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 a39e6cff86e7..d6d58684712b 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);