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

Pull i2c updates from Wolfram Sang:
 "Here is the pull request from the i2c subsystem.  It got a little
  delayed because I needed to wait for a dependency to be included
  (commit b424080a9e08: "reset: Add optional resets and stubs").  Plus,
  I had some email problems.  All done now, the highlights are:

   - drivers can now deprecate their use of i2c classes.  That shouldn't
     be used on embedded platforms anyhow and was often blindly
     copy&pasted.  This mechanism gives users time to switch away and
     ultimately boot faster once the use of classes for those drivers is
     gone for good.

   - new drivers for QUP, Cadence, efm32

   - tracepoint support for I2C and SMBus

   - bigger cleanups for the mv64xxx, nomadik, and designware drivers

  And the usual bugfixes, cleanups, feature additions.  Most stuff has
  been in linux-next for a while.  Just some hot fixes and new drivers
  were added a bit more recently."

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (63 commits)
  i2c: cadence: fix Kconfig dependency
  i2c: Add driver for Cadence I2C controller
  i2c: cadence: Document device tree bindings
  Documentation: i2c: improve section about flags mangling the protocol
  i2c: qup: use proper type fro clk_freq
  i2c: qup: off by ones in qup_i2c_probe()
  i2c: efm32: fix binding doc
  MAINTAINERS: update I2C web resources
  i2c: qup: New bus driver for the Qualcomm QUP I2C controller
  i2c: qup: Add device tree bindings information
  i2c: i2c-xiic: deprecate class based instantiation
  i2c: i2c-sirf: deprecate class based instantiation
  i2c: i2c-mv64xxx: deprecate class based instantiation
  i2c: i2c-designware-platdrv: deprecate class based instantiation
  i2c: i2c-davinci: deprecate class based instantiation
  i2c: i2c-bcm2835: deprecate class based instantiation
  i2c: mv64xxx: Fix reset controller handling
  i2c: omap: fix usage of IS_ERR_VALUE with pm_runtime_get_sync
  i2c: efm32: new bus driver
  i2c: exynos5: remove unnecessary cast of void pointer
  ...

1 files changed, 34 insertions, 5 deletions

diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 684d21e71e4a..ae4491062e41 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -601,6 +601,31 @@ static irqreturn_t s3c24xx_i2c_irq(int irqno, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+/*
+ * Disable the bus so that we won't get any interrupts from now on, or try
+ * to drive any lines. This is the default state when we don't have
+ * anything to send/receive.
+ *
+ * If there is an event on the bus, or we have a pre-existing event at
+ * kernel boot time, we may not notice the event and the I2C controller
+ * will lock the bus with the I2C clock line low indefinitely.
+ */
+static inline void s3c24xx_i2c_disable_bus(struct s3c24xx_i2c *i2c)
+{
+	unsigned long tmp;
+
+	/* Stop driving the I2C pins */
+	tmp = readl(i2c->regs + S3C2410_IICSTAT);
+	tmp &= ~S3C2410_IICSTAT_TXRXEN;
+	writel(tmp, i2c->regs + S3C2410_IICSTAT);
+
+	/* We don't expect any interrupts now, and don't want send acks */
+	tmp = readl(i2c->regs + S3C2410_IICCON);
+	tmp &= ~(S3C2410_IICCON_IRQEN | S3C2410_IICCON_IRQPEND |
+		S3C2410_IICCON_ACKEN);
+	writel(tmp, i2c->regs + S3C2410_IICCON);
+}
+
 
 /* s3c24xx_i2c_set_master
  *
@@ -735,7 +760,11 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
 
 	s3c24xx_i2c_wait_idle(i2c);
 
+	s3c24xx_i2c_disable_bus(i2c);
+
  out:
+	i2c->state = STATE_IDLE;
+
 	return ret;
 }
 
@@ -1004,7 +1033,6 @@ static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c)
 
 static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
 {
-	unsigned long iicon = S3C2410_IICCON_IRQEN | S3C2410_IICCON_ACKEN;
 	struct s3c2410_platform_i2c *pdata;
 	unsigned int freq;
 
@@ -1018,12 +1046,12 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
 
 	dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr);
 
-	writel(iicon, i2c->regs + S3C2410_IICCON);
+	writel(0, i2c->regs + S3C2410_IICCON);
+	writel(0, i2c->regs + S3C2410_IICSTAT);
 
 	/* we need to work out the divisors for the clock... */
 
 	if (s3c24xx_i2c_clockrate(i2c, &freq) != 0) {
-		writel(0, i2c->regs + S3C2410_IICCON);
 		dev_err(i2c->dev, "cannot meet bus frequency required\n");
 		return -EINVAL;
 	}
@@ -1031,7 +1059,8 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
 	/* todo - check that the i2c lines aren't being dragged anywhere */
 
 	dev_info(i2c->dev, "bus frequency set to %d KHz\n", freq);
-	dev_dbg(i2c->dev, "S3C2410_IICCON=0x%02lx\n", iicon);
+	dev_dbg(i2c->dev, "S3C2410_IICCON=0x%02x\n",
+		readl(i2c->regs + S3C2410_IICCON));
 
 	return 0;
 }
@@ -1106,7 +1135,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
 	i2c->adap.owner   = THIS_MODULE;
 	i2c->adap.algo    = &s3c24xx_i2c_algorithm;
 	i2c->adap.retries = 2;
-	i2c->adap.class   = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+	i2c->adap.class   = I2C_CLASS_HWMON | I2C_CLASS_SPD | I2C_CLASS_DEPRECATED;
 	i2c->tx_setup     = 50;
 
 	init_waitqueue_head(&i2c->wait);