Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1046 insertions, 0 deletions

diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
new file mode 100644
index 0000000000..b9b206fcd7
--- /dev/null
+++ b/drivers/iio/adc/ad7124.c
@@ -0,0 +1,1046 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * AD7124 SPI ADC driver
+ *
+ * Copyright 2018 Analog Devices Inc.
+ */
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/kfifo.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/adc/ad_sigma_delta.h>
+#include <linux/iio/sysfs.h>
+
+/* AD7124 registers */
+#define AD7124_COMMS			0x00
+#define AD7124_STATUS			0x00
+#define AD7124_ADC_CONTROL		0x01
+#define AD7124_DATA			0x02
+#define AD7124_IO_CONTROL_1		0x03
+#define AD7124_IO_CONTROL_2		0x04
+#define AD7124_ID			0x05
+#define AD7124_ERROR			0x06
+#define AD7124_ERROR_EN		0x07
+#define AD7124_MCLK_COUNT		0x08
+#define AD7124_CHANNEL(x)		(0x09 + (x))
+#define AD7124_CONFIG(x)		(0x19 + (x))
+#define AD7124_FILTER(x)		(0x21 + (x))
+#define AD7124_OFFSET(x)		(0x29 + (x))
+#define AD7124_GAIN(x)			(0x31 + (x))
+
+/* AD7124_STATUS */
+#define AD7124_STATUS_POR_FLAG_MSK	BIT(4)
+
+/* AD7124_ADC_CONTROL */
+#define AD7124_ADC_STATUS_EN_MSK	BIT(10)
+#define AD7124_ADC_STATUS_EN(x)		FIELD_PREP(AD7124_ADC_STATUS_EN_MSK, x)
+#define AD7124_ADC_CTRL_REF_EN_MSK	BIT(8)
+#define AD7124_ADC_CTRL_REF_EN(x)	FIELD_PREP(AD7124_ADC_CTRL_REF_EN_MSK, x)
+#define AD7124_ADC_CTRL_PWR_MSK	GENMASK(7, 6)
+#define AD7124_ADC_CTRL_PWR(x)		FIELD_PREP(AD7124_ADC_CTRL_PWR_MSK, x)
+#define AD7124_ADC_CTRL_MODE_MSK	GENMASK(5, 2)
+#define AD7124_ADC_CTRL_MODE(x)	FIELD_PREP(AD7124_ADC_CTRL_MODE_MSK, x)
+
+/* AD7124 ID */
+#define AD7124_DEVICE_ID_MSK		GENMASK(7, 4)
+#define AD7124_DEVICE_ID_GET(x)		FIELD_GET(AD7124_DEVICE_ID_MSK, x)
+#define AD7124_SILICON_REV_MSK		GENMASK(3, 0)
+#define AD7124_SILICON_REV_GET(x)	FIELD_GET(AD7124_SILICON_REV_MSK, x)
+
+#define CHIPID_AD7124_4			0x0
+#define CHIPID_AD7124_8			0x1
+
+/* AD7124_CHANNEL_X */
+#define AD7124_CHANNEL_EN_MSK		BIT(15)
+#define AD7124_CHANNEL_EN(x)		FIELD_PREP(AD7124_CHANNEL_EN_MSK, x)
+#define AD7124_CHANNEL_SETUP_MSK	GENMASK(14, 12)
+#define AD7124_CHANNEL_SETUP(x)	FIELD_PREP(AD7124_CHANNEL_SETUP_MSK, x)
+#define AD7124_CHANNEL_AINP_MSK	GENMASK(9, 5)
+#define AD7124_CHANNEL_AINP(x)		FIELD_PREP(AD7124_CHANNEL_AINP_MSK, x)
+#define AD7124_CHANNEL_AINM_MSK	GENMASK(4, 0)
+#define AD7124_CHANNEL_AINM(x)		FIELD_PREP(AD7124_CHANNEL_AINM_MSK, x)
+
+/* AD7124_CONFIG_X */
+#define AD7124_CONFIG_BIPOLAR_MSK	BIT(11)
+#define AD7124_CONFIG_BIPOLAR(x)	FIELD_PREP(AD7124_CONFIG_BIPOLAR_MSK, x)
+#define AD7124_CONFIG_REF_SEL_MSK	GENMASK(4, 3)
+#define AD7124_CONFIG_REF_SEL(x)	FIELD_PREP(AD7124_CONFIG_REF_SEL_MSK, x)
+#define AD7124_CONFIG_PGA_MSK		GENMASK(2, 0)
+#define AD7124_CONFIG_PGA(x)		FIELD_PREP(AD7124_CONFIG_PGA_MSK, x)
+#define AD7124_CONFIG_IN_BUFF_MSK	GENMASK(6, 5)
+#define AD7124_CONFIG_IN_BUFF(x)	FIELD_PREP(AD7124_CONFIG_IN_BUFF_MSK, x)
+
+/* AD7124_FILTER_X */
+#define AD7124_FILTER_FS_MSK		GENMASK(10, 0)
+#define AD7124_FILTER_FS(x)		FIELD_PREP(AD7124_FILTER_FS_MSK, x)
+#define AD7124_FILTER_TYPE_MSK		GENMASK(23, 21)
+#define AD7124_FILTER_TYPE_SEL(x)	FIELD_PREP(AD7124_FILTER_TYPE_MSK, x)
+
+#define AD7124_SINC3_FILTER 2
+#define AD7124_SINC4_FILTER 0
+
+#define AD7124_CONF_ADDR_OFFSET	20
+#define AD7124_MAX_CONFIGS	8
+#define AD7124_MAX_CHANNELS	16
+
+enum ad7124_ids {
+	ID_AD7124_4,
+	ID_AD7124_8,
+};
+
+enum ad7124_ref_sel {
+	AD7124_REFIN1,
+	AD7124_REFIN2,
+	AD7124_INT_REF,
+	AD7124_AVDD_REF,
+};
+
+enum ad7124_power_mode {
+	AD7124_LOW_POWER,
+	AD7124_MID_POWER,
+	AD7124_FULL_POWER,
+};
+
+static const unsigned int ad7124_gain[8] = {
+	1, 2, 4, 8, 16, 32, 64, 128
+};
+
+static const unsigned int ad7124_reg_size[] = {
+	1, 2, 3, 3, 2, 1, 3, 3, 1, 2, 2, 2, 2,
+	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+	2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3,
+	3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+	3, 3, 3, 3, 3
+};
+
+static const int ad7124_master_clk_freq_hz[3] = {
+	[AD7124_LOW_POWER] = 76800,
+	[AD7124_MID_POWER] = 153600,
+	[AD7124_FULL_POWER] = 614400,
+};
+
+static const char * const ad7124_ref_names[] = {
+	[AD7124_REFIN1] = "refin1",
+	[AD7124_REFIN2] = "refin2",
+	[AD7124_INT_REF] = "int",
+	[AD7124_AVDD_REF] = "avdd",
+};
+
+struct ad7124_chip_info {
+	const char *name;
+	unsigned int chip_id;
+	unsigned int num_inputs;
+};
+
+struct ad7124_channel_config {
+	bool live;
+	unsigned int cfg_slot;
+	enum ad7124_ref_sel refsel;
+	bool bipolar;
+	bool buf_positive;
+	bool buf_negative;
+	unsigned int vref_mv;
+	unsigned int pga_bits;
+	unsigned int odr;
+	unsigned int odr_sel_bits;
+	unsigned int filter_type;
+};
+
+struct ad7124_channel {
+	unsigned int nr;
+	struct ad7124_channel_config cfg;
+	unsigned int ain;
+	unsigned int slot;
+};
+
+struct ad7124_state {
+	const struct ad7124_chip_info *chip_info;
+	struct ad_sigma_delta sd;
+	struct ad7124_channel *channels;
+	struct regulator *vref[4];
+	struct clk *mclk;
+	unsigned int adc_control;
+	unsigned int num_channels;
+	struct mutex cfgs_lock; /* lock for configs access */
+	unsigned long cfg_slots_status; /* bitmap with slot status (1 means it is used) */
+	DECLARE_KFIFO(live_cfgs_fifo, struct ad7124_channel_config *, AD7124_MAX_CONFIGS);
+};
+
+static const struct iio_chan_spec ad7124_channel_template = {
+	.type = IIO_VOLTAGE,
+	.indexed = 1,
+	.differential = 1,
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+		BIT(IIO_CHAN_INFO_SCALE) |
+		BIT(IIO_CHAN_INFO_OFFSET) |
+		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+	.scan_type = {
+		.sign = 'u',
+		.realbits = 24,
+		.storagebits = 32,
+		.endianness = IIO_BE,
+	},
+};
+
+static struct ad7124_chip_info ad7124_chip_info_tbl[] = {
+	[ID_AD7124_4] = {
+		.name = "ad7124-4",
+		.chip_id = CHIPID_AD7124_4,
+		.num_inputs = 8,
+	},
+	[ID_AD7124_8] = {
+		.name = "ad7124-8",
+		.chip_id = CHIPID_AD7124_8,
+		.num_inputs = 16,
+	},
+};
+
+static int ad7124_find_closest_match(const int *array,
+				     unsigned int size, int val)
+{
+	int i, idx;
+	unsigned int diff_new, diff_old;
+
+	diff_old = U32_MAX;
+	idx = 0;
+
+	for (i = 0; i < size; i++) {
+		diff_new = abs(val - array[i]);
+		if (diff_new < diff_old) {
+			diff_old = diff_new;
+			idx = i;
+		}
+	}
+
+	return idx;
+}
+
+static int ad7124_spi_write_mask(struct ad7124_state *st,
+				 unsigned int addr,
+				 unsigned long mask,
+				 unsigned int val,
+				 unsigned int bytes)
+{
+	unsigned int readval;
+	int ret;
+
+	ret = ad_sd_read_reg(&st->sd, addr, bytes, &readval);
+	if (ret < 0)
+		return ret;
+
+	readval &= ~mask;
+	readval |= val;
+
+	return ad_sd_write_reg(&st->sd, addr, bytes, readval);
+}
+
+static int ad7124_set_mode(struct ad_sigma_delta *sd,
+			   enum ad_sigma_delta_mode mode)
+{
+	struct ad7124_state *st = container_of(sd, struct ad7124_state, sd);
+
+	st->adc_control &= ~AD7124_ADC_CTRL_MODE_MSK;
+	st->adc_control |= AD7124_ADC_CTRL_MODE(mode);
+
+	return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control);
+}
+
+static void ad7124_set_channel_odr(struct ad7124_state *st, unsigned int channel, unsigned int odr)
+{
+	unsigned int fclk, odr_sel_bits;
+
+	fclk = clk_get_rate(st->mclk);
+	/*
+	 * FS[10:0] = fCLK / (fADC x 32) where:
+	 * fADC is the output data rate
+	 * fCLK is the master clock frequency
+	 * FS[10:0] are the bits in the filter register
+	 * FS[10:0] can have a value from 1 to 2047
+	 */
+	odr_sel_bits = DIV_ROUND_CLOSEST(fclk, odr * 32);
+	if (odr_sel_bits < 1)
+		odr_sel_bits = 1;
+	else if (odr_sel_bits > 2047)
+		odr_sel_bits = 2047;
+
+	if (odr_sel_bits != st->channels[channel].cfg.odr_sel_bits)
+		st->channels[channel].cfg.live = false;
+
+	/* fADC = fCLK / (FS[10:0] x 32) */
+	st->channels[channel].cfg.odr = DIV_ROUND_CLOSEST(fclk, odr_sel_bits * 32);
+	st->channels[channel].cfg.odr_sel_bits = odr_sel_bits;
+}
+
+static int ad7124_get_3db_filter_freq(struct ad7124_state *st,
+				      unsigned int channel)
+{
+	unsigned int fadc;
+
+	fadc = st->channels[channel].cfg.odr;
+
+	switch (st->channels[channel].cfg.filter_type) {
+	case AD7124_SINC3_FILTER:
+		return DIV_ROUND_CLOSEST(fadc * 230, 1000);
+	case AD7124_SINC4_FILTER:
+		return DIV_ROUND_CLOSEST(fadc * 262, 1000);
+	default:
+		return -EINVAL;
+	}
+}
+
+static void ad7124_set_3db_filter_freq(struct ad7124_state *st, unsigned int channel,
+				       unsigned int freq)
+{
+	unsigned int sinc4_3db_odr;
+	unsigned int sinc3_3db_odr;
+	unsigned int new_filter;
+	unsigned int new_odr;
+
+	sinc4_3db_odr = DIV_ROUND_CLOSEST(freq * 1000, 230);
+	sinc3_3db_odr = DIV_ROUND_CLOSEST(freq * 1000, 262);
+
+	if (sinc4_3db_odr > sinc3_3db_odr) {
+		new_filter = AD7124_SINC3_FILTER;
+		new_odr = sinc4_3db_odr;
+	} else {
+		new_filter = AD7124_SINC4_FILTER;
+		new_odr = sinc3_3db_odr;
+	}
+
+	if (new_odr != st->channels[channel].cfg.odr)
+		st->channels[channel].cfg.live = false;
+
+	st->channels[channel].cfg.filter_type = new_filter;
+	st->channels[channel].cfg.odr = new_odr;
+}
+
+static struct ad7124_channel_config *ad7124_find_similar_live_cfg(struct ad7124_state *st,
+								  struct ad7124_channel_config *cfg)
+{
+	struct ad7124_channel_config *cfg_aux;
+	ptrdiff_t cmp_size;
+	int i;
+
+	cmp_size = (u8 *)&cfg->live - (u8 *)cfg;
+	for (i = 0; i < st->num_channels; i++) {
+		cfg_aux = &st->channels[i].cfg;
+
+		if (cfg_aux->live && !memcmp(cfg, cfg_aux, cmp_size))
+			return cfg_aux;
+	}
+
+	return NULL;
+}
+
+static int ad7124_find_free_config_slot(struct ad7124_state *st)
+{
+	unsigned int free_cfg_slot;
+
+	free_cfg_slot = find_first_zero_bit(&st->cfg_slots_status, AD7124_MAX_CONFIGS);
+	if (free_cfg_slot == AD7124_MAX_CONFIGS)
+		return -1;
+
+	return free_cfg_slot;
+}
+
+static int ad7124_init_config_vref(struct ad7124_state *st, struct ad7124_channel_config *cfg)
+{
+	unsigned int refsel = cfg->refsel;
+
+	switch (refsel) {
+	case AD7124_REFIN1:
+	case AD7124_REFIN2:
+	case AD7124_AVDD_REF:
+		if (IS_ERR(st->vref[refsel])) {
+			dev_err(&st->sd.spi->dev,
+				"Error, trying to use external voltage reference without a %s regulator.\n",
+				ad7124_ref_names[refsel]);
+			return PTR_ERR(st->vref[refsel]);
+		}
+		cfg->vref_mv = regulator_get_voltage(st->vref[refsel]);
+		/* Conversion from uV to mV */
+		cfg->vref_mv /= 1000;
+		return 0;
+	case AD7124_INT_REF:
+		cfg->vref_mv = 2500;
+		st->adc_control &= ~AD7124_ADC_CTRL_REF_EN_MSK;
+		st->adc_control |= AD7124_ADC_CTRL_REF_EN(1);
+		return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL,
+				      2, st->adc_control);
+	default:
+		dev_err(&st->sd.spi->dev, "Invalid reference %d\n", refsel);
+		return -EINVAL;
+	}
+}
+
+static int ad7124_write_config(struct ad7124_state *st, struct ad7124_channel_config *cfg,
+			       unsigned int cfg_slot)
+{
+	unsigned int tmp;
+	unsigned int val;
+	int ret;
+
+	cfg->cfg_slot = cfg_slot;
+
+	tmp = (cfg->buf_positive << 1) + cfg->buf_negative;
+	val = AD7124_CONFIG_BIPOLAR(cfg->bipolar) | AD7124_CONFIG_REF_SEL(cfg->refsel) |
+	      AD7124_CONFIG_IN_BUFF(tmp);
+	ret = ad_sd_write_reg(&st->sd, AD7124_CONFIG(cfg->cfg_slot), 2, val);
+	if (ret < 0)
+		return ret;
+
+	tmp = AD7124_FILTER_TYPE_SEL(cfg->filter_type);
+	ret = ad7124_spi_write_mask(st, AD7124_FILTER(cfg->cfg_slot), AD7124_FILTER_TYPE_MSK,
+				    tmp, 3);
+	if (ret < 0)
+		return ret;
+
+	ret = ad7124_spi_write_mask(st, AD7124_FILTER(cfg->cfg_slot), AD7124_FILTER_FS_MSK,
+				    AD7124_FILTER_FS(cfg->odr_sel_bits), 3);
+	if (ret < 0)
+		return ret;
+
+	return ad7124_spi_write_mask(st, AD7124_CONFIG(cfg->cfg_slot), AD7124_CONFIG_PGA_MSK,
+				     AD7124_CONFIG_PGA(cfg->pga_bits), 2);
+}
+
+static struct ad7124_channel_config *ad7124_pop_config(struct ad7124_state *st)
+{
+	struct ad7124_channel_config *lru_cfg;
+	struct ad7124_channel_config *cfg;
+	int ret;
+	int i;
+
+	/*
+	 * Pop least recently used config from the fifo
+	 * in order to make room for the new one
+	 */
+	ret = kfifo_get(&st->live_cfgs_fifo, &lru_cfg);
+	if (ret <= 0)
+		return NULL;
+
+	lru_cfg->live = false;
+
+	/* mark slot as free */
+	assign_bit(lru_cfg->cfg_slot, &st->cfg_slots_status, 0);
+
+	/* invalidate all other configs that pointed to this one */
+	for (i = 0; i < st->num_channels; i++) {
+		cfg = &st->channels[i].cfg;
+
+		if (cfg->cfg_slot == lru_cfg->cfg_slot)
+			cfg->live = false;
+	}
+
+	return lru_cfg;
+}
+
+static int ad7124_push_config(struct ad7124_state *st, struct ad7124_channel_config *cfg)
+{
+	struct ad7124_channel_config *lru_cfg;
+	int free_cfg_slot;
+
+	free_cfg_slot = ad7124_find_free_config_slot(st);
+	if (free_cfg_slot >= 0) {
+		/* push the new config in configs queue */
+		kfifo_put(&st->live_cfgs_fifo, cfg);
+	} else {
+		/* pop one config to make room for the new one */
+		lru_cfg = ad7124_pop_config(st);
+		if (!lru_cfg)
+			return -EINVAL;
+
+		/* push the new config in configs queue */
+		free_cfg_slot = lru_cfg->cfg_slot;
+		kfifo_put(&st->live_cfgs_fifo, cfg);
+	}
+
+	/* mark slot as used */
+	assign_bit(free_cfg_slot, &st->cfg_slots_status, 1);
+
+	return ad7124_write_config(st, cfg, free_cfg_slot);
+}
+
+static int ad7124_enable_channel(struct ad7124_state *st, struct ad7124_channel *ch)
+{
+	ch->cfg.live = true;
+	return ad_sd_write_reg(&st->sd, AD7124_CHANNEL(ch->nr), 2, ch->ain |
+			      AD7124_CHANNEL_SETUP(ch->cfg.cfg_slot) | AD7124_CHANNEL_EN(1));
+}
+
+static int ad7124_prepare_read(struct ad7124_state *st, int address)
+{
+	struct ad7124_channel_config *cfg = &st->channels[address].cfg;
+	struct ad7124_channel_config *live_cfg;
+
+	/*
+	 * Before doing any reads assign the channel a configuration.
+	 * Check if channel's config is on the device
+	 */
+	if (!cfg->live) {
+		/* check if config matches another one */
+		live_cfg = ad7124_find_similar_live_cfg(st, cfg);
+		if (!live_cfg)
+			ad7124_push_config(st, cfg);
+		else
+			cfg->cfg_slot = live_cfg->cfg_slot;
+	}
+
+	/* point channel to the config slot and enable */
+	return ad7124_enable_channel(st, &st->channels[address]);
+}
+
+static int __ad7124_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
+{
+	struct ad7124_state *st = container_of(sd, struct ad7124_state, sd);
+
+	return ad7124_prepare_read(st, channel);
+}
+
+static int ad7124_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
+{
+	struct ad7124_state *st = container_of(sd, struct ad7124_state, sd);
+	int ret;
+
+	mutex_lock(&st->cfgs_lock);
+	ret = __ad7124_set_channel(sd, channel);
+	mutex_unlock(&st->cfgs_lock);
+
+	return ret;
+}
+
+static int ad7124_append_status(struct ad_sigma_delta *sd, bool append)
+{
+	struct ad7124_state *st = container_of(sd, struct ad7124_state, sd);
+	unsigned int adc_control = st->adc_control;
+	int ret;
+
+	adc_control &= ~AD7124_ADC_STATUS_EN_MSK;
+	adc_control |= AD7124_ADC_STATUS_EN(append);
+
+	ret = ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, adc_control);
+	if (ret < 0)
+		return ret;
+
+	st->adc_control = adc_control;
+
+	return 0;
+}
+
+static int ad7124_disable_all(struct ad_sigma_delta *sd)
+{
+	struct ad7124_state *st = container_of(sd, struct ad7124_state, sd);
+	int ret;
+	int i;
+
+	for (i = 0; i < st->num_channels; i++) {
+		ret = ad7124_spi_write_mask(st, AD7124_CHANNEL(i), AD7124_CHANNEL_EN_MSK, 0, 2);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct ad_sigma_delta_info ad7124_sigma_delta_info = {
+	.set_channel = ad7124_set_channel,
+	.append_status = ad7124_append_status,
+	.disable_all = ad7124_disable_all,
+	.set_mode = ad7124_set_mode,
+	.has_registers = true,
+	.addr_shift = 0,
+	.read_mask = BIT(6),
+	.status_ch_mask = GENMASK(3, 0),
+	.data_reg = AD7124_DATA,
+	.num_slots = 8,
+	.irq_flags = IRQF_TRIGGER_FALLING,
+};
+
+static int ad7124_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long info)
+{
+	struct ad7124_state *st = iio_priv(indio_dev);
+	int idx, ret;
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		ret = ad_sigma_delta_single_conversion(indio_dev, chan, val);
+		if (ret < 0)
+			return ret;
+
+		/* After the conversion is performed, disable the channel */
+		ret = ad_sd_write_reg(&st->sd, AD7124_CHANNEL(chan->address), 2,
+				      st->channels[chan->address].ain | AD7124_CHANNEL_EN(0));
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		mutex_lock(&st->cfgs_lock);
+
+		idx = st->channels[chan->address].cfg.pga_bits;
+		*val = st->channels[chan->address].cfg.vref_mv;
+		if (st->channels[chan->address].cfg.bipolar)
+			*val2 = chan->scan_type.realbits - 1 + idx;
+		else
+			*val2 = chan->scan_type.realbits + idx;
+
+		mutex_unlock(&st->cfgs_lock);
+		return IIO_VAL_FRACTIONAL_LOG2;
+	case IIO_CHAN_INFO_OFFSET:
+		mutex_lock(&st->cfgs_lock);
+		if (st->channels[chan->address].cfg.bipolar)
+			*val = -(1 << (chan->scan_type.realbits - 1));
+		else
+			*val = 0;
+
+		mutex_unlock(&st->cfgs_lock);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		mutex_lock(&st->cfgs_lock);
+		*val = st->channels[chan->address].cfg.odr;
+		mutex_unlock(&st->cfgs_lock);
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		mutex_lock(&st->cfgs_lock);
+		*val = ad7124_get_3db_filter_freq(st, chan->scan_index);
+		mutex_unlock(&st->cfgs_lock);
+
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad7124_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val, int val2, long info)
+{
+	struct ad7124_state *st = iio_priv(indio_dev);
+	unsigned int res, gain, full_scale, vref;
+	int ret = 0;
+
+	mutex_lock(&st->cfgs_lock);
+
+	switch (info) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (val2 != 0) {
+			ret = -EINVAL;
+			break;
+		}
+
+		ad7124_set_channel_odr(st, chan->address, val);
+		break;
+	case IIO_CHAN_INFO_SCALE:
+		if (val != 0) {
+			ret = -EINVAL;
+			break;
+		}
+
+		if (st->channels[chan->address].cfg.bipolar)
+			full_scale = 1 << (chan->scan_type.realbits - 1);
+		else
+			full_scale = 1 << chan->scan_type.realbits;
+
+		vref = st->channels[chan->address].cfg.vref_mv * 1000000LL;
+		res = DIV_ROUND_CLOSEST(vref, full_scale);
+		gain = DIV_ROUND_CLOSEST(res, val2);
+		res = ad7124_find_closest_match(ad7124_gain, ARRAY_SIZE(ad7124_gain), gain);
+
+		if (st->channels[chan->address].cfg.pga_bits != res)
+			st->channels[chan->address].cfg.live = false;
+
+		st->channels[chan->address].cfg.pga_bits = res;
+		break;
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		if (val2 != 0) {
+			ret = -EINVAL;
+			break;
+		}
+
+		ad7124_set_3db_filter_freq(st, chan->address, val);
+		break;
+	default:
+		ret =  -EINVAL;
+	}
+
+	mutex_unlock(&st->cfgs_lock);
+	return ret;
+}
+
+static int ad7124_reg_access(struct iio_dev *indio_dev,
+			     unsigned int reg,
+			     unsigned int writeval,
+			     unsigned int *readval)
+{
+	struct ad7124_state *st = iio_priv(indio_dev);
+	int ret;
+
+	if (reg >= ARRAY_SIZE(ad7124_reg_size))
+		return -EINVAL;
+
+	if (readval)
+		ret = ad_sd_read_reg(&st->sd, reg, ad7124_reg_size[reg],
+				     readval);
+	else
+		ret = ad_sd_write_reg(&st->sd, reg, ad7124_reg_size[reg],
+				      writeval);
+
+	return ret;
+}
+
+static IIO_CONST_ATTR(in_voltage_scale_available,
+	"0.000001164 0.000002328 0.000004656 0.000009313 0.000018626 0.000037252 0.000074505 0.000149011 0.000298023");
+
+static struct attribute *ad7124_attributes[] = {
+	&iio_const_attr_in_voltage_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad7124_attrs_group = {
+	.attrs = ad7124_attributes,
+};
+
+static int ad7124_update_scan_mode(struct iio_dev *indio_dev,
+				   const unsigned long *scan_mask)
+{
+	struct ad7124_state *st = iio_priv(indio_dev);
+	bool bit_set;
+	int ret;
+	int i;
+
+	mutex_lock(&st->cfgs_lock);
+	for (i = 0; i < st->num_channels; i++) {
+		bit_set = test_bit(i, scan_mask);
+		if (bit_set)
+			ret = __ad7124_set_channel(&st->sd, i);
+		else
+			ret = ad7124_spi_write_mask(st, AD7124_CHANNEL(i), AD7124_CHANNEL_EN_MSK,
+						    0, 2);
+		if (ret < 0) {
+			mutex_unlock(&st->cfgs_lock);
+
+			return ret;
+		}
+	}
+
+	mutex_unlock(&st->cfgs_lock);
+
+	return 0;
+}
+
+static const struct iio_info ad7124_info = {
+	.read_raw = ad7124_read_raw,
+	.write_raw = ad7124_write_raw,
+	.debugfs_reg_access = &ad7124_reg_access,
+	.validate_trigger = ad_sd_validate_trigger,
+	.update_scan_mode = ad7124_update_scan_mode,
+	.attrs = &ad7124_attrs_group,
+};
+
+static int ad7124_soft_reset(struct ad7124_state *st)
+{
+	unsigned int readval, timeout;
+	int ret;
+
+	ret = ad_sd_reset(&st->sd, 64);
+	if (ret < 0)
+		return ret;
+
+	timeout = 100;
+	do {
+		ret = ad_sd_read_reg(&st->sd, AD7124_STATUS, 1, &readval);
+		if (ret < 0)
+			return ret;
+
+		if (!(readval & AD7124_STATUS_POR_FLAG_MSK))
+			return 0;
+
+		/* The AD7124 requires typically 2ms to power up and settle */
+		usleep_range(100, 2000);
+	} while (--timeout);
+
+	dev_err(&st->sd.spi->dev, "Soft reset failed\n");
+
+	return -EIO;
+}
+
+static int ad7124_check_chip_id(struct ad7124_state *st)
+{
+	unsigned int readval, chip_id, silicon_rev;
+	int ret;
+
+	ret = ad_sd_read_reg(&st->sd, AD7124_ID, 1, &readval);
+	if (ret < 0)
+		return ret;
+
+	chip_id = AD7124_DEVICE_ID_GET(readval);
+	silicon_rev = AD7124_SILICON_REV_GET(readval);
+
+	if (chip_id != st->chip_info->chip_id) {
+		dev_err(&st->sd.spi->dev,
+			"Chip ID mismatch: expected %u, got %u\n",
+			st->chip_info->chip_id, chip_id);
+		return -ENODEV;
+	}
+
+	if (silicon_rev == 0) {
+		dev_err(&st->sd.spi->dev,
+			"Silicon revision empty. Chip may not be present\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev,
+					  struct device_node *np)
+{
+	struct ad7124_state *st = iio_priv(indio_dev);
+	struct ad7124_channel_config *cfg;
+	struct ad7124_channel *channels;
+	struct device_node *child;
+	struct iio_chan_spec *chan;
+	unsigned int ain[2], channel = 0, tmp;
+	int ret;
+
+	st->num_channels = of_get_available_child_count(np);
+	if (!st->num_channels) {
+		dev_err(indio_dev->dev.parent, "no channel children\n");
+		return -ENODEV;
+	}
+
+	chan = devm_kcalloc(indio_dev->dev.parent, st->num_channels,
+			    sizeof(*chan), GFP_KERNEL);
+	if (!chan)
+		return -ENOMEM;
+
+	channels = devm_kcalloc(indio_dev->dev.parent, st->num_channels, sizeof(*channels),
+				GFP_KERNEL);
+	if (!channels)
+		return -ENOMEM;
+
+	indio_dev->channels = chan;
+	indio_dev->num_channels = st->num_channels;
+	st->channels = channels;
+
+	for_each_available_child_of_node(np, child) {
+		cfg = &st->channels[channel].cfg;
+
+		ret = of_property_read_u32(child, "reg", &channel);
+		if (ret)
+			goto err;
+
+		if (channel >= indio_dev->num_channels) {
+			dev_err(indio_dev->dev.parent,
+				"Channel index >= number of channels\n");
+			ret = -EINVAL;
+			goto err;
+		}
+
+		ret = of_property_read_u32_array(child, "diff-channels",
+						 ain, 2);
+		if (ret)
+			goto err;
+
+		st->channels[channel].nr = channel;
+		st->channels[channel].ain = AD7124_CHANNEL_AINP(ain[0]) |
+						  AD7124_CHANNEL_AINM(ain[1]);
+
+		cfg->bipolar = of_property_read_bool(child, "bipolar");
+
+		ret = of_property_read_u32(child, "adi,reference-select", &tmp);
+		if (ret)
+			cfg->refsel = AD7124_INT_REF;
+		else
+			cfg->refsel = tmp;
+
+		cfg->buf_positive = of_property_read_bool(child, "adi,buffered-positive");
+		cfg->buf_negative = of_property_read_bool(child, "adi,buffered-negative");
+
+		chan[channel] = ad7124_channel_template;
+		chan[channel].address = channel;
+		chan[channel].scan_index = channel;
+		chan[channel].channel = ain[0];
+		chan[channel].channel2 = ain[1];
+	}
+
+	return 0;
+err:
+	of_node_put(child);
+
+	return ret;
+}
+
+static int ad7124_setup(struct ad7124_state *st)
+{
+	unsigned int fclk, power_mode;
+	int i, ret;
+
+	fclk = clk_get_rate(st->mclk);
+	if (!fclk)
+		return -EINVAL;
+
+	/* The power mode changes the master clock frequency */
+	power_mode = ad7124_find_closest_match(ad7124_master_clk_freq_hz,
+					ARRAY_SIZE(ad7124_master_clk_freq_hz),
+					fclk);
+	if (fclk != ad7124_master_clk_freq_hz[power_mode]) {
+		ret = clk_set_rate(st->mclk, fclk);
+		if (ret)
+			return ret;
+	}
+
+	/* Set the power mode */
+	st->adc_control &= ~AD7124_ADC_CTRL_PWR_MSK;
+	st->adc_control |= AD7124_ADC_CTRL_PWR(power_mode);
+	ret = ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control);
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&st->cfgs_lock);
+	INIT_KFIFO(st->live_cfgs_fifo);
+	for (i = 0; i < st->num_channels; i++) {
+
+		ret = ad7124_init_config_vref(st, &st->channels[i].cfg);
+		if (ret < 0)
+			return ret;
+
+		/*
+		 * 9.38 SPS is the minimum output data rate supported
+		 * regardless of the selected power mode. Round it up to 10 and
+		 * set all channels to this default value.
+		 */
+		ad7124_set_channel_odr(st, i, 10);
+	}
+
+	return ret;
+}
+
+static void ad7124_reg_disable(void *r)
+{
+	regulator_disable(r);
+}
+
+static int ad7124_probe(struct spi_device *spi)
+{
+	const struct ad7124_chip_info *info;
+	struct ad7124_state *st;
+	struct iio_dev *indio_dev;
+	int i, ret;
+
+	info = of_device_get_match_data(&spi->dev);
+	if (!info)
+		info = (void *)spi_get_device_id(spi)->driver_data;
+	if (!info)
+		return -ENODEV;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	st->chip_info = info;
+
+	indio_dev->name = st->chip_info->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &ad7124_info;
+
+	ret = ad_sd_init(&st->sd, indio_dev, spi, &ad7124_sigma_delta_info);
+	if (ret < 0)
+		return ret;
+
+	ret = ad7124_of_parse_channel_config(indio_dev, spi->dev.of_node);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(st->vref); i++) {
+		if (i == AD7124_INT_REF)
+			continue;
+
+		st->vref[i] = devm_regulator_get_optional(&spi->dev,
+						ad7124_ref_names[i]);
+		if (PTR_ERR(st->vref[i]) == -ENODEV)
+			continue;
+		else if (IS_ERR(st->vref[i]))
+			return PTR_ERR(st->vref[i]);
+
+		ret = regulator_enable(st->vref[i]);
+		if (ret)
+			return ret;
+
+		ret = devm_add_action_or_reset(&spi->dev, ad7124_reg_disable,
+					       st->vref[i]);
+		if (ret)
+			return ret;
+	}
+
+	st->mclk = devm_clk_get_enabled(&spi->dev, "mclk");
+	if (IS_ERR(st->mclk))
+		return PTR_ERR(st->mclk);
+
+	ret = ad7124_soft_reset(st);
+	if (ret < 0)
+		return ret;
+
+	ret = ad7124_check_chip_id(st);
+	if (ret)
+		return ret;
+
+	ret = ad7124_setup(st);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
+	if (ret < 0)
+		return ret;
+
+	return devm_iio_device_register(&spi->dev, indio_dev);
+
+}
+
+static const struct of_device_id ad7124_of_match[] = {
+	{ .compatible = "adi,ad7124-4",
+		.data = &ad7124_chip_info_tbl[ID_AD7124_4], },
+	{ .compatible = "adi,ad7124-8",
+		.data = &ad7124_chip_info_tbl[ID_AD7124_8], },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ad7124_of_match);
+
+static const struct spi_device_id ad71124_ids[] = {
+	{ "ad7124-4", (kernel_ulong_t)&ad7124_chip_info_tbl[ID_AD7124_4] },
+	{ "ad7124-8", (kernel_ulong_t)&ad7124_chip_info_tbl[ID_AD7124_8] },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad71124_ids);
+
+static struct spi_driver ad71124_driver = {
+	.driver = {
+		.name = "ad7124",
+		.of_match_table = ad7124_of_match,
+	},
+	.probe = ad7124_probe,
+	.id_table = ad71124_ids,
+};
+module_spi_driver(ad71124_driver);
+
+MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7124 SPI driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(IIO_AD_SIGMA_DELTA);