[PATCH v4 1/1] iio: adc: ad7124: allow more than 8 channels

From: alexandru.tachici
Date: Mon Mar 01 2021 - 11:14:10 EST

From: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx>

Currently AD7124-8 driver cannot use more than 8 IIO channels
because it was assigning the channel configurations bijectively
to channels specified in the device-tree. This is not possible
to do when using more than 8 channels as AD7124-8 has only 8
configuration registers.

To allow the user to use all channels at once the driver
will keep in memory configurations for all channels but
will program only 8 of them at a time on the device.
If multiple channels have the same configuration, only
one configuration register will be used. If there
are more configurations than available registers only
the last 8 used configurations will be allowed to exist
on the device in a LRU fashion.

Signed-off-by: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx>
---
drivers/iio/adc/ad7124.c | 470 ++++++++++++++++++++++++++-------------
1 file changed, 313 insertions(+), 157 deletions(-)

diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
index 766c73333604..9588df981e4e 100644
--- a/drivers/iio/adc/ad7124.c
+++ b/drivers/iio/adc/ad7124.c
@@ -5,12 +5,14 @@
* 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_device.h>
#include <linux/regulator/consumer.h>
@@ -86,6 +88,10 @@
#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,
@@ -136,25 +142,37 @@ struct ad7124_chip_info {
};

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 ain;
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_config *channel_config;
+ 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 = {
@@ -238,33 +256,9 @@ static int ad7124_set_mode(struct ad_sigma_delta *sd,
return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control);
}

-static int ad7124_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
-{
- struct ad7124_state *st = container_of(sd, struct ad7124_state, sd);
- unsigned int val;
-
- val = st->channel_config[channel].ain | AD7124_CHANNEL_EN(1) |
- AD7124_CHANNEL_SETUP(channel);
-
- return ad_sd_write_reg(&st->sd, AD7124_CHANNEL(channel), 2, val);
-}
-
-static const struct ad_sigma_delta_info ad7124_sigma_delta_info = {
- .set_channel = ad7124_set_channel,
- .set_mode = ad7124_set_mode,
- .has_registers = true,
- .addr_shift = 0,
- .read_mask = BIT(6),
- .data_reg = AD7124_DATA,
- .irq_flags = IRQF_TRIGGER_FALLING,
-};
-
-static int ad7124_set_channel_odr(struct ad7124_state *st,
- unsigned int channel,
- unsigned int odr)
+static void ad7124_set_channel_odr(struct ad7124_state *st, unsigned int channel, unsigned int odr)
{
unsigned int fclk, odr_sel_bits;
- int ret;

fclk = clk_get_rate(st->mclk);
/*
@@ -280,36 +274,12 @@ static int ad7124_set_channel_odr(struct ad7124_state *st,
else if (odr_sel_bits > 2047)
odr_sel_bits = 2047;

- ret = ad7124_spi_write_mask(st, AD7124_FILTER(channel),
- AD7124_FILTER_FS_MSK,
- AD7124_FILTER_FS(odr_sel_bits), 3);
- if (ret < 0)
- return ret;
- /* fADC = fCLK / (FS[10:0] x 32) */
- st->channel_config[channel].odr =
- DIV_ROUND_CLOSEST(fclk, odr_sel_bits * 32);
-
- return 0;
-}
-
-static int ad7124_set_channel_gain(struct ad7124_state *st,
- unsigned int channel,
- unsigned int gain)
-{
- unsigned int res;
- int ret;
+ if (odr_sel_bits != st->channels[channel].cfg.odr_sel_bits)
+ st->channels[channel].cfg.live = false;

- res = ad7124_find_closest_match(ad7124_gain,
- ARRAY_SIZE(ad7124_gain), gain);
- ret = ad7124_spi_write_mask(st, AD7124_CONFIG(channel),
- AD7124_CONFIG_PGA_MSK,
- AD7124_CONFIG_PGA(res), 2);
- if (ret < 0)
- return ret;
-
- st->channel_config[channel].pga_bits = res;
-
- return 0;
+ /* 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,
@@ -317,9 +287,9 @@ static int ad7124_get_3db_filter_freq(struct ad7124_state *st,
{
unsigned int fadc;

- fadc = st->channel_config[channel].odr;
+ fadc = st->channels[channel].cfg.odr;

- switch (st->channel_config[channel].filter_type) {
+ switch (st->channels[channel].cfg.filter_type) {
case AD7124_SINC3_FILTER:
return DIV_ROUND_CLOSEST(fadc * 230, 1000);
case AD7124_SINC4_FILTER:
@@ -329,9 +299,8 @@ static int ad7124_get_3db_filter_freq(struct ad7124_state *st,
}
}

-static int ad7124_set_3db_filter_freq(struct ad7124_state *st,
- unsigned int channel,
- unsigned int freq)
+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;
@@ -349,21 +318,223 @@ static int ad7124_set_3db_filter_freq(struct ad7124_state *st,
new_odr = sinc3_3db_odr;
}

- if (st->channel_config[channel].filter_type != new_filter) {
- int ret;
+ if (new_odr != st->channels[channel].cfg.odr)
+ st->channels[channel].cfg.live = false;

- st->channel_config[channel].filter_type = new_filter;
- ret = ad7124_spi_write_mask(st, AD7124_FILTER(channel),
- AD7124_FILTER_TYPE_MSK,
- AD7124_FILTER_TYPE_SEL(new_filter),
- 3);
- if (ret < 0)
- return ret;
+ st->channels[channel].cfg.filter_type = new_filter;
+ st->channels[channel].cfg.odr = new_odr;
+}
+
+static bool ad7124_configs_equal(struct ad7124_channel_config *cfg1,
+ struct ad7124_channel_config *cfg2)
+{
+ return ((cfg1->refsel == cfg2->refsel) &&
+ (cfg1->bipolar == cfg2->bipolar) &&
+ (cfg1->buf_positive == cfg2->buf_positive) &&
+ (cfg1->buf_negative == cfg2->buf_negative) &&
+ (cfg1->vref_mv == cfg2->vref_mv) &&
+ (cfg1->pga_bits == cfg2->pga_bits) &&
+ (cfg1->odr == cfg2->odr) &&
+ (cfg1->odr_sel_bits == cfg2->odr_sel_bits) &&
+ (cfg1->filter_type == cfg2->filter_type));
+}
+
+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;
+ int i;
+
+ for (i = 0; i < st->num_channels; i++) {
+ cfg_aux = &st->channels[i].cfg;
+
+ if (cfg_aux->live && ad7124_configs_equal(cfg, cfg_aux))
+ return cfg_aux;
}

- return ad7124_set_channel_odr(st, channel, new_odr);
+ return NULL;
}

+static int ad7124_find_free_config_slot(struct ad7124_state *st)
+{
+ unsigned int free_cfg_slot;
+
+ free_cfg_slot = find_next_zero_bit(&st->cfg_slots_status, AD7124_MAX_CONFIGS, 0);
+ 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);
+ int ret;
+
+ mutex_lock(&st->cfgs_lock);
+ ret = ad7124_prepare_read(st, channel);
+ mutex_unlock(&st->cfgs_lock);
+
+ return ret;
+}
+
+static const struct ad_sigma_delta_info ad7124_sigma_delta_info = {
+ .set_channel = ad7124_set_channel,
+ .set_mode = ad7124_set_mode,
+ .has_registers = true,
+ .addr_shift = 0,
+ .read_mask = BIT(6),
+ .data_reg = AD7124_DATA,
+ .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)
@@ -378,36 +549,44 @@ static int ad7124_read_raw(struct iio_dev *indio_dev,
return ret;

/* After the conversion is performed, disable the channel */
- ret = ad_sd_write_reg(&st->sd,
- AD7124_CHANNEL(chan->address), 2,
- st->channel_config[chan->address].ain |
- AD7124_CHANNEL_EN(0));
+ 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:
- idx = st->channel_config[chan->address].pga_bits;
- *val = st->channel_config[chan->address].vref_mv;
- if (st->channel_config[chan->address].bipolar)
+ 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:
- if (st->channel_config[chan->address].bipolar)
+ 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:
- *val = st->channel_config[chan->address].odr;
+ 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;
@@ -420,35 +599,54 @@ static int ad7124_write_raw(struct iio_dev *indio_dev,
{
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)
- return -EINVAL;
+ if (val2 != 0) {
+ ret = -EINVAL;
+ break;
+ }

- return ad7124_set_channel_odr(st, chan->address, val);
+ ad7124_set_channel_odr(st, chan->address, val);
+ break;
case IIO_CHAN_INFO_SCALE:
- if (val != 0)
- return -EINVAL;
+ if (val != 0) {
+ ret = -EINVAL;
+ break;
+ }

- if (st->channel_config[chan->address].bipolar)
+ 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->channel_config[chan->address].vref_mv * 1000000LL;
+ 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);

- return ad7124_set_channel_gain(st, chan->address, 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)
- return -EINVAL;
+ if (val2 != 0) {
+ ret = -EINVAL;
+ break;
+ }

- return ad7124_set_3db_filter_freq(st, chan->address, val);
+ ad7124_set_3db_filter_freq(st, chan->address, val);
+ break;
default:
- return -EINVAL;
+ ret = -EINVAL;
}
+
+ mutex_unlock(&st->cfgs_lock);
+ return ret;
}

static int ad7124_reg_access(struct iio_dev *indio_dev,
@@ -547,47 +745,14 @@ static int ad7124_check_chip_id(struct ad7124_state *st)
return 0;
}

-static int ad7124_init_channel_vref(struct ad7124_state *st,
- unsigned int channel_number)
-{
- unsigned int refsel = st->channel_config[channel_number].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]);
- }
- st->channel_config[channel_number].vref_mv =
- regulator_get_voltage(st->vref[refsel]);
- /* Conversion from uV to mV */
- st->channel_config[channel_number].vref_mv /= 1000;
- break;
- case AD7124_INT_REF:
- st->channel_config[channel_number].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;
- }
-
- 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;
- struct ad7124_channel_config *chan_config;
unsigned int ain[2], channel = 0, tmp;
int ret;

@@ -602,16 +767,18 @@ static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev,
if (!chan)
return -ENOMEM;

- chan_config = devm_kcalloc(indio_dev->dev.parent, st->num_channels,
- sizeof(*chan_config), GFP_KERNEL);
- if (!chan_config)
+ 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->channel_config = chan_config;
+ 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;
@@ -621,21 +788,20 @@ static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev,
if (ret)
goto err;

- st->channel_config[channel].ain = AD7124_CHANNEL_AINP(ain[0]) |
+ st->channels[channel].nr = channel;
+ st->channels[channel].ain = AD7124_CHANNEL_AINP(ain[0]) |
AD7124_CHANNEL_AINM(ain[1]);
- st->channel_config[channel].bipolar =
- of_property_read_bool(child, "bipolar");
+
+ cfg->bipolar = of_property_read_bool(child, "bipolar");

ret = of_property_read_u32(child, "adi,reference-select", &tmp);
if (ret)
- st->channel_config[channel].refsel = AD7124_INT_REF;
+ cfg->refsel = AD7124_INT_REF;
else
- st->channel_config[channel].refsel = tmp;
+ cfg->refsel = tmp;

- st->channel_config[channel].buf_positive =
- of_property_read_bool(child, "adi,buffered-positive");
- st->channel_config[channel].buf_negative =
- of_property_read_bool(child, "adi,buffered-negative");
+ 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;
@@ -654,7 +820,7 @@ static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev,
static int ad7124_setup(struct ad7124_state *st)
{
unsigned int val, fclk, power_mode;
- int i, ret, tmp;
+ int i, ret;

fclk = clk_get_rate(st->mclk);
if (!fclk)
@@ -677,31 +843,21 @@ static int ad7124_setup(struct ad7124_state *st)
if (ret < 0)
return ret;

+ mutex_init(&st->cfgs_lock);
+ INIT_KFIFO(st->live_cfgs_fifo);
for (i = 0; i < st->num_channels; i++) {
- val = st->channel_config[i].ain | AD7124_CHANNEL_SETUP(i);
- ret = ad_sd_write_reg(&st->sd, AD7124_CHANNEL(i), 2, val);
- if (ret < 0)
- return ret;
+ val = st->channels[i].ain;

- ret = ad7124_init_channel_vref(st, i);
+ ret = ad7124_init_config_vref(st, &st->channels[i].cfg);
if (ret < 0)
return ret;

- tmp = (st->channel_config[i].buf_positive << 1) +
- st->channel_config[i].buf_negative;
-
- val = AD7124_CONFIG_BIPOLAR(st->channel_config[i].bipolar) |
- AD7124_CONFIG_REF_SEL(st->channel_config[i].refsel) |
- AD7124_CONFIG_IN_BUFF(tmp);
- ret = ad_sd_write_reg(&st->sd, AD7124_CONFIG(i), 2, val);
- 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 the enabled channels to this default value.
+ * set all channels to this default value.
*/
- ret = ad7124_set_channel_odr(st, i, 10);
+ ad7124_set_channel_odr(st, i, 10);
}

return ret;
--
2.20.1