i2c-octeon and i2c-thunderx drivers

index 4275007..471d06e 100644
@@ -55,13 +55,35 @@
 #define TWSI_CTL_IFLG		0x08	/* HW event, SW writes 0 to ACK */
 #define TWSI_CTL_AAK		0x04	/* Assert ACK */
 
-/* Some status values */
+/* Status values */
+#define STAT_ERROR		0x00
 #define STAT_START		0x08
-#define STAT_RSTART		0x10
+#define STAT_REP_START		0x10
 #define STAT_TXADDR_ACK		0x18
+#define STAT_TXADDR_NAK		0x20
 #define STAT_TXDATA_ACK		0x28
+#define STAT_TXDATA_NAK		0x30
+#define STAT_LOST_ARB_38	0x38
 #define STAT_RXADDR_ACK		0x40
+#define STAT_RXADDR_NAK		0x48
 #define STAT_RXDATA_ACK		0x50
+#define STAT_RXDATA_NAK		0x58
+#define STAT_SLAVE_60		0x60
+#define STAT_LOST_ARB_68	0x68
+#define STAT_SLAVE_70		0x70
+#define STAT_LOST_ARB_78	0x78
+#define STAT_SLAVE_80		0x80
+#define STAT_SLAVE_88		0x88
+#define STAT_GENDATA_ACK	0x90
+#define STAT_GENDATA_NAK	0x98
+#define STAT_SLAVE_A0		0xA0
+#define STAT_SLAVE_A8		0xA8
+#define STAT_LOST_ARB_B0	0xB0
+#define STAT_SLAVE_LOST		0xB8
+#define STAT_SLAVE_NAK		0xC0
+#define STAT_SLAVE_ACK		0xC8
+#define STAT_AD2W_ACK		0xD0
+#define STAT_AD2W_NAK		0xD8
 #define STAT_IDLE		0xF8
 
 /* TWSI_INT values */

@@ -225,6 +247,67 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 	return 0;
 }
 
+static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
+{
+	u8 stat = octeon_i2c_stat_read(i2c);
+
+	switch (stat) {
+	/* Everything is fine */
+	case STAT_IDLE:
+	case STAT_AD2W_ACK:
+	case STAT_RXADDR_ACK:
+	case STAT_TXADDR_ACK:
+	case STAT_TXDATA_ACK:
+		return 0;
+
+	/* ACK allowed on pre-terminal bytes only */
+	case STAT_RXDATA_ACK:
+		if (!final_read)
+			return 0;
+		return -EIO;
+
+	/* NAK allowed on terminal byte only */
+	case STAT_RXDATA_NAK:
+		if (final_read)
+			return 0;
+		return -EIO;
+
+	/* Arbitration lost */
+	case STAT_LOST_ARB_38:
+	case STAT_LOST_ARB_68:
+	case STAT_LOST_ARB_78:
+	case STAT_LOST_ARB_B0:
+		return -EAGAIN;
+
+	/* Being addressed as slave, should back off & listen */
+	case STAT_SLAVE_60:
+	case STAT_SLAVE_70:
+	case STAT_GENDATA_ACK:
+	case STAT_GENDATA_NAK:
+		return -EOPNOTSUPP;
+
+	/* Core busy as slave */
+	case STAT_SLAVE_80:
+	case STAT_SLAVE_88:
+	case STAT_SLAVE_A0:
+	case STAT_SLAVE_A8:
+	case STAT_SLAVE_LOST:
+	case STAT_SLAVE_NAK:
+	case STAT_SLAVE_ACK:
+		return -EOPNOTSUPP;
+
+	case STAT_TXDATA_NAK:
+		return -EIO;
+	case STAT_TXADDR_NAK:
+	case STAT_RXADDR_NAK:
+	case STAT_AD2W_NAK:
+		return -ENXIO;
+	default:
+		dev_err(i2c->dev, "unhandled state: %d\n", stat);
+		return -EIO;
+	}
+}
+
 /* calculate and set clock divisors */
 static void octeon_i2c_set_clock(struct octeon_i2c *i2c)
 {

@@ -318,7 +401,7 @@ static int octeon_i2c_start(struct octeon_i2c *i2c)
 	}
 
 	data = octeon_i2c_stat_read(i2c);
-	if ((data != STAT_START) && (data != STAT_RSTART)) {
+	if ((data != STAT_START) && (data != STAT_REP_START)) {
 		dev_err(i2c->dev, "%s: bad status (0x%x)\n", __func__, data);
 		return -EIO;
 	}

@@ -347,7 +430,6 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
 			    const u8 *data, int length)
 {
 	int i, result;
-	u8 tmp;
 
 	result = octeon_i2c_start(i2c);
 	if (result)

@@ -361,14 +443,9 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
 		return result;
 
 	for (i = 0; i < length; i++) {
-		tmp = octeon_i2c_stat_read(i2c);
-
-		if ((tmp != STAT_TXADDR_ACK) && (tmp != STAT_TXDATA_ACK)) {
-			dev_err(i2c->dev,
-				"%s: bad status before write (0x%x)\n",
-				__func__, tmp);
-			return -EIO;
-		}
+		result = octeon_i2c_check_status(i2c, false);
+		if (result)
+			return result;
 
 		octeon_i2c_data_write(i2c, data[i]);
 		octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);

@@ -397,7 +474,7 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 			   u8 *data, u16 *rlength, bool recv_len)
 {
 	int i, result, length = *rlength;
-	u8 tmp;
+	bool final_read = false;
 
 	if (length < 1)
 		return -EINVAL;

@@ -413,19 +490,21 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 	if (result)
 		return result;
 
+	/* address OK ? */
+	result = octeon_i2c_check_status(i2c, false);
+	if (result)
+		return result;
+
 	for (i = 0; i < length; i++) {
-		tmp = octeon_i2c_stat_read(i2c);
-		if ((tmp != STAT_RXDATA_ACK) && (tmp != STAT_RXADDR_ACK)) {
-			dev_err(i2c->dev,
-				"%s: bad status before read (0x%x)\n",
-				__func__, tmp);
-			return -EIO;
-		}
+		/* for the last byte TWSI_CTL_AAK must not be set */
+		if (i + 1 == length)
+			final_read = true;
 
-		if (i + 1 < length)
-			octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_AAK);
-		else
+		/* clear iflg to allow next event */
+		if (final_read)
 			octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+		else
+			octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_AAK);
 
 		result = octeon_i2c_wait(i2c);
 		if (result)

@@ -441,6 +520,10 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 			}
 			length += data[i];
 		}
+
+		result = octeon_i2c_check_status(i2c, final_read);
+		if (result)
+			return result;
 	}
 	*rlength = length;
 	return 0;

index 471d06e..0f536a1 100644
@@ -90,6 +90,8 @@
 #define TWSI_INT_CORE_EN	BIT_ULL(6)
 #define TWSI_INT_SDA_OVR	BIT_ULL(8)
 #define TWSI_INT_SCL_OVR	BIT_ULL(9)
+#define TWSI_INT_SDA		BIT_ULL(10)
+#define TWSI_INT_SCL		BIT_ULL(11)
 
 struct octeon_i2c {
 	wait_queue_head_t queue;

@@ -152,6 +154,18 @@ static u8 octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg)
 #define octeon_i2c_stat_read(i2c)					\
 	octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT)
 
+
+/**
+ * octeon_i2c_read_int - read the TWSI_INT register
+ * @i2c: The struct octeon_i2c
+ *
+ * Returns the value of the register.
+ */
+static u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
+{
+	return __raw_readq(i2c->twsi_base + TWSI_INT);
+}
+
 /**
  * octeon_i2c_write_int - write the TWSI_INT register
  * @i2c: The struct octeon_i2c

@@ -182,33 +196,6 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
 	octeon_i2c_write_int(i2c, 0);
 }
 
-/**
- * octeon_i2c_unblock - unblock the bus
- * @i2c: The struct octeon_i2c
- *
- * If there was a reset while a device was driving 0 to bus, bus is blocked.
- * We toggle it free manually by some clock cycles and send a stop.
- */
-static void octeon_i2c_unblock(struct octeon_i2c *i2c)
-{
-	int i;
-
-	dev_dbg(i2c->dev, "%s\n", __func__);
-
-	for (i = 0; i < 9; i++) {
-		octeon_i2c_write_int(i2c, 0);
-		udelay(5);
-		octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
-		udelay(5);
-	}
-	/* hand-crank a STOP */
-	octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR | TWSI_INT_SCL_OVR);
-	udelay(5);
-	octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR);
-	udelay(5);
-	octeon_i2c_write_int(i2c, 0);
-}
-
 /* interrupt service routine */
 static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
 {

@@ -371,6 +358,17 @@ static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
 	return -EIO;
 }
 
+static int octeon_i2c_recovery(struct octeon_i2c *i2c)
+{
+	int ret;
+
+	ret = i2c_recover_bus(&i2c->adap);
+	if (ret)
+		/* recover failed, try hardware re-init */
+		ret = octeon_i2c_init_lowlevel(i2c);
+	return ret;
+}
+
 /**
  * octeon_i2c_start - send START to the bus
  * @i2c: The struct octeon_i2c

@@ -379,34 +377,23 @@ static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
  */
 static int octeon_i2c_start(struct octeon_i2c *i2c)
 {
-	int result;
-	u8 data;
+	int ret;
+	u8 stat;
 
 	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
+	ret = octeon_i2c_wait(i2c);
+	if (ret)
+		goto error;
 
-	result = octeon_i2c_wait(i2c);
-	if (result) {
-		if (octeon_i2c_stat_read(i2c) == STAT_IDLE) {
-			/*
-			 * Controller refused to send start flag May
-			 * be a client is holding SDA low - let's try
-			 * to free it.
-			 */
-			octeon_i2c_unblock(i2c);
-			octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
-			result = octeon_i2c_wait(i2c);
-		}
-		if (result)
-			return result;
-	}
-
-	data = octeon_i2c_stat_read(i2c);
-	if ((data != STAT_START) && (data != STAT_REP_START)) {
-		dev_err(i2c->dev, "%s: bad status (0x%x)\n", __func__, data);
-		return -EIO;
-	}
+	stat = octeon_i2c_stat_read(i2c);
+	if (stat == STAT_START || stat == STAT_REP_START)
+		/* START successful, bail out */
+		return 0;
 
-	return 0;
+error:
+	/* START failed, try to recover */
+	ret = octeon_i2c_recovery(i2c);
+	return (ret) ? ret : -EAGAIN;
 }
 
 /* send STOP to the bus */

@@ -431,10 +418,6 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
 {
 	int i, result;
 
-	result = octeon_i2c_start(i2c);
-	if (result)
-		return result;
-
 	octeon_i2c_data_write(i2c, target << 1);
 	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
 

@@ -479,10 +462,6 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 	if (length < 1)
 		return -EINVAL;
 
-	result = octeon_i2c_start(i2c);
-	if (result)
-		return result;
-
 	octeon_i2c_data_write(i2c, (target << 1) | 1);
 	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
 

@@ -546,10 +525,10 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	for (i = 0; ret == 0 && i < num; i++) {
 		struct i2c_msg *pmsg = &msgs[i];
 
-		dev_dbg(i2c->dev,
-			"Doing %s %d byte(s) to/from 0x%02x - %d of %d messages\n",
-			 pmsg->flags & I2C_M_RD ? "read" : "write",
-			 pmsg->len, pmsg->addr, i + 1, num);
+		ret = octeon_i2c_start(i2c);
+		if (ret)
+			return ret;
+
 		if (pmsg->flags & I2C_M_RD)
 			ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
 					      &pmsg->len, pmsg->flags & I2C_M_RECV_LEN);

@@ -562,6 +541,60 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	return (ret != 0) ? ret : num;
 }
 
+static int octeon_i2c_get_scl(struct i2c_adapter *adap)
+{
+	struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+	u64 state;
+
+	state = octeon_i2c_read_int(i2c);
+	return state & TWSI_INT_SCL;
+}
+
+static void octeon_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+	struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+	octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
+}
+
+static int octeon_i2c_get_sda(struct i2c_adapter *adap)
+{
+	struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+	u64 state;
+
+	state = octeon_i2c_read_int(i2c);
+	return state & TWSI_INT_SDA;
+}
+
+static void octeon_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+	struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+	/*
+	 * The stop resets the state machine, does not _transmit_ STOP unless
+	 * engine was active.
+	 */
+	octeon_i2c_stop(i2c);
+
+	octeon_i2c_write_int(i2c, 0);
+}
+
+static void octeon_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+	struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+	octeon_i2c_write_int(i2c, 0);
+}
+
+static struct i2c_bus_recovery_info octeon_i2c_recovery_info = {
+	.recover_bus = i2c_generic_scl_recovery,
+	.get_scl = octeon_i2c_get_scl,
+	.set_scl = octeon_i2c_set_scl,
+	.get_sda = octeon_i2c_get_sda,
+	.prepare_recovery = octeon_i2c_prepare_recovery,
+	.unprepare_recovery = octeon_i2c_unprepare_recovery,
+};
+
 static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
 {
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |

@@ -642,6 +675,7 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 	i2c->adap = octeon_i2c_ops;
 	i2c->adap.timeout = msecs_to_jiffies(2);
 	i2c->adap.retries = 5;
+	i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
 	i2c->adap.dev.parent = &pdev->dev;
 	i2c->adap.dev.of_node = node;
 	i2c_set_adapdata(&i2c->adap, i2c);

index 0f536a1..ad563cf 100644
@@ -459,9 +459,6 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 	int i, result, length = *rlength;
 	bool final_read = false;
 
-	if (length < 1)
-		return -EINVAL;
-
 	octeon_i2c_data_write(i2c, (target << 1) | 1);
 	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
 

@@ -597,7 +594,7 @@ static struct i2c_bus_recovery_info octeon_i2c_recovery_info = {
 
 static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
 	       I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
 }
 

index 9f11e19..e8a65f5 100644
@@ -837,9 +837,6 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 	int i, result, length = *rlength;
 	bool final_read = false;
 
-	if (length < 1)
-		return -EINVAL;
-
 	octeon_i2c_data_write(i2c, (target << 1) | 1);
 	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
 

@@ -925,6 +922,12 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	for (i = 0; ret == 0 && i < num; i++) {
 		struct i2c_msg *pmsg = &msgs[i];
 
+		/* zero-length messages are not supported */
+		if (!pmsg->len) {
+			ret = -EOPNOTSUPP;
+			break;
+		}
+
 		ret = octeon_i2c_start(i2c);
 		if (ret)
 			return ret;

@@ -998,7 +1001,7 @@ static struct i2c_bus_recovery_info octeon_i2c_recovery_info = {
 
 static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
 	       I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
 }
 

index ad563cf..60a02b2 100644
@@ -103,6 +103,12 @@ struct octeon_i2c {
 	struct device *dev;
 };
 
+static void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
+{
+	__raw_writeq(val, addr);
+	__raw_readq(addr);	/* wait for write to land */
+}
+
 /**
  * octeon_i2c_reg_write - write an I2C core register
  * @i2c: The struct octeon_i2c

@@ -173,8 +179,7 @@ static u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
  */
 static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
 {
-	__raw_writeq(data, i2c->twsi_base + TWSI_INT);
-	__raw_readq(i2c->twsi_base + TWSI_INT);
+	octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT);
 }
 
 /**

index 60a02b2..9520f78 100644
@@ -29,13 +29,23 @@
 /* Register offsets */
 #define SW_TWSI			0x00
 #define TWSI_INT		0x10
+#define SW_TWSI_EXT		0x18
 
 /* Controller command patterns */
 #define SW_TWSI_V		BIT_ULL(63)	/* Valid bit */
+#define SW_TWSI_EIA		BIT_ULL(61)	/* Extended internal address */
 #define SW_TWSI_R		BIT_ULL(56)	/* Result or read bit */
+#define SW_TWSI_SOVR		BIT_ULL(55)	/* Size override */
+#define SW_TWSI_SIZE_SHIFT	52
+#define SW_TWSI_ADDR_SHIFT	40
+#define SW_TWSI_IA_SHIFT	32		/* Internal address */
 
 /* Controller opcode word (bits 60:57) */
 #define SW_TWSI_OP_SHIFT	57
+#define SW_TWSI_OP_7		(0ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_7_IA		(1ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_10		(2ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_10_IA	(3ULL << SW_TWSI_OP_SHIFT)
 #define SW_TWSI_OP_TWSI_CLK	(4ULL << SW_TWSI_OP_SHIFT)
 #define SW_TWSI_OP_EOP		(6ULL << SW_TWSI_OP_SHIFT) /* Extended opcode */
 

@@ -48,7 +58,7 @@
 #define SW_TWSI_EOP_TWSI_RST	(SW_TWSI_OP_EOP | 7ULL << SW_TWSI_EOP_SHIFT)
 
 /* Controller command and status bits */
-#define TWSI_CTL_CE		0x80
+#define TWSI_CTL_CE		0x80	/* High level controller enable */
 #define TWSI_CTL_ENAB		0x40	/* Bus enable */
 #define TWSI_CTL_STA		0x20	/* Master-mode start, HW clears when done */
 #define TWSI_CTL_STP		0x10	/* Master-mode stop, HW clears when done */

@@ -87,6 +97,11 @@
 #define STAT_IDLE		0xF8
 
 /* TWSI_INT values */
+#define TWSI_INT_ST_INT		BIT_ULL(0)
+#define TWSI_INT_TS_INT		BIT_ULL(1)
+#define TWSI_INT_CORE_INT	BIT_ULL(2)
+#define TWSI_INT_ST_EN		BIT_ULL(4)
+#define TWSI_INT_TS_EN		BIT_ULL(5)
 #define TWSI_INT_CORE_EN	BIT_ULL(6)
 #define TWSI_INT_SDA_OVR	BIT_ULL(8)
 #define TWSI_INT_SCL_OVR	BIT_ULL(9)

@@ -101,6 +116,7 @@ struct octeon_i2c {
 	int sys_freq;
 	void __iomem *twsi_base;
 	struct device *dev;
+	bool hlc_enabled;
 };
 
 static void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)

@@ -201,6 +217,47 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
 	octeon_i2c_write_int(i2c, 0);
 }
 
+/*
+ * Cleanup low-level state & enable high-level controller.
+ */
+static void octeon_i2c_hlc_enable(struct octeon_i2c *i2c)
+{
+	int try = 0;
+	u64 val;
+
+	if (i2c->hlc_enabled)
+		return;
+	i2c->hlc_enabled = true;
+
+	while (1) {
+		val = octeon_i2c_ctl_read(i2c);
+		if (!(val & (TWSI_CTL_STA | TWSI_CTL_STP)))
+			break;
+
+		/* clear IFLG event */
+		if (val & TWSI_CTL_IFLG)
+			octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+
+		if (try++ > 100) {
+			pr_err("%s: giving up\n", __func__);
+			break;
+		}
+
+		/* spin until any start/stop has finished */
+		udelay(10);
+	}
+	octeon_i2c_ctl_write(i2c, TWSI_CTL_CE | TWSI_CTL_AAK | TWSI_CTL_ENAB);
+}
+
+static void octeon_i2c_hlc_disable(struct octeon_i2c *i2c)
+{
+	if (!i2c->hlc_enabled)
+		return;
+
+	i2c->hlc_enabled = false;
+	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+}
+
 /* interrupt service routine */
 static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
 {

@@ -300,6 +357,243 @@ static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
 	}
 }
 
+static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c)
+{
+	u64 val = __raw_readq(i2c->twsi_base + SW_TWSI);
+
+	return (val & SW_TWSI_V) == 0;
+}
+
+static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
+{
+	octeon_i2c_write_int(i2c, TWSI_INT_ST_EN);
+}
+
+static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
+{
+	/* clear ST/TS events, listen for neither */
+	octeon_i2c_write_int(i2c, TWSI_INT_ST_INT | TWSI_INT_TS_INT);
+}
+
+/**
+ * octeon_i2c_hlc_wait - wait for an HLC operation to complete
+ * @i2c: The struct octeon_i2c
+ *
+ * Returns 0 on success, otherwise -ETIMEDOUT.
+ */
+static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
+{
+	int time_left;
+
+	octeon_i2c_hlc_int_enable(i2c);
+	time_left = wait_event_timeout(i2c->queue,
+				       octeon_i2c_hlc_test_ready(i2c),
+				       i2c->adap.timeout);
+	octeon_i2c_int_disable(i2c);
+	if (!time_left) {
+		octeon_i2c_hlc_int_clear(i2c);
+		return -ETIMEDOUT;
+	}
+	return 0;
+}
+
+/* high-level-controller pure read of up to 8 bytes */
+static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	int i, j, ret = 0;
+	u64 cmd;
+
+	octeon_i2c_hlc_enable(i2c);
+	octeon_i2c_hlc_int_clear(i2c);
+
+	cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
+	/* SIZE */
+	cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
+	/* A */
+	cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+	if (msgs[0].flags & I2C_M_TEN)
+		cmd |= SW_TWSI_OP_10;
+	else
+		cmd |= SW_TWSI_OP_7;
+
+	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+	ret = octeon_i2c_hlc_wait(i2c);
+	if (ret)
+		goto err;
+
+	cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+	if ((cmd & SW_TWSI_R) == 0)
+		return -EAGAIN;
+
+	for (i = 0, j = msgs[0].len - 1; i  < msgs[0].len && i < 4; i++, j--)
+		msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
+
+	if (msgs[0].len > 4) {
+		cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+		for (i = 0; i  < msgs[0].len - 4 && i < 4; i++, j--)
+			msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
+	}
+
+err:
+	return ret;
+}
+
+/* high-level-controller pure write of up to 8 bytes */
+static int octeon_i2c_hlc_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	int i, j, ret = 0;
+	u64 cmd;
+
+	octeon_i2c_hlc_enable(i2c);
+	octeon_i2c_hlc_int_clear(i2c);
+
+	cmd = SW_TWSI_V | SW_TWSI_SOVR;
+	/* SIZE */
+	cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
+	/* A */
+	cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+	if (msgs[0].flags & I2C_M_TEN)
+		cmd |= SW_TWSI_OP_10;
+	else
+		cmd |= SW_TWSI_OP_7;
+
+	for (i = 0, j = msgs[0].len - 1; i  < msgs[0].len && i < 4; i++, j--)
+		cmd |= (u64)msgs[0].buf[j] << (8 * i);
+
+	if (msgs[0].len > 4) {
+		u64 ext = 0;
+
+		for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
+			ext |= (u64) msgs[0].buf[j] << (8 * i);
+		octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+	}
+
+	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+	ret = octeon_i2c_hlc_wait(i2c);
+	if (ret)
+		goto err;
+
+	cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+	if ((cmd & SW_TWSI_R) == 0)
+		return -EAGAIN;
+
+	ret = octeon_i2c_check_status(i2c, false);
+
+err:
+	return ret;
+}
+
+/* high-level-controller composite write+read, msg0=addr, msg1=data */
+static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	int i, j, ret = 0;
+	u64 cmd;
+
+	octeon_i2c_hlc_enable(i2c);
+
+	cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
+	/* SIZE */
+	cmd |= (u64)(msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
+	/* A */
+	cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+	if (msgs[0].flags & I2C_M_TEN)
+		cmd |= SW_TWSI_OP_10_IA;
+	else
+		cmd |= SW_TWSI_OP_7_IA;
+
+	if (msgs[0].len == 2) {
+		u64 ext = 0;
+
+		cmd |= SW_TWSI_EIA;
+		ext = (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+		cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
+		octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+	} else
+		cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+
+	octeon_i2c_hlc_int_clear(i2c);
+	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+
+	ret = octeon_i2c_hlc_wait(i2c);
+	if (ret)
+		goto err;
+
+	cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+	if ((cmd & SW_TWSI_R) == 0)
+		return -EAGAIN;
+
+	for (i = 0, j = msgs[1].len - 1; i  < msgs[1].len && i < 4; i++, j--)
+		msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
+
+	if (msgs[1].len > 4) {
+		cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+		for (i = 0; i  < msgs[1].len - 4 && i < 4; i++, j--)
+			msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
+	}
+
+err:
+	return ret;
+}
+
+/* high-level-controller composite write+write, m[0]len<=2, m[1]len<=8 */
+static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+	bool set_ext = false;
+	int i, j, ret = 0;
+	u64 cmd, ext = 0;
+
+	octeon_i2c_hlc_enable(i2c);
+
+	cmd = SW_TWSI_V | SW_TWSI_SOVR;
+	/* SIZE */
+	cmd |= (u64) (msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
+	/* A */
+	cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+	if (msgs[0].flags & I2C_M_TEN)
+		cmd |= SW_TWSI_OP_10_IA;
+	else
+		cmd |= SW_TWSI_OP_7_IA;
+
+	if (msgs[0].len == 2) {
+		cmd |= SW_TWSI_EIA;
+		ext |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+		set_ext = true;
+		cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
+	} else
+		cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+
+	for (i = 0, j = msgs[1].len - 1; i  < msgs[1].len && i < 4; i++, j--)
+		cmd |= (u64) msgs[1].buf[j] << (8 * i);
+
+	if (msgs[1].len > 4) {
+		for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
+			ext |= (u64)msgs[1].buf[j] << (8 * i);
+		set_ext = true;
+	}
+	if (set_ext)
+		octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+
+	octeon_i2c_hlc_int_clear(i2c);
+	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+
+	ret = octeon_i2c_hlc_wait(i2c);
+	if (ret)
+		goto err;
+
+	cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+	if ((cmd & SW_TWSI_R) == 0)
+		return -EAGAIN;
+
+	ret = octeon_i2c_check_status(i2c, false);
+
+err:
+	return ret;
+}
+
 /* calculate and set clock divisors */
 static void octeon_i2c_set_clock(struct octeon_i2c *i2c)
 {

@@ -344,23 +638,29 @@ static void octeon_i2c_set_clock(struct octeon_i2c *i2c)
 
 static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
 {
-	u8 status;
+	u8 status = 0;
 	int tries;
 
-	/* disable high level controller, enable bus access */
-	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
-
 	/* reset controller */
 	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_RST, 0);
 
-	for (tries = 10; tries; tries--) {
+	for (tries = 10; tries && status != STAT_IDLE; tries--) {
 		udelay(1);
 		status = octeon_i2c_stat_read(i2c);
 		if (status == STAT_IDLE)
-			return 0;
+			break;
 	}
-	dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n", __func__, status);
-	return -EIO;
+
+	if (status != STAT_IDLE) {
+		dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n",
+			__func__, status);
+		return -EIO;
+	}
+
+	/* toggle twice to force both teardowns */
+	octeon_i2c_hlc_enable(i2c);
+	octeon_i2c_hlc_disable(i2c);
+	return 0;
 }
 
 static int octeon_i2c_recovery(struct octeon_i2c *i2c)

@@ -385,6 +685,8 @@ static int octeon_i2c_start(struct octeon_i2c *i2c)
 	int ret;
 	u8 stat;
 
+	octeon_i2c_hlc_disable(i2c);
+
 	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
 	ret = octeon_i2c_wait(i2c);
 	if (ret)

@@ -524,6 +826,28 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	struct octeon_i2c *i2c = i2c_get_adapdata(adap);
 	int i, ret = 0;
 
+	if (num == 1) {
+		if (msgs[0].len > 0 && msgs[0].len <= 8) {
+			if (msgs[0].flags & I2C_M_RD)
+				ret = octeon_i2c_hlc_read(i2c, msgs);
+			else
+				ret = octeon_i2c_hlc_write(i2c, msgs);
+			goto out;
+		}
+	} else if (num == 2) {
+		if ((msgs[0].flags & I2C_M_RD) == 0 &&
+		    (msgs[1].flags & I2C_M_RECV_LEN) == 0 &&
+		    msgs[0].len > 0 && msgs[0].len <= 2 &&
+		    msgs[1].len > 0 && msgs[1].len <= 8 &&
+		    msgs[0].addr == msgs[1].addr) {
+			if (msgs[1].flags & I2C_M_RD)
+				ret = octeon_i2c_hlc_comp_read(i2c, msgs);
+			else
+				ret = octeon_i2c_hlc_comp_write(i2c, msgs);
+			goto out;
+		}
+	}
+
 	for (i = 0; ret == 0 && i < num; i++) {
 		struct i2c_msg *pmsg = &msgs[i];
 

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

@@ -578,6 +902,7 @@ static void octeon_i2c_prepare_recovery(struct i2c_adapter *adap)
 	 */
 	octeon_i2c_stop(i2c);
 
+	octeon_i2c_hlc_disable(i2c);
 	octeon_i2c_write_int(i2c, 0);
 }
 

index 9520f78..76fa479 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>

@@ -112,11 +113,18 @@ struct octeon_i2c {
 	wait_queue_head_t queue;
 	struct i2c_adapter adap;
 	int irq;
+	int hlc_irq;		/* For cn7890 only */
 	u32 twsi_freq;
 	int sys_freq;
 	void __iomem *twsi_base;
 	struct device *dev;
 	bool hlc_enabled;
+	void (*int_enable)(struct octeon_i2c *);
+	void (*int_disable)(struct octeon_i2c *);
+	void (*hlc_int_enable)(struct octeon_i2c *);
+	void (*hlc_int_disable)(struct octeon_i2c *);
+	atomic_t int_enable_cnt;
+	atomic_t hlc_int_enable_cnt;
 };
 
 static void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)

@@ -217,6 +225,58 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
 	octeon_i2c_write_int(i2c, 0);
 }
 
+/**
+ * octeon_i2c_int_enable78 - enable the CORE interrupt
+ * @i2c: The struct octeon_i2c
+ *
+ * The interrupt will be asserted when there is non-STAT_IDLE state in the
+ * SW_TWSI_EOP_TWSI_STAT register.
+ */
+static void octeon_i2c_int_enable78(struct octeon_i2c *i2c)
+{
+	atomic_inc_return(&i2c->int_enable_cnt);
+	enable_irq(i2c->irq);
+}
+
+static void __octeon_i2c_irq_disable(atomic_t *cnt, int irq)
+{
+	int count;
+
+	/*
+	 * The interrupt can be disabled in two places, but we only
+	 * want to make the disable_irq_nosync() call once, so keep
+	 * track with the atomic variable.
+	 */
+	count = atomic_dec_if_positive(cnt);
+	if (count >= 0)
+		disable_irq_nosync(irq);
+}
+
+/* disable the CORE interrupt */
+static void octeon_i2c_int_disable78(struct octeon_i2c *i2c)
+{
+	__octeon_i2c_irq_disable(&i2c->int_enable_cnt, i2c->irq);
+}
+
+/**
+ * octeon_i2c_hlc_int_enable78 - enable the ST interrupt
+ * @i2c: The struct octeon_i2c
+ *
+ * The interrupt will be asserted when there is non-STAT_IDLE state in
+ * the SW_TWSI_EOP_TWSI_STAT register.
+ */
+static void octeon_i2c_hlc_int_enable78(struct octeon_i2c *i2c)
+{
+	atomic_inc_return(&i2c->hlc_int_enable_cnt);
+	enable_irq(i2c->hlc_irq);
+}
+
+/* disable the ST interrupt */
+static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c)
+{
+	__octeon_i2c_irq_disable(&i2c->hlc_int_enable_cnt, i2c->hlc_irq);
+}
+
 /*
  * Cleanup low-level state & enable high-level controller.
  */

@@ -263,7 +323,18 @@ static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
 {
 	struct octeon_i2c *i2c = dev_id;
 
-	octeon_i2c_int_disable(i2c);
+	i2c->int_disable(i2c);
+	wake_up(&i2c->queue);
+
+	return IRQ_HANDLED;
+}
+
+/* HLC interrupt service routine */
+static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
+{
+	struct octeon_i2c *i2c = dev_id;
+
+	i2c->hlc_int_disable(i2c);
 	wake_up(&i2c->queue);
 
 	return IRQ_HANDLED;

@@ -284,10 +355,10 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 {
 	long time_left;
 
-	octeon_i2c_int_enable(i2c);
+	i2c->int_enable(i2c);
 	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
 				       i2c->adap.timeout);
-	octeon_i2c_int_disable(i2c);
+	i2c->int_disable(i2c);
 	if (!time_left) {
 		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
 		return -ETIMEDOUT;

@@ -385,11 +456,11 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
 {
 	int time_left;
 
-	octeon_i2c_hlc_int_enable(i2c);
+	i2c->hlc_int_enable(i2c);
 	time_left = wait_event_timeout(i2c->queue,
 				       octeon_i2c_hlc_test_ready(i2c),
 				       i2c->adap.timeout);
-	octeon_i2c_int_disable(i2c);
+	i2c->hlc_int_disable(i2c);
 	if (!time_left) {
 		octeon_i2c_hlc_int_clear(i2c);
 		return -ETIMEDOUT;

@@ -942,14 +1013,26 @@ static struct i2c_adapter octeon_i2c_ops = {
 static int octeon_i2c_probe(struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
+	int irq, result = 0, hlc_irq = 0;
 	struct resource *res_mem;
 	struct octeon_i2c *i2c;
-	int irq, result = 0;
-
-	/* All adaptors have an irq.  */
-	irq = platform_get_irq(pdev, 0);
-	if (irq < 0)
-		return irq;
+	bool cn78xx_style;
+
+	cn78xx_style = of_device_is_compatible(node, "cavium,octeon-7890-twsi");
+	if (cn78xx_style) {
+		hlc_irq = platform_get_irq(pdev, 0);
+		if (hlc_irq < 0)
+			return hlc_irq;
+
+		irq = platform_get_irq(pdev, 2);
+		if (irq < 0)
+			return irq;
+	} else {
+		/* All adaptors have an irq.  */
+		irq = platform_get_irq(pdev, 0);
+		if (irq < 0)
+			return irq;
+	}
 
 	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
 	if (!i2c) {

@@ -984,6 +1067,31 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 
 	i2c->irq = irq;
 
+	if (cn78xx_style) {
+		i2c->hlc_irq = hlc_irq;
+
+		i2c->int_enable = octeon_i2c_int_enable78;
+		i2c->int_disable = octeon_i2c_int_disable78;
+		i2c->hlc_int_enable = octeon_i2c_hlc_int_enable78;
+		i2c->hlc_int_disable = octeon_i2c_hlc_int_disable78;
+
+		irq_set_status_flags(i2c->irq, IRQ_NOAUTOEN);
+		irq_set_status_flags(i2c->hlc_irq, IRQ_NOAUTOEN);
+
+		result = devm_request_irq(&pdev->dev, i2c->hlc_irq,
+					  octeon_i2c_hlc_isr78, 0,
+					  DRV_NAME, i2c);
+		if (result < 0) {
+			dev_err(i2c->dev, "failed to attach interrupt\n");
+			goto out;
+		}
+	} else {
+		i2c->int_enable = octeon_i2c_int_enable;
+		i2c->int_disable = octeon_i2c_int_disable;
+		i2c->hlc_int_enable = octeon_i2c_hlc_int_enable;
+		i2c->hlc_int_disable = octeon_i2c_int_disable;
+	}
+
 	result = devm_request_irq(&pdev->dev, i2c->irq,
 				  octeon_i2c_isr, 0, DRV_NAME, i2c);
 	if (result < 0) {

@@ -1030,6 +1138,7 @@ static int octeon_i2c_remove(struct platform_device *pdev)
 
 static const struct of_device_id octeon_i2c_match[] = {
 	{ .compatible = "cavium,octeon-3860-twsi", },
+	{ .compatible = "cavium,octeon-7890-twsi", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, octeon_i2c_match);

index 76fa479..3144fe9 100644
@@ -109,6 +109,8 @@
 #define TWSI_INT_SDA		BIT_ULL(10)
 #define TWSI_INT_SCL		BIT_ULL(11)
 
+#define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */
+
 struct octeon_i2c {
 	wait_queue_head_t queue;
 	struct i2c_adapter adap;

@@ -340,11 +342,29 @@ static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
+static bool octeon_i2c_test_iflg(struct octeon_i2c *i2c)
 {
 	return (octeon_i2c_ctl_read(i2c) & TWSI_CTL_IFLG);
 }
 
+static bool octeon_i2c_test_ready(struct octeon_i2c *i2c, bool *first)
+{
+	if (octeon_i2c_test_iflg(i2c))
+		return true;
+
+	if (*first) {
+		*first = false;
+		return false;
+	}
+
+	/*
+	 * IRQ has signaled an event but IFLG hasn't changed.
+	 * Sleep and retry once.
+	 */
+	usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+	return octeon_i2c_test_iflg(i2c);
+}
+
 /**
  * octeon_i2c_wait - wait for the IFLG to be set
  * @i2c: The struct octeon_i2c

@@ -354,15 +374,14 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
 static int octeon_i2c_wait(struct octeon_i2c *i2c)
 {
 	long time_left;
+	bool first = 1;
 
 	i2c->int_enable(i2c);
-	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
+	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
 				       i2c->adap.timeout);
 	i2c->int_disable(i2c);
-	if (!time_left) {
-		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
+	if (!time_left)
 		return -ETIMEDOUT;
-	}
 
 	return 0;
 }

@@ -428,11 +447,28 @@ static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
 	}
 }
 
-static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c)
+static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c)
+{
+	return (__raw_readq(i2c->twsi_base + SW_TWSI) & SW_TWSI_V) == 0;
+}
+
+static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c, bool *first)
 {
-	u64 val = __raw_readq(i2c->twsi_base + SW_TWSI);
+	/* check if valid bit is cleared */
+	if (octeon_i2c_hlc_test_valid(i2c))
+		return true;
 
-	return (val & SW_TWSI_V) == 0;
+	if (*first) {
+		*first = false;
+		return false;
+	}
+
+	/*
+	 * IRQ has signaled an event but valid bit isn't cleared.
+	 * Sleep and retry once.
+	 */
+	usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+	return octeon_i2c_hlc_test_valid(i2c);
 }
 
 static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)

@@ -454,11 +490,12 @@ static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
  */
 static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
 {
+	bool first = 1;
 	int time_left;
 
 	i2c->hlc_int_enable(i2c);
 	time_left = wait_event_timeout(i2c->queue,
-				       octeon_i2c_hlc_test_ready(i2c),
+				       octeon_i2c_hlc_test_ready(i2c, &first),
 				       i2c->adap.timeout);
 	i2c->hlc_int_disable(i2c);
 	if (!time_left) {

index 3144fe9..009cc33 100644
@@ -121,6 +121,8 @@ struct octeon_i2c {
 	void __iomem *twsi_base;
 	struct device *dev;
 	bool hlc_enabled;
+	bool broken_irq_mode;
+	bool broken_irq_check;
 	void (*int_enable)(struct octeon_i2c *);
 	void (*int_disable)(struct octeon_i2c *);
 	void (*hlc_int_enable)(struct octeon_i2c *);

@@ -376,10 +378,32 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 	long time_left;
 	bool first = 1;
 
+	/*
+	 * Some chip revisions don't assert the irq in the interrupt
+	 * controller. So we must poll for the IFLG change.
+	 */
+	if (i2c->broken_irq_mode) {
+		u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+		while (!octeon_i2c_test_iflg(i2c) &&
+		       time_before64(get_jiffies_64(), end))
+			udelay(50);
+
+		return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
+	}
+
 	i2c->int_enable(i2c);
 	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
 				       i2c->adap.timeout);
 	i2c->int_disable(i2c);
+
+	if (i2c->broken_irq_check && !time_left &&
+	    octeon_i2c_test_iflg(i2c)) {
+		dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+		i2c->broken_irq_mode = true;
+		return 0;
+	}
+
 	if (!time_left)
 		return -ETIMEDOUT;
 

@@ -493,15 +517,37 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
 	bool first = 1;
 	int time_left;
 
+	/*
+	 * Some cn38xx boards don't assert the irq in the interrupt
+	 * controller. So we must poll for the valid bit change.
+	 */
+	if (i2c->broken_irq_mode) {
+		u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+		while (!octeon_i2c_hlc_test_valid(i2c) &&
+		       time_before64(get_jiffies_64(), end))
+			udelay(50);
+
+		return octeon_i2c_hlc_test_valid(i2c) ? 0 : -ETIMEDOUT;
+	}
+
 	i2c->hlc_int_enable(i2c);
 	time_left = wait_event_timeout(i2c->queue,
 				       octeon_i2c_hlc_test_ready(i2c, &first),
 				       i2c->adap.timeout);
 	i2c->hlc_int_disable(i2c);
-	if (!time_left) {
+	if (!time_left)
 		octeon_i2c_hlc_int_clear(i2c);
-		return -ETIMEDOUT;
+
+	if (i2c->broken_irq_check && !time_left &&
+	    octeon_i2c_hlc_test_valid(i2c)) {
+		dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+			i2c->broken_irq_mode = true;
+			return 0;
 	}
+
+	if (!time_left)
+		return -ETIMEDOUT;
 	return 0;
 }
 

@@ -1136,6 +1182,9 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 		goto out;
 	}
 
+	if (OCTEON_IS_MODEL(OCTEON_CN38XX))
+		i2c->broken_irq_check = true;
+
 	result = octeon_i2c_init_lowlevel(i2c);
 	if (result) {
 		dev_err(i2c->dev, "init low level failed\n");

index 3144fe9..5b32a02 100644
@@ -121,6 +121,8 @@ struct octeon_i2c {
 	void __iomem *twsi_base;
 	struct device *dev;
 	bool hlc_enabled;
+	bool broken_irq_mode;
+	bool broken_irq_check;
 	void (*int_enable)(struct octeon_i2c *);
 	void (*int_disable)(struct octeon_i2c *);
 	void (*hlc_int_enable)(struct octeon_i2c *);

@@ -376,10 +378,32 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 	long time_left;
 	bool first = 1;
 
+	/*
+	 * Some chip revisions don't assert the irq in the interrupt
+	 * controller. So we must poll for the IFLG change.
+	 */
+	if (i2c->broken_irq_mode) {
+		u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+		while (!octeon_i2c_test_iflg(i2c) &&
+		       time_before64(get_jiffies_64(), end))
+			usleep_range(I2C_OCTEON_EVENT_WAIT / 2, I2C_OCTEON_EVENT_WAIT);
+
+		return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
+	}
+
 	i2c->int_enable(i2c);
 	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
 				       i2c->adap.timeout);
 	i2c->int_disable(i2c);
+
+	if (i2c->broken_irq_check && !time_left &&
+	    octeon_i2c_test_iflg(i2c)) {
+		dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+		i2c->broken_irq_mode = true;
+		return 0;
+	}
+
 	if (!time_left)
 		return -ETIMEDOUT;
 

@@ -493,15 +517,37 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
 	bool first = 1;
 	int time_left;
 
+	/*
+	 * Some cn38xx boards don't assert the irq in the interrupt
+	 * controller. So we must poll for the valid bit change.
+	 */
+	if (i2c->broken_irq_mode) {
+		u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+		while (!octeon_i2c_hlc_test_valid(i2c) &&
+		       time_before64(get_jiffies_64(), end))
+			usleep_range(I2C_OCTEON_EVENT_WAIT / 2, I2C_OCTEON_EVENT_WAIT);
+
+		return octeon_i2c_hlc_test_valid(i2c) ? 0 : -ETIMEDOUT;
+	}
+
 	i2c->hlc_int_enable(i2c);
 	time_left = wait_event_timeout(i2c->queue,
 				       octeon_i2c_hlc_test_ready(i2c, &first),
 				       i2c->adap.timeout);
 	i2c->hlc_int_disable(i2c);
-	if (!time_left) {
+	if (!time_left)
 		octeon_i2c_hlc_int_clear(i2c);
-		return -ETIMEDOUT;
+
+	if (i2c->broken_irq_check && !time_left &&
+	    octeon_i2c_hlc_test_valid(i2c)) {
+		dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+		i2c->broken_irq_mode = true;
+		return 0;
 	}
+
+	if (!time_left)
+		return -ETIMEDOUT;
 	return 0;
 }
 

@@ -1136,6 +1182,9 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 		goto out;
 	}
 
+	if (OCTEON_IS_MODEL(OCTEON_CN38XX))
+		i2c->broken_irq_check = true;
+
 	result = octeon_i2c_init_lowlevel(i2c);
 	if (result) {
 		dev_err(i2c->dev, "init low level failed\n");

index 009cc33..2bc32b9 100644
@@ -864,45 +864,6 @@ static void octeon_i2c_stop(struct octeon_i2c *i2c)
 }
 
 /**
- * octeon_i2c_write - send data to the bus via low-level controller
- * @i2c: The struct octeon_i2c
- * @target: Target address
- * @data: Pointer to the data to be sent
- * @length: Length of the data
- *
- * The address is sent over the bus, then the data.
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
-			    const u8 *data, int length)
-{
-	int i, result;
-
-	octeon_i2c_data_write(i2c, target << 1);
-	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
-
-	result = octeon_i2c_wait(i2c);
-	if (result)
-		return result;
-
-	for (i = 0; i < length; i++) {
-		result = octeon_i2c_check_status(i2c, false);
-		if (result)
-			return result;
-
-		octeon_i2c_data_write(i2c, data[i]);
-		octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
-
-		result = octeon_i2c_wait(i2c);
-		if (result)
-			return result;
-	}
-
-	return 0;
-}
-
-/**
  * octeon_i2c_read - receive data from the bus via low-level controller
  * @i2c: The struct octeon_i2c
  * @target: Target address

@@ -967,6 +928,45 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
 }
 
 /**
+ * octeon_i2c_write - send data to the bus via low-level controller
+ * @i2c: The struct octeon_i2c
+ * @target: Target address
+ * @data: Pointer to the data to be sent
+ * @length: Length of the data
+ *
+ * The address is sent over the bus, then the data.
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
+			    const u8 *data, int length)
+{
+	int i, result;
+
+	octeon_i2c_data_write(i2c, target << 1);
+	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+
+	result = octeon_i2c_wait(i2c);
+	if (result)
+		return result;
+
+	for (i = 0; i < length; i++) {
+		result = octeon_i2c_check_status(i2c, false);
+		if (result)
+			return result;
+
+		octeon_i2c_data_write(i2c, data[i]);
+		octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
+
+		result = octeon_i2c_wait(i2c);
+		if (result)
+			return result;
+	}
+
+	return 0;
+}
+
+/**
  * octeon_i2c_xfer - The driver's master_xfer function
  * @adap: Pointer to the i2c_adapter structure
  * @msgs: Pointer to the messages to be processed

similarity index 100%
rename from drivers/i2c/busses/i2c-octeon.c
rename to drivers/i2c/busses/i2c-octeon-core.c

799 lines not on this page · raw message

197 lines not on this page · raw message

989 lines not on this page · raw message

index 81c6a81..33c7e1f 100644
@@ -8,9 +8,15 @@
 #include <linux/pci.h>
 
 /* Register offsets */
-#define SW_TWSI			0x00
-#define TWSI_INT		0x10
-#define SW_TWSI_EXT		0x18
+#if IS_ENABLED(CONFIG_I2C_THUNDERX)
+	#define SW_TWSI			0x1000
+	#define TWSI_INT		0x1010
+	#define SW_TWSI_EXT		0x1018
+#else
+	#define SW_TWSI			0x00
+	#define TWSI_INT		0x10
+	#define SW_TWSI_EXT		0x18
+#endif
 
 /* Controller command patterns */
 #define SW_TWSI_V		BIT_ULL(63)	/* Valid bit */

@@ -94,6 +100,7 @@
 struct octeon_i2c {
 	wait_queue_head_t queue;
 	struct i2c_adapter adap;
+	struct clk *clk;
 	int irq;
 	int hlc_irq;		/* For cn7890 only */
 	u32 twsi_freq;

@@ -109,6 +116,9 @@ struct octeon_i2c {
 	void (*hlc_int_disable)(struct octeon_i2c *);
 	atomic_t int_enable_cnt;
 	atomic_t hlc_int_enable_cnt;
+#if IS_ENABLED(CONFIG_I2C_THUNDERX)
+	struct msix_entry i2c_msix;
+#endif
 };
 
 static inline void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)

267 lines not on this page · raw message

index ac37ae1..6ac9d63 100644
@@ -99,7 +99,7 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 
 static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c)
 {
-	return (__raw_readq(i2c->twsi_base + SW_TWSI) & SW_TWSI_V) == 0;
+	return (__raw_readq(i2c->twsi_base + SW_TWSI(i2c)) & SW_TWSI_V) == 0;
 }
 
 static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c, bool *first)

@@ -443,12 +443,12 @@ static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
 	else
 		cmd |= SW_TWSI_OP_7;
 
-	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));
 	ret = octeon_i2c_hlc_wait(i2c);
 	if (ret)
 		goto err;
 
-	cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+	cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
 	if ((cmd & SW_TWSI_R) == 0)
 		return -EAGAIN;
 

@@ -456,7 +456,7 @@ static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
 		msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
 
 	if (msgs[0].len > 4) {
-		cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+		cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT(i2c));
 		for (i = 0; i  < msgs[0].len - 4 && i < 4; i++, j--)
 			msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
 	}

@@ -493,15 +493,15 @@ static int octeon_i2c_hlc_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
 
 		for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
 			ext |= (u64) msgs[0].buf[j] << (8 * i);
-		octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+		octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT(i2c));
 	}
 
-	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));
 	ret = octeon_i2c_hlc_wait(i2c);
 	if (ret)
 		goto err;
 
-	cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+	cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
 	if ((cmd & SW_TWSI_R) == 0)
 		return -EAGAIN;
 

@@ -536,18 +536,18 @@ static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs
 		cmd |= SW_TWSI_EIA;
 		ext = (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
 		cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
-		octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+		octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT(i2c));
 	} else
 		cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
 
 	octeon_i2c_hlc_int_clear(i2c);
-	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));
 
 	ret = octeon_i2c_hlc_wait(i2c);
 	if (ret)
 		goto err;
 
-	cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+	cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
 	if ((cmd & SW_TWSI_R) == 0)
 		return -EAGAIN;
 

@@ -555,7 +555,7 @@ static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs
 		msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
 
 	if (msgs[1].len > 4) {
-		cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+		cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT(i2c));
 		for (i = 0; i  < msgs[1].len - 4 && i < 4; i++, j--)
 			msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
 	}

@@ -601,16 +601,16 @@ static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msg
 		set_ext = true;
 	}
 	if (set_ext)
-		octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT);
+		octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT(i2c));
 
 	octeon_i2c_hlc_int_clear(i2c);
-	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI);
+	octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));
 
 	ret = octeon_i2c_hlc_wait(i2c);
 	if (ret)
 		goto err;
 
-	cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+	cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
 	if ((cmd & SW_TWSI_R) == 0)
 		return -EAGAIN;
 

index 33c7e1f..ad57b03 100644
@@ -7,17 +7,6 @@
 #include <linux/kernel.h>
 #include <linux/pci.h>
 
-/* Register offsets */
-#if IS_ENABLED(CONFIG_I2C_THUNDERX)
-	#define SW_TWSI			0x1000
-	#define TWSI_INT		0x1010
-	#define SW_TWSI_EXT		0x1018
-#else
-	#define SW_TWSI			0x00
-	#define TWSI_INT		0x10
-	#define SW_TWSI_EXT		0x18
-#endif
-
 /* Controller command patterns */
 #define SW_TWSI_V		BIT_ULL(63)	/* Valid bit */
 #define SW_TWSI_EIA		BIT_ULL(61)	/* Extended internal address */

@@ -97,9 +86,21 @@
 
 #define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */
 
+/* Register offsets */
+struct octeon_i2c_reg_offset {
+	unsigned int sw_twsi;
+	unsigned int twsi_int;
+	unsigned int sw_twsi_ext;
+};
+
+#define SW_TWSI(x)	(x->roff.sw_twsi)
+#define TWSI_INT(x)	(x->roff.twsi_int)
+#define SW_TWSI_EXT(x)	(x->roff.sw_twsi_ext)
+
 struct octeon_i2c {
 	wait_queue_head_t queue;
 	struct i2c_adapter adap;
+	struct octeon_i2c_reg_offset roff;
 	struct clk *clk;
 	int irq;
 	int hlc_irq;		/* For cn7890 only */

@@ -139,9 +140,9 @@ static inline void octeon_i2c_reg_write(struct octeon_i2c *i2c, u64 eop_reg, u8
 {
 	u64 tmp;
 
-	__raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI);
+	__raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI(i2c));
 	do {
-		tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
+		tmp = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
 	} while ((tmp & SW_TWSI_V) != 0);
 }
 

@@ -163,9 +164,9 @@ static inline u8 octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg)
 {
 	u64 tmp;
 
-	__raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI);
+	__raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI(i2c));
 	do {
-		tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
+		tmp = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
 	} while ((tmp & SW_TWSI_V) != 0);
 
 	return tmp & 0xFF;

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

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

index fec4306..038007d 100644
@@ -163,6 +163,10 @@ static int octeon_i2c_probe(struct platform_device *pdev)
 	}
 	i2c->dev = &pdev->dev;
 
+	i2c->roff.sw_twsi = 0x00;
+	i2c->roff.twsi_int = 0x10;
+	i2c->roff.sw_twsi_ext = 0x18;
+
 	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	i2c->twsi_base = devm_ioremap_resource(&pdev->dev, res_mem);
 	if (IS_ERR(i2c->twsi_base)) {

index 656b405..8fcd26c 100644
@@ -134,6 +134,10 @@ static int thunder_i2c_probe_pci(struct pci_dev *pdev,
 	if (!i2c)
 		return -ENOMEM;
 
+	i2c->roff.sw_twsi = 0x1000;
+	i2c->roff.twsi_int = 0x1010;
+	i2c->roff.sw_twsi_ext = 0x1018;
+
 	i2c->dev = dev;
 	pci_set_drvdata(pdev, i2c);
 	ret = pci_enable_device(pdev);

index ad57b03..749dffc 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>

@@ -120,6 +121,11 @@ struct octeon_i2c {
 #if IS_ENABLED(CONFIG_I2C_THUNDERX)
 	struct msix_entry i2c_msix;
 #endif
+
+#if IS_ENABLED(CONFIG_I2C_SMBUS)
+	struct i2c_smbus_alert_setup alert_data;
+	struct i2c_client *ara;
+#endif
 };
 
 static inline void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)

index 8fcd26c..e1a111d 100644
@@ -9,9 +9,11 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of_irq.h>
 #include <linux/pci.h>
 
 #include "i2c-cavium.h"

@@ -106,6 +108,35 @@ static void thunder_i2c_clock_disable(struct device *dev, struct clk *clk)
 	devm_clk_put(dev, clk);
 }
 
+static int thunder_i2c_smbus_setup(struct octeon_i2c *i2c,
+				   struct device_node *node)
+{
+#if IS_ENABLED(CONFIG_I2C_SMBUS)
+	u32 type;
+
+	i2c->alert_data.irq = irq_of_parse_and_map(node, 0);
+	if (!i2c->alert_data.irq)
+		return -EINVAL;
+
+	type = irqd_get_trigger_type(irq_get_irq_data(i2c->alert_data.irq));
+	i2c->alert_data.alert_edge_triggered =
+		(type & IRQ_TYPE_LEVEL_MASK) ? 1 : 0;
+
+	i2c->ara = i2c_setup_smbus_alert(&i2c->adap, &i2c->alert_data);
+	if (!i2c->ara)
+		return -ENODEV;
+#endif
+	return 0;
+}
+
+static void thunder_i2c_smbus_remove(struct octeon_i2c *i2c)
+{
+#if IS_ENABLED(CONFIG_I2C_SMBUS)
+	if (i2c->ara)
+		i2c_unregister_device(i2c->ara);
+#endif
+}
+
 static void thunder_i2c_set_name(struct pci_dev *pdev, struct octeon_i2c *i2c,
 				 char *name)
 {

@@ -210,6 +241,9 @@ static int thunder_i2c_probe_pci(struct pci_dev *pdev,
 		goto out_irq;
 	}
 
+	ret = thunder_i2c_smbus_setup(i2c, node);
+	if (ret < 0)
+		dev_info(dev, "Failed to setup smbus alert\n");
 	dev_info(i2c->dev, "probed\n");
 	return 0;
 

@@ -240,6 +274,7 @@ static void thunder_i2c_remove_pci(struct pci_dev *pdev)
 
 	dev = i2c->dev;
 	thunder_i2c_clock_disable(dev, i2c->clk);
+	thunder_i2c_smbus_remove(i2c);
 	i2c_del_adapter(&i2c->adap);
 	devm_free_irq(dev, i2c->i2c_msix.vector, i2c);
 	pci_disable_msix(pdev);