From 7b8d045e497a04dd88546da51f34fa3b102778d2 Mon Sep 17 00:00:00 2001 From: Alexandru Tachici Date: Thu, 11 Mar 2021 11:11:54 +0200 Subject: [PATCH] iio: adc: ad7124: allow more than 8 channels 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 Reported-by: kernel test robot Link: https://lore.kernel.org/r/20210311091154.47785-2-alexandru.tachici@analog.com Signed-off-by: Jonathan Cameron --- drivers/iio/adc/ad7124.c | 461 +++++++++++++++++++++++++-------------- 1 file changed, 302 insertions(+), 159 deletions(-) diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c index 766c73333604..9d3952b4674f 100644 --- a/drivers/iio/adc/ad7124.c +++ b/drivers/iio/adc/ad7124.c @@ -5,12 +5,14 @@ * Copyright 2018 Analog Devices Inc. */ #include +#include #include #include #include #include #include #include +#include #include #include #include @@ -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; + if (odr_sel_bits != st->channels[channel].cfg.odr_sel_bits) + st->channels[channel].cfg.live = false; + /* fADC = fCLK / (FS[10:0] x 32) */ - st->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; + 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 +318,211 @@ 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 struct ad7124_channel_config *ad7124_find_similar_live_cfg(struct ad7124_state *st, + struct ad7124_channel_config *cfg) +{ + struct ad7124_channel_config *cfg_aux; + ptrdiff_t cmp_size; + int i; + + cmp_size = (u8 *)&cfg->live - (u8 *)cfg; + for (i = 0; i < st->num_channels; i++) { + cfg_aux = &st->channels[i].cfg; + + if (cfg_aux->live && !memcmp(cfg, cfg_aux, cmp_size)) + return cfg_aux; } - return 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 +537,44 @@ 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 +587,54 @@ 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 +733,14 @@ 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 +755,18 @@ 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 +776,20 @@ 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; @@ -653,8 +807,8 @@ err: static int ad7124_setup(struct ad7124_state *st) { - unsigned int val, fclk, power_mode; - int i, ret, tmp; + unsigned int fclk, power_mode; + int i, ret; fclk = clk_get_rate(st->mclk); if (!fclk) @@ -677,31 +831,20 @@ 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); + + ret = ad7124_init_config_vref(st, &st->channels[i].cfg); if (ret < 0) return ret; - ret = ad7124_init_channel_vref(st, i); - 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;