1 files changed, 92 insertions, 25 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 10be7b5fbe97..c2258a51fe0c 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -34,17 +34,17 @@
 #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"
 
 
-/* core_lock protects i2c_adapter_idr, userspace_devices, and guarantees
+/* core_lock protects i2c_adapter_idr, and guarantees
    that device detection, deletion of detected devices, and attach_adapter
    and detach_adapter calls are serialized */
 static DEFINE_MUTEX(core_lock);
 static DEFINE_IDR(i2c_adapter_idr);
-static LIST_HEAD(userspace_devices);
 
 static struct device_type i2c_client_type;
 static int i2c_check_addr(struct i2c_adapter *adapter, int addr);
@@ -116,8 +116,10 @@ static int i2c_device_probe(struct device *dev)
 	dev_dbg(dev, "probe\n");
 
 	status = driver->probe(client, i2c_match_id(driver->id_table, client));
-	if (status)
+	if (status) {
 		client->driver = NULL;
+		i2c_set_clientdata(client, NULL);
+	}
 	return status;
 }
 
@@ -138,8 +140,10 @@ static int i2c_device_remove(struct device *dev)
 		dev->driver = NULL;
 		status = 0;
 	}
-	if (status == 0)
+	if (status == 0) {
 		client->driver = NULL;
+		i2c_set_clientdata(client, NULL);
+	}
 	return status;
 }
 
@@ -184,6 +188,52 @@ 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);
@@ -251,6 +301,9 @@ static const struct attribute_group *i2c_dev_attr_groups[] = {
 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 = {
@@ -488,9 +541,9 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
 		return -EEXIST;
 
 	/* Keep track of the added device */
-	mutex_lock(&core_lock);
-	list_add_tail(&client->detected, &userspace_devices);
-	mutex_unlock(&core_lock);
+	i2c_lock_adapter(adap);
+	list_add_tail(&client->detected, &adap->userspace_clients);
+	i2c_unlock_adapter(adap);
 	dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
 		 info.type, info.addr);
 
@@ -529,9 +582,10 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
 
 	/* Make sure the device was added through sysfs */
 	res = -ENOENT;
-	mutex_lock(&core_lock);
-	list_for_each_entry_safe(client, next, &userspace_devices, detected) {
-		if (client->addr == addr && client->adapter == adap) {
+	i2c_lock_adapter(adap);
+	list_for_each_entry_safe(client, next, &adap->userspace_clients,
+				 detected) {
+		if (client->addr == addr) {
 			dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
 				 "delete_device", client->name, client->addr);
 
@@ -541,7 +595,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
 			break;
 		}
 	}
-	mutex_unlock(&core_lock);
+	i2c_unlock_adapter(adap);
 
 	if (res < 0)
 		dev_err(dev, "%s: Can't find device in list\n",
@@ -623,6 +677,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	}
 
 	rt_mutex_init(&adap->bus_lock);
+	INIT_LIST_HEAD(&adap->userspace_clients);
 
 	/* Set default timeout to 1 second if not already set */
 	if (adap->timeout == 0)
@@ -825,14 +880,15 @@ int i2c_del_adapter(struct i2c_adapter *adap)
 		return res;
 
 	/* Remove devices instantiated from sysfs */
-	list_for_each_entry_safe(client, next, &userspace_devices, detected) {
-		if (client->adapter == adap) {
-			dev_dbg(&adap->dev, "Removing %s at 0x%x\n",
-				client->name, client->addr);
-			list_del(&client->detected);
-			i2c_unregister_device(client);
-		}
+	i2c_lock_adapter(adap);
+	list_for_each_entry_safe(client, next, &adap->userspace_clients,
+				 detected) {
+		dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
+			client->addr);
+		list_del(&client->detected);
+		i2c_unregister_device(client);
 	}
+	i2c_unlock_adapter(adap);
 
 	/* Detach any active clients. This can't fail, thus we do not
 	   checking the returned value. */
@@ -1133,7 +1189,7 @@ 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.
  */
@@ -1160,7 +1216,7 @@ 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.
  */
@@ -1210,12 +1266,23 @@ static int i2c_detect_address(struct i2c_client *temp_client,
 		return 0;
 
 	/* Make sure there is something at this address */
-	if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) < 0)
-		return 0;
+	if (addr == 0x73 && (adapter->class & I2C_CLASS_HWMON)) {
+		/* Special probe for FSC hwmon chips */
+		union i2c_smbus_data dummy;
 
-	/* Prevent 24RF08 corruption */
-	if ((addr & ~0x0f) == 0x50)
-		i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL);
+		if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_READ, 0,
+				   I2C_SMBUS_BYTE_DATA, &dummy) < 0)
+			return 0;
+	} else {
+		if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0,
+				   I2C_SMBUS_QUICK, NULL) < 0)
+			return 0;
+
+		/* Prevent 24RF08 corruption */
+		if ((addr & ~0x0f) == 0x50)
+			i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0,
+				       I2C_SMBUS_QUICK, NULL);
+	}
 
 	/* Finally call the custom detection function */
 	memset(&info, 0, sizeof(struct i2c_board_info));