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Commit c411f600 authored by Jonathan Cameron's avatar Jonathan Cameron
Browse files

staging:iio:magnetometer:ak8975 use standard i2c_smbus read functions. 



Now the mysterious NOSTART flag is gone from the read, we can use the
i2c_smbus_read_byte/word/i2c_block_data functions instead of the
local reimplementation of these standard functions.

Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
Acked-by: default avatarLaxman Dewangan <ldewangan@nvidia.com>
parent aa992257

drivers/staging/iio/magnetometer/ak8975.c

+17 −49
Original line number Diff line number Diff line
@@ -122,35 +122,6 @@ static int ak8975_write_data(struct i2c_client *client, 
	return 0;

}



/*

 * Helper function to read a contiguous set of the I2C device's registers.

 */

static int ak8975_read_data(struct i2c_client *client,

			    u8 reg, u8 length, u8 *buffer)

{

	int ret;

	struct i2c_msg msg[2] = {

		{

			.addr = client->addr,

			.len = 1,

			.buf = &reg,

		}, {

			.addr = client->addr,

			.flags = I2C_M_RD,

			.len = length,

			.buf = buffer,

		}

	};



	ret = i2c_transfer(client->adapter, msg, 2);

	if (ret < 0) {

		dev_err(&client->dev, "Read from device fails\n");

		return ret;

	}



	return 0;

}



/*

 * Perform some start-of-day setup, including reading the asa calibration

 * values and caching them.
@@ -163,11 +134,12 @@ static int ak8975_setup(struct i2c_client *client) 
	int ret;



	/* Confirm that the device we're talking to is really an AK8975. */

	ret = ak8975_read_data(client, AK8975_REG_WIA, 1, &device_id);

	ret = i2c_smbus_read_byte_data(client, AK8975_REG_WIA);

	if (ret < 0) {

		dev_err(&client->dev, "Error reading WIA\n");

		return ret;

	}

	device_id = ret;

	if (device_id != AK8975_DEVICE_ID) {

		dev_err(&client->dev, "Device ak8975 not found\n");

		return -ENODEV;
@@ -185,7 +157,8 @@ static int ak8975_setup(struct i2c_client *client) 
	}



	/* Get asa data and store in the device data. */

	ret = ak8975_read_data(client, AK8975_REG_ASAX, 3, data->asa);

	ret = i2c_smbus_read_i2c_block_data(client, AK8975_REG_ASAX,

					    3, data->asa);

	if (ret < 0) {

		dev_err(&client->dev, "Not able to read asa data\n");

		return ret;
@@ -247,7 +220,6 @@ static int ak8975_setup(struct i2c_client *client) 
static int wait_conversion_complete_gpio(struct ak8975_data *data)

{

	struct i2c_client *client = data->client;

	u8 read_status;

	u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;

	int ret;
@@ -263,13 +235,12 @@ static int wait_conversion_complete_gpio(struct ak8975_data *data) 
		return -EINVAL;

	}



	ret = ak8975_read_data(client, AK8975_REG_ST1, 1, &read_status);

	if (ret < 0) {

	ret = i2c_smbus_read_byte_data(client, AK8975_REG_ST1);

	if (ret < 0)

		dev_err(&client->dev, "Error in reading ST1\n");



	return ret;

}

	return read_status;

}



static int wait_conversion_complete_polled(struct ak8975_data *data)

{
@@ -281,11 +252,12 @@ static int wait_conversion_complete_polled(struct ak8975_data *data) 
	/* Wait for the conversion to complete. */

	while (timeout_ms) {

		msleep(AK8975_CONVERSION_DONE_POLL_TIME);

		ret = ak8975_read_data(client, AK8975_REG_ST1, 1, &read_status);

		ret = i2c_smbus_read_byte_data(client, AK8975_REG_ST1);

		if (ret < 0) {

			dev_err(&client->dev, "Error in reading ST1\n");

			return ret;

		}

		read_status = ret;

		if (read_status)

			break;

		timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
@@ -306,7 +278,6 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) 
	struct i2c_client *client = data->client;

	u16 meas_reg;

	s16 raw;

	u8 read_status;

	int ret;



	mutex_lock(&data->lock);
@@ -330,18 +301,15 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) 
	if (ret < 0)

		goto exit;



	read_status = ret;



	if (read_status & AK8975_REG_ST1_DRDY_MASK) {

		ret = ak8975_read_data(client, AK8975_REG_ST2, 1, &read_status);

	if (ret & AK8975_REG_ST1_DRDY_MASK) {

		ret = i2c_smbus_read_byte_data(client, AK8975_REG_ST2);

		if (ret < 0) {

			dev_err(&client->dev, "Error in reading ST2\n");

			goto exit;

		}

		if (read_status & (AK8975_REG_ST2_DERR_MASK |

		if (ret & (AK8975_REG_ST2_DERR_MASK |

			   AK8975_REG_ST2_HOFL_MASK)) {

			dev_err(&client->dev, "ST2 status error 0x%x\n",

				read_status);

			dev_err(&client->dev, "ST2 status error 0x%x\n", ret);

			ret = -EINVAL;

			goto exit;

		}
@@ -349,12 +317,12 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) 


	/* Read the flux value from the appropriate register

	   (the register is specified in the iio device attributes). */

	ret = ak8975_read_data(client, ak8975_index_to_reg[index],

			       2, (u8 *)&meas_reg);

	ret = i2c_smbus_read_word_data(client, ak8975_index_to_reg[index]);

	if (ret < 0) {

		dev_err(&client->dev, "Read axis data fails\n");

		goto exit;

	}

	meas_reg = ret;



	mutex_unlock(&data->lock);