Commit 8293a60c authored by David Lechner's avatar David Lechner Committed by Jonathan Cameron
Browse files

iio: adc: mcp3564: use devm_regulator_get_enable_read_voltage() 



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: default avatarDavid Lechner <dlechner@baylibre.com>
Reviewed-by: default avatarMarius Cristea <marius.cristea@microchip.com>
Link: https://patch.msgid.link/20240723-iio-regulator-refactor-round-3-v2-1-ae9291201785@baylibre.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent f44e94af

drivers/iio/adc/mcp3564.c

+16 −38
Original line number Diff line number Diff line
@@ -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;