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-rw-r--r--drivers/i2c/i2c-core.c78
-rw-r--r--drivers/i2c/i2c-dev.c29
-rw-r--r--include/linux/i2c.h8
3 files changed, 63 insertions, 52 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index ddd1b83f44d4..c8bbd672226b 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -199,6 +199,25 @@ static struct bus_type i2c_bus_type = {
.resume = i2c_device_resume,
};
+
+/**
+ * i2c_verify_client - return parameter as i2c_client, or NULL
+ * @dev: device, probably from some driver model iterator
+ *
+ * When traversing the driver model tree, perhaps using driver model
+ * iterators like @device_for_each_child(), you can't assume very much
+ * about the nodes you find. Use this function to avoid oopses caused
+ * by wrongly treating some non-I2C device as an i2c_client.
+ */
+struct i2c_client *i2c_verify_client(struct device *dev)
+{
+ return (dev->bus == &i2c_bus_type)
+ ? to_i2c_client(dev)
+ : NULL;
+}
+EXPORT_SYMBOL(i2c_verify_client);
+
+
/**
* i2c_new_device - instantiate an i2c device for use with a new style driver
* @adap: the adapter managing the device
@@ -670,28 +689,19 @@ EXPORT_SYMBOL(i2c_del_driver);
/* ------------------------------------------------------------------------- */
-static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr)
+static int __i2c_check_addr(struct device *dev, void *addrp)
{
- struct list_head *item;
- struct i2c_client *client;
+ struct i2c_client *client = i2c_verify_client(dev);
+ int addr = *(int *)addrp;
- list_for_each(item,&adapter->clients) {
- client = list_entry(item, struct i2c_client, list);
- if (client->addr == addr)
- return -EBUSY;
- }
+ if (client && client->addr == addr)
+ return -EBUSY;
return 0;
}
static int i2c_check_addr(struct i2c_adapter *adapter, int addr)
{
- int rval;
-
- mutex_lock(&adapter->clist_lock);
- rval = __i2c_check_addr(adapter, addr);
- mutex_unlock(&adapter->clist_lock);
-
- return rval;
+ return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr);
}
int i2c_attach_client(struct i2c_client *client)
@@ -700,7 +710,7 @@ int i2c_attach_client(struct i2c_client *client)
int res = 0;
mutex_lock(&adapter->clist_lock);
- if (__i2c_check_addr(client->adapter, client->addr)) {
+ if (i2c_check_addr(client->adapter, client->addr)) {
res = -EBUSY;
goto out_unlock;
}
@@ -804,24 +814,28 @@ void i2c_release_client(struct i2c_client *client)
}
EXPORT_SYMBOL(i2c_release_client);
+struct i2c_cmd_arg {
+ unsigned cmd;
+ void *arg;
+};
+
+static int i2c_cmd(struct device *dev, void *_arg)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_cmd_arg *arg = _arg;
+
+ if (client && client->driver && client->driver->command)
+ client->driver->command(client, arg->cmd, arg->arg);
+ return 0;
+}
+
void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
{
- struct list_head *item;
- struct i2c_client *client;
+ struct i2c_cmd_arg cmd_arg;
- mutex_lock(&adap->clist_lock);
- list_for_each(item,&adap->clients) {
- client = list_entry(item, struct i2c_client, list);
- if (!try_module_get(client->driver->driver.owner))
- continue;
- if (NULL != client->driver->command) {
- mutex_unlock(&adap->clist_lock);
- client->driver->command(client,cmd,arg);
- mutex_lock(&adap->clist_lock);
- }
- module_put(client->driver->driver.owner);
- }
- mutex_unlock(&adap->clist_lock);
+ cmd_arg.cmd = cmd;
+ cmd_arg.arg = arg;
+ device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
}
EXPORT_SYMBOL(i2c_clients_command);
@@ -1087,7 +1101,7 @@ i2c_new_probed_device(struct i2c_adapter *adap,
}
/* Check address availability */
- if (__i2c_check_addr(adap, addr_list[i])) {
+ if (i2c_check_addr(adap, addr_list[i])) {
dev_dbg(&adap->dev, "Address 0x%02x already in "
"use, not probing\n", addr_list[i]);
continue;
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index df540d5dfaf4..393e679d9faa 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -182,27 +182,22 @@ static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t c
return ret;
}
+static int i2cdev_check(struct device *dev, void *addrp)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+
+ if (!client || client->addr != *(unsigned int *)addrp)
+ return 0;
+
+ return dev->driver ? -EBUSY : 0;
+}
+
/* This address checking function differs from the one in i2c-core
in that it considers an address with a registered device, but no
- bound driver, as NOT busy. */
+ driver bound to it, as NOT busy. */
static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
{
- struct list_head *item;
- struct i2c_client *client;
- int res = 0;
-
- mutex_lock(&adapter->clist_lock);
- list_for_each(item, &adapter->clients) {
- client = list_entry(item, struct i2c_client, list);
- if (client->addr == addr) {
- if (client->driver)
- res = -EBUSY;
- break;
- }
- }
- mutex_unlock(&adapter->clist_lock);
-
- return res;
+ return device_for_each_child(&adapter->dev, &addr, i2cdev_check);
}
static int i2cdev_ioctl(struct inode *inode, struct file *file,
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 0fc59efd80e4..731928ae972c 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -158,7 +158,7 @@ struct i2c_driver {
* @irq: indicates the IRQ generated by this device (if any)
* @driver_name: Identifies new-style driver used with this device; also
* used as the module name for hotplug/coldplug modprobe support.
- * @list: list of active/busy clients
+ * @list: list of active/busy clients (DEPRECATED)
* @released: used to synchronize client releases & detaches and references
*
* An i2c_client identifies a single device (i.e. chip) connected to an
@@ -176,11 +176,13 @@ struct i2c_client {
struct device dev; /* the device structure */
int irq; /* irq issued by device (or -1) */
char driver_name[KOBJ_NAME_LEN];
- struct list_head list;
+ struct list_head list; /* DEPRECATED */
struct completion released;
};
#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
+extern struct i2c_client *i2c_verify_client(struct device *dev);
+
static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
{
struct device * const dev = container_of(kobj, struct device, kobj);
@@ -315,7 +317,7 @@ struct i2c_adapter {
struct device dev; /* the adapter device */
int nr;
- struct list_head clients;
+ struct list_head clients; /* DEPRECATED */
char name[48];
struct completion dev_released;
};