 @@ 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_en)(struct octeon_i2c *);
+	void (*int_dis)(struct octeon_i2c *);
+	void (*hlc_int_en)(struct octeon_i2c *);
+	void (*hlc_int_dis)(struct octeon_i2c *);
+	atomic_t int_en_cnt;
+	atomic_t hlc_int_en_cnt;
 };
 
 static int reset_how;
@@ -211,6 +219,58 @@ static void octeon_i2c_disable_hlc(struct octeon_i2c *i2c)
 }
 
 /**
+ * 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_en_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_en_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_en_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_en_cnt, i2c->hlc_irq);
+}
+
+/**
  * octeon_i2c_unblock - unblock the bus
  * @i2c: The struct octeon_i2c
  *
@@ -247,7 +307,18 @@ static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
 {
 	struct octeon_i2c *i2c = dev_id;
 
-	octeon_i2c_int_disable(i2c);
+	i2c->int_dis(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_dis(i2c);
 	wake_up(&i2c->queue);
 
 	return IRQ_HANDLED;
@@ -273,10 +344,10 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 {
 	long time_left;
 
-	octeon_i2c_int_enable(i2c);
+	i2c->int_en(i2c);
 	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
 				       i2c->adap.timeout);
-	octeon_i2c_int_disable(i2c);
+	i2c->int_dis(i2c);
 	if (!time_left) {
 		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
 		return -ETIMEDOUT;
@@ -411,11 +482,11 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
 {
 	int result;
 
-	octeon_i2c_hlc_int_enable(i2c);
+	i2c->hlc_int_en(i2c);
 	result = wait_event_interruptible_timeout(i2c->queue,
 						  octeon_i2c_hlc_test_ready(i2c),
 						  i2c->adap.timeout);
-	octeon_i2c_int_disable(i2c);
+	i2c->hlc_int_dis(i2c);
 	if (!result)
 		octeon_i2c_hlc_int_clear(i2c);
 	if (result < 0) {
@@ -966,14 +1037,26 @@ 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) {
@@ -1017,11 +1100,44 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 
 	i2c->irq = irq;
 
-	result = devm_request_irq(&pdev->dev, i2c->irq,
-				  octeon_i2c_isr, 0, DRV_NAME, i2c);
-	if (result < 0) {
-		dev_err(i2c->dev, "failed to attach interrupt\n");
-		goto out;
+	if (cn78xx_style) {
+		i2c->hlc_irq = hlc_irq;
+
+		i2c->int_en = octeon_i2c_int_enable78;
+		i2c->int_dis = octeon_i2c_int_disable78;
+		i2c->hlc_int_en = octeon_i2c_hlc_int_enable78;
+		i2c->hlc_int_dis = 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->irq,
+					  octeon_i2c_isr, 0, DRV_NAME, i2c);
+
+		if (result < 0) {
+			dev_err(i2c->dev, "failed to attach interrupt\n");
+			goto out;
+		}
+		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_en = octeon_i2c_int_enable;
+		i2c->int_dis = octeon_i2c_int_disable;
+		i2c->hlc_int_en = octeon_i2c_hlc_int_enable;
+		i2c->hlc_int_dis = octeon_i2c_int_disable;
+
+		result = devm_request_irq(&pdev->dev, i2c->irq,
+					  octeon_i2c_isr, 0, DRV_NAME, i2c);
+		if (result < 0) {
+			dev_err(i2c->dev, "failed to attach interrupt\n");
+			goto out;
+		}
 	}
 
 	result = octeon_i2c_initlowlevel(i2c);
@@ -1062,6 +1178,7 @@ 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

[PATCH v3 09/14] i2c-octeon: Flush TWSI writes with readback

[Jan Glauber]

From: Peter Swain <pswain@cavium.com>

Signed-off-by: Peter Swain <pswain@cavium.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Acked-by: David Daney <ddaney@caviumnetworks.com>
---
 drivers/i2c/busses/i2c-octeon.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index b76ccd5..a8a56a0 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -126,6 +126,12 @@ static int timeout = 2;
 module_param(timeout, int, 0444);
 MODULE_PARM_DESC(timeout, "Low-level device timeout (ms)");
 
+static void writeqflush(u64 val, void __iomem *addr)
+{
+	__raw_writeq(val, addr);
+	__raw_readq(addr);	/* wait for write to land */
+}
+
 /**
  * octeon_i2c_write_sw - write an I2C core register
  * @i2c: The struct octeon_i2c
@@ -186,8 +192,7 @@ static u8 octeon_i2c_read_sw(struct octeon_i2c *i2c, u64 eop_reg)
  */
 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);
+	writeqflush(data, i2c->twsi_base + TWSI_INT);
 }
 
 /**
@@ -573,10 +578,10 @@ static int octeon_i2c_simple_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);
-		__raw_writeq(ext, i2c->twsi_base + SW_TWSI_EXT);
+		writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
 	}
 
-	__raw_writeq(cmd, i2c->twsi_base + SW_TWSI);
+	writeqflush(cmd, i2c->twsi_base + SW_TWSI);
 
 	ret = octeon_i2c_hlc_wait(i2c);
 	if (ret)
@@ -622,7 +627,7 @@ static int octeon_i2c_ia_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
 		cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
 
 	octeon_i2c_hlc_int_clear(i2c);
-	__raw_writeq(cmd, i2c->twsi_base + SW_TWSI);
+	writeqflush(cmd, i2c->twsi_base + SW_TWSI);
 
 	ret = octeon_i2c_hlc_wait(i2c);
 	if (ret)
@@ -682,10 +687,10 @@ static int octeon_i2c_ia_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
 		set_ext = true;
 	}
 	if (set_ext)
-		__raw_writeq(ext, i2c->twsi_base + SW_TWSI_EXT);
+		writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
 
 	octeon_i2c_hlc_int_clear(i2c);
-	__raw_writeq(cmd, i2c->twsi_base + SW_TWSI);
+	writeqflush(cmd, i2c->twsi_base + SW_TWSI);
 
 	ret = octeon_i2c_hlc_wait(i2c);
 	if (ret)
-- 
1.9.1

[PATCH v3 10/14] i2c-octeon: Faster operation when IFLG signals late

[Jan Glauber]

From: Peter Swain <pswain@cavium.com>

Some versions can deliver low-level twsi irq before twsi_ctl.iflg
is set, leading to timeout-driven i/o.
When an irq signals event, but woken task does not see the expected
twsi_ctl.iflg, re-check about 80uS later.

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.

Signed-off-by: Peter Swain <pswain@cavium.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Acked-by: David Daney <ddaney@caviumnetworks.com>
---
 drivers/i2c/busses/i2c-octeon.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index a8a56a0..afca316 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -126,6 +126,14 @@ static int timeout = 2;
 module_param(timeout, int, 0444);
 MODULE_PARM_DESC(timeout, "Low-level device timeout (ms)");
 
+/*
+ * On some hardware IFLG is not visible in TWSI_CTL until after low-level IRQ,
+ * so re-sample CTL a short time later to avoid stalls.
+ */
+static int irq_early_us = 80;
+module_param(irq_early_us, int, 0644);
+MODULE_PARM_DESC(irq_early_us, "Re-poll for IFLG after IRQ (us)");
+
 static void writeqflush(u64 val, void __iomem *addr)
 {
 	__raw_writeq(val, addr);
@@ -339,6 +347,26 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
 	return (octeon_i2c_read_ctl(i2c) & TWSI_CTL_IFLG) != 0;
 }
 
+/*
+ * Wait-helper which addresses the delayed-IFLAG problem by re-polling for
+ * missing TWSI_CTL[IFLG] a few us later, when irq has signalled an event,
+ * but none found. Skip this re-poll on the first (non-wakeup) call.
+ */
+static int poll_iflg(struct octeon_i2c *i2c, int *first_p)
+{
+	int iflg = octeon_i2c_test_iflg(i2c);
+
+	if (iflg)
+		return 1;
+	if (*first_p)
+		*first_p = 0;
+	else {
+		usleep_range(irq_early_us, 2 * irq_early_us);
+		iflg = octeon_i2c_test_iflg(i2c);
+	}
+	return iflg;
+}
+
 /**
  * octeon_i2c_wait - wait for the IFLG to be set
  * @i2c: The struct octeon_i2c
@@ -348,9 +376,10 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
 static int octeon_i2c_wait(struct octeon_i2c *i2c)
 {
 	long time_left;
+	int first = 1;
 
 	i2c->int_en(i2c);
-	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
+	time_left = wait_event_timeout(i2c->queue, poll_iflg(i2c, &first),
 				       i2c->adap.timeout);
 	i2c->int_dis(i2c);
 	if (!time_left) {
-- 
1.9.1

[PATCH v3 11/14] i2c-octeon: Add workaround for broken irqs on CN3860

[Jan Glauber]

From: David Daney <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 <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/i2c/busses/i2c-octeon.c | 46 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index afca316..6868802 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -112,6 +112,7 @@ struct octeon_i2c {
 	void __iomem *twsi_base;
 	struct device *dev;
 	bool hlc_enabled;
+	bool broken_irq_mode;
 	void (*int_en)(struct octeon_i2c *);
 	void (*int_dis)(struct octeon_i2c *);
 	void (*hlc_int_en)(struct octeon_i2c *);
@@ -378,10 +379,33 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 	long time_left;
 	int first = 1;
 
+	if (i2c->broken_irq_mode) {
+		/*
+		 * Some chip revisions seem to not assert the irq in
+		 * the interrupt controller.  So we must poll for the
+		 * IFLG change.
+		 */
+		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_en(i2c);
 	time_left = wait_event_timeout(i2c->queue, poll_iflg(i2c, &first),
 				       i2c->adap.timeout);
 	i2c->int_dis(i2c);
+
+	if (time_left <= 0 && OCTEON_IS_MODEL(OCTEON_CN38XX) &&
+	    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) {
 		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
 		return -ETIMEDOUT;
@@ -516,6 +540,21 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
 {
 	int result;
 
+	if (i2c->broken_irq_mode) {
+		/*
+		 * Some cn38xx boards did not assert the irq in
+		 * the interrupt controller.  So we must poll for the
+		 * IFLG change.
+		 */
+		u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+		while (!octeon_i2c_hlc_test_ready(i2c) &&
+		       time_before64(get_jiffies_64(), end))
+			udelay(50);
+
+		return octeon_i2c_hlc_test_ready(i2c) ? 0 : -ETIMEDOUT;
+	}
+
 	i2c->hlc_int_en(i2c);
 	result = wait_event_interruptible_timeout(i2c->queue,
 						  octeon_i2c_hlc_test_ready(i2c),
@@ -523,6 +562,13 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
 	i2c->hlc_int_dis(i2c);
 	if (!result)
 		octeon_i2c_hlc_int_clear(i2c);
+	if (result <= 0 && OCTEON_IS_MODEL(OCTEON_CN38XX) &&
+	    octeon_i2c_hlc_test_ready(i2c)) {
+		dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+			i2c->broken_irq_mode = true;
+			return 0;
+	}
+
 	if (result < 0) {
 		dev_dbg(i2c->dev, "%s: wait interrupted\n", __func__);
 		return result;
-- 
1.9.1

[PATCH v3 12/14] i2c-octeon: Split the driver into two parts

[Jan Glauber]

Move common functionality into a separate file in preparation of the
re-use from the ThunderX i2c driver.

Use a broken_irq_check flag to avoid including the
OCTEON_IS_MODEL test in the shared part.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/i2c/busses/Makefile          |    1 +
 drivers/i2c/busses/i2c-cavium.c      |  828 ++++++++++++++++++++++
 drivers/i2c/busses/i2c-cavium.h      |  187 +++++
 drivers/i2c/busses/i2c-octeon-core.c |  304 ++++++++
 drivers/i2c/busses/i2c-octeon.c      | 1279 ----------------------------------
 5 files changed, 1320 insertions(+), 1279 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

diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 37f2819..282f781 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -91,6 +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
+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
diff --git a/drivers/i2c/busses/i2c-cavium.c b/drivers/i2c/busses/i2c-cavium.c
new file mode 100644
index 0000000..5ed9e2d
--- /dev/null
+++ b/drivers/i2c/busses/i2c-cavium.c
@@ -0,0 +1,828 @@
+/*
+ * (C) Copyright 2009-2010
+ * Nokia Siemens Networks, michael.lawnick.ext@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"
+
+static int reset_how;
+
+/*
+ * On some hardware IFLG is not visible in TWSI_CTL until after low-level IRQ,
+ * so re-sample CTL a short time later to avoid stalls.
+ */
+static int irq_early_us = 80;
+module_param(irq_early_us, int, 0644);
+MODULE_PARM_DESC(irq_early_us, "Re-poll for IFLG after IRQ (us)");
+
+static void octeon_i2c_disable_hlc(struct octeon_i2c *i2c)
+{
+	if (!i2c->hlc_enabled)
+		return;
+
+	i2c->hlc_enabled = false;
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+}
+
+/* interrupt service routine */
+irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
+{
+	struct octeon_i2c *i2c = dev_id;
+
+	i2c->int_dis(i2c);
+	wake_up(&i2c->queue);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Wait-helper which addresses the delayed-IFLAG problem by re-polling for
+ * missing TWSI_CTL[IFLG] a few us later, when irq has signalled an event,
+ * but none found. Skip this re-poll on the first (non-wakeup) call.
+ */
+static int poll_iflg(struct octeon_i2c *i2c, int *first_p)
+{
+	int iflg = octeon_i2c_test_iflg(i2c);
+
+	if (iflg)
+		return 1;
+	if (*first_p)
+		*first_p = 0;
+	else {
+		usleep_range(irq_early_us, 2 * irq_early_us);
+		iflg = octeon_i2c_test_iflg(i2c);
+	}
+	return iflg;
+}
+
+/**
+ * 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;
+	int first = 1;
+
+	if (i2c->broken_irq_mode) {
+		/*
+		 * Some chip revisions seem to not assert the irq in
+		 * the interrupt controller.  So we must poll for the
+		 * IFLG change.
+		 */
+		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_en(i2c);
+	time_left = wait_event_timeout(i2c->queue, poll_iflg(i2c, &first),
+				       i2c->adap.timeout);
+	i2c->int_dis(i2c);
+
+	if (time_left <= 0 && i2c->broken_irq_check &&
+	    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) {
+		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+/*
+ * Cleanup low-level state & enable high-level.
+ *
+ * Returns -EAGAIN if low-level state could not be cleaned
+ */
+static int octeon_i2c_enable_hlc(struct octeon_i2c *i2c)
+{
+	int try = 0, ret = 0;
+	u64 val;
+
+	if (i2c->hlc_enabled)
+		return 0;
+	i2c->hlc_enabled = true;
+
+	while (1) {
+		val = octeon_i2c_read_ctl(i2c) & (TWSI_CTL_STA | TWSI_CTL_STP);
+		if (!val)
+			break;
+
+		/* clear IFLG event */
+		if (val & TWSI_CTL_IFLG)
+			octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+		if (try++ > 100) {
+			pr_err("%s: giving up\n", __func__);
+			ret = -EAGAIN;
+			break;
+		}
+
+		/* spin until any start/stop has finished */
+		udelay(10);
+	}
+
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+			    TWSI_CTL_CE | TWSI_CTL_AAK | TWSI_CTL_ENAB);
+	return ret;
+}
+
+static int octeon_i2c_lost_arb(u8 code, int final_read)
+{
+	switch (code) {
+	/* 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 -EIO;
+
+	/* 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 -EIO;
+
+	/* ACK allowed on pre-terminal bytes only */
+	case STAT_RXDATA_ACK:
+		if (!final_read)
+			return 0;
+		return -EAGAIN;
+
+	/* NAK allowed on terminal byte only */
+	case STAT_RXDATA_NAK:
+		if (final_read)
+			return 0;
+		return -EAGAIN;
+	case STAT_TXDATA_NAK:
+	case STAT_TXADDR_NAK:
+	case STAT_RXADDR_NAK:
+	case STAT_AD2W_NAK:
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+static int check_arb(struct octeon_i2c *i2c, int final_read)
+{
+	return octeon_i2c_lost_arb(octeon_i2c_read_sw(i2c,
+			SW_TWSI_EOP_TWSI_STAT),	final_read);
+}
+
+/* send STOP to the bus */
+static void octeon_i2c_stop(struct octeon_i2c *i2c)
+{
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+			    TWSI_CTL_ENAB | TWSI_CTL_STP);
+}
+
+int octeon_i2c_initlowlevel(struct octeon_i2c *i2c)
+{
+	u8 status = 0;
+	int tries;
+
+	/* reset controller */
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_RST, 0);
+
+	for (tries = 10; tries && status != STAT_IDLE; tries--) {
+		udelay(1);
+		status = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+	}
+
+	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_enable_hlc(i2c);
+	octeon_i2c_disable_hlc(i2c);
+	return 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 state, i;
+
+	octeon_i2c_disable_hlc(i2c);
+	dev_dbg(i2c->dev, "%s\n", __func__);
+
+	/* cycle 8+1 clocks with SDA high */
+	for (i = 0; i < 9; i++) {
+		octeon_i2c_write_int(i2c, 0);
+		udelay(5);
+		state = __raw_readq(i2c->twsi_base + TWSI_INT);
+		if (state & (TWSI_INT_SDA | TWSI_INT_SCL))
+			break;
+		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);
+}
+
+/*
+ * TWSI state seems stuck. Not sure if it's TWSI-engine state or something
+ * else on bus. The initial _stop() is always harmless, it just resets state
+ * machine, does not _transmit_ STOP unless engine was active.
+ */
+static int start_unstick(struct octeon_i2c *i2c)
+{
+	octeon_i2c_stop(i2c);
+
+	/*
+	 * Response is escalated over successive calls,
+	 * as EAGAIN provokes retries from i2c/core.
+	 */
+	switch (reset_how++ % 4) {
+	case 0:
+		/* just the stop above */
+		break;
+	case 1:
+		/*
+		 * Controller refused to send start flag. May be a
+		 * client is holding SDA low? Let's try to free it.
+		 */
+		octeon_i2c_unblock(i2c);
+		break;
+	case 2:
+		/* re-init our TWSI hardware */
+		octeon_i2c_initlowlevel(i2c);
+		break;
+	default:
+		/* retry in caller */
+		reset_how = 0;
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+/**
+ * octeon_i2c_start - send START to the bus
+ * @i2c: The struct octeon_i2c
+ * @first: first msg in combined operation?
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_start(struct octeon_i2c *i2c, int first)
+{
+	int result;
+	u8 data;
+
+	octeon_i2c_disable_hlc(i2c);
+
+	while (1) {
+		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+				    TWSI_CTL_ENAB | TWSI_CTL_STA);
+
+		result = octeon_i2c_wait(i2c);
+		data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+
+		switch (data) {
+		case STAT_START:
+		case STAT_RSTART:
+			if (!first)
+				return -EAGAIN;
+			reset_how = 0;
+			return 0;
+		case STAT_RXADDR_ACK:
+			if (first)
+				return -EAGAIN;
+			return start_unstick(i2c);
+		/*
+		 * case STAT_IDLE:
+		 * case STAT_ERROR:
+		 */
+		default:
+			if (!first)
+				return -EAGAIN;
+			start_unstick(i2c);
+		}
+	}
+	return 0;
+}
+
+/* calculate and set clock divisors */
+void octeon_i2c_setclock(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_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp);
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
+}
+
+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_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 a negative errno.
+ */
+static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
+{
+	int result;
+
+	if (i2c->broken_irq_mode) {
+		/*
+		 * Some cn38xx boards did not assert the irq in
+		 * the interrupt controller.  So we must poll for the
+		 * IFLG change.
+		 */
+		u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+		while (!octeon_i2c_hlc_test_ready(i2c) &&
+		       time_before64(get_jiffies_64(), end))
+			udelay(50);
+
+		return octeon_i2c_hlc_test_ready(i2c) ? 0 : -ETIMEDOUT;
+	}
+
+	i2c->hlc_int_en(i2c);
+	result = wait_event_interruptible_timeout(i2c->queue,
+						  octeon_i2c_hlc_test_ready(i2c),
+						  i2c->adap.timeout);
+	i2c->hlc_int_dis(i2c);
+	if (!result)
+		octeon_i2c_hlc_int_clear(i2c);
+	if (result <= 0 && i2c->broken_irq_check &&
+	    octeon_i2c_hlc_test_ready(i2c)) {
+		dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+			i2c->broken_irq_mode = true;
+			return 0;
+	}
+
+	if (result < 0) {
+		dev_dbg(i2c->dev, "%s: wait interrupted\n", __func__);
+		return result;
+	} else if (!result) {
+		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
+		return -ETIMEDOUT;
+	}
+	return 0;
+}
+
+/**
+ * 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
+ * @phase: which phase of a combined operation.
+ * @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 first, bool last, bool recv_len)
+{
+	u8 ctl = TWSI_CTL_ENAB | TWSI_CTL_AAK;
+	int i, result, length = *rlength;
+	u8 tmp;
+
+	if (length < 1)
+		return -EINVAL;
+
+	result = octeon_i2c_start(i2c, first);
+	if (result)
+		return result;
+
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, (target << 1) | 1);
+
+	for (i = 0; i < length; ) {
+		tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+		result = octeon_i2c_lost_arb(tmp, !(ctl & TWSI_CTL_AAK));
+		if (result)
+			return result;
+
+		switch (tmp) {
+		case STAT_RXDATA_ACK:
+		case STAT_RXDATA_NAK:
+			data[i++] = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_DATA);
+		}
+
+
+		/* NAK last recv'd byte, as a no-more-please */
+		if (last && i == length - 1)
+			ctl &= ~TWSI_CTL_AAK;
+
+		/* clr iflg to allow next event */
+		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, ctl);
+		result = octeon_i2c_wait(i2c);
+		if (result)
+			return result;
+		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 -EIO;
+			}
+			length += data[i];
+		}
+	}
+	*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
+ * @last: is last msg in combined operation?
+ *
+ * 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 first, int last)
+{
+	int i, result;
+
+	result = octeon_i2c_start(i2c, first);
+	if (result)
+		return result;
+
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, target << 1);
+	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+	result = octeon_i2c_wait(i2c);
+	if (result)
+		return result;
+
+	for (i = 0; i < length; i++) {
+		result = check_arb(i2c, false);
+		if (result)
+			return result;
+
+		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, data[i]);
+		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+		result = octeon_i2c_wait(i2c);
+		if (result)
+			return result;
+		result = check_arb(i2c, false);
+		if (result)
+			return result;
+	}
+
+	return 0;
+}
+
+/* high-level-controller pure read of up to 8 bytes */
+static int octeon_i2c_simple_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	int i, j, ret = 0;
+	u64 cmd;
+
+	octeon_i2c_enable_hlc(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_A_SHIFT;
+
+	if (msgs[0].flags & I2C_M_TEN)
+		cmd |= SW_TWSI_OP_10;
+	else
+		cmd |= SW_TWSI_OP_7;
+
+	octeon_i2c_hlc_int_clear(i2c);
+	__raw_writeq(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_simple_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	int i, j, ret = 0;
+	u64 cmd;
+
+	octeon_i2c_enable_hlc(i2c);
+	octeon_i2c_hlc_int_clear(i2c);
+
+	ret = check_arb(i2c, false);
+	if (ret)
+		goto err;
+
+	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_A_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);
+		writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
+	}
+
+	writeqflush(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 = check_arb(i2c, false);
+
+err:
+	return ret;
+}
+
+/* high-level-controller composite write+read, msg0=addr, msg1=data */
+static int octeon_i2c_ia_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	int i, j, ret = 0;
+	u64 cmd;
+
+	octeon_i2c_enable_hlc(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_A_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;
+		__raw_writeq(ext, i2c->twsi_base + SW_TWSI_EXT);
+	} else
+		cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+
+	octeon_i2c_hlc_int_clear(i2c);
+	writeqflush(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_ia_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	bool set_ext = false;
+	int i, j, ret = 0;
+	u64 cmd, ext = 0;
+
+	octeon_i2c_enable_hlc(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_A_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)
+		writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
+
+	octeon_i2c_hlc_int_clear(i2c);
+	writeqflush(cmd, i2c->twsi_base + SW_TWSI);
+
+	ret = octeon_i2c_hlc_wait(i2c);
+	if (ret)
+		goto err;
+
+	cmd = octeon_i2c_read_sw64(i2c, SW_TWSI_EOP_TWSI_STAT);
+	if ((cmd & SW_TWSI_R) == 0)
+		return -EAGAIN;
+	ret = octeon_i2c_lost_arb(cmd, 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_simple_read(i2c, msgs);
+			else
+				ret = octeon_i2c_simple_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_ia_read(i2c, msgs);
+			else
+				ret = octeon_i2c_ia_write(i2c, msgs);
+			goto out;
+		}
+	}
+
+	for (i = 0; ret == 0 && i < num; i++) {
+		struct i2c_msg *pmsg = &msgs[i];
+		bool last = (i == (num - 1));
+
+		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);
+		if (pmsg->flags & I2C_M_RD)
+			ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
+					      &pmsg->len, !i, last,
+					      pmsg->flags & I2C_M_RECV_LEN);
+		else
+			ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
+					       pmsg->len, !i, last);
+	}
+	octeon_i2c_stop(i2c);
+
+out:
+	return ret ? -EAGAIN : num;
+}
diff --git a/drivers/i2c/busses/i2c-cavium.h b/drivers/i2c/busses/i2c-cavium.h
new file mode 100644
index 0000000..18f08b2
--- /dev/null
+++ b/drivers/i2c/busses/i2c-cavium.h
@@ -0,0 +1,187 @@
+#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>
+
+/* 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)
+#define SW_TWSI_EIA		BIT_ULL(61)
+#define SW_TWSI_OP_TWSI_CLK	BIT_ULL(59)
+#define SW_TWSI_OP_7		(0ULL << 57)
+#define SW_TWSI_OP_7_IA		BIT_ULL(57)
+#define SW_TWSI_OP_10		(2ULL << 57)
+#define SW_TWSI_OP_10_IA	(3ULL << 57)
+#define SW_TWSI_R		BIT_ULL(56)
+#define SW_TWSI_SOVR		BIT_ULL(55)
+#define SW_TWSI_SIZE_SHIFT	52
+#define SW_TWSI_A_SHIFT		40
+#define SW_TWSI_IA_SHIFT	32
+#define SW_TWSI_EOP_TWSI_DATA	0x0C00000100000000ULL
+#define SW_TWSI_EOP_TWSI_CTL	0x0C00000200000000ULL
+#define SW_TWSI_EOP_TWSI_CLKCTL	0x0C00000300000000ULL
+#define SW_TWSI_EOP_TWSI_STAT	0x0C00000300000000ULL
+#define SW_TWSI_EOP_TWSI_RST	0x0C00000700000000ULL
+
+/* 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 */
+
+/* Some status values */
+#define STAT_ERROR		0x00
+#define STAT_START		0x08
+#define STAT_RSTART		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)
+
+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_en)(struct octeon_i2c *);
+	void (*int_dis)(struct octeon_i2c *);
+	void (*hlc_int_en)(struct octeon_i2c *);
+	void (*hlc_int_dis)(struct octeon_i2c *);
+	atomic_t int_en_cnt;
+	atomic_t hlc_int_en_cnt;
+};
+
+static inline void writeqflush(u64 val, void __iomem *addr)
+{
+	__raw_writeq(val, addr);
+	__raw_readq(addr);	/* wait for write to land */
+}
+
+/**
+ * octeon_i2c_write_sw - 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_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u32 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);
+}
+
+/**
+ * octeon_i2c_read_sw64 - read 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 u64 octeon_i2c_read_sw64(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;
+}
+
+/**
+ * octeon_i2c_read_sw - 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_read_sw(struct octeon_i2c *i2c, u64 eop_reg)
+{
+	return octeon_i2c_read_sw64(i2c, eop_reg) & 0xFF;
+}
+
+/**
+ * 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)
+{
+	writeqflush(data, i2c->twsi_base + TWSI_INT);
+}
+
+static inline u64 octeon_i2c_read_ctl(struct octeon_i2c *i2c)
+{
+	return octeon_i2c_read_sw64(i2c, SW_TWSI_EOP_TWSI_CTL);
+}
+
+static inline int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
+{
+	return (octeon_i2c_read_ctl(i2c) & TWSI_CTL_IFLG) != 0;
+}
+
+/* Prototypes */
+int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
+irqreturn_t octeon_i2c_isr(int irq, void *dev_id);
+int octeon_i2c_initlowlevel(struct octeon_i2c *i2c);
+void octeon_i2c_setclock(struct octeon_i2c *i2c);
diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
new file mode 100644
index 0000000..75c5f30
--- /dev/null
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -0,0 +1,304 @@
+/*
+ * (C) Copyright 2009-2010
+ * Nokia Siemens Networks, michael.lawnick.ext@nsn.com
+ *
+ * Portions Copyright (C) 2010 - 2016 Cavium, Inc.
+ *
+ * This is a driver for the i2c adapter in Cavium Networks' OCTEON processors.
+ *
+ * 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/atomic.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#include <asm/octeon/octeon.h>
+#include "i2c-cavium.h"
+
+#define DRV_NAME "i2c-octeon"
+
+static int timeout = 2;
+module_param(timeout, int, 0444);
+MODULE_PARM_DESC(timeout, "Low-level device timeout (ms)");
+
+/**
+ * octeon_i2c_int_enable - 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_enable(struct octeon_i2c *i2c)
+{
+	octeon_i2c_write_int(i2c, TWSI_INT_CORE_EN);
+}
+
+/* disable the CORE interrupt */
+static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
+{
+	/* clear TS/ST/IFLG events */
+	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_en_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_en_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_en_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_en_cnt, i2c->hlc_irq);
+}
+
+/* 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_dis(i2c);
+	wake_up(&i2c->queue);
+
+	return IRQ_HANDLED;
+}
+
+static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
+{
+	octeon_i2c_write_int(i2c, TWSI_INT_ST_EN);
+}
+
+static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm octeon_i2c_algo = {
+	.master_xfer = octeon_i2c_xfer,
+	.functionality = octeon_i2c_functionality,
+};
+
+static struct i2c_adapter octeon_i2c_ops = {
+	.owner = THIS_MODULE,
+	.name = "OCTEON adapter",
+	.algo = &octeon_i2c_algo,
+};
+
+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;
+	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) {
+		result = -ENOMEM;
+		goto out;
+	}
+	i2c->dev = &pdev->dev;
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	if (res_mem == NULL) {
+		dev_err(i2c->dev, "found no memory resource\n");
+		result = -ENXIO;
+		goto out;
+	}
+
+	/*
+	 * "clock-rate" is a legacy binding, the official binding is
+	 * "clock-frequency".  Try the official one first and then
+	 * fall back if it doesn't exist.
+	 */
+	if (of_property_read_u32(node, "clock-frequency", &i2c->twsi_freq) &&
+	    of_property_read_u32(node, "clock-rate", &i2c->twsi_freq)) {
+		dev_err(i2c->dev,
+			"no I2C 'clock-rate' or 'clock-frequency' property\n");
+		result = -ENXIO;
+		goto out;
+	}
+
+	i2c->sys_freq = octeon_get_io_clock_rate();
+
+	if (!devm_request_mem_region(&pdev->dev, res_mem->start,
+				     resource_size(res_mem), res_mem->name)) {
+		dev_err(i2c->dev, "request_mem_region failed\n");
+		goto out;
+	}
+	i2c->twsi_base = devm_ioremap(&pdev->dev, res_mem->start,
+				      resource_size(res_mem));
+
+	init_waitqueue_head(&i2c->queue);
+
+	i2c->irq = irq;
+
+	if (cn78xx_style) {
+		i2c->hlc_irq = hlc_irq;
+
+		i2c->int_en = octeon_i2c_int_enable78;
+		i2c->int_dis = octeon_i2c_int_disable78;
+		i2c->hlc_int_en = octeon_i2c_hlc_int_enable78;
+		i2c->hlc_int_dis = 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->irq,
+					  octeon_i2c_isr, 0, DRV_NAME, i2c);
+
+		if (result < 0) {
+			dev_err(i2c->dev, "failed to attach interrupt\n");
+			goto out;
+		}
+		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_en = octeon_i2c_int_enable;
+		i2c->int_dis = octeon_i2c_int_disable;
+		i2c->hlc_int_en = octeon_i2c_hlc_int_enable;
+		i2c->hlc_int_dis = octeon_i2c_int_disable;
+
+		result = devm_request_irq(&pdev->dev, i2c->irq,
+					  octeon_i2c_isr, 0, DRV_NAME, i2c);
+		if (result < 0) {
+			dev_err(i2c->dev, "failed to attach interrupt\n");
+			goto out;
+		}
+	}
+
+	if (OCTEON_IS_MODEL(OCTEON_CN38XX))
+		i2c->broken_irq_check = true;
+
+	result = octeon_i2c_initlowlevel(i2c);
+	if (result) {
+		dev_err(i2c->dev, "init low level failed\n");
+		goto  out;
+	}
+
+	octeon_i2c_setclock(i2c);
+
+	i2c->adap = octeon_i2c_ops;
+	i2c->adap.timeout = msecs_to_jiffies(50);
+	i2c->adap.timeout = msecs_to_jiffies(timeout);
+	i2c->adap.retries = 10;
+	i2c->adap.dev.parent = &pdev->dev;
+	i2c->adap.dev.of_node = node;
+	i2c_set_adapdata(&i2c->adap, i2c);
+	platform_set_drvdata(pdev, i2c);
+
+	result = i2c_add_adapter(&i2c->adap);
+	if (result < 0) {
+		dev_err(i2c->dev, "failed to add adapter\n");
+		goto out;
+	}
+	dev_info(i2c->dev, "probed\n");
+	return 0;
+
+out:
+	return result;
+};
+
+static int octeon_i2c_remove(struct platform_device *pdev)
+{
+	struct octeon_i2c *i2c = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&i2c->adap);
+	return 0;
+};
+
+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);
+
+static struct platform_driver octeon_i2c_driver = {
+	.probe		= octeon_i2c_probe,
+	.remove		= octeon_i2c_remove,
+	.driver		= {
+		.name	= DRV_NAME,
+		.of_match_table = octeon_i2c_match,
+	},
+};
+
+module_platform_driver(octeon_i2c_driver);
+
+MODULE_AUTHOR("Michael Lawnick <michael.lawnick.ext@nsn.com>");
+MODULE_DESCRIPTION("I2C-Bus adapter for Cavium OCTEON processors");
+MODULE_LICENSE("GPL");
diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
deleted file mode 100644
index 6868802..0000000
--- a/drivers/i2c/busses/i2c-octeon.c
+++ /dev/null
@@ -1,1279 +0,0 @@
-/*
- * (C) Copyright 2009-2010
- * Nokia Siemens Networks, michael.lawnick.ext@nsn.com
- *
- * Portions Copyright (C) 2010 - 2016 Cavium, Inc.
- *
- * This is a driver for the i2c adapter in Cavium Networks' OCTEON processors.
- *
- * 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/atomic.h>
-#include <linux/platform_device.h>
-#include <linux/interrupt.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/delay.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include <linux/i2c.h>
-#include <linux/io.h>
-#include <linux/of.h>
-
-#include <asm/octeon/octeon.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)
-#define SW_TWSI_EIA		BIT_ULL(61)
-#define SW_TWSI_OP_TWSI_CLK	BIT_ULL(59)
-#define SW_TWSI_OP_7		(0ULL << 57)
-#define SW_TWSI_OP_7_IA		BIT_ULL(57)
-#define SW_TWSI_OP_10		(2ULL << 57)
-#define SW_TWSI_OP_10_IA	(3ULL << 57)
-#define SW_TWSI_R		BIT_ULL(56)
-#define SW_TWSI_SOVR		BIT_ULL(55)
-#define SW_TWSI_SIZE_SHIFT	52
-#define SW_TWSI_A_SHIFT		40
-#define SW_TWSI_IA_SHIFT	32
-#define SW_TWSI_EOP_TWSI_DATA	0x0C00000100000000ULL
-#define SW_TWSI_EOP_TWSI_CTL	0x0C00000200000000ULL
-#define SW_TWSI_EOP_TWSI_CLKCTL	0x0C00000300000000ULL
-#define SW_TWSI_EOP_TWSI_STAT	0x0C00000300000000ULL
-#define SW_TWSI_EOP_TWSI_RST	0x0C00000700000000ULL
-
-/* 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 */
-
-/* Some status values */
-#define STAT_ERROR		0x00
-#define STAT_START		0x08
-#define STAT_RSTART		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)
-
-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;
-	void (*int_en)(struct octeon_i2c *);
-	void (*int_dis)(struct octeon_i2c *);
-	void (*hlc_int_en)(struct octeon_i2c *);
-	void (*hlc_int_dis)(struct octeon_i2c *);
-	atomic_t int_en_cnt;
-	atomic_t hlc_int_en_cnt;
-};
-
-static int reset_how;
-
-static int timeout = 2;
-module_param(timeout, int, 0444);
-MODULE_PARM_DESC(timeout, "Low-level device timeout (ms)");
-
-/*
- * On some hardware IFLG is not visible in TWSI_CTL until after low-level IRQ,
- * so re-sample CTL a short time later to avoid stalls.
- */
-static int irq_early_us = 80;
-module_param(irq_early_us, int, 0644);
-MODULE_PARM_DESC(irq_early_us, "Re-poll for IFLG after IRQ (us)");
-
-static void writeqflush(u64 val, void __iomem *addr)
-{
-	__raw_writeq(val, addr);
-	__raw_readq(addr);	/* wait for write to land */
-}
-
-/**
- * octeon_i2c_write_sw - 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_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u32 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);
-}
-
-/**
- * octeon_i2c_read_sw64 - read 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 u64 octeon_i2c_read_sw64(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;
-}
-
-/**
- * octeon_i2c_read_sw - 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_read_sw(struct octeon_i2c *i2c, u64 eop_reg)
-{
-	return octeon_i2c_read_sw64(i2c, eop_reg) & 0xFF;
-}
-
-/**
- * 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)
-{
-	writeqflush(data, i2c->twsi_base + TWSI_INT);
-}
-
-/**
- * octeon_i2c_int_enable - 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_enable(struct octeon_i2c *i2c)
-{
-	octeon_i2c_write_int(i2c, TWSI_INT_CORE_EN);
-}
-
-/* disable the CORE interrupt */
-static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
-{
-	/* clear TS/ST/IFLG events */
-	octeon_i2c_write_int(i2c, 0);
-}
-
-static void octeon_i2c_disable_hlc(struct octeon_i2c *i2c)
-{
-	if (!i2c->hlc_enabled)
-		return;
-
-	i2c->hlc_enabled = false;
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
-}
-
-/**
- * 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_en_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_en_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_en_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_en_cnt, i2c->hlc_irq);
-}
-
-/**
- * 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 state, i;
-
-	octeon_i2c_disable_hlc(i2c);
-	dev_dbg(i2c->dev, "%s\n", __func__);
-
-	/* cycle 8+1 clocks with SDA high */
-	for (i = 0; i < 9; i++) {
-		octeon_i2c_write_int(i2c, 0);
-		udelay(5);
-		state = __raw_readq(i2c->twsi_base + TWSI_INT);
-		if (state & (TWSI_INT_SDA | TWSI_INT_SCL))
-			break;
-		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)
-{
-	struct octeon_i2c *i2c = dev_id;
-
-	i2c->int_dis(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_dis(i2c);
-	wake_up(&i2c->queue);
-
-	return IRQ_HANDLED;
-}
-
-static u64 octeon_i2c_read_ctl(struct octeon_i2c *i2c)
-{
-	return octeon_i2c_read_sw64(i2c, SW_TWSI_EOP_TWSI_CTL);
-}
-
-static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
-{
-	return (octeon_i2c_read_ctl(i2c) & TWSI_CTL_IFLG) != 0;
-}
-
-/*
- * Wait-helper which addresses the delayed-IFLAG problem by re-polling for
- * missing TWSI_CTL[IFLG] a few us later, when irq has signalled an event,
- * but none found. Skip this re-poll on the first (non-wakeup) call.
- */
-static int poll_iflg(struct octeon_i2c *i2c, int *first_p)
-{
-	int iflg = octeon_i2c_test_iflg(i2c);
-
-	if (iflg)
-		return 1;
-	if (*first_p)
-		*first_p = 0;
-	else {
-		usleep_range(irq_early_us, 2 * irq_early_us);
-		iflg = octeon_i2c_test_iflg(i2c);
-	}
-	return iflg;
-}
-
-/**
- * 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;
-	int first = 1;
-
-	if (i2c->broken_irq_mode) {
-		/*
-		 * Some chip revisions seem to not assert the irq in
-		 * the interrupt controller.  So we must poll for the
-		 * IFLG change.
-		 */
-		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_en(i2c);
-	time_left = wait_event_timeout(i2c->queue, poll_iflg(i2c, &first),
-				       i2c->adap.timeout);
-	i2c->int_dis(i2c);
-
-	if (time_left <= 0 && OCTEON_IS_MODEL(OCTEON_CN38XX) &&
-	    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) {
-		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
-		return -ETIMEDOUT;
-	}
-
-	return 0;
-}
-
-/*
- * Cleanup low-level state & enable high-level.
- *
- * Returns -EAGAIN if low-level state could not be cleaned
- */
-static int octeon_i2c_enable_hlc(struct octeon_i2c *i2c)
-{
-	int try = 0, ret = 0;
-	u64 val;
-
-	if (i2c->hlc_enabled)
-		return 0;
-	i2c->hlc_enabled = true;
-
-	while (1) {
-		val = octeon_i2c_read_ctl(i2c) & (TWSI_CTL_STA | TWSI_CTL_STP);
-		if (!val)
-			break;
-
-		/* clear IFLG event */
-		if (val & TWSI_CTL_IFLG)
-			octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
-
-		if (try++ > 100) {
-			pr_err("%s: giving up\n", __func__);
-			ret = -EAGAIN;
-			break;
-		}
-
-		/* spin until any start/stop has finished */
-		udelay(10);
-	}
-
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
-			    TWSI_CTL_CE | TWSI_CTL_AAK | TWSI_CTL_ENAB);
-	return ret;
-}
-
-static int octeon_i2c_lost_arb(u8 code, int final_read)
-{
-	switch (code) {
-	/* 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 -EIO;
-
-	/* 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 -EIO;
-
-	/* ACK allowed on pre-terminal bytes only */
-	case STAT_RXDATA_ACK:
-		if (!final_read)
-			return 0;
-		return -EAGAIN;
-
-	/* NAK allowed on terminal byte only */
-	case STAT_RXDATA_NAK:
-		if (final_read)
-			return 0;
-		return -EAGAIN;
-	case STAT_TXDATA_NAK:
-	case STAT_TXADDR_NAK:
-	case STAT_RXADDR_NAK:
-	case STAT_AD2W_NAK:
-		return -EAGAIN;
-	}
-	return 0;
-}
-
-static int check_arb(struct octeon_i2c *i2c, int final_read)
-{
-	return octeon_i2c_lost_arb(octeon_i2c_read_sw(i2c,
-			SW_TWSI_EOP_TWSI_STAT),	final_read);
-}
-
-/* send STOP to the bus */
-static void octeon_i2c_stop(struct octeon_i2c *i2c)
-{
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
-			    TWSI_CTL_ENAB | TWSI_CTL_STP);
-}
-
-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 a negative errno.
- */
-static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
-{
-	int result;
-
-	if (i2c->broken_irq_mode) {
-		/*
-		 * Some cn38xx boards did not assert the irq in
-		 * the interrupt controller.  So we must poll for the
-		 * IFLG change.
-		 */
-		u64 end = get_jiffies_64() + i2c->adap.timeout;
-
-		while (!octeon_i2c_hlc_test_ready(i2c) &&
-		       time_before64(get_jiffies_64(), end))
-			udelay(50);
-
-		return octeon_i2c_hlc_test_ready(i2c) ? 0 : -ETIMEDOUT;
-	}
-
-	i2c->hlc_int_en(i2c);
-	result = wait_event_interruptible_timeout(i2c->queue,
-						  octeon_i2c_hlc_test_ready(i2c),
-						  i2c->adap.timeout);
-	i2c->hlc_int_dis(i2c);
-	if (!result)
-		octeon_i2c_hlc_int_clear(i2c);
-	if (result <= 0 && OCTEON_IS_MODEL(OCTEON_CN38XX) &&
-	    octeon_i2c_hlc_test_ready(i2c)) {
-		dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
-			i2c->broken_irq_mode = true;
-			return 0;
-	}
-
-	if (result < 0) {
-		dev_dbg(i2c->dev, "%s: wait interrupted\n", __func__);
-		return result;
-	} else if (!result) {
-		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
-		return -ETIMEDOUT;
-	}
-	return 0;
-}
-
-/* high-level-controller pure read of up to 8 bytes */
-static int octeon_i2c_simple_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
-	int i, j, ret = 0;
-	u64 cmd;
-
-	octeon_i2c_enable_hlc(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_A_SHIFT;
-
-	if (msgs[0].flags & I2C_M_TEN)
-		cmd |= SW_TWSI_OP_10;
-	else
-		cmd |= SW_TWSI_OP_7;
-
-	octeon_i2c_hlc_int_clear(i2c);
-	__raw_writeq(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_simple_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
-	int i, j, ret = 0;
-	u64 cmd;
-
-	octeon_i2c_enable_hlc(i2c);
-	octeon_i2c_hlc_int_clear(i2c);
-
-	ret = check_arb(i2c, false);
-	if (ret)
-		goto err;
-
-	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_A_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);
-		writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
-	}
-
-	writeqflush(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 = check_arb(i2c, false);
-
-err:
-	return ret;
-}
-
-/* high-level-controller composite write+read, msg0=addr, msg1=data */
-static int octeon_i2c_ia_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
-	int i, j, ret = 0;
-	u64 cmd;
-
-	octeon_i2c_enable_hlc(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_A_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;
-		__raw_writeq(ext, i2c->twsi_base + SW_TWSI_EXT);
-	} else
-		cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
-
-	octeon_i2c_hlc_int_clear(i2c);
-	writeqflush(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_ia_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
-	bool set_ext = false;
-	int i, j, ret = 0;
-	u64 cmd, ext = 0;
-
-	octeon_i2c_enable_hlc(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_A_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)
-		writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
-
-	octeon_i2c_hlc_int_clear(i2c);
-	writeqflush(cmd, i2c->twsi_base + SW_TWSI);
-
-	ret = octeon_i2c_hlc_wait(i2c);
-	if (ret)
-		goto err;
-
-	cmd = octeon_i2c_read_sw64(i2c, SW_TWSI_EOP_TWSI_STAT);
-	if ((cmd & SW_TWSI_R) == 0)
-		return -EAGAIN;
-	ret = octeon_i2c_lost_arb(cmd, false);
-
-err:
-	return ret;
-}
-
-/* calculate and set clock divisors */
-static void octeon_i2c_setclock(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_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp);
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
-}
-
-static int octeon_i2c_initlowlevel(struct octeon_i2c *i2c)
-{
-	u8 status = 0;
-	int tries;
-
-	/* reset controller */
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_RST, 0);
-
-	for (tries = 10; tries && status != STAT_IDLE; tries--) {
-		udelay(1);
-		status = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
-	}
-
-	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_enable_hlc(i2c);
-	octeon_i2c_disable_hlc(i2c);
-	return 0;
-}
-
-/*
- * TWSI state seems stuck. Not sure if it's TWSI-engine state or something
- * else on bus. The initial _stop() is always harmless, it just resets state
- * machine, does not _transmit_ STOP unless engine was active.
- */
-static int start_unstick(struct octeon_i2c *i2c)
-{
-	octeon_i2c_stop(i2c);
-
-	/*
-	 * Response is escalated over successive calls,
-	 * as EAGAIN provokes retries from i2c/core.
-	 */
-	switch (reset_how++ % 4) {
-	case 0:
-		/* just the stop above */
-		break;
-	case 1:
-		/*
-		 * Controller refused to send start flag. May be a
-		 * client is holding SDA low? Let's try to free it.
-		 */
-		octeon_i2c_unblock(i2c);
-		break;
-	case 2:
-		/* re-init our TWSI hardware */
-		octeon_i2c_initlowlevel(i2c);
-		break;
-	default:
-		/* retry in caller */
-		reset_how = 0;
-		return -EAGAIN;
-	}
-	return 0;
-}
-
-/**
- * octeon_i2c_start - send START to the bus
- * @i2c: The struct octeon_i2c
- * @first: first msg in combined operation?
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_start(struct octeon_i2c *i2c, int first)
-{
-	int result;
-	u8 data;
-
-	octeon_i2c_disable_hlc(i2c);
-
-	while (1) {
-		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
-				    TWSI_CTL_ENAB | TWSI_CTL_STA);
-
-		result = octeon_i2c_wait(i2c);
-		data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
-
-		switch (data) {
-		case STAT_START:
-		case STAT_RSTART:
-			if (!first)
-				return -EAGAIN;
-			reset_how = 0;
-			return 0;
-		case STAT_RXADDR_ACK:
-			if (first)
-				return -EAGAIN;
-			return start_unstick(i2c);
-		/*
-		 * case STAT_IDLE:
-		 * case STAT_ERROR:
-		 */
-		default:
-			if (!first)
-				return -EAGAIN;
-			start_unstick(i2c);
-		}
-	}
-	return 0;
-}
-
-/**
- * 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
- * @phase: which phase of a combined operation.
- * @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 first, bool last, bool recv_len)
-{
-	u8 ctl = TWSI_CTL_ENAB | TWSI_CTL_AAK;
-	int i, result, length = *rlength;
-	u8 tmp;
-
-	if (length < 1)
-		return -EINVAL;
-
-	result = octeon_i2c_start(i2c, first);
-	if (result)
-		return result;
-
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, (target << 1) | 1);
-
-	for (i = 0; i < length; ) {
-		tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
-		result = octeon_i2c_lost_arb(tmp, !(ctl & TWSI_CTL_AAK));
-		if (result)
-			return result;
-
-		switch (tmp) {
-		case STAT_RXDATA_ACK:
-		case STAT_RXDATA_NAK:
-			data[i++] = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_DATA);
-		}
-
-
-		/* NAK last recv'd byte, as a no-more-please */
-		if (last && i == length - 1)
-			ctl &= ~TWSI_CTL_AAK;
-
-		/* clr iflg to allow next event */
-		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, ctl);
-		result = octeon_i2c_wait(i2c);
-		if (result)
-			return result;
-		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 -EIO;
-			}
-			length += data[i];
-		}
-	}
-	*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
- * @last: is last msg in combined operation?
- *
- * 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 first, int last)
-{
-	int i, result;
-
-	result = octeon_i2c_start(i2c, first);
-	if (result)
-		return result;
-
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, target << 1);
-	octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
-
-	result = octeon_i2c_wait(i2c);
-	if (result)
-		return result;
-
-	for (i = 0; i < length; i++) {
-		result = check_arb(i2c, false);
-		if (result)
-			return result;
-
-		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, data[i]);
-		octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
-
-		result = octeon_i2c_wait(i2c);
-		if (result)
-			return result;
-		result = check_arb(i2c, false);
-		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_simple_read(i2c, msgs);
-			else
-				ret = octeon_i2c_simple_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_ia_read(i2c, msgs);
-			else
-				ret = octeon_i2c_ia_write(i2c, msgs);
-			goto out;
-		}
-	}
-
-	for (i = 0; ret == 0 && i < num; i++) {
-		struct i2c_msg *pmsg = &msgs[i];
-		bool last = (i == (num - 1));
-
-		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);
-		if (pmsg->flags & I2C_M_RD)
-			ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
-					      &pmsg->len, !i, last,
-					      pmsg->flags & I2C_M_RECV_LEN);
-		else
-			ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
-					       pmsg->len, !i, last);
-	}
-	octeon_i2c_stop(i2c);
-
-out:
-	return ret ? -EAGAIN : num;
-}
-
-static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
-{
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
-}
-
-static const struct i2c_algorithm octeon_i2c_algo = {
-	.master_xfer = octeon_i2c_xfer,
-	.functionality = octeon_i2c_functionality,
-};
-
-static struct i2c_adapter octeon_i2c_ops = {
-	.owner = THIS_MODULE,
-	.name = "OCTEON adapter",
-	.algo = &octeon_i2c_algo,
-};
-
-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;
-	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) {
-		result = -ENOMEM;
-		goto out;
-	}
-	i2c->dev = &pdev->dev;
-
-	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-
-	if (res_mem == NULL) {
-		dev_err(i2c->dev, "found no memory resource\n");
-		result = -ENXIO;
-		goto out;
-	}
-
-	/*
-	 * "clock-rate" is a legacy binding, the official binding is
-	 * "clock-frequency".  Try the official one first and then
-	 * fall back if it doesn't exist.
-	 */
-	if (of_property_read_u32(node, "clock-frequency", &i2c->twsi_freq) &&
-	    of_property_read_u32(node, "clock-rate", &i2c->twsi_freq)) {
-		dev_err(i2c->dev,
-			"no I2C 'clock-rate' or 'clock-frequency' property\n");
-		result = -ENXIO;
-		goto out;
-	}
-
-	i2c->sys_freq = octeon_get_io_clock_rate();
-
-	if (!devm_request_mem_region(&pdev->dev, res_mem->start,
-				     resource_size(res_mem), res_mem->name)) {
-		dev_err(i2c->dev, "request_mem_region failed\n");
-		goto out;
-	}
-	i2c->twsi_base = devm_ioremap(&pdev->dev, res_mem->start,
-				      resource_size(res_mem));
-
-	init_waitqueue_head(&i2c->queue);
-
-	i2c->irq = irq;
-
-	if (cn78xx_style) {
-		i2c->hlc_irq = hlc_irq;
-
-		i2c->int_en = octeon_i2c_int_enable78;
-		i2c->int_dis = octeon_i2c_int_disable78;
-		i2c->hlc_int_en = octeon_i2c_hlc_int_enable78;
-		i2c->hlc_int_dis = 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->irq,
-					  octeon_i2c_isr, 0, DRV_NAME, i2c);
-
-		if (result < 0) {
-			dev_err(i2c->dev, "failed to attach interrupt\n");
-			goto out;
-		}
-		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_en = octeon_i2c_int_enable;
-		i2c->int_dis = octeon_i2c_int_disable;
-		i2c->hlc_int_en = octeon_i2c_hlc_int_enable;
-		i2c->hlc_int_dis = octeon_i2c_int_disable;
-
-		result = devm_request_irq(&pdev->dev, i2c->irq,
-					  octeon_i2c_isr, 0, DRV_NAME, i2c);
-		if (result < 0) {
-			dev_err(i2c->dev, "failed to attach interrupt\n");
-			goto out;
-		}
-	}
-
-	result = octeon_i2c_initlowlevel(i2c);
-	if (result) {
-		dev_err(i2c->dev, "init low level failed\n");
-		goto  out;
-	}
-
-	octeon_i2c_setclock(i2c);
-
-	i2c->adap = octeon_i2c_ops;
-	i2c->adap.timeout = msecs_to_jiffies(timeout);
-	i2c->adap.retries = 10;
-	i2c->adap.dev.parent = &pdev->dev;
-	i2c->adap.dev.of_node = node;
-	i2c_set_adapdata(&i2c->adap, i2c);
-	platform_set_drvdata(pdev, i2c);
-
-	result = i2c_add_adapter(&i2c->adap);
-	if (result < 0) {
-		dev_err(i2c->dev, "failed to add adapter\n");
-		goto out;
-	}
-	dev_info(i2c->dev, "probed\n");
-	return 0;
-
-out:
-	return result;
-};
-
-static int octeon_i2c_remove(struct platform_device *pdev)
-{
-	struct octeon_i2c *i2c = platform_get_drvdata(pdev);
-
-	i2c_del_adapter(&i2c->adap);
-	return 0;
-};
-
-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);
-
-static struct platform_driver octeon_i2c_driver = {
-	.probe		= octeon_i2c_probe,
-	.remove		= octeon_i2c_remove,
-	.driver		= {
-		.name	= DRV_NAME,
-		.of_match_table = octeon_i2c_match,
-	},
-};
-
-module_platform_driver(octeon_i2c_driver);
-
-MODULE_AUTHOR("Michael Lawnick <michael.lawnick.ext@nsn.com>");
-MODULE_DESCRIPTION("I2C-Bus adapter for Cavium OCTEON processors");
-MODULE_LICENSE("GPL");
-- 
1.9.1

[PATCH v3 13/14] i2c-thunderx: Add i2c driver for ThunderX SOC

[Jan Glauber]

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 <jglauber@cavium.com>
---
 drivers/i2c/busses/Kconfig             |  10 ++
 drivers/i2c/busses/Makefile            |   2 +
 drivers/i2c/busses/i2c-cavium.h        |  17 ++-
 drivers/i2c/busses/i2c-thunderx-core.c | 266 +++++++++++++++++++++++++++++++++
 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 0299dfa..d1e7341 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 18f08b2..739a4d3 100644
--- a/drivers/i2c/busses/i2c-cavium.h
+++ b/drivers/i2c/busses/i2c-cavium.h
@@ -5,11 +5,18 @@
 #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
+#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)
@@ -84,6 +91,7 @@
 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;
@@ -99,6 +107,9 @@ struct octeon_i2c {
 	void (*hlc_int_dis)(struct octeon_i2c *);
 	atomic_t int_en_cnt;
 	atomic_t hlc_int_en_cnt;
+#if IS_ENABLED(CONFIG_I2C_THUNDERX)
+	struct msix_entry i2c_msix;
+#endif
 };
 
 static inline void writeqflush(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..8748d93
--- /dev/null
+++ b/drivers/i2c/busses/i2c-thunderx-core.c
@@ -0,0 +1,266 @@
+/*
+ * Cavium ThunderX i2c driver.
+ *
+ * Copyright (C) 2015,2016 Cavium Inc.
+ * Authors: Fred Martin <fmartin@caviumnetworks.com>
+ *	    Jan Glauber <jglauber@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)
+{
+	__raw_writeq(TWSI_INT_CORE_INT, i2c->twsi_base + TWSI_INT_ENA_W1S);
+	__raw_readq(i2c->twsi_base + TWSI_INT_ENA_W1S);
+}
+
+/*
+ * Disable the CORE interrupt.
+ */
+static void thunder_i2c_int_disable(struct octeon_i2c *i2c)
+{
+	__raw_writeq(TWSI_INT_CORE_INT, i2c->twsi_base + TWSI_INT_ENA_W1C);
+	__raw_readq(i2c->twsi_base + TWSI_INT_ENA_W1C);
+}
+
+static void thunder_i2c_hlc_int_enable(struct octeon_i2c *i2c)
+{
+	__raw_writeq(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
+		     i2c->twsi_base + TWSI_INT_ENA_W1S);
+	__raw_readq(i2c->twsi_base + TWSI_INT_ENA_W1S);
+}
+
+static void thunder_i2c_hlc_int_disable(struct octeon_i2c *i2c)
+{
+	__raw_writeq(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
+		     i2c->twsi_base + TWSI_INT_ENA_W1C);
+	__raw_readq(i2c->twsi_base + TWSI_INT_ENA_W1C);
+}
+
+static u32 thunderx_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+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_en = thunder_i2c_int_enable;
+	i2c->int_dis = thunder_i2c_int_disable;
+	i2c->hlc_int_en = thunder_i2c_hlc_int_enable;
+	i2c->hlc_int_dis = 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_initlowlevel(i2c);
+	if (ret) {
+		dev_err(dev, "Init low level failed\n");
+		goto out_msix;
+	}
+
+	octeon_i2c_setclock(i2c);
+
+	i2c->adap = thunderx_i2c_ops;
+	i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+	i2c->adap.timeout = HZ / 50;
+	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 <fmartin@caviumnetworks.com>");
+MODULE_DESCRIPTION("I2C-Bus adapter for Cavium ThunderX SOC");
-- 
1.9.1

[PATCH v3 14/14] i2c-thunderx: Add smbus support

[Jan Glauber]

Add smbus alert interrupt support.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/i2c/busses/i2c-cavium.h        |  5 +++++
 drivers/i2c/busses/i2c-thunderx-core.c | 35 ++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/drivers/i2c/busses/i2c-cavium.h b/drivers/i2c/busses/i2c-cavium.h
index 739a4d3..5b66cd5 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>
@@ -110,6 +111,10 @@ 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 writeqflush(u64 val, void __iomem *addr)
diff --git a/drivers/i2c/busses/i2c-thunderx-core.c b/drivers/i2c/busses/i2c-thunderx-core.c
index 8748d93..d50b5ec 100644
--- a/drivers/i2c/busses/i2c-thunderx-core.c
+++ b/drivers/i2c/busses/i2c-thunderx-core.c
@@ -9,10 +9,12 @@
 #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/pci.h>
+#include <linux/of_irq.h>
 
 #include "i2c-cavium.h"
 
@@ -107,6 +109,35 @@ 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)
 {
@@ -205,6 +236,9 @@ static int thunder_i2c_probe_pci(struct pci_dev *pdev,
 		goto out_irq;
 	}
 
+	ret = thunder_i2c_smbus_setup(i2c, node);
+	if (ret < 0)
+		dev_err(dev, "Failed to setup smbus alert\n");
 	dev_info(i2c->dev, "probed\n");
 	return 0;
 
@@ -235,6 +269,7 @@ 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