i2c: export i2c_adapter_depth()

For crazy setups in which an i2c gpio expander is behind an i2c gpio
multiplexer controlled by a gpio provided a second expander using the
same device driver we need to explicitly tell lockdep how to handle
nested locking.

Export i2c_adapter_depth() as public API to be reused outside of i2c
core code.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Peter Rosin <peda@axentia.se>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Bartosz Golaszewski 2016-09-16 18:02:42 +02:00 committed by Wolfram Sang
parent 72cf8c565c
commit 8dd1fe1594
2 changed files with 3 additions and 7 deletions

View file

@ -1426,13 +1426,7 @@ static void i2c_adapter_dev_release(struct device *dev)
complete(&adap->dev_released);
}
/*
* This function is only needed for mutex_lock_nested, so it is never
* called unless locking correctness checking is enabled. Thus we
* make it inline to avoid a compiler warning. That's what gcc ends up
* doing anyway.
*/
static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
{
unsigned int depth = 0;
@ -1441,6 +1435,7 @@ static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
return depth;
}
EXPORT_SYMBOL_GPL(i2c_adapter_depth);
/*
* Let users instantiate I2C devices through sysfs. This can be used when

View file

@ -698,6 +698,7 @@ extern void i2c_clients_command(struct i2c_adapter *adap,
extern struct i2c_adapter *i2c_get_adapter(int nr);
extern void i2c_put_adapter(struct i2c_adapter *adap);
extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);