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

Pull i2c updates from Wolfram Sang:
 "Most notable:

   - introducing the i2c_quirk infrastructure.  Now, flaws of I2C
     controllers can be described and the core will check if the flaws
     collide with the messages to be sent

   - wait_for_completion return type cleanup series

   - new drivers for Digicolor, Netlogic XLP, Ingenic JZ4780

   - updates to the I2C slave framework which include API changes.  Its
     only user was updated, too.  Documentation was finally added

   - changed dynamic bus numbering for the DT case.  This could change
     bus numbers for users.  However, it fixes a collision where dynamic
     and static busses request the same id.

   - driver bugfixes, cleanups"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (52 commits)
  i2c: xlp9xx: Driver for Netlogic XLP9XX/5XX I2C controller
  of: Add vendor prefix 'netlogic'
  i2c: davinci: use ICPFUNC to toggle I2C as gpio for bus recovery
  i2c: davinci: use bus recovery infrastructure
  i2c: change input parameter to i2c_adapter for prepare/unprepare_recovery
  i2c: i2c-mux-gpio: remove error messages for probe deferrals
  i2c: jz4780: Add i2c bus controller driver for Ingenic JZ4780
  i2c: dln2: set the device tree node of the adapter
  i2c: davinci: fixup wait_for_completion_timeout handling
  i2c: mpc: Fix ISR return value
  i2c: slave-eeprom: add more info when to increase the pointer
  i2c: slave: add documentation for i2c-slave-eeprom
  Documentation: i2c: describe the new slave mode
  i2c: slave: rework the slave API
  i2c: add support for the Digicolor I2C controller
  i2c: busses with dynamic ids should start after fixed ids for DT
  of: base: add function to get highest id of an alias stem
  i2c: designware: Suppress error message if platform_get_irq() < 0
  i2c: mpc: assign the correct prescaler from SVR
  i2c: img-scb: fixup of wait_for_completion_timeout return handling
  ...

1 files changed, 15 insertions, 24 deletions

diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
index 636fd2efad88..ff23d1bdd230 100644
--- a/drivers/i2c/busses/i2c-at91.c
+++ b/drivers/i2c/busses/i2c-at91.c
@@ -381,6 +381,7 @@ static irqreturn_t atmel_twi_interrupt(int irq, void *dev_id)
 static int at91_do_twi_transfer(struct at91_twi_dev *dev)
 {
 	int ret;
+	unsigned long time_left;
 	bool has_unre_flag = dev->pdata->has_unre_flag;
 
 	dev_dbg(dev->dev, "transfer: %s %d bytes.\n",
@@ -436,9 +437,9 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
 		}
 	}
 
-	ret = wait_for_completion_timeout(&dev->cmd_complete,
-					     dev->adapter.timeout);
-	if (ret == 0) {
+	time_left = wait_for_completion_timeout(&dev->cmd_complete,
+					      dev->adapter.timeout);
+	if (time_left == 0) {
 		dev_err(dev->dev, "controller timed out\n");
 		at91_init_twi_bus(dev);
 		ret = -ETIMEDOUT;
@@ -487,30 +488,10 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
 	if (ret < 0)
 		goto out;
 
-	/*
-	 * The hardware can handle at most two messages concatenated by a
-	 * repeated start via it's internal address feature.
-	 */
-	if (num > 2) {
-		dev_err(dev->dev,
-			"cannot handle more than two concatenated messages.\n");
-		ret = 0;
-		goto out;
-	} else if (num == 2) {
+	if (num == 2) {
 		int internal_address = 0;
 		int i;
 
-		if (msg->flags & I2C_M_RD) {
-			dev_err(dev->dev, "first transfer must be write.\n");
-			ret = -EINVAL;
-			goto out;
-		}
-		if (msg->len > 3) {
-			dev_err(dev->dev, "first message size must be <= 3.\n");
-			ret = -EINVAL;
-			goto out;
-		}
-
 		/* 1st msg is put into the internal address, start with 2nd */
 		m_start = &msg[1];
 		for (i = 0; i < msg->len; ++i) {
@@ -540,6 +521,15 @@ out:
 	return ret;
 }
 
+/*
+ * The hardware can handle at most two messages concatenated by a
+ * repeated start via it's internal address feature.
+ */
+static struct i2c_adapter_quirks at91_twi_quirks = {
+	.flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR,
+	.max_comb_1st_msg_len = 3,
+};
+
 static u32 at91_twi_func(struct i2c_adapter *adapter)
 {
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
@@ -777,6 +767,7 @@ static int at91_twi_probe(struct platform_device *pdev)
 	dev->adapter.owner = THIS_MODULE;
 	dev->adapter.class = I2C_CLASS_DEPRECATED;
 	dev->adapter.algo = &at91_twi_algorithm;
+	dev->adapter.quirks = &at91_twi_quirks;
 	dev->adapter.dev.parent = dev->dev;
 	dev->adapter.nr = pdev->id;
 	dev->adapter.timeout = AT91_I2C_TIMEOUT;