i2c-algo-pcf: Add adapter hooks around xfer begin and end
Some I2C bus implementations need to synchronize with external
entities, such as system firmware, which might also be programming the
same I2C bus.
In order to facilitate this add ->xfer_begin() and ->xfer_end() hooks
which are invoked around pcf_xfer().
[JD: Make these hooks optional.]
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/include/linux/i2c-algo-pcf.h b/include/linux/i2c-algo-pcf.h
index 5de8a31..0f91a95 100644
--- a/include/linux/i2c-algo-pcf.h
+++ b/include/linux/i2c-algo-pcf.h
@@ -33,6 +33,9 @@
int (*getclock) (void *data);
void (*waitforpin) (void *data);
+ void (*xfer_begin) (void *data);
+ void (*xfer_end) (void *data);
+
/* Multi-master lost arbitration back-off delay (msecs)
* This should be set by the bus adapter or knowledgable client
* if bus is multi-mastered, else zero