i2c-octeon and i2c-thunderx drivers

index 32914ab..4a08418 100644
@@ -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;

index 4a08418..03dd3d9 100644
@@ -2,7 +2,7 @@
  * (C) Copyright 2009-2010
  * Nokia Siemens Networks, [email protected]
  *
- * 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 <[email protected]>");
 MODULE_DESCRIPTION("I2C-Bus adapter for Cavium OCTEON processors");
 MODULE_LICENSE("GPL");
-MODULE_VERSION(DRV_VERSION);

index 03dd3d9..519e328 100644
@@ -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);
 

index 519e328..6041cd7 100644
@@ -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);

index 6041cd7..ef1720f 100644
@@ -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);

index ef1720f..8762473 100644
@@ -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;

index 8762473..b76ccd5 100644
@@ -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);

index b76ccd5..a8a56a0 100644
@@ -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)

index a8a56a0..afca316 100644
@@ -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) {

index afca316..6868802 100644
@@ -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;

828 lines not on this page · raw message

187 lines not on this page · raw message

304 lines not on this page · raw message

1,279 lines not on this page · raw message

index 18f08b2..739a4d3 100644
@@ -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)

266 lines not on this page · raw message

index 739a4d3..5b66cd5 100644
@@ -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)

index 8748d93..d50b5ec 100644
@@ -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);