1 files changed, 33 insertions, 18 deletions

diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index a39e6cff86e..d6d58684712 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -232,9 +232,17 @@ static int i2c_inb(struct i2c_adapter *i2c_adap)
  * Sanity check for the adapter hardware - check the reaction of
  * the bus lines only if it seems to be idle.
  */
-static int test_bus(struct i2c_algo_bit_data *adap, char *name)
+static int test_bus(struct i2c_adapter *i2c_adap)
 {
-	int scl, sda;
+	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
+	const char *name = i2c_adap->name;
+	int scl, sda, ret;
+
+	if (adap->pre_xfer) {
+		ret = adap->pre_xfer(i2c_adap);
+		if (ret < 0)
+			return -ENODEV;
+	}
 
 	if (adap->getscl == NULL)
 		pr_info("%s: Testing SDA only, SCL is not readable\n", name);
@@ -297,11 +305,19 @@ static int test_bus(struct i2c_algo_bit_data *adap, char *name)
 		       "while pulling SCL high!\n", name);
 		goto bailout;
 	}
+
+	if (adap->post_xfer)
+		adap->post_xfer(i2c_adap);
+
 	pr_info("%s: Test OK\n", name);
 	return 0;
 bailout:
 	sdahi(adap);
 	sclhi(adap);
+
+	if (adap->post_xfer)
+		adap->post_xfer(i2c_adap);
+
 	return -ENODEV;
 }
 
@@ -600,12 +616,14 @@ 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(adap);
 		if (ret < 0)
 			return -ENODEV;
 	}
@@ -614,30 +632,27 @@ 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);