From: Alexandru Tachici <[email protected]>
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.
All configurations are marked as live if they are
programmed on the device. Any change that happens from
userspace (sampling rate, filters etc.) will invalidate
them.
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 needed than available registers
only the last 8 used configurations will be allowed to exist
on the device in a LRU fashion. (in case of raw reads).
If a read is requested on a channel whose configuration
is not programmed:
- check if there are similar configurations already programmed
if yes: - point channel to that config
if no: - check if there are empty config slots
- if yes: write config, push into queue of LRU configs
- if no: pop one config, get it's config slot nr,
write new config on the old slot, push new config
in queue of LRU configs.
Alexandru Tachici (1):
iio: adc: ad7124: allow more than 8 channels
drivers/iio/adc/ad7124.c | 461 ++++++++++++++++++++++++++-------------
1 file changed, 308 insertions(+), 153 deletions(-)
--
2.20.1
From: Alexandru Tachici <[email protected]>
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 <[email protected]>
---
drivers/iio/adc/ad7124.c | 461 ++++++++++++++++++++++++++-------------
1 file changed, 308 insertions(+), 153 deletions(-)
diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
index 766c73333604..d5d0596eb6ed 100644
--- a/drivers/iio/adc/ad7124.c
+++ b/drivers/iio/adc/ad7124.c
@@ -11,6 +11,7 @@
#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 +87,10 @@
#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 +141,36 @@ 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 */
+ DECLARE_KFIFO(live_cfgs_fifo, struct ad7124_channel_config *, AD7124_MAX_CONFIGS);
};
static const struct iio_chan_spec ad7124_channel_template = {
@@ -238,33 +254,9 @@ 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 +272,10 @@ 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;
-
- 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 +283,9 @@ 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 +295,8 @@ 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 +314,224 @@ 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;
+ st->channels[channel].cfg.filter_type = new_filter;
+ st->channels[channel].cfg.odr = new_odr;
+}
- 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;
+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 NULL;
+}
+
+static int ad7124_find_free_config_slot(struct ad7124_state *st)
+{
+ int slots[AD7124_MAX_CONFIGS] = {0};
+ struct ad7124_channel_config *cfg;
+ int i = 0;
+
+ /* mark all currently used configuration slots */
+ for (i = 0; i < st->num_channels; i++) {
+ cfg = &st->channels[i].cfg;
+
+ if (cfg->live)
+ slots[cfg->cfg_slot] = 1;
+ }
+
+ /* find a free one */
+ for (i = 0; i < AD7124_MAX_CONFIGS; i++) {
+ if (slots[i] == 0)
+ return i;
+ }
+
+ return -1;
+}
+
+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;
+ break;
+ 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;
+ }
+
+ return 0;
+}
+
+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;
+
+ /* 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 ad7124_set_channel_odr(st, channel, new_odr);
+ return lru_cfg;
+}
+
+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;
+ struct ad7124_channel_config *lru_cfg;
+ int free_cfg_slot;
+ int ret;
+
+ /* 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) {
+ free_cfg_slot = ad7124_find_free_config_slot(st);
+ if (free_cfg_slot >= 0) {
+ ret = ad7124_write_config(st, cfg, free_cfg_slot);
+ if (ret < 0)
+ return ret;
+
+ /* push the new config in configs queue */
+ cfg->cfg_slot = free_cfg_slot;
+ kfifo_put(&st->live_cfgs_fifo, cfg);
+ } else {
+ lru_cfg = ad7124_pop_config(st);
+ if (!lru_cfg)
+ return -EINVAL;
+
+ /* push the new config in configs queue */
+ cfg->cfg_slot = lru_cfg->cfg_slot;
+ kfifo_put(&st->live_cfgs_fifo, 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 +546,44 @@ 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;
@@ -421,32 +597,53 @@ 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;
+ mutex_lock(&st->cfgs_lock);
+ /* any change to the configs will make them different to
+ * the ones written on the device
+ */
+ st->channels[chan->address].cfg.live = false;
+
switch (info) {
case IIO_CHAN_INFO_SAMP_FREQ:
- if (val2 != 0)
+ if (val2 != 0) {
+ mutex_unlock(&st->cfgs_lock);
return -EINVAL;
+ }
- return ad7124_set_channel_odr(st, chan->address, val);
+ ad7124_set_channel_odr(st, chan->address, val);
+
+ mutex_unlock(&st->cfgs_lock);
+ return 0;
case IIO_CHAN_INFO_SCALE:
- if (val != 0)
+ if (val != 0) {
+ mutex_unlock(&st->cfgs_lock);
return -EINVAL;
+ }
- 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);
+ st->channels[chan->address].cfg.pga_bits = res;
- return ad7124_set_channel_gain(st, chan->address, gain);
+ mutex_unlock(&st->cfgs_lock);
+ return 0;
case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
- if (val2 != 0)
+ if (val2 != 0) {
+ mutex_unlock(&st->cfgs_lock);
return -EINVAL;
+ }
- return ad7124_set_3db_filter_freq(st, chan->address, val);
+ ad7124_set_3db_filter_freq(st, chan->address, val);
+ mutex_unlock(&st->cfgs_lock);
+ return 0;
default:
+ mutex_unlock(&st->cfgs_lock);
return -EINVAL;
}
}
@@ -547,47 +744,14 @@ 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 +766,18 @@ 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 +787,20 @@ 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 +819,7 @@ 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 +842,21 @@ 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
On Tue, 23 Feb 2021 18:44:04 +0200
<[email protected]> wrote:
> From: Alexandru Tachici <[email protected]>
>
> 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 <[email protected]>
Hi Alexandru,
I like the solution you've gone with here. Its fairly intuitive
solution to a fiddly problem :)
All comments inline are fairly minor tweaks.
Thanks,
Jonathan
> ---
> drivers/iio/adc/ad7124.c | 461 ++++++++++++++++++++++++++-------------
> 1 file changed, 308 insertions(+), 153 deletions(-)
>
> diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
> index 766c73333604..d5d0596eb6ed 100644
> --- a/drivers/iio/adc/ad7124.c
> +++ b/drivers/iio/adc/ad7124.c
> @@ -11,6 +11,7 @@
> #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 +87,10 @@
> #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 +141,36 @@ 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 */
> + DECLARE_KFIFO(live_cfgs_fifo, struct ad7124_channel_config *, AD7124_MAX_CONFIGS);
> };
>
> static const struct iio_chan_spec ad7124_channel_template = {
> @@ -238,33 +254,9 @@ 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 +272,10 @@ 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;
> -
> - 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 +283,9 @@ 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 +295,8 @@ 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 +314,224 @@ 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;
> + st->channels[channel].cfg.filter_type = new_filter;
> + st->channels[channel].cfg.odr = new_odr;
> +}
>
> - 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;
> +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 NULL;
> +}
> +
> +static int ad7124_find_free_config_slot(struct ad7124_state *st)
> +{
> + int slots[AD7124_MAX_CONFIGS] = {0};
> + struct ad7124_channel_config *cfg;
> + int i = 0;
> +
> + /* mark all currently used configuration slots */
> + for (i = 0; i < st->num_channels; i++) {
> + cfg = &st->channels[i].cfg;
> +
> + if (cfg->live)
> + slots[cfg->cfg_slot] = 1;
Worth maintaining a bitmap as we make use of configs
rather than computing this here?
Defintiely use a bitmap here if not and find_next_zero_bit() to
find an empty hole.
> + }
> +
> + /* find a free one */
> + for (i = 0; i < AD7124_MAX_CONFIGS; i++) {
> + if (slots[i] == 0)
> + return i;
> + }
> +
> + return -1;
> +}
> +
> +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;
> + break;
> + 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;
> + }
> +
> + return 0;
Move this up to the the one break path above? (trivial!)
> +}
> +
> +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
/*
* Pop
> + * 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;
> +
> + /* 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 ad7124_set_channel_odr(st, channel, new_odr);
> + return lru_cfg;
> +}
> +
> +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;
> + struct ad7124_channel_config *lru_cfg;
> + int free_cfg_slot;
> + int ret;
> +
> + /* Before doing any reads assign the channel a configuration.
/*
* Before
> + * 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) {
> + free_cfg_slot = ad7124_find_free_config_slot(st);
> + if (free_cfg_slot >= 0) {
> + ret = ad7124_write_config(st, cfg, free_cfg_slot);
> + if (ret < 0)
> + return ret;
> +
> + /* push the new config in configs queue */
> + cfg->cfg_slot = free_cfg_slot;
> + kfifo_put(&st->live_cfgs_fifo, cfg);
> + } else {
> + lru_cfg = ad7124_pop_config(st);
> + if (!lru_cfg)
> + return -EINVAL;
> +
> + /* push the new config in configs queue */
> + cfg->cfg_slot = lru_cfg->cfg_slot;
> + kfifo_put(&st->live_cfgs_fifo, 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 +546,44 @@ 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;
> @@ -421,32 +597,53 @@ 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;
>
> + mutex_lock(&st->cfgs_lock);
Taking a lock outside of a switch but then always unlocking it
in the case statements is a little unintuitive.
Can we move a
goto err;
or
break; as appropriate.
err:
mutex_unlock() path and move the unlock out of the switch
as well?
> + /* any change to the configs will make them different to
/*
* Any change...
> + * the ones written on the device
> + */
Technically we don't yet know it is a change. - Could be a rewrite
of the existing config. It might be worth identifying that there
is an actual change before we do this.
> + st->channels[chan->address].cfg.live = false;
> +
> switch (info) {
> case IIO_CHAN_INFO_SAMP_FREQ:
> - if (val2 != 0)
> + if (val2 != 0) {
> + mutex_unlock(&st->cfgs_lock);
> return -EINVAL;
> + }
>
> - return ad7124_set_channel_odr(st, chan->address, val);
> + ad7124_set_channel_odr(st, chan->address, val);
> +
> + mutex_unlock(&st->cfgs_lock);
> + return 0;
> case IIO_CHAN_INFO_SCALE:
> - if (val != 0)
> + if (val != 0) {
> + mutex_unlock(&st->cfgs_lock);
> return -EINVAL;
> + }
>
> - 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);
> + st->channels[chan->address].cfg.pga_bits = res;
>
> - return ad7124_set_channel_gain(st, chan->address, gain);
> + mutex_unlock(&st->cfgs_lock);
> + return 0;
> case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> - if (val2 != 0)
> + if (val2 != 0) {
> + mutex_unlock(&st->cfgs_lock);
> return -EINVAL;
> + }
>
> - return ad7124_set_3db_filter_freq(st, chan->address, val);
> + ad7124_set_3db_filter_freq(st, chan->address, val);
> + mutex_unlock(&st->cfgs_lock);
> + return 0;
> default:
> + mutex_unlock(&st->cfgs_lock);
> return -EINVAL;
> }
> }
> @@ -547,47 +744,14 @@ 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 +766,18 @@ 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 +787,20 @@ 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 +819,7 @@ 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 +842,21 @@ 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;