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

…kernel/git/wsa/linux

Pull i2c fixes from Wolfram Sang:
 "Some bugfixes from I2C:

   - fix a uevent triggered boot problem by removing a useless debug
     print

   - fix sysfs-attributes of the new i2c-demux-pinctrl driver to follow
     standard kernel behaviour

   - fix a potential division-by-zero error (needed two takes)"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: jz4780: really prevent potential division by zero
  Revert "i2c: jz4780: prevent potential division by zero"
  i2c: jz4780: prevent potential division by zero
  i2c: mux: demux-pinctrl: Update docs to new sysfs-attributes
  i2c: mux: demux-pinctrl: Clean up sysfs attributes
  i2c: prevent endless uevent loop with CONFIG_I2C_DEBUG_CORE

Documentation/ABI/testing/sysfs-platform-i2c-demux-pinctrl

@@ -1,23 +1,18 @@
-What:		/sys/devices/platform/<i2c-demux-name>/cur_master
+What:		/sys/devices/platform/<i2c-demux-name>/available_masters
 Date:		January 2016
 KernelVersion:	4.6
 Contact:	Wolfram Sang <wsa@the-dreams.de>
 Description:
+		Reading the file will give you a list of masters which can be
+		selected for a demultiplexed bus. The format is
+		"<index>:<name>". Example from a Renesas Lager board:
 
-This file selects the active I2C master for a demultiplexed bus.
+		0:/i2c@e6500000 1:/i2c@e6508000
 
-Write 0 there for the first master, 1 for the second etc. Reading the file will
-give you a list with the active master marked. Example from a Renesas Lager
-board:
-
-root@Lager:~# cat /sys/devices/platform/i2c@8/cur_master
-* 0 - /i2c@9
-  1 - /i2c@e6520000
-  2 - /i2c@e6530000
-
-root@Lager:~# echo 2 > /sys/devices/platform/i2c@8/cur_master
-
-root@Lager:~# cat /sys/devices/platform/i2c@8/cur_master
-  0 - /i2c@9
-  1 - /i2c@e6520000
-* 2 - /i2c@e6530000
+What:		/sys/devices/platform/<i2c-demux-name>/current_master
+Date:		January 2016
+KernelVersion:	4.6
+Contact:	Wolfram Sang <wsa@the-dreams.de>
+Description:
+		This file selects/shows the active I2C master for a demultiplexed
+		bus. It uses the <index> value from the file 'available_masters'.

drivers/i2c/busses/i2c-jz4780.c

@@ -771,11 +771,16 @@ static int jz4780_i2c_probe(struct platform_device *pdev)
 	ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 				   &clk_freq);
 	if (ret) {
-		dev_err(&pdev->dev, "clock-frequency not specified in DT");
+		dev_err(&pdev->dev, "clock-frequency not specified in DT\n");
 		goto err;
 	}
 
 	i2c->speed = clk_freq / 1000;
+	if (i2c->speed == 0) {
+		ret = -EINVAL;
+		dev_err(&pdev->dev, "clock-frequency minimum is 1000\n");
+		goto err;
+	}
 	jz4780_i2c_set_speed(i2c);
 
 	dev_info(&pdev->dev, "Bus frequency is %d KHz\n", i2c->speed);

drivers/i2c/i2c-core.c

@@ -525,22 +525,16 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv)
 	return 0;
 }
 
-
-/* uevent helps with hotplug: modprobe -q $(MODALIAS) */
 static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
-	struct i2c_client	*client = to_i2c_client(dev);
+	struct i2c_client *client = to_i2c_client(dev);
 	int rc;
 
 	rc = acpi_device_uevent_modalias(dev, env);
 	if (rc != -ENODEV)
 		return rc;
 
-	if (add_uevent_var(env, "MODALIAS=%s%s",
-			   I2C_MODULE_PREFIX, client->name))
-		return -ENOMEM;
-	dev_dbg(dev, "uevent\n");
-	return 0;
+	return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name);
 }
 
 /* i2c bus recovery routines */

drivers/i2c/muxes/i2c-demux-pinctrl.c

@@ -140,22 +140,34 @@ static int i2c_demux_change_master(struct i2c_demux_pinctrl_priv *priv, u32 new_
 	return i2c_demux_activate_master(priv, new_chan);
 }
 
-static ssize_t cur_master_show(struct device *dev, struct device_attribute *attr,
-			   char *buf)
+static ssize_t available_masters_show(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
 {
 	struct i2c_demux_pinctrl_priv *priv = dev_get_drvdata(dev);
 	int count = 0, i;
 
 	for (i = 0; i < priv->num_chan && count < PAGE_SIZE; i++)
-		count += scnprintf(buf + count, PAGE_SIZE - count, "%c %d - %s\n",
-				 i == priv->cur_chan ? '*' : ' ', i,
-				 priv->chan[i].parent_np->full_name);
+		count += scnprintf(buf + count, PAGE_SIZE - count, "%d:%s%c",
+				   i, priv->chan[i].parent_np->full_name,
+				   i == priv->num_chan - 1 ? '\n' : ' ');
 
 	return count;
 }
+static DEVICE_ATTR_RO(available_masters);
 
-static ssize_t cur_master_store(struct device *dev, struct device_attribute *attr,
-			    const char *buf, size_t count)
+static ssize_t current_master_show(struct device *dev,
+				   struct device_attribute *attr,
+				   char *buf)
+{
+	struct i2c_demux_pinctrl_priv *priv = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", priv->cur_chan);
+}
+
+static ssize_t current_master_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
 {
 	struct i2c_demux_pinctrl_priv *priv = dev_get_drvdata(dev);
 	unsigned int val;
@@ -172,7 +184,7 @@ static ssize_t cur_master_store(struct device *dev, struct device_attribute *att
 
 	return ret < 0 ? ret : count;
 }
-static DEVICE_ATTR_RW(cur_master);
+static DEVICE_ATTR_RW(current_master);
 
 static int i2c_demux_pinctrl_probe(struct platform_device *pdev)
 {
@@ -218,12 +230,18 @@ static int i2c_demux_pinctrl_probe(struct platform_device *pdev)
 	/* switch to first parent as active master */
 	i2c_demux_activate_master(priv, 0);
 
-	err = device_create_file(&pdev->dev, &dev_attr_cur_master);
+	err = device_create_file(&pdev->dev, &dev_attr_available_masters);
 	if (err)
 		goto err_rollback;
 
+	err = device_create_file(&pdev->dev, &dev_attr_current_master);
+	if (err)
+		goto err_rollback_available;
+
 	return 0;
 
+err_rollback_available:
+	device_remove_file(&pdev->dev, &dev_attr_available_masters);
 err_rollback:
 	for (j = 0; j < i; j++) {
 		of_node_put(priv->chan[j].parent_np);
@@ -238,7 +256,8 @@ static int i2c_demux_pinctrl_remove(struct platform_device *pdev)
 	struct i2c_demux_pinctrl_priv *priv = platform_get_drvdata(pdev);
 	int i;
 
-	device_remove_file(&pdev->dev, &dev_attr_cur_master);
+	device_remove_file(&pdev->dev, &dev_attr_current_master);
+	device_remove_file(&pdev->dev, &dev_attr_available_masters);
 
 	i2c_demux_deactivate_master(priv);