diff options
| author | Stephen Warren <swarren@nvidia.com> | 2012-04-17 12:43:33 -0600 |
|---|---|---|
| committer | Wolfram Sang <w.sang@pengutronix.de> | 2012-05-12 14:28:16 +0200 |
| commit | 643dd09eb27b40ced671564edbe2640935fe37c2 (patch) | |
| tree | 2237d5e572351e2d740c34050f7f20c2ec06745b | |
| parent | ec39ef83eb9b22cc732329e85fc4ec03e76d9dda (diff) | |
i2c: implement i2c_verify_adapter
This converts a struct device * to a struct i2c_adapter * while verifying
that the device really is an I2C adapter. Just like i2c_verify_client.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
| -rw-r--r-- | drivers/i2c/i2c-core.c | 17 | ||||
| -rw-r--r-- | include/linux/i2c.h | 1 |
2 files changed, 18 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index feb7dc359186..a6ad32bc0a96 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -772,6 +772,23 @@ struct device_type i2c_adapter_type = { }; EXPORT_SYMBOL_GPL(i2c_adapter_type); +/** + * i2c_verify_adapter - return parameter as i2c_adapter 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_adapter. + */ +struct i2c_adapter *i2c_verify_adapter(struct device *dev) +{ + return (dev->type == &i2c_adapter_type) + ? to_i2c_adapter(dev) + : NULL; +} +EXPORT_SYMBOL(i2c_verify_adapter); + #ifdef CONFIG_I2C_COMPAT static struct class_compat *i2c_adapter_compat_class; #endif diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 195d8b3d9cfb..b66cb601435f 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -232,6 +232,7 @@ struct i2c_client { #define to_i2c_client(d) container_of(d, struct i2c_client, dev) extern struct i2c_client *i2c_verify_client(struct device *dev); +extern struct i2c_adapter *i2c_verify_adapter(struct device *dev); static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) { |