bq20z75: Add i2c retry mechanism

With the support of platform data, now adding support for option i2c
retries on read/write failures. Ths is specified through the optional
platform data.

Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

1 files changed, 31 insertions, 6 deletions

diff --git a/drivers/power/bq20z75.c b/drivers/power/bq20z75.c
index a51e98d74d34..e82d10e25e8c 100644
--- a/drivers/power/bq20z75.c
+++ b/drivers/power/bq20z75.c
@@ -156,30 +156,55 @@ struct bq20z75_info {
 
 static int bq20z75_read_word_data(struct i2c_client *client, u8 address)
 {
-        s32 ret;
+        struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+        s32 ret = 0;
+        int retries = 1;
+
+        if (bq20z75_device->pdata)
+                retries = max(bq20z75_device->pdata->i2c_retry_count + 1, 1);
+
+        while (retries > 0) {
+                ret = i2c_smbus_read_word_data(client, address);
+                if (ret >= 0)
+                        break;
+                retries--;
+        }
 
-        ret = i2c_smbus_read_word_data(client, address);
         if (ret < 0) {
-                dev_err(&client->dev,
+                dev_warn(&client->dev,
                         "%s: i2c read at address 0x%x failed\n",
                         __func__, address);
                 return ret;
         }
+
         return le16_to_cpu(ret);
 }
 
 static int bq20z75_write_word_data(struct i2c_client *client, u8 address,
         u16 value)
 {
-        s32 ret;
+        struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+        s32 ret = 0;
+        int retries = 1;
+
+        if (bq20z75_device->pdata)
+                retries = max(bq20z75_device->pdata->i2c_retry_count + 1, 1);
+
+        while (retries > 0) {
+                ret = i2c_smbus_write_word_data(client, address,
+                        le16_to_cpu(value));
+                if (ret >= 0)
+                        break;
+                retries--;
+        }
 
-        ret = i2c_smbus_write_word_data(client, address, le16_to_cpu(value));
         if (ret < 0) {
-                dev_err(&client->dev,
+                dev_warn(&client->dev,
                         "%s: i2c write to address 0x%x failed\n",
                         __func__, address);
                 return ret;
         }
+
         return 0;
 }