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iio: adc: mcp3564: use devm_regulator_get_enable_read_voltage()

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This makes use of the new devm_regulator_get_enable_read_voltage()
helper function to reduce boilerplate code in the MCP3564 ADC driver.

The error message is slightly changed since there are fewer error
return paths.

Setting adc->vref_mv is consolidated into a single place to make the
logic easier to follow.

A use_internal_vref_attr local variable is added to make it more
obvious what the difference between the two iio info structures is.

The return value of the "Unknown Vref" dev_err_probe() is hard-coded to
-ENODEV instead of ret since it was getting a bit far from where ret
was set and logically that is the only value it could have.

Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Marius Cristea <marius.cristea@microchip.com>
Link: https://patch.msgid.link/20240723-iio-regulator-refactor-round-3-v2-1-ae9291201785@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
David Lechner 2024-07-23 13:59:50 -05:00 committed by Jonathan Cameron
parent f44e94afbb
commit 8293a60cb5
1 changed files with 16 additions and 38 deletions
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54
drivers/iio/adc/mcp3564.c
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@ -349,8 +349,6 @@ struct mcp3564_chip_info {
* struct mcp3564_state - working data for a ADC device
* @chip_info: chip specific data
* @spi: SPI device structure
* @vref: the regulator device used as a voltage reference in case
* external voltage reference is used
* @vref_mv: voltage reference value in miliVolts
* @lock: synchronize access to driver's state members
* @dev_addr: hardware device address
@ -369,7 +367,6 @@ struct mcp3564_chip_info {
struct mcp3564_state {
const struct mcp3564_chip_info *chip_info;
struct spi_device *spi;
struct regulator *vref;
unsigned short vref_mv;
struct mutex lock; /* Synchronize access to driver's state members */
u8 dev_addr;
@ -1085,11 +1082,6 @@ static int mcp3564_parse_fw_children(struct iio_dev *indio_dev)
return 0;
}
static void mcp3564_disable_reg(void *reg)
{
regulator_disable(reg);
}
static void mcp3564_fill_scale_tbls(struct mcp3564_state *adc)
{
unsigned int pow = adc->chip_info->resolution - 1;
@ -1110,7 +1102,7 @@ static void mcp3564_fill_scale_tbls(struct mcp3564_state *adc)
}
}
static int mcp3564_config(struct iio_dev *indio_dev)
static int mcp3564_config(struct iio_dev *indio_dev, bool *use_internal_vref_attr)
{
struct mcp3564_state *adc = iio_priv(indio_dev);
struct device *dev = &adc->spi->dev;
@ -1119,6 +1111,7 @@ static int mcp3564_config(struct iio_dev *indio_dev)
enum mcp3564_ids ids;
int ret = 0;
unsigned int tmp = 0x01;
bool internal_vref;
bool err = false;
/*
@ -1218,36 +1211,22 @@ static int mcp3564_config(struct iio_dev *indio_dev)
dev_dbg(dev, "Found %s chip\n", adc->chip_info->name);
adc->vref = devm_regulator_get_optional(dev, "vref");
if (IS_ERR(adc->vref)) {
if (PTR_ERR(adc->vref) != -ENODEV)
return dev_err_probe(dev, PTR_ERR(adc->vref),
"failed to get regulator\n");
ret = devm_regulator_get_enable_read_voltage(dev, "vref");
if (ret < 0 && ret != -ENODEV)
return dev_err_probe(dev, ret, "Failed to get vref voltage\n");
internal_vref = ret == -ENODEV;
adc->vref_mv = internal_vref ? MCP3564R_INT_VREF_MV : ret / MILLI;
*use_internal_vref_attr = internal_vref;
if (internal_vref) {
/* Check if chip has internal vref */
if (!adc->have_vref)
return dev_err_probe(dev, PTR_ERR(adc->vref),
"Unknown Vref\n");
adc->vref = NULL;
return dev_err_probe(dev, -ENODEV, "Unknown Vref\n");
dev_dbg(dev, "%s: Using internal Vref\n", __func__);
} else {
ret = regulator_enable(adc->vref);
if (ret)
return ret;
ret = devm_add_action_or_reset(dev, mcp3564_disable_reg,
adc->vref);
if (ret)
return ret;
dev_dbg(dev, "%s: Using External Vref\n", __func__);
ret = regulator_get_voltage(adc->vref);
if (ret < 0)
return dev_err_probe(dev, ret,
"Failed to read vref regulator\n");
adc->vref_mv = ret / MILLI;
}
ret = mcp3564_parse_fw_children(indio_dev);
@ -1350,10 +1329,8 @@ static int mcp3564_config(struct iio_dev *indio_dev)
tmp_reg |= FIELD_PREP(MCP3564_CONFIG0_CLK_SEL_MASK, MCP3564_CONFIG0_USE_INT_CLK);
tmp_reg |= MCP3456_CONFIG0_BIT6_DEFAULT;
if (!adc->vref) {
if (internal_vref)
tmp_reg |= FIELD_PREP(MCP3456_CONFIG0_VREF_MASK, 1);
adc->vref_mv = MCP3564R_INT_VREF_MV;
}
ret = mcp3564_write_8bits(adc, MCP3564_CONFIG0_REG, tmp_reg);
@ -1412,6 +1389,7 @@ static int mcp3564_probe(struct spi_device *spi)
int ret;
struct iio_dev *indio_dev;
struct mcp3564_state *adc;
bool use_internal_vref_attr;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
if (!indio_dev)
@ -1428,7 +1406,7 @@ static int mcp3564_probe(struct spi_device *spi)
* enable/disable certain channels
* change the sampling rate to the requested value
*/
ret = mcp3564_config(indio_dev);
ret = mcp3564_config(indio_dev, &use_internal_vref_attr);
if (ret)
return dev_err_probe(&spi->dev, ret,
"Can't configure MCP356X device\n");
@ -1440,7 +1418,7 @@ static int mcp3564_probe(struct spi_device *spi)
indio_dev->name = adc->chip_info->name;
indio_dev->modes = INDIO_DIRECT_MODE;
if (!adc->vref)
if (use_internal_vref_attr)
indio_dev->info = &mcp3564r_info;
else
indio_dev->info = &mcp3564_info;