Commit ff28fcef authored by Rhyland Klein's avatar Rhyland Klein Committed by Anton Vorontsov
Browse files

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: default avatarRhyland Klein <rklein@nvidia.com>
Signed-off-by: default avatarAnton Vorontsov <cbouatmailru@gmail.com>
parent bb879101

drivers/power/bq20z75.c

+31 −6
Original line number Diff line number Diff line
@@ -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--;

	}



	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;

}

include/linux/power/bq20z75.h

+2 −0
Original line number Diff line number Diff line
@@ -28,10 +28,12 @@ 
 * struct bq20z75_platform_data - platform data for bq20z75 devices

 * @battery_detect:		GPIO which is used to detect battery presence

 * @battery_detect_present:	gpio state when battery is present (0 / 1)

 * @i2c_retry_count:		# of times to retry on i2c IO failure

 */

struct bq20z75_platform_data {

	int battery_detect;

	int battery_detect_present;

	int i2c_retry_count;

};



#endif

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