Commit a405b00e authored by Guenter Roeck's avatar Guenter Roeck Committed by Jonathan Cameron
Browse files

iio/adc: (max1363) Add support for external reference voltage 



Implement external reference voltage as regulator named "vref".

Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 7c3e8675

drivers/iio/adc/max1363.c

+39 −13
Original line number Diff line number Diff line
@@ -163,6 +163,8 @@ struct max1363_chip_info { 
 * @mask_low:		bitmask for enabled low thresholds

 * @thresh_high:	high threshold values

 * @thresh_low:		low threshold values

 * @vref:		Reference voltage regulator

 * @vref_uv:		Actual (external or internal) reference voltage

 */

struct max1363_state {

	struct i2c_client		*client;
@@ -182,6 +184,8 @@ struct max1363_state { 
	/* 4x unipolar first then the fours bipolar ones */

	s16				thresh_high[8];

	s16				thresh_low[8];

	struct regulator		*vref;

	u32				vref_uv;

};



#define MAX1363_MODE_SINGLE(_num, _mask) {				\
@@ -393,6 +397,8 @@ static int max1363_read_raw(struct iio_dev *indio_dev, 
{

	struct max1363_state *st = iio_priv(indio_dev);

	int ret;

	unsigned long scale_uv;



	switch (m) {

	case IIO_CHAN_INFO_RAW:

		ret = max1363_read_single_chan(indio_dev, chan, val, m);
@@ -400,16 +406,10 @@ static int max1363_read_raw(struct iio_dev *indio_dev, 
			return ret;

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:

		if ((1 << (st->chip_info->bits + 1)) >

		    st->chip_info->int_vref_mv) {

			*val = 0;

			*val2 = 500000;

		scale_uv = st->vref_uv >> st->chip_info->bits;

		*val = scale_uv / 1000;

		*val2 = (scale_uv % 1000) * 1000;

		return IIO_VAL_INT_PLUS_MICRO;

		} else {

			*val = (st->chip_info->int_vref_mv)

				>> st->chip_info->bits;

			return IIO_VAL_INT;

		}

	default:

		return -EINVAL;

	}
@@ -1390,12 +1390,16 @@ static const struct max1363_chip_info max1363_chip_info_tbl[] = { 


static int max1363_initial_setup(struct max1363_state *st)

{

	st->setupbyte = MAX1363_SETUP_AIN3_IS_AIN3_REF_IS_VDD

		| MAX1363_SETUP_POWER_UP_INT_REF

		| MAX1363_SETUP_INT_CLOCK

	st->setupbyte = MAX1363_SETUP_INT_CLOCK

		| MAX1363_SETUP_UNIPOLAR

		| MAX1363_SETUP_NORESET;



	if (st->vref)

		st->setupbyte |= MAX1363_SETUP_AIN3_IS_REF_EXT_TO_REF;

	else

		st->setupbyte |= MAX1363_SETUP_POWER_UP_INT_REF

		  | MAX1363_SETUP_AIN3_IS_AIN3_REF_IS_INT;



	/* Set scan mode writes the config anyway so wait until then */

	st->setupbyte = MAX1363_SETUP_BYTE(st->setupbyte);

	st->current_mode = &max1363_mode_table[st->chip_info->default_mode];
@@ -1491,6 +1495,7 @@ static int max1363_probe(struct i2c_client *client, 
	int ret;

	struct max1363_state *st;

	struct iio_dev *indio_dev;

	struct regulator *vref;



	indio_dev = iio_device_alloc(sizeof(struct max1363_state));

	if (indio_dev == NULL) {
@@ -1521,6 +1526,23 @@ static int max1363_probe(struct i2c_client *client, 
	st->chip_info = &max1363_chip_info_tbl[id->driver_data];

	st->client = client;



	st->vref_uv = st->chip_info->int_vref_mv * 1000;

	vref = devm_regulator_get(&client->dev, "vref");

	if (!IS_ERR(vref)) {

		int vref_uv;



		ret = regulator_enable(vref);

		if (ret)

			goto error_disable_reg;

		st->vref = vref;

		vref_uv = regulator_get_voltage(vref);

		if (vref_uv <= 0) {

			ret = -EINVAL;

			goto error_disable_reg;

		}

		st->vref_uv = vref_uv;

	}



	ret = max1363_alloc_scan_masks(indio_dev);

	if (ret)

		goto error_disable_reg;
@@ -1562,6 +1584,8 @@ static int max1363_probe(struct i2c_client *client, 
error_uninit_buffer:

	iio_triggered_buffer_cleanup(indio_dev);

error_disable_reg:

	if (st->vref)

		regulator_disable(st->vref);

	regulator_disable(st->reg);

error_unregister_map:

	iio_map_array_unregister(indio_dev);
@@ -1578,6 +1602,8 @@ static int max1363_remove(struct i2c_client *client) 


	iio_device_unregister(indio_dev);

	iio_triggered_buffer_cleanup(indio_dev);

	if (st->vref)

		regulator_disable(st->vref);

	regulator_disable(st->reg);

	iio_map_array_unregister(indio_dev);

	iio_device_free(indio_dev);