Commit 949abd1c authored by Esteban Blanc's avatar Esteban Blanc Committed by Jonathan Cameron
Browse files

iio: adc: ad4030: add averaging support 



This add support for the averaging mode of AD4030 using oversampling IIO
attribute

Signed-off-by: default avatarEsteban Blanc <eblanc@baylibre.com>
Link: https://patch.msgid.link/20250214-eblanc-ad4630_v1-v4-3-135dd66cab6a@baylibre.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 0cb8b324

drivers/iio/adc/ad4030.c

+119 −17
Original line number Diff line number Diff line
@@ -112,6 +112,11 @@ enum ad4030_out_mode { 
	AD4030_OUT_DATA_MD_32_PATTERN,

};



enum {

	AD4030_SCAN_TYPE_NORMAL,

	AD4030_SCAN_TYPE_AVG,

};



struct ad4030_chip_info {

	const char *name;

	const unsigned long *available_masks;
@@ -127,10 +132,12 @@ struct ad4030_state { 
	struct spi_device *spi;

	struct regmap *regmap;

	const struct ad4030_chip_info *chip;

	const struct iio_scan_type *current_scan_type;

	struct gpio_desc *cnv_gpio;

	int vref_uv;

	int vio_uv;

	int offset_avail[3];

	unsigned int avg_log2;

	enum ad4030_out_mode mode;



	/*
@@ -184,7 +191,11 @@ struct ad4030_state { 
 * - voltage0-voltage1

 * - voltage2-voltage3

 */

#define AD4030_CHAN_DIFF(_idx, _storage, _real, _shift) {		\

#define AD4030_CHAN_DIFF(_idx, _scan_type) {				\

	.info_mask_shared_by_all =					\

		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),			\

	.info_mask_shared_by_all_available =				\

		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),			\

	.info_mask_separate = BIT(IIO_CHAN_INFO_SCALE) |		\

		BIT(IIO_CHAN_INFO_CALIBSCALE) |				\

		BIT(IIO_CHAN_INFO_CALIBBIAS) |				\
@@ -198,15 +209,17 @@ struct ad4030_state { 
	.channel2 = (_idx) * 2 + 1,					\

	.scan_index = (_idx),						\

	.differential = true,						\

	.scan_type = {							\

		.sign = 's',						\

		.storagebits = _storage,				\

		.realbits = _real,					\

		.shift = _shift,					\

		.endianness = IIO_BE,					\

	},								\

	.has_ext_scan_type = 1,						\

	.ext_scan_type = _scan_type,					\

	.num_ext_scan_type = ARRAY_SIZE(_scan_type),			\

}



static const int ad4030_average_modes[] = {

	1, 2, 4, 8, 16, 32, 64, 128,

	256, 512, 1024, 2048, 4096, 8192, 16384, 32768,

	65536,

};



static int ad4030_enter_config_mode(struct ad4030_state *st)

{

	st->tx_data[0] = AD4030_REG_ACCESS;
@@ -356,10 +369,13 @@ static int ad4030_get_chan_scale(struct iio_dev *indio_dev, 
				 int *val2)

{

	struct ad4030_state *st = iio_priv(indio_dev);

	const struct iio_scan_type *scan_type;



	if (chan->differential) {

		scan_type = iio_get_current_scan_type(indio_dev,

						      st->chip->channels);

		*val = (st->vref_uv * 2) / MILLI;

		*val2 = chan->scan_type.realbits;

		*val2 = scan_type->realbits;

		return IIO_VAL_FRACTIONAL_LOG2;

	}
@@ -474,6 +490,27 @@ static int ad4030_set_chan_calibbias(struct iio_dev *indio_dev, 
				 st->tx_data, AD4030_REG_OFFSET_BYTES_NB);

}



static int ad4030_set_avg_frame_len(struct iio_dev *dev, int avg_val)

{

	struct ad4030_state *st = iio_priv(dev);

	unsigned int avg_log2 = ilog2(avg_val);

	unsigned int last_avg_idx = ARRAY_SIZE(ad4030_average_modes) - 1;

	int ret;



	if (avg_val < 0 || avg_val > ad4030_average_modes[last_avg_idx])

		return -EINVAL;



	ret = regmap_write(st->regmap, AD4030_REG_AVG,

			   AD4030_REG_AVG_MASK_AVG_SYNC |

			   FIELD_PREP(AD4030_REG_AVG_MASK_AVG_VAL, avg_log2));

	if (ret)

		return ret;



	st->avg_log2 = avg_log2;



	return 0;

}



static bool ad4030_is_common_byte_asked(struct ad4030_state *st,

					unsigned int mask)

{
@@ -484,11 +521,18 @@ static int ad4030_set_mode(struct iio_dev *indio_dev, unsigned long mask) 
{

	struct ad4030_state *st = iio_priv(indio_dev);



	if (ad4030_is_common_byte_asked(st, mask))

	if (st->avg_log2 > 0)

		st->mode = AD4030_OUT_DATA_MD_30_AVERAGED_DIFF;

	else if (ad4030_is_common_byte_asked(st, mask))

		st->mode = AD4030_OUT_DATA_MD_24_DIFF_8_COM;

	else

		st->mode = AD4030_OUT_DATA_MD_DIFF;



	st->current_scan_type = iio_get_current_scan_type(indio_dev,

							  st->chip->channels);

	if (IS_ERR(st->current_scan_type))

		return PTR_ERR(st->current_scan_type);



	return regmap_update_bits(st->regmap, AD4030_REG_MODES,

				  AD4030_REG_MODES_MASK_OUT_DATA_MODE,

				  st->mode);
@@ -497,9 +541,11 @@ static int ad4030_set_mode(struct iio_dev *indio_dev, unsigned long mask) 
static int ad4030_conversion(struct iio_dev *indio_dev)

{

	struct ad4030_state *st = iio_priv(indio_dev);

	const struct iio_scan_type scan_type = indio_dev->channels->scan_type;

	unsigned char diff_realbytes = BITS_TO_BYTES(scan_type.realbits);

	unsigned char diff_realbytes =

		BITS_TO_BYTES(st->current_scan_type->realbits);

	unsigned int bytes_to_read;

	unsigned long cnv_nb = BIT(st->avg_log2);

	unsigned int i;

	int ret;



	/* Number of bytes for one differential channel */
@@ -510,10 +556,12 @@ static int ad4030_conversion(struct iio_dev *indio_dev) 
	/* Mulitiply by the number of hardware channels */

	bytes_to_read *= st->chip->num_voltage_inputs;



	for (i = 0; i < cnv_nb; i++) {

		gpiod_set_value_cansleep(st->cnv_gpio, 1);

		ndelay(AD4030_TCNVH_NS);

		gpiod_set_value_cansleep(st->cnv_gpio, 0);

		ndelay(st->chip->tcyc_ns);

	}



	ret = spi_read(st->spi, st->rx_data.raw, bytes_to_read);

	if (ret)
@@ -593,6 +641,12 @@ static int ad4030_read_avail(struct iio_dev *indio_dev, 
		*type = IIO_VAL_INT_PLUS_NANO;

		return IIO_AVAIL_RANGE;



	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:

		*vals = ad4030_average_modes;

		*type = IIO_VAL_INT;

		*length = ARRAY_SIZE(ad4030_average_modes);

		return IIO_AVAIL_LIST;



	default:

		return -EINVAL;

	}
@@ -602,6 +656,8 @@ static int ad4030_read_raw_dispatch(struct iio_dev *indio_dev, 
				    struct iio_chan_spec const *chan, int *val,

				    int *val2, long info)

{

	struct ad4030_state *st = iio_priv(indio_dev);



	switch (info) {

	case IIO_CHAN_INFO_RAW:

		return ad4030_single_conversion(indio_dev, chan, val);
@@ -612,6 +668,10 @@ static int ad4030_read_raw_dispatch(struct iio_dev *indio_dev, 
	case IIO_CHAN_INFO_CALIBBIAS:

		return ad4030_get_chan_calibbias(indio_dev, chan, val);



	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:

		*val = BIT(st->avg_log2);

		return IIO_VAL_INT;



	default:

		return -EINVAL;

	}
@@ -650,6 +710,9 @@ static int ad4030_write_raw_dispatch(struct iio_dev *indio_dev, 
			return -EINVAL;

		return ad4030_set_chan_calibbias(indio_dev, chan, val);



	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:

		return ad4030_set_avg_frame_len(indio_dev, val);



	default:

		return -EINVAL;

	}
@@ -701,12 +764,21 @@ static int ad4030_read_label(struct iio_dev *indio_dev, 
	return sprintf(label, "common-mode%lu\n", chan->address);

}



static int ad4030_get_current_scan_type(const struct iio_dev *indio_dev,

					const struct iio_chan_spec *chan)

{

	struct ad4030_state *st = iio_priv(indio_dev);



	return st->avg_log2 ? AD4030_SCAN_TYPE_AVG : AD4030_SCAN_TYPE_NORMAL;

}



static const struct iio_info ad4030_iio_info = {

	.read_avail = ad4030_read_avail,

	.read_raw = ad4030_read_raw,

	.write_raw = ad4030_write_raw,

	.debugfs_reg_access = ad4030_reg_access,

	.read_label = ad4030_read_label,

	.get_current_scan_type = ad4030_get_current_scan_type,

};



static int ad4030_buffer_preenable(struct iio_dev *indio_dev)
@@ -714,8 +786,21 @@ static int ad4030_buffer_preenable(struct iio_dev *indio_dev) 
	return ad4030_set_mode(indio_dev, *indio_dev->active_scan_mask);

}



static bool ad4030_validate_scan_mask(struct iio_dev *indio_dev,

				      const unsigned long *scan_mask)

{

	struct ad4030_state *st = iio_priv(indio_dev);



	/* Asking for both common channels and averaging */

	if (st->avg_log2 && ad4030_is_common_byte_asked(st, *scan_mask))

		return false;



	return true;

}



static const struct iio_buffer_setup_ops ad4030_buffer_setup_ops = {

	.preenable = ad4030_buffer_preenable,

	.validate_scan_mask = ad4030_validate_scan_mask,

};



static int ad4030_regulators_get(struct ad4030_state *st)
@@ -881,11 +966,28 @@ static const unsigned long ad4030_channel_masks[] = { 
	0,

};



static const struct iio_scan_type ad4030_24_scan_types[] = {

	[AD4030_SCAN_TYPE_NORMAL] = {

		.sign = 's',

		.storagebits = 32,

		.realbits = 24,

		.shift = 8,

		.endianness = IIO_BE,

	},

	[AD4030_SCAN_TYPE_AVG] = {

		.sign = 's',

		.storagebits = 32,

		.realbits = 30,

		.shift = 2,

		.endianness = IIO_BE,

	},

};



static const struct ad4030_chip_info ad4030_24_chip_info = {

	.name = "ad4030-24",

	.available_masks = ad4030_channel_masks,

	.channels = {

		AD4030_CHAN_DIFF(0, 32, 24, 8),

		AD4030_CHAN_DIFF(0, ad4030_24_scan_types),

		AD4030_CHAN_CMO(1, 0),

		IIO_CHAN_SOFT_TIMESTAMP(2),

	},