/*
* Emits the raw flux value for the x, y, or z axis.
*/
static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
{
struct ak8975_data *data = iio_priv(indio_dev);
struct i2c_client *client = data->client;
u16 meas_reg;
s16 raw;
int ret;
mutex_lock(&data->lock);
/* Set up the device for taking a sample. */
ret = ak8975_write_data(client,
AK8975_REG_CNTL,
AK8975_REG_CNTL_MODE_ONCE,
AK8975_REG_CNTL_MODE_MASK,
AK8975_REG_CNTL_MODE_SHIFT);
if (ret < 0) {
dev_err(&client->dev, "Error in setting operating mode\n");
goto exit;
}
/* Wait for the conversion to complete. */
if (gpio_is_valid(data->eoc_gpio))
ret = wait_conversion_complete_gpio(data);
else
ret = wait_conversion_complete_polled(data);
if (ret < 0)
goto exit;
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 (ret & (AK8975_REG_ST2_DERR_MASK |
AK8975_REG_ST2_HOFL_MASK)) {
dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
ret = -EINVAL;
goto exit;
}
}
/* Read the flux value from the appropriate register
(the register is specified in the iio device attributes). */
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);
/* Endian conversion of the measured values. */
raw = (s16) (le16_to_cpu(meas_reg));
/* Clamp to valid range. */
raw = clamp_t(s16, raw, -4096, 4095);
*val = raw;
return IIO_VAL_INT;
exit:
mutex_unlock(&data->lock);
return ret;
}
/*
* Emits the raw flux value for the x, y, or z axis.
*/
static ssize_t show_raw(struct device *dev, struct device_attribute *devattr,
char *buf)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ak8975_data *data = indio_dev->dev_data;
struct i2c_client *client = data->client;
struct iio_dev_attr *this_attr = to_iio_dev_attr(devattr);
u16 meas_reg;
s16 raw;
u8 read_status;
int ret;
mutex_lock(&data->lock);
if (data->mode == 0) {
dev_err(&client->dev, "Operating mode is in power down mode\n");
ret = -EBUSY;
goto exit;
}
/* Set up the device for taking a sample. */
ret = ak8975_write_data(client,
AK8975_REG_CNTL,
AK8975_REG_CNTL_MODE_ONCE,
AK8975_REG_CNTL_MODE_MASK,
AK8975_REG_CNTL_MODE_SHIFT);
if (ret < 0) {
dev_err(&client->dev, "Error in setting operating mode\n");
goto exit;
}
/* Wait for the conversion to complete. */
if (data->eoc_gpio)
ret = wait_conversion_complete_gpio(data);
else
ret = wait_conversion_complete_polled(data);
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 < 0) {
dev_err(&client->dev, "Error in reading ST2\n");
goto exit;
}
if (read_status & (AK8975_REG_ST2_DERR_MASK |
AK8975_REG_ST2_HOFL_MASK)) {
dev_err(&client->dev, "ST2 status error 0x%x\n",
read_status);
ret = -EINVAL;
goto exit;
}
}
/* Read the flux value from the appropriate register
(the register is specified in the iio device attributes). */
ret = ak8975_read_data(client, this_attr->address, 2, (u8 *)&meas_reg);
if (ret < 0) {
dev_err(&client->dev, "Read axis data fails\n");
goto exit;
}
mutex_unlock(&data->lock);
/* Endian conversion of the measured values. */
raw = (s16) (le16_to_cpu(meas_reg));
/* Clamp to valid range. */
raw = clamp_t(s16, raw, -4096, 4095);
return sprintf(buf, "%d\n", raw);
exit:
mutex_unlock(&data->lock);
return ret;
}
