1 files changed, 24 insertions, 17 deletions

diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index e25e13980af..38319a69bd0 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -24,7 +24,6 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/delay.h>
-#include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
@@ -522,6 +521,12 @@ 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 +575,9 @@ 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;
 }
 
@@ -592,12 +600,14 @@ static const struct i2c_algorithm i2c_bit_algo = {
 /*
  * registering functions to load algorithms at runtime
  */
-static int i2c_bit_prepare_bus(struct i2c_adapter *adap)
+static int __i2c_bit_add_bus(struct i2c_adapter *adap,
+			     int (*add_adapter)(struct i2c_adapter *))
 {
 	struct i2c_algo_bit_data *bit_adap = adap->algo_data;
+	int ret;
 
 	if (bit_test) {
-		int ret = test_bus(bit_adap, adap->name);
+		ret = test_bus(bit_adap, adap->name);
 		if (ret < 0)
 			return -ENODEV;
 	}
@@ -606,30 +616,27 @@ static int i2c_bit_prepare_bus(struct i2c_adapter *adap)
 	adap->algo = &i2c_bit_algo;
 	adap->retries = 3;
 
+	ret = add_adapter(adap);
+	if (ret < 0)
+		return ret;
+
+	/* Complain if SCL can't be read */
+	if (bit_adap->getscl == NULL) {
+		dev_warn(&adap->dev, "Not I2C compliant: can't read SCL\n");
+		dev_warn(&adap->dev, "Bus may be unreliable\n");
+	}
 	return 0;
 }
 
 int i2c_bit_add_bus(struct i2c_adapter *adap)
 {
-	int err;
-
-	err = i2c_bit_prepare_bus(adap);
-	if (err)
-		return err;
-
-	return i2c_add_adapter(adap);
+	return __i2c_bit_add_bus(adap, i2c_add_adapter);
 }
 EXPORT_SYMBOL(i2c_bit_add_bus);
 
 int i2c_bit_add_numbered_bus(struct i2c_adapter *adap)
 {
-	int err;
-
-	err = i2c_bit_prepare_bus(adap);
-	if (err)
-		return err;
-
-	return i2c_add_numbered_adapter(adap);
+	return __i2c_bit_add_bus(adap, i2c_add_numbered_adapter);
 }
 EXPORT_SYMBOL(i2c_bit_add_numbered_bus);