1 files changed, 56 insertions, 5 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 0ac2f90ab84..3202a86f420 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -34,6 +34,7 @@
 #include <linux/hardirq.h>
 #include <linux/irqflags.h>
 #include <linux/rwsem.h>
+#include <linux/pm_runtime.h>
 #include <asm/uaccess.h>
 
 #include "i2c-core.h"
@@ -184,6 +185,52 @@ static int i2c_device_pm_resume(struct device *dev)
 #define i2c_device_pm_resume	NULL
 #endif
 
+#ifdef CONFIG_PM_RUNTIME
+static int i2c_device_runtime_suspend(struct device *dev)
+{
+	const struct dev_pm_ops *pm;
+
+	if (!dev->driver)
+		return 0;
+	pm = dev->driver->pm;
+	if (!pm || !pm->runtime_suspend)
+		return 0;
+	return pm->runtime_suspend(dev);
+}
+
+static int i2c_device_runtime_resume(struct device *dev)
+{
+	const struct dev_pm_ops *pm;
+
+	if (!dev->driver)
+		return 0;
+	pm = dev->driver->pm;
+	if (!pm || !pm->runtime_resume)
+		return 0;
+	return pm->runtime_resume(dev);
+}
+
+static int i2c_device_runtime_idle(struct device *dev)
+{
+	const struct dev_pm_ops *pm = NULL;
+	int ret;
+
+	if (dev->driver)
+		pm = dev->driver->pm;
+	if (pm && pm->runtime_idle) {
+		ret = pm->runtime_idle(dev);
+		if (ret)
+			return ret;
+	}
+
+	return pm_runtime_suspend(dev);
+}
+#else
+#define i2c_device_runtime_suspend	NULL
+#define i2c_device_runtime_resume	NULL
+#define i2c_device_runtime_idle		NULL
+#endif
+
 static int i2c_device_suspend(struct device *dev, pm_message_t mesg)
 {
 	struct i2c_client *client = i2c_verify_client(dev);
@@ -248,9 +295,12 @@ static const struct attribute_group *i2c_dev_attr_groups[] = {
 	NULL
 };
 
-const static struct dev_pm_ops i2c_device_pm_ops = {
+static const struct dev_pm_ops i2c_device_pm_ops = {
 	.suspend = i2c_device_pm_suspend,
 	.resume = i2c_device_pm_resume,
+	.runtime_suspend = i2c_device_runtime_suspend,
+	.runtime_resume = i2c_device_runtime_resume,
+	.runtime_idle = i2c_device_runtime_idle,
 };
 
 struct bus_type i2c_bus_type = {
@@ -843,6 +893,9 @@ int i2c_del_adapter(struct i2c_adapter *adap)
 				 adap->dev.parent);
 #endif
 
+	/* device name is gone after device_unregister */
+	dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
+
 	/* clean up the sysfs representation */
 	init_completion(&adap->dev_released);
 	device_unregister(&adap->dev);
@@ -855,8 +908,6 @@ int i2c_del_adapter(struct i2c_adapter *adap)
 	idr_remove(&i2c_adapter_idr, adap->nr);
 	mutex_unlock(&core_lock);
 
-	dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
-
 	/* Clear the device structure in case this adapter is ever going to be
 	   added again */
 	memset(&adap->dev, 0, sizeof(adap->dev));
@@ -1132,7 +1183,7 @@ EXPORT_SYMBOL(i2c_transfer);
  * i2c_master_send - issue a single I2C message in master transmit mode
  * @client: Handle to slave device
  * @buf: Data that will be written to the slave
- * @count: How many bytes to write
+ * @count: How many bytes to write, must be less than 64k since msg.len is u16
  *
  * Returns negative errno, or else the number of bytes written.
  */
@@ -1159,7 +1210,7 @@ EXPORT_SYMBOL(i2c_master_send);
  * i2c_master_recv - issue a single I2C message in master receive mode
  * @client: Handle to slave device
  * @buf: Where to store data read from slave
- * @count: How many bytes to read
+ * @count: How many bytes to read, must be less than 64k since msg.len is u16
  *
  * Returns negative errno, or else the number of bytes read.
  */