| Message ID | 20210223164404.93540-2-alexandru.tachici@analog.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: adc: ad7124: allow more than 8 channels | expand |
On Tue, 23 Feb 2021 18:44:04 +0200 <alexandru.tachici@analog.com> wrote: > From: Alexandru Tachici <alexandru.tachici@analog.com> > > 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@analog.com> 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;
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;