diff options
| -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 feb7dc35918..a6ad32bc0a9 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 195d8b3d9cf..b66cb601435 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) { |