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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: Jonathan Cameron <jic23@kernel.org>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
This commit is contained in:
Jonathan Cameron 2013-03-24 16:58:00 +00:00
parent aa9922579f
commit c411f600ce
1 changed files with 17 additions and 49 deletions
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66
drivers/staging/iio/magnetometer/ak8975.c
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@ -122,35 +122,6 @@ static int ak8975_write_data(struct i2c_client *client,
return 0; 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 * Perform some start-of-day setup, including reading the asa calibration
* values and caching them. * values and caching them.
@ -163,11 +134,12 @@ static int ak8975_setup(struct i2c_client *client)
int ret; int ret;
/* Confirm that the device we're talking to is really an AK8975. */ /* 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) { if (ret < 0) {
dev_err(&client->dev, "Error reading WIA\n"); dev_err(&client->dev, "Error reading WIA\n");
return ret; return ret;
} }
device_id = ret;
if (device_id != AK8975_DEVICE_ID) { if (device_id != AK8975_DEVICE_ID) {
dev_err(&client->dev, "Device ak8975 not found\n"); dev_err(&client->dev, "Device ak8975 not found\n");
return -ENODEV; return -ENODEV;
@ -185,7 +157,8 @@ static int ak8975_setup(struct i2c_client *client)
} }
/* Get asa data and store in the device data. */ /* 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) { if (ret < 0) {
dev_err(&client->dev, "Not able to read asa data\n"); dev_err(&client->dev, "Not able to read asa data\n");
return ret; return ret;
@ -247,7 +220,6 @@ static int ak8975_setup(struct i2c_client *client)
static int wait_conversion_complete_gpio(struct ak8975_data *data) static int wait_conversion_complete_gpio(struct ak8975_data *data)
{ {
struct i2c_client *client = data->client; struct i2c_client *client = data->client;
u8 read_status;
u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT; u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
int ret; int ret;
@ -263,12 +235,11 @@ static int wait_conversion_complete_gpio(struct ak8975_data *data)
return -EINVAL; return -EINVAL;
} }
ret = ak8975_read_data(client, AK8975_REG_ST1, 1, &read_status); ret = i2c_smbus_read_byte_data(client, AK8975_REG_ST1);
if (ret < 0) { if (ret < 0)
dev_err(&client->dev, "Error in reading ST1\n"); dev_err(&client->dev, "Error in reading ST1\n");
return ret;
} return ret;
return read_status;
} }
static int wait_conversion_complete_polled(struct ak8975_data *data) 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. */ /* Wait for the conversion to complete. */
while (timeout_ms) { while (timeout_ms) {
msleep(AK8975_CONVERSION_DONE_POLL_TIME); 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) { if (ret < 0) {
dev_err(&client->dev, "Error in reading ST1\n"); dev_err(&client->dev, "Error in reading ST1\n");
return ret; return ret;
} }
read_status = ret;
if (read_status) if (read_status)
break; break;
timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME; 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; struct i2c_client *client = data->client;
u16 meas_reg; u16 meas_reg;
s16 raw; s16 raw;
u8 read_status;
int ret; int ret;
mutex_lock(&data->lock); 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) if (ret < 0)
goto exit; goto exit;
read_status = ret; if (ret & AK8975_REG_ST1_DRDY_MASK) {
ret = i2c_smbus_read_byte_data(client, AK8975_REG_ST2);
if (read_status & AK8975_REG_ST1_DRDY_MASK) {
ret = ak8975_read_data(client, AK8975_REG_ST2, 1, &read_status);
if (ret < 0) { if (ret < 0) {
dev_err(&client->dev, "Error in reading ST2\n"); dev_err(&client->dev, "Error in reading ST2\n");
goto exit; goto exit;
} }
if (read_status & (AK8975_REG_ST2_DERR_MASK | if (ret & (AK8975_REG_ST2_DERR_MASK |
AK8975_REG_ST2_HOFL_MASK)) { AK8975_REG_ST2_HOFL_MASK)) {
dev_err(&client->dev, "ST2 status error 0x%x\n", dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
read_status);
ret = -EINVAL; ret = -EINVAL;
goto exit; 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 /* Read the flux value from the appropriate register
(the register is specified in the iio device attributes). */ (the register is specified in the iio device attributes). */
ret = ak8975_read_data(client, ak8975_index_to_reg[index], ret = i2c_smbus_read_word_data(client, ak8975_index_to_reg[index]);
2, (u8 *)&meas_reg);
if (ret < 0) { if (ret < 0) {
dev_err(&client->dev, "Read axis data fails\n"); dev_err(&client->dev, "Read axis data fails\n");
goto exit; goto exit;
} }
meas_reg = ret;
mutex_unlock(&data->lock); mutex_unlock(&data->lock);