diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/iio/adc/ad7124.c | 1036 |
1 files changed, 1036 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c new file mode 100644 index 000000000..4088786e1 --- /dev/null +++ b/drivers/iio/adc/ad7124.c @@ -0,0 +1,1036 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * AD7124 SPI ADC driver + * + * Copyright 2018 Analog Devices Inc. + */ +#include <linux/bitfield.h> +#include <linux/bitops.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/kfifo.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/regulator/consumer.h> +#include <linux/spi/spi.h> + +#include <linux/iio/iio.h> +#include <linux/iio/adc/ad_sigma_delta.h> +#include <linux/iio/sysfs.h> + +/* AD7124 registers */ +#define AD7124_COMMS 0x00 +#define AD7124_STATUS 0x00 +#define AD7124_ADC_CONTROL 0x01 +#define AD7124_DATA 0x02 +#define AD7124_IO_CONTROL_1 0x03 +#define AD7124_IO_CONTROL_2 0x04 +#define AD7124_ID 0x05 +#define AD7124_ERROR 0x06 +#define AD7124_ERROR_EN 0x07 +#define AD7124_MCLK_COUNT 0x08 +#define AD7124_CHANNEL(x) (0x09 + (x)) +#define AD7124_CONFIG(x) (0x19 + (x)) +#define AD7124_FILTER(x) (0x21 + (x)) +#define AD7124_OFFSET(x) (0x29 + (x)) +#define AD7124_GAIN(x) (0x31 + (x)) + +/* AD7124_STATUS */ +#define AD7124_STATUS_POR_FLAG_MSK BIT(4) + +/* AD7124_ADC_CONTROL */ +#define AD7124_ADC_STATUS_EN_MSK BIT(10) +#define AD7124_ADC_STATUS_EN(x) FIELD_PREP(AD7124_ADC_STATUS_EN_MSK, x) +#define AD7124_ADC_CTRL_REF_EN_MSK BIT(8) +#define AD7124_ADC_CTRL_REF_EN(x) FIELD_PREP(AD7124_ADC_CTRL_REF_EN_MSK, x) +#define AD7124_ADC_CTRL_PWR_MSK GENMASK(7, 6) +#define AD7124_ADC_CTRL_PWR(x) FIELD_PREP(AD7124_ADC_CTRL_PWR_MSK, x) +#define AD7124_ADC_CTRL_MODE_MSK GENMASK(5, 2) +#define AD7124_ADC_CTRL_MODE(x) FIELD_PREP(AD7124_ADC_CTRL_MODE_MSK, x) + +/* AD7124 ID */ +#define AD7124_DEVICE_ID_MSK GENMASK(7, 4) +#define AD7124_DEVICE_ID_GET(x) FIELD_GET(AD7124_DEVICE_ID_MSK, x) +#define AD7124_SILICON_REV_MSK GENMASK(3, 0) +#define AD7124_SILICON_REV_GET(x) FIELD_GET(AD7124_SILICON_REV_MSK, x) + +#define CHIPID_AD7124_4 0x0 +#define CHIPID_AD7124_8 0x1 + +/* AD7124_CHANNEL_X */ +#define AD7124_CHANNEL_EN_MSK BIT(15) +#define AD7124_CHANNEL_EN(x) FIELD_PREP(AD7124_CHANNEL_EN_MSK, x) +#define AD7124_CHANNEL_SETUP_MSK GENMASK(14, 12) +#define AD7124_CHANNEL_SETUP(x) FIELD_PREP(AD7124_CHANNEL_SETUP_MSK, x) +#define AD7124_CHANNEL_AINP_MSK GENMASK(9, 5) +#define AD7124_CHANNEL_AINP(x) FIELD_PREP(AD7124_CHANNEL_AINP_MSK, x) +#define AD7124_CHANNEL_AINM_MSK GENMASK(4, 0) +#define AD7124_CHANNEL_AINM(x) FIELD_PREP(AD7124_CHANNEL_AINM_MSK, x) + +/* AD7124_CONFIG_X */ +#define AD7124_CONFIG_BIPOLAR_MSK BIT(11) +#define AD7124_CONFIG_BIPOLAR(x) FIELD_PREP(AD7124_CONFIG_BIPOLAR_MSK, x) +#define AD7124_CONFIG_REF_SEL_MSK GENMASK(4, 3) +#define AD7124_CONFIG_REF_SEL(x) FIELD_PREP(AD7124_CONFIG_REF_SEL_MSK, x) +#define AD7124_CONFIG_PGA_MSK GENMASK(2, 0) +#define AD7124_CONFIG_PGA(x) FIELD_PREP(AD7124_CONFIG_PGA_MSK, x) +#define AD7124_CONFIG_IN_BUFF_MSK GENMASK(6, 5) +#define AD7124_CONFIG_IN_BUFF(x) FIELD_PREP(AD7124_CONFIG_IN_BUFF_MSK, x) + +/* AD7124_FILTER_X */ +#define AD7124_FILTER_FS_MSK GENMASK(10, 0) +#define AD7124_FILTER_FS(x) FIELD_PREP(AD7124_FILTER_FS_MSK, x) +#define AD7124_FILTER_TYPE_MSK GENMASK(23, 21) +#define AD7124_FILTER_TYPE_SEL(x) FIELD_PREP(AD7124_FILTER_TYPE_MSK, x) + +#define AD7124_SINC3_FILTER 2 +#define AD7124_SINC4_FILTER 0 + +#define AD7124_CONF_ADDR_OFFSET 20 +#define AD7124_MAX_CONFIGS 8 +#define AD7124_MAX_CHANNELS 16 + +enum ad7124_ids { + ID_AD7124_4, + ID_AD7124_8, +}; + +enum ad7124_ref_sel { + AD7124_REFIN1, + AD7124_REFIN2, + AD7124_INT_REF, + AD7124_AVDD_REF, +}; + +enum ad7124_power_mode { + AD7124_LOW_POWER, + AD7124_MID_POWER, + AD7124_FULL_POWER, +}; + +static const unsigned int ad7124_gain[8] = { + 1, 2, 4, 8, 16, 32, 64, 128 +}; + +static const unsigned int ad7124_reg_size[] = { + 1, 2, 3, 3, 2, 1, 3, 3, 1, 2, 2, 2, 2, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, + 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, + 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, + 3, 3, 3, 3, 3 +}; + +static const int ad7124_master_clk_freq_hz[3] = { + [AD7124_LOW_POWER] = 76800, + [AD7124_MID_POWER] = 153600, + [AD7124_FULL_POWER] = 614400, +}; + +static const char * const ad7124_ref_names[] = { + [AD7124_REFIN1] = "refin1", + [AD7124_REFIN2] = "refin2", + [AD7124_INT_REF] = "int", + [AD7124_AVDD_REF] = "avdd", +}; + +struct ad7124_chip_info { + const char *name; + unsigned int chip_id; + unsigned int num_inputs; +}; + +struct ad7124_channel_config { + bool live; + unsigned int cfg_slot; + enum ad7124_ref_sel refsel; + bool bipolar; + bool buf_positive; + bool buf_negative; + unsigned int vref_mv; + unsigned int pga_bits; + unsigned int odr; + unsigned int odr_sel_bits; + unsigned int filter_type; +}; + +struct ad7124_channel { + unsigned int nr; + struct ad7124_channel_config cfg; + unsigned int ain; + unsigned int slot; +}; + +struct ad7124_state { + const struct ad7124_chip_info *chip_info; + struct ad_sigma_delta sd; + struct ad7124_channel *channels; + struct regulator *vref[4]; + struct clk *mclk; + unsigned int adc_control; + unsigned int num_channels; + struct mutex cfgs_lock; /* lock for configs access */ + unsigned long cfg_slots_status; /* bitmap with slot status (1 means it is used) */ + DECLARE_KFIFO(live_cfgs_fifo, struct ad7124_channel_config *, AD7124_MAX_CONFIGS); +}; + +static const struct iio_chan_spec ad7124_channel_template = { + .type = IIO_VOLTAGE, + .indexed = 1, + .differential = 1, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OFFSET) | + BIT(IIO_CHAN_INFO_SAMP_FREQ) | + BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), + .scan_type = { + .sign = 'u', + .realbits = 24, + .storagebits = 32, + .endianness = IIO_BE, + }, +}; + +static struct ad7124_chip_info ad7124_chip_info_tbl[] = { + [ID_AD7124_4] = { + .name = "ad7124-4", + .chip_id = CHIPID_AD7124_4, + .num_inputs = 8, + }, + [ID_AD7124_8] = { + .name = "ad7124-8", + .chip_id = CHIPID_AD7124_8, + .num_inputs = 16, + }, +}; + +static int ad7124_find_closest_match(const int *array, + unsigned int size, int val) +{ + int i, idx; + unsigned int diff_new, diff_old; + + diff_old = U32_MAX; + idx = 0; + + for (i = 0; i < size; i++) { + diff_new = abs(val - array[i]); + if (diff_new < diff_old) { + diff_old = diff_new; + idx = i; + } + } + + return idx; +} + +static int ad7124_spi_write_mask(struct ad7124_state *st, + unsigned int addr, + unsigned long mask, + unsigned int val, + unsigned int bytes) +{ + unsigned int readval; + int ret; + + ret = ad_sd_read_reg(&st->sd, addr, bytes, &readval); + if (ret < 0) + return ret; + + readval &= ~mask; + readval |= val; + + return ad_sd_write_reg(&st->sd, addr, bytes, readval); +} + +static int ad7124_set_mode(struct ad_sigma_delta *sd, + enum ad_sigma_delta_mode mode) +{ + struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); + + st->adc_control &= ~AD7124_ADC_CTRL_MODE_MSK; + st->adc_control |= AD7124_ADC_CTRL_MODE(mode); + + return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control); +} + +static void ad7124_set_channel_odr(struct ad7124_state *st, unsigned int channel, unsigned int odr) +{ + unsigned int fclk, odr_sel_bits; + + fclk = clk_get_rate(st->mclk); + /* + * FS[10:0] = fCLK / (fADC x 32) where: + * fADC is the output data rate + * fCLK is the master clock frequency + * FS[10:0] are the bits in the filter register + * FS[10:0] can have a value from 1 to 2047 + */ + odr_sel_bits = DIV_ROUND_CLOSEST(fclk, odr * 32); + if (odr_sel_bits < 1) + odr_sel_bits = 1; + else if (odr_sel_bits > 2047) + odr_sel_bits = 2047; + + if (odr_sel_bits != st->channels[channel].cfg.odr_sel_bits) + st->channels[channel].cfg.live = false; + + /* fADC = fCLK / (FS[10:0] x 32) */ + st->channels[channel].cfg.odr = DIV_ROUND_CLOSEST(fclk, odr_sel_bits * 32); + st->channels[channel].cfg.odr_sel_bits = odr_sel_bits; +} + +static int ad7124_get_3db_filter_freq(struct ad7124_state *st, + unsigned int channel) +{ + unsigned int fadc; + + fadc = st->channels[channel].cfg.odr; + + switch (st->channels[channel].cfg.filter_type) { + case AD7124_SINC3_FILTER: + return DIV_ROUND_CLOSEST(fadc * 230, 1000); + case AD7124_SINC4_FILTER: + return DIV_ROUND_CLOSEST(fadc * 262, 1000); + default: + return -EINVAL; + } +} + +static void ad7124_set_3db_filter_freq(struct ad7124_state *st, unsigned int channel, + unsigned int freq) +{ + unsigned int sinc4_3db_odr; + unsigned int sinc3_3db_odr; + unsigned int new_filter; + unsigned int new_odr; + + sinc4_3db_odr = DIV_ROUND_CLOSEST(freq * 1000, 230); + sinc3_3db_odr = DIV_ROUND_CLOSEST(freq * 1000, 262); + + if (sinc4_3db_odr > sinc3_3db_odr) { + new_filter = AD7124_SINC3_FILTER; + new_odr = sinc4_3db_odr; + } else { + new_filter = AD7124_SINC4_FILTER; + new_odr = sinc3_3db_odr; + } + + if (new_odr != st->channels[channel].cfg.odr) + st->channels[channel].cfg.live = false; + + st->channels[channel].cfg.filter_type = new_filter; + st->channels[channel].cfg.odr = new_odr; +} + +static struct ad7124_channel_config *ad7124_find_similar_live_cfg(struct ad7124_state *st, + struct ad7124_channel_config *cfg) +{ + struct ad7124_channel_config *cfg_aux; + ptrdiff_t cmp_size; + int i; + + cmp_size = (u8 *)&cfg->live - (u8 *)cfg; + for (i = 0; i < st->num_channels; i++) { + cfg_aux = &st->channels[i].cfg; + + if (cfg_aux->live && !memcmp(cfg, cfg_aux, cmp_size)) + return cfg_aux; + } + + return NULL; +} + +static int ad7124_find_free_config_slot(struct ad7124_state *st) +{ + unsigned int free_cfg_slot; + + free_cfg_slot = find_first_zero_bit(&st->cfg_slots_status, AD7124_MAX_CONFIGS); + if (free_cfg_slot == AD7124_MAX_CONFIGS) + return -1; + + return free_cfg_slot; +} + +static int ad7124_init_config_vref(struct ad7124_state *st, struct ad7124_channel_config *cfg) +{ + unsigned int refsel = cfg->refsel; + + switch (refsel) { + case AD7124_REFIN1: + case AD7124_REFIN2: + case AD7124_AVDD_REF: + if (IS_ERR(st->vref[refsel])) { + dev_err(&st->sd.spi->dev, + "Error, trying to use external voltage reference without a %s regulator.\n", + ad7124_ref_names[refsel]); + return PTR_ERR(st->vref[refsel]); + } + cfg->vref_mv = regulator_get_voltage(st->vref[refsel]); + /* Conversion from uV to mV */ + cfg->vref_mv /= 1000; + return 0; + case AD7124_INT_REF: + cfg->vref_mv = 2500; + st->adc_control &= ~AD7124_ADC_CTRL_REF_EN_MSK; + st->adc_control |= AD7124_ADC_CTRL_REF_EN(1); + return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, + 2, st->adc_control); + default: + dev_err(&st->sd.spi->dev, "Invalid reference %d\n", refsel); + return -EINVAL; + } +} + +static int ad7124_write_config(struct ad7124_state *st, struct ad7124_channel_config *cfg, + unsigned int cfg_slot) +{ + unsigned int tmp; + unsigned int val; + int ret; + + cfg->cfg_slot = cfg_slot; + + tmp = (cfg->buf_positive << 1) + cfg->buf_negative; + val = AD7124_CONFIG_BIPOLAR(cfg->bipolar) | AD7124_CONFIG_REF_SEL(cfg->refsel) | + AD7124_CONFIG_IN_BUFF(tmp); + ret = ad_sd_write_reg(&st->sd, AD7124_CONFIG(cfg->cfg_slot), 2, val); + if (ret < 0) + return ret; + + tmp = AD7124_FILTER_TYPE_SEL(cfg->filter_type); + ret = ad7124_spi_write_mask(st, AD7124_FILTER(cfg->cfg_slot), AD7124_FILTER_TYPE_MSK, + tmp, 3); + if (ret < 0) + return ret; + + ret = ad7124_spi_write_mask(st, AD7124_FILTER(cfg->cfg_slot), AD7124_FILTER_FS_MSK, + AD7124_FILTER_FS(cfg->odr_sel_bits), 3); + if (ret < 0) + return ret; + + return ad7124_spi_write_mask(st, AD7124_CONFIG(cfg->cfg_slot), AD7124_CONFIG_PGA_MSK, + AD7124_CONFIG_PGA(cfg->pga_bits), 2); +} + +static struct ad7124_channel_config *ad7124_pop_config(struct ad7124_state *st) +{ + struct ad7124_channel_config *lru_cfg; + struct ad7124_channel_config *cfg; + int ret; + int i; + + /* + * Pop least recently used config from the fifo + * in order to make room for the new one + */ + ret = kfifo_get(&st->live_cfgs_fifo, &lru_cfg); + if (ret <= 0) + return NULL; + + lru_cfg->live = false; + + /* mark slot as free */ + assign_bit(lru_cfg->cfg_slot, &st->cfg_slots_status, 0); + + /* invalidate all other configs that pointed to this one */ + for (i = 0; i < st->num_channels; i++) { + cfg = &st->channels[i].cfg; + + if (cfg->cfg_slot == lru_cfg->cfg_slot) + cfg->live = false; + } + + return lru_cfg; +} + +static int ad7124_push_config(struct ad7124_state *st, struct ad7124_channel_config *cfg) +{ + struct ad7124_channel_config *lru_cfg; + int free_cfg_slot; + + free_cfg_slot = ad7124_find_free_config_slot(st); + if (free_cfg_slot >= 0) { + /* push the new config in configs queue */ + kfifo_put(&st->live_cfgs_fifo, cfg); + } else { + /* pop one config to make room for the new one */ + lru_cfg = ad7124_pop_config(st); + if (!lru_cfg) + return -EINVAL; + + /* push the new config in configs queue */ + free_cfg_slot = lru_cfg->cfg_slot; + kfifo_put(&st->live_cfgs_fifo, cfg); + } + + /* mark slot as used */ + assign_bit(free_cfg_slot, &st->cfg_slots_status, 1); + + return ad7124_write_config(st, cfg, free_cfg_slot); +} + +static int ad7124_enable_channel(struct ad7124_state *st, struct ad7124_channel *ch) +{ + ch->cfg.live = true; + return ad_sd_write_reg(&st->sd, AD7124_CHANNEL(ch->nr), 2, ch->ain | + AD7124_CHANNEL_SETUP(ch->cfg.cfg_slot) | AD7124_CHANNEL_EN(1)); +} + +static int ad7124_prepare_read(struct ad7124_state *st, int address) +{ + struct ad7124_channel_config *cfg = &st->channels[address].cfg; + struct ad7124_channel_config *live_cfg; + + /* + * Before doing any reads assign the channel a configuration. + * Check if channel's config is on the device + */ + if (!cfg->live) { + /* check if config matches another one */ + live_cfg = ad7124_find_similar_live_cfg(st, cfg); + if (!live_cfg) + ad7124_push_config(st, cfg); + else + cfg->cfg_slot = live_cfg->cfg_slot; + } + + /* point channel to the config slot and enable */ + return ad7124_enable_channel(st, &st->channels[address]); +} + +static int __ad7124_set_channel(struct ad_sigma_delta *sd, unsigned int channel) +{ + struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); + + return ad7124_prepare_read(st, channel); +} + +static int ad7124_set_channel(struct ad_sigma_delta *sd, unsigned int channel) +{ + struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); + int ret; + + mutex_lock(&st->cfgs_lock); + ret = __ad7124_set_channel(sd, channel); + mutex_unlock(&st->cfgs_lock); + + return ret; +} + +static int ad7124_append_status(struct ad_sigma_delta *sd, bool append) +{ + struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); + unsigned int adc_control = st->adc_control; + int ret; + + adc_control &= ~AD7124_ADC_STATUS_EN_MSK; + adc_control |= AD7124_ADC_STATUS_EN(append); + + ret = ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, adc_control); + if (ret < 0) + return ret; + + st->adc_control = adc_control; + + return 0; +} + +static int ad7124_disable_all(struct ad_sigma_delta *sd) +{ + struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); + int ret; + int i; + + for (i = 0; i < st->num_channels; i++) { + ret = ad7124_spi_write_mask(st, AD7124_CHANNEL(i), AD7124_CHANNEL_EN_MSK, 0, 2); + if (ret < 0) + return ret; + } + + return 0; +} + +static const struct ad_sigma_delta_info ad7124_sigma_delta_info = { + .set_channel = ad7124_set_channel, + .append_status = ad7124_append_status, + .disable_all = ad7124_disable_all, + .set_mode = ad7124_set_mode, + .has_registers = true, + .addr_shift = 0, + .read_mask = BIT(6), + .status_ch_mask = GENMASK(3, 0), + .data_reg = AD7124_DATA, + .num_slots = 8, + .irq_flags = IRQF_TRIGGER_FALLING, +}; + +static int ad7124_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long info) +{ + struct ad7124_state *st = iio_priv(indio_dev); + int idx, ret; + + switch (info) { + case IIO_CHAN_INFO_RAW: + ret = ad_sigma_delta_single_conversion(indio_dev, chan, val); + if (ret < 0) + return ret; + + /* After the conversion is performed, disable the channel */ + ret = ad_sd_write_reg(&st->sd, AD7124_CHANNEL(chan->address), 2, + st->channels[chan->address].ain | AD7124_CHANNEL_EN(0)); + if (ret < 0) + return ret; + + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + mutex_lock(&st->cfgs_lock); + + idx = st->channels[chan->address].cfg.pga_bits; + *val = st->channels[chan->address].cfg.vref_mv; + if (st->channels[chan->address].cfg.bipolar) + *val2 = chan->scan_type.realbits - 1 + idx; + else + *val2 = chan->scan_type.realbits + idx; + + mutex_unlock(&st->cfgs_lock); + return IIO_VAL_FRACTIONAL_LOG2; + case IIO_CHAN_INFO_OFFSET: + mutex_lock(&st->cfgs_lock); + if (st->channels[chan->address].cfg.bipolar) + *val = -(1 << (chan->scan_type.realbits - 1)); + else + *val = 0; + + mutex_unlock(&st->cfgs_lock); + return IIO_VAL_INT; + case IIO_CHAN_INFO_SAMP_FREQ: + mutex_lock(&st->cfgs_lock); + *val = st->channels[chan->address].cfg.odr; + mutex_unlock(&st->cfgs_lock); + + return IIO_VAL_INT; + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: + mutex_lock(&st->cfgs_lock); + *val = ad7124_get_3db_filter_freq(st, chan->scan_index); + mutex_unlock(&st->cfgs_lock); + + return IIO_VAL_INT; + default: + return -EINVAL; + } +} + +static int ad7124_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long info) +{ + struct ad7124_state *st = iio_priv(indio_dev); + unsigned int res, gain, full_scale, vref; + int ret = 0; + + mutex_lock(&st->cfgs_lock); + + switch (info) { + case IIO_CHAN_INFO_SAMP_FREQ: + if (val2 != 0) { + ret = -EINVAL; + break; + } + + ad7124_set_channel_odr(st, chan->address, val); + break; + case IIO_CHAN_INFO_SCALE: + if (val != 0) { + ret = -EINVAL; + break; + } + + if (st->channels[chan->address].cfg.bipolar) + full_scale = 1 << (chan->scan_type.realbits - 1); + else + full_scale = 1 << chan->scan_type.realbits; + + vref = st->channels[chan->address].cfg.vref_mv * 1000000LL; + res = DIV_ROUND_CLOSEST(vref, full_scale); + gain = DIV_ROUND_CLOSEST(res, val2); + res = ad7124_find_closest_match(ad7124_gain, ARRAY_SIZE(ad7124_gain), gain); + + if (st->channels[chan->address].cfg.pga_bits != res) + st->channels[chan->address].cfg.live = false; + + st->channels[chan->address].cfg.pga_bits = res; + break; + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: + if (val2 != 0) { + ret = -EINVAL; + break; + } + + ad7124_set_3db_filter_freq(st, chan->address, val); + break; + default: + ret = -EINVAL; + } + + mutex_unlock(&st->cfgs_lock); + return ret; +} + +static int ad7124_reg_access(struct iio_dev *indio_dev, + unsigned int reg, + unsigned int writeval, + unsigned int *readval) +{ + struct ad7124_state *st = iio_priv(indio_dev); + int ret; + + if (reg >= ARRAY_SIZE(ad7124_reg_size)) + return -EINVAL; + + if (readval) + ret = ad_sd_read_reg(&st->sd, reg, ad7124_reg_size[reg], + readval); + else + ret = ad_sd_write_reg(&st->sd, reg, ad7124_reg_size[reg], + writeval); + + return ret; +} + +static IIO_CONST_ATTR(in_voltage_scale_available, + "0.000001164 0.000002328 0.000004656 0.000009313 0.000018626 0.000037252 0.000074505 0.000149011 0.000298023"); + +static struct attribute *ad7124_attributes[] = { + &iio_const_attr_in_voltage_scale_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group ad7124_attrs_group = { + .attrs = ad7124_attributes, +}; + +static int ad7124_update_scan_mode(struct iio_dev *indio_dev, + const unsigned long *scan_mask) +{ + struct ad7124_state *st = iio_priv(indio_dev); + bool bit_set; + int ret; + int i; + + mutex_lock(&st->cfgs_lock); + for (i = 0; i < st->num_channels; i++) { + bit_set = test_bit(i, scan_mask); + if (bit_set) + ret = __ad7124_set_channel(&st->sd, i); + else + ret = ad7124_spi_write_mask(st, AD7124_CHANNEL(i), AD7124_CHANNEL_EN_MSK, + 0, 2); + if (ret < 0) { + mutex_unlock(&st->cfgs_lock); + + return ret; + } + } + + mutex_unlock(&st->cfgs_lock); + + return 0; +} + +static const struct iio_info ad7124_info = { + .read_raw = ad7124_read_raw, + .write_raw = ad7124_write_raw, + .debugfs_reg_access = &ad7124_reg_access, + .validate_trigger = ad_sd_validate_trigger, + .update_scan_mode = ad7124_update_scan_mode, + .attrs = &ad7124_attrs_group, +}; + +static int ad7124_soft_reset(struct ad7124_state *st) +{ + unsigned int readval, timeout; + int ret; + + ret = ad_sd_reset(&st->sd, 64); + if (ret < 0) + return ret; + + timeout = 100; + do { + ret = ad_sd_read_reg(&st->sd, AD7124_STATUS, 1, &readval); + if (ret < 0) + return ret; + + if (!(readval & AD7124_STATUS_POR_FLAG_MSK)) + return 0; + + /* The AD7124 requires typically 2ms to power up and settle */ + usleep_range(100, 2000); + } while (--timeout); + + dev_err(&st->sd.spi->dev, "Soft reset failed\n"); + + return -EIO; +} + +static int ad7124_check_chip_id(struct ad7124_state *st) +{ + unsigned int readval, chip_id, silicon_rev; + int ret; + + ret = ad_sd_read_reg(&st->sd, AD7124_ID, 1, &readval); + if (ret < 0) + return ret; + + chip_id = AD7124_DEVICE_ID_GET(readval); + silicon_rev = AD7124_SILICON_REV_GET(readval); + + if (chip_id != st->chip_info->chip_id) { + dev_err(&st->sd.spi->dev, + "Chip ID mismatch: expected %u, got %u\n", + st->chip_info->chip_id, chip_id); + return -ENODEV; + } + + if (silicon_rev == 0) { + dev_err(&st->sd.spi->dev, + "Silicon revision empty. Chip may not be present\n"); + return -ENODEV; + } + + return 0; +} + +static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev, + struct device_node *np) +{ + struct ad7124_state *st = iio_priv(indio_dev); + struct ad7124_channel_config *cfg; + struct ad7124_channel *channels; + struct device_node *child; + struct iio_chan_spec *chan; + unsigned int ain[2], channel = 0, tmp; + int ret; + + st->num_channels = of_get_available_child_count(np); + if (!st->num_channels) { + dev_err(indio_dev->dev.parent, "no channel children\n"); + return -ENODEV; + } + + chan = devm_kcalloc(indio_dev->dev.parent, st->num_channels, + sizeof(*chan), GFP_KERNEL); + if (!chan) + return -ENOMEM; + + channels = devm_kcalloc(indio_dev->dev.parent, st->num_channels, sizeof(*channels), + GFP_KERNEL); + if (!channels) + return -ENOMEM; + + indio_dev->channels = chan; + indio_dev->num_channels = st->num_channels; + st->channels = channels; + + for_each_available_child_of_node(np, child) { + cfg = &st->channels[channel].cfg; + + ret = of_property_read_u32(child, "reg", &channel); + if (ret) + goto err; + + if (channel >= indio_dev->num_channels) { + dev_err(indio_dev->dev.parent, + "Channel index >= number of channels\n"); + ret = -EINVAL; + goto err; + } + + ret = of_property_read_u32_array(child, "diff-channels", + ain, 2); + if (ret) + goto err; + + st->channels[channel].nr = channel; + st->channels[channel].ain = AD7124_CHANNEL_AINP(ain[0]) | + AD7124_CHANNEL_AINM(ain[1]); + + cfg->bipolar = of_property_read_bool(child, "bipolar"); + + ret = of_property_read_u32(child, "adi,reference-select", &tmp); + if (ret) + cfg->refsel = AD7124_INT_REF; + else + cfg->refsel = tmp; + + cfg->buf_positive = of_property_read_bool(child, "adi,buffered-positive"); + cfg->buf_negative = of_property_read_bool(child, "adi,buffered-negative"); + + chan[channel] = ad7124_channel_template; + chan[channel].address = channel; + chan[channel].scan_index = channel; + chan[channel].channel = ain[0]; + chan[channel].channel2 = ain[1]; + } + + return 0; +err: + of_node_put(child); + + return ret; +} + +static int ad7124_setup(struct ad7124_state *st) +{ + unsigned int fclk, power_mode; + int i, ret; + + fclk = clk_get_rate(st->mclk); + if (!fclk) + return -EINVAL; + + /* The power mode changes the master clock frequency */ + power_mode = ad7124_find_closest_match(ad7124_master_clk_freq_hz, + ARRAY_SIZE(ad7124_master_clk_freq_hz), + fclk); + if (fclk != ad7124_master_clk_freq_hz[power_mode]) { + ret = clk_set_rate(st->mclk, fclk); + if (ret) + return ret; + } + + /* Set the power mode */ + st->adc_control &= ~AD7124_ADC_CTRL_PWR_MSK; + st->adc_control |= AD7124_ADC_CTRL_PWR(power_mode); + ret = ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control); + if (ret < 0) + return ret; + + mutex_init(&st->cfgs_lock); + INIT_KFIFO(st->live_cfgs_fifo); + for (i = 0; i < st->num_channels; i++) { + + ret = ad7124_init_config_vref(st, &st->channels[i].cfg); + if (ret < 0) + return ret; + + /* + * 9.38 SPS is the minimum output data rate supported + * regardless of the selected power mode. Round it up to 10 and + * set all channels to this default value. + */ + ad7124_set_channel_odr(st, i, 10); + } + + return ret; +} + +static void ad7124_reg_disable(void *r) +{ + regulator_disable(r); +} + +static int ad7124_probe(struct spi_device *spi) +{ + const struct ad7124_chip_info *info; + struct ad7124_state *st; + struct iio_dev *indio_dev; + int i, ret; + + info = of_device_get_match_data(&spi->dev); + if (!info) + return -ENODEV; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + + st->chip_info = info; + + indio_dev->name = st->chip_info->name; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &ad7124_info; + + ret = ad_sd_init(&st->sd, indio_dev, spi, &ad7124_sigma_delta_info); + if (ret < 0) + return ret; + + ret = ad7124_of_parse_channel_config(indio_dev, spi->dev.of_node); + if (ret < 0) + return ret; + + for (i = 0; i < ARRAY_SIZE(st->vref); i++) { + if (i == AD7124_INT_REF) + continue; + + st->vref[i] = devm_regulator_get_optional(&spi->dev, + ad7124_ref_names[i]); + if (PTR_ERR(st->vref[i]) == -ENODEV) + continue; + else if (IS_ERR(st->vref[i])) + return PTR_ERR(st->vref[i]); + + ret = regulator_enable(st->vref[i]); + if (ret) + return ret; + + ret = devm_add_action_or_reset(&spi->dev, ad7124_reg_disable, + st->vref[i]); + if (ret) + return ret; + } + + st->mclk = devm_clk_get_enabled(&spi->dev, "mclk"); + if (IS_ERR(st->mclk)) + return PTR_ERR(st->mclk); + + ret = ad7124_soft_reset(st); + if (ret < 0) + return ret; + + ret = ad7124_check_chip_id(st); + if (ret) + return ret; + + ret = ad7124_setup(st); + if (ret < 0) + return ret; + + ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev); + if (ret < 0) + return ret; + + return devm_iio_device_register(&spi->dev, indio_dev); + +} + +static const struct of_device_id ad7124_of_match[] = { + { .compatible = "adi,ad7124-4", + .data = &ad7124_chip_info_tbl[ID_AD7124_4], }, + { .compatible = "adi,ad7124-8", + .data = &ad7124_chip_info_tbl[ID_AD7124_8], }, + { }, +}; +MODULE_DEVICE_TABLE(of, ad7124_of_match); + +static struct spi_driver ad71124_driver = { + .driver = { + .name = "ad7124", + .of_match_table = ad7124_of_match, + }, + .probe = ad7124_probe, +}; +module_spi_driver(ad71124_driver); + +MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>"); +MODULE_DESCRIPTION("Analog Devices AD7124 SPI driver"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(IIO_AD_SIGMA_DELTA); |