i2c-algo-bit: Add pre- and post-xfer hooks

Drivers might have to do random things before and/or after I2C
transfers. Add hooks to the i2c-algo-bit implementation to let them do
so.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Alex Deucher <alexdeucher@gmail.com>

2 files changed, 11 insertions, 0 deletions

diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index e25e13980af3..e8d568c3fb09 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -522,6 +522,12 @@ static int bit_xfer(struct i2c_adapter *i2c_adap,
         int i, ret;
         unsigned short nak_ok;
 
+        if (adap->pre_xfer) {
+                ret = adap->pre_xfer(i2c_adap);
+                if (ret < 0)
+                        return ret;
+        }
+
         bit_dbg(3, &i2c_adap->dev, "emitting start condition\n");
         i2c_start(adap);
         for (i = 0; i < num; i++) {
@@ -570,6 +576,9 @@ static int bit_xfer(struct i2c_adapter *i2c_adap,
 bailout:
         bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n");
         i2c_stop(adap);
+
+        if (adap->post_xfer)
+                adap->post_xfer(i2c_adap);
         return ret;
 }
 
diff --git a/include/linux/i2c-algo-bit.h b/include/linux/i2c-algo-bit.h
index 111334f5b922..4f98148c11c3 100644
--- a/include/linux/i2c-algo-bit.h
+++ b/include/linux/i2c-algo-bit.h
@@ -36,6 +36,8 @@ struct i2c_algo_bit_data {
         void (*setscl) (void *data, int state);
         int  (*getsda) (void *data);
         int  (*getscl) (void *data);
+        int  (*pre_xfer)  (struct i2c_adapter *);
+        void (*post_xfer) (struct i2c_adapter *);
 
         /* local settings */
         int udelay;             /* half clock cycle time in us,