Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "Highlights:

   - new drivers for Intel ismt & Broadcom bcm2835
   - a number of drivers got support for more variants and mostly got
     cleaned up on the way (sis630, i801, at91, tegra, designware)
   - i2c got rid of all *_set_drvdata(..., NULL) on remove/probe failure
   - removed the i2c_smbus_process_call from the core since there are no
     users
   - mxs can now switch between PIO and DMA depending on the message
     size and the bus speed can now be arbitrary

  In addition, there is the usual bunch of fixes, cleanups, devm_*
  conversions, etc"

Fixed conflict (and buggy devm_* conversion) in i2c-s3c2410.c

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (39 commits)
  i2c: Remove unneeded xxx_set_drvdata(..., NULL) calls
  i2c: pxa: remove incorrect __exit annotations
  i2c: ocores: Fix pointer to integer cast warning
  i2c: tegra: remove warning dump if timeout happen in transfer
  i2c: fix i2c-ismt.c printk format warning
  i2c: i801: Add Device IDs for Intel Wellsburg PCH
  i2c: add bcm2835 driver
  i2c: ismt: Add Seth and Myself as maintainers
  i2c: sis630: checkpatch cleanup
  i2c: sis630: display unsigned hex
  i2c: sis630: use hex to constants for SMBus commands
  i2c: sis630: fix behavior after collision
  i2c: sis630: clear sticky bits
  i2c: sis630: Add SIS964 support
  i2c: isch: Add module parameter for backbone clock rate if divider is unset
  i2c: at91: fix unsed variable warning when building with !CONFIG_OF
  i2c: Adding support for Intel iSMT SMBus 2.0 host controller
  i2c: sh_mobile: don't send a stop condition by default inside transfers
  i2c: sh_mobile: eliminate an open-coded "goto" loop
  i2c: sh_mobile: fix timeout error handling
  ...

1 files changed, 98 insertions, 54 deletions

diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index b6e7a83a8296..debf745c0268 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -38,21 +38,21 @@
 /* Transmit operation:                                                      */
 /*                                                                          */
 /* 0 byte transmit                                                          */
-/* BUS:     S     A8     ACK   P                                            */
+/* BUS:     S     A8     ACK   P(*)                                         */
 /* IRQ:       DTE   WAIT                                                    */
 /* ICIC:                                                                    */
 /* ICCR: 0x94 0x90                                                          */
 /* ICDR:      A8                                                            */
 /*                                                                          */
 /* 1 byte transmit                                                          */
-/* BUS:     S     A8     ACK   D8(1)   ACK   P                              */
+/* BUS:     S     A8     ACK   D8(1)   ACK   P(*)                           */
 /* IRQ:       DTE   WAIT         WAIT                                       */
 /* ICIC:      -DTE                                                          */
 /* ICCR: 0x94       0x90                                                    */
 /* ICDR:      A8    D8(1)                                                   */
 /*                                                                          */
 /* 2 byte transmit                                                          */
-/* BUS:     S     A8     ACK   D8(1)   ACK   D8(2)   ACK   P                */
+/* BUS:     S     A8     ACK   D8(1)   ACK   D8(2)   ACK   P(*)             */
 /* IRQ:       DTE   WAIT         WAIT          WAIT                         */
 /* ICIC:      -DTE                                                          */
 /* ICCR: 0x94                    0x90                                       */
@@ -66,20 +66,20 @@
 /* 0 byte receive - not supported since slave may hold SDA low              */
 /*                                                                          */
 /* 1 byte receive       [TX] | [RX]                                         */
-/* BUS:     S     A8     ACK | D8(1)   ACK   P                              */
+/* BUS:     S     A8     ACK | D8(1)   ACK   P(*)                           */
 /* IRQ:       DTE   WAIT     |   WAIT     DTE                               */
 /* ICIC:      -DTE           |   +DTE                                       */
 /* ICCR: 0x94       0x81     |   0xc0                                       */
 /* ICDR:      A8             |            D8(1)                             */
 /*                                                                          */
 /* 2 byte receive        [TX]| [RX]                                         */
-/* BUS:     S     A8     ACK | D8(1)   ACK   D8(2)   ACK   P                */
+/* BUS:     S     A8     ACK | D8(1)   ACK   D8(2)   ACK   P(*)             */
 /* IRQ:       DTE   WAIT     |   WAIT          WAIT     DTE                 */
 /* ICIC:      -DTE           |                 +DTE                         */
 /* ICCR: 0x94       0x81     |                 0xc0                         */
 /* ICDR:      A8             |                 D8(1)    D8(2)               */
 /*                                                                          */
-/* 3 byte receive       [TX] | [RX]                                         */
+/* 3 byte receive       [TX] | [RX]                                     (*) */
 /* BUS:     S     A8     ACK | D8(1)   ACK   D8(2)   ACK   D8(3)   ACK    P */
 /* IRQ:       DTE   WAIT     |   WAIT          WAIT         WAIT      DTE   */
 /* ICIC:      -DTE           |                              +DTE            */
@@ -94,7 +94,7 @@
 /* SDA ___\___XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXAAAAAAAAA___/                 */
 /* SCL      \_/1\_/2\_/3\_/4\_/5\_/6\_/7\_/8\___/9\_____/                   */
 /*                                                                          */
-/*        S   D7  D6  D5  D4  D3  D2  D1  D0              P                 */
+/*        S   D7  D6  D5  D4  D3  D2  D1  D0              P(*)              */
 /*                                           ___                            */
 /* WAIT IRQ ________________________________/   \___________                */
 /* TACK IRQ ____________________________________/   \_______                */
@@ -103,6 +103,11 @@
 /*         _______________________________________________                  */
 /* BUSY __/                                               \_                */
 /*                                                                          */
+/* (*) The STOP condition is only sent by the master at the end of the last */
+/* I2C message or if the I2C_M_STOP flag is set. Similarly, the BUSY bit is */
+/* only cleared after the STOP condition, so, between messages we have to   */
+/* poll for the DTE bit.                                                    */
+/*                                                                          */
 
 enum sh_mobile_i2c_op {
 	OP_START = 0,
@@ -132,6 +137,7 @@ struct sh_mobile_i2c_data {
 	struct i2c_msg *msg;
 	int pos;
 	int sr;
+	bool send_stop;
 };
 
 #define IIC_FLAG_HAS_ICIC67	(1 << 0)
@@ -322,7 +328,7 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
 		break;
 	case OP_TX_STOP: /* write data and issue a stop afterwards */
 		iic_wr(pd, ICDR, data);
-		iic_wr(pd, ICCR, 0x90);
+		iic_wr(pd, ICCR, pd->send_stop ? 0x90 : 0x94);
 		break;
 	case OP_TX_TO_RX: /* select read mode */
 		iic_wr(pd, ICCR, 0x81);
@@ -349,20 +355,14 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
 	return ret;
 }
 
-static int sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd)
+static bool sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd)
 {
-	if (pd->pos == -1)
-		return 1;
-
-	return 0;
+	return pd->pos == -1;
 }
 
-static int sh_mobile_i2c_is_last_byte(struct sh_mobile_i2c_data *pd)
+static bool sh_mobile_i2c_is_last_byte(struct sh_mobile_i2c_data *pd)
 {
-	if (pd->pos == (pd->msg->len - 1))
-		return 1;
-
-	return 0;
+	return pd->pos == pd->msg->len - 1;
 }
 
 static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd,
@@ -475,22 +475,25 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg)
+static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
+		    bool do_init)
 {
 	if (usr_msg->len == 0 && (usr_msg->flags & I2C_M_RD)) {
 		dev_err(pd->dev, "Unsupported zero length i2c read\n");
 		return -EIO;
 	}
 
-	/* Initialize channel registers */
-	iic_set_clr(pd, ICCR, 0, ICCR_ICE);
+	if (do_init) {
+		/* Initialize channel registers */
+		iic_set_clr(pd, ICCR, 0, ICCR_ICE);
 
-	/* Enable channel and configure rx ack */
-	iic_set_clr(pd, ICCR, ICCR_ICE, 0);
+		/* Enable channel and configure rx ack */
+		iic_set_clr(pd, ICCR, ICCR_ICE, 0);
 
-	/* Set the clock */
-	iic_wr(pd, ICCL, pd->iccl & 0xff);
-	iic_wr(pd, ICCH, pd->icch & 0xff);
+		/* Set the clock */
+		iic_wr(pd, ICCL, pd->iccl & 0xff);
+		iic_wr(pd, ICCH, pd->icch & 0xff);
+	}
 
 	pd->msg = usr_msg;
 	pd->pos = -1;
@@ -501,6 +504,61 @@ static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg)
 	return 0;
 }
 
+static int poll_dte(struct sh_mobile_i2c_data *pd)
+{
+	int i;
+
+	for (i = 1000; i; i--) {
+		u_int8_t val = iic_rd(pd, ICSR);
+
+		if (val & ICSR_DTE)
+			break;
+
+		if (val & ICSR_TACK)
+			return -EIO;
+
+		udelay(10);
+	}
+
+	if (!i) {
+		dev_warn(pd->dev, "Timeout polling for DTE!\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int poll_busy(struct sh_mobile_i2c_data *pd)
+{
+	int i;
+
+	for (i = 1000; i; i--) {
+		u_int8_t val = iic_rd(pd, ICSR);
+
+		dev_dbg(pd->dev, "val 0x%02x pd->sr 0x%02x\n", val, pd->sr);
+
+		/* the interrupt handler may wake us up before the
+		 * transfer is finished, so poll the hardware
+		 * until we're done.
+		 */
+		if (!(val & ICSR_BUSY)) {
+			/* handle missing acknowledge and arbitration lost */
+			if ((val | pd->sr) & (ICSR_TACK | ICSR_AL))
+				return -EIO;
+			break;
+		}
+
+		udelay(10);
+	}
+
+	if (!i) {
+		dev_err(pd->dev, "Polling timed out\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
 static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
 			      struct i2c_msg *msgs,
 			      int num)
@@ -508,53 +566,39 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
 	struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
 	struct i2c_msg	*msg;
 	int err = 0;
-	u_int8_t val;
-	int i, k, retry_count;
+	int i, k;
 
 	activate_ch(pd);
 
 	/* Process all messages */
 	for (i = 0; i < num; i++) {
+		bool do_start = pd->send_stop || !i;
 		msg = &msgs[i];
+		pd->send_stop = i == num - 1 || msg->flags & I2C_M_STOP;
 
-		err = start_ch(pd, msg);
+		err = start_ch(pd, msg, do_start);
 		if (err)
 			break;
 
-		i2c_op(pd, OP_START, 0);
+		if (do_start)
+			i2c_op(pd, OP_START, 0);
 
 		/* The interrupt handler takes care of the rest... */
 		k = wait_event_timeout(pd->wait,
 				       pd->sr & (ICSR_TACK | SW_DONE),
 				       5 * HZ);
-		if (!k)
+		if (!k) {
 			dev_err(pd->dev, "Transfer request timed out\n");
-
-		retry_count = 1000;
-again:
-		val = iic_rd(pd, ICSR);
-
-		dev_dbg(pd->dev, "val 0x%02x pd->sr 0x%02x\n", val, pd->sr);
-
-		/* the interrupt handler may wake us up before the
-		 * transfer is finished, so poll the hardware
-		 * until we're done.
-		 */
-		if (val & ICSR_BUSY) {
-			udelay(10);
-			if (retry_count--)
-				goto again;
-
-			err = -EIO;
-			dev_err(pd->dev, "Polling timed out\n");
+			err = -ETIMEDOUT;
 			break;
 		}
 
-		/* handle missing acknowledge and arbitration lost */
-		if ((val | pd->sr) & (ICSR_TACK | ICSR_AL)) {
-			err = -EIO;
+		if (pd->send_stop)
+			err = poll_busy(pd);
+		else
+			err = poll_dte(pd);
+		if (err < 0)
 			break;
-		}
 	}
 
 	deactivate_ch(pd);
@@ -566,7 +610,7 @@ again:
 
 static u32 sh_mobile_i2c_func(struct i2c_adapter *adapter)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
 }
 
 static struct i2c_algorithm sh_mobile_i2c_algorithm = {