Commit baa781e1 authored by Julien Stephan's avatar Julien Stephan Committed by Jonathan Cameron
Browse files

iio: adc: ad7380: prepare for parts with more channels 



The current driver supports only parts with 2 channels.
In order to prepare the support of new compatible ADCs with more
channels, this commit:
  - defines MAX_NUM_CHANNEL to specify the maximum number of
    channels currently supported by the driver
  - adds available_scan_mask member in ad7380_chip_info structure
  - fixes spi xfer struct len depending on number of channels
  - fixes scan_data.raw buffer size to handle more channels
  - adds a timing specifications structure in ad7380_chip_info structure

Signed-off-by: default avatarJulien Stephan <jstephan@baylibre.com>
Link: https://lore.kernel.org/r/20240528-adding-new-ad738x-driver-v7-5-4cd70a4c12c8@baylibre.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 2920b6ee

drivers/iio/adc/ad7380.c

+33 −10
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <linux/iio/trigger_consumer.h>

#include <linux/iio/triggered_buffer.h>



#define MAX_NUM_CHANNELS		2

/* 2.5V internal reference voltage */

#define AD7380_INTERNAL_REF_MV		2500
@@ -63,12 +64,19 @@ 
#define AD7380_ALERT_LOW_TH		GENMASK(11, 0)

#define AD7380_ALERT_HIGH_TH		GENMASK(11, 0)



#define T_CONVERT_NS 190		/* conversion time */

struct ad7380_timing_specs {

	const unsigned int t_csh_ns;	/* CS minimum high time */

};



struct ad7380_chip_info {

	const char *name;

	const struct iio_chan_spec *channels;

	unsigned int num_channels;

	const char * const *vcm_supplies;

	unsigned int num_vcm_supplies;

	const unsigned long *available_scan_masks;

	const struct ad7380_timing_specs *timing_specs;

};



#define AD7380_CHANNEL(index, bits, diff) {			\
@@ -113,16 +121,24 @@ static const unsigned long ad7380_2_channel_scan_masks[] = { 
	0

};



static const struct ad7380_timing_specs ad7380_timing = {

	.t_csh_ns = 10,

};



static const struct ad7380_chip_info ad7380_chip_info = {

	.name = "ad7380",

	.channels = ad7380_channels,

	.num_channels = ARRAY_SIZE(ad7380_channels),

	.available_scan_masks = ad7380_2_channel_scan_masks,

	.timing_specs = &ad7380_timing,

};



static const struct ad7380_chip_info ad7381_chip_info = {

	.name = "ad7381",

	.channels = ad7381_channels,

	.num_channels = ARRAY_SIZE(ad7381_channels),

	.available_scan_masks = ad7380_2_channel_scan_masks,

	.timing_specs = &ad7380_timing,

};



static const struct ad7380_chip_info ad7383_chip_info = {
@@ -131,6 +147,8 @@ static const struct ad7380_chip_info ad7383_chip_info = { 
	.num_channels = ARRAY_SIZE(ad7383_channels),

	.vcm_supplies = ad7380_2_channel_vcm_supplies,

	.num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),

	.available_scan_masks = ad7380_2_channel_scan_masks,

	.timing_specs = &ad7380_timing,

};



static const struct ad7380_chip_info ad7384_chip_info = {
@@ -139,6 +157,8 @@ static const struct ad7380_chip_info ad7384_chip_info = { 
	.num_channels = ARRAY_SIZE(ad7384_channels),

	.vcm_supplies = ad7380_2_channel_vcm_supplies,

	.num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),

	.available_scan_masks = ad7380_2_channel_scan_masks,

	.timing_specs = &ad7380_timing,

};



struct ad7380_state {
@@ -146,15 +166,16 @@ struct ad7380_state { 
	struct spi_device *spi;

	struct regmap *regmap;

	unsigned int vref_mv;

	unsigned int vcm_mv[2];

	unsigned int vcm_mv[MAX_NUM_CHANNELS];

	/*

	 * DMA (thus cache coherency maintenance) requires the

	 * transfer buffers to live in their own cache lines.

	 * Make the buffer large enough for 2 16-bit samples and one 64-bit

	 * Make the buffer large enough for MAX_NUM_CHANNELS 16-bit samples and one 64-bit

	 * aligned 64 bit timestamp.

	 * As MAX_NUM_CHANNELS is 2 the layout of the structure is the same for all parts

	 */

	struct {

		u16 raw[2];

		u16 raw[MAX_NUM_CHANNELS];



		s64 ts __aligned(8);

	} scan_data __aligned(IIO_DMA_MINALIGN);
@@ -192,7 +213,7 @@ static int ad7380_regmap_reg_read(void *context, unsigned int reg, 
			.tx_buf = &st->tx,

			.cs_change = 1,

			.cs_change_delay = {

				.value = 10, /* t[CSH] */

				.value = st->chip_info->timing_specs->t_csh_ns,

				.unit = SPI_DELAY_UNIT_NSECS,

			},

		}, {
@@ -247,7 +268,8 @@ static irqreturn_t ad7380_trigger_handler(int irq, void *p) 
	struct ad7380_state *st = iio_priv(indio_dev);

	struct spi_transfer xfer = {

		.bits_per_word = st->chip_info->channels[0].scan_type.realbits,

		.len = 4,

		.len = (st->chip_info->num_channels - 1) *

		       BITS_TO_BYTES(st->chip_info->channels->scan_type.storagebits),

		.rx_buf = st->scan_data.raw,

	};

	int ret;
@@ -274,21 +296,22 @@ static int ad7380_read_direct(struct ad7380_state *st, 
			.speed_hz = AD7380_REG_WR_SPEED_HZ,

			.bits_per_word = chan->scan_type.realbits,

			.delay = {

				.value = 190, /* t[CONVERT] */

				.value = T_CONVERT_NS,

				.unit = SPI_DELAY_UNIT_NSECS,

			},

			.cs_change = 1,

			.cs_change_delay = {

				.value = 10, /* t[CSH] */

				.value = st->chip_info->timing_specs->t_csh_ns,

				.unit = SPI_DELAY_UNIT_NSECS,

			},

		},

		/* then read both channels */

		/* then read all channels */

		{

			.speed_hz = AD7380_REG_WR_SPEED_HZ,

			.bits_per_word = chan->scan_type.realbits,

			.rx_buf = st->scan_data.raw,

			.len = 4,

			.len = (st->chip_info->num_channels - 1) *

			       ((chan->scan_type.storagebits > 16) ? 4 : 2),

		},

	};

	int ret;
@@ -469,7 +492,7 @@ static int ad7380_probe(struct spi_device *spi) 
	indio_dev->name = st->chip_info->name;

	indio_dev->info = &ad7380_info;

	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->available_scan_masks = ad7380_2_channel_scan_masks;

	indio_dev->available_scan_masks = st->chip_info->available_scan_masks;



	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,

					      iio_pollfunc_store_time,