From b37d2a3a75cb0e72e18c29336cb2095b63dabfc8 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Fri, 29 Jun 2012 07:47:19 -0300 Subject: [media] i2c: Export an unlocked flavor of i2c_transfer Some drivers (in particular for TV cards) need exclusive access to their I2C buses for specific operations. Export an unlocked flavor of i2c_transfer to give them full control. The unlocked flavor has the following limitations: * Obviously, caller must hold the i2c adapter lock. * No debug messages are logged. We don't want to log messages while holding a rt_mutex. * No check is done on the existence of adap->algo->master_xfer. It is thus the caller's responsibility to ensure that the function is OK to call. Signed-off-by: Jean Delvare Signed-off-by: Mauro Carvalho Chehab --- include/linux/i2c.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/i2c.h') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 195d8b3d9cf..a121c012309 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -68,6 +68,9 @@ extern int i2c_master_recv(const struct i2c_client *client, char *buf, */ extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); +/* Unlocked flavor */ +extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num); /* This is the very generalized SMBus access routine. You probably do not want to use this, though; one of the functions below may be much easier, -- cgit v1.2.3-70-g09d2