// SPDX-License-Identifier: GPL-2.0+ /* * AD7124 SPI ADC driver * * Copyright 2018 Analog Devices Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* 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; /* Following fields are used to compare equality. */ struct_group(config_props, 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 = sizeof_field(struct ad7124_channel_config, config_props); for (i = 0; i < st->num_channels; i++) { cfg_aux = &st->channels[i].cfg; if (cfg_aux->live && !memcmp(&cfg->config_props, &cfg_aux->config_props, 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 0; 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) | AD7124_CONFIG_PGA(cfg->pga_bits); 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) | AD7124_FILTER_FS(cfg->odr_sel_bits); return ad7124_spi_write_mask(st, AD7124_FILTER(cfg->cfg_slot), AD7124_FILTER_TYPE_MSK | AD7124_FILTER_FS_MSK, tmp, 3); } 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 int ad7124_disable_one(struct ad_sigma_delta *sd, unsigned int chan) { struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); return ad7124_spi_write_mask(st, AD7124_CHANNEL(chan), AD7124_CHANNEL_EN_MSK, 0, 2); } 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, .disable_one = ad7124_disable_one, .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; 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; fsleep(200); 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_parse_channel_config(struct iio_dev *indio_dev, struct device *dev) { struct ad7124_state *st = iio_priv(indio_dev); struct ad7124_channel_config *cfg; struct ad7124_channel *channels; struct iio_chan_spec *chan; unsigned int ain[2], channel = 0, tmp; int ret; st->num_channels = device_get_child_node_count(dev); if (!st->num_channels) return dev_err_probe(dev, -ENODEV, "no channel children\n"); 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; device_for_each_child_node_scoped(dev, child) { ret = fwnode_property_read_u32(child, "reg", &channel); if (ret) return ret; if (channel >= indio_dev->num_channels) return dev_err_probe(dev, -EINVAL, "Channel index >= number of channels\n"); ret = fwnode_property_read_u32_array(child, "diff-channels", ain, 2); if (ret) return ret; st->channels[channel].nr = channel; st->channels[channel].ain = AD7124_CHANNEL_AINP(ain[0]) | AD7124_CHANNEL_AINM(ain[1]); cfg = &st->channels[channel].cfg; cfg->bipolar = fwnode_property_read_bool(child, "bipolar"); ret = fwnode_property_read_u32(child, "adi,reference-select", &tmp); if (ret) cfg->refsel = AD7124_INT_REF; else cfg->refsel = tmp; cfg->buf_positive = fwnode_property_read_bool(child, "adi,buffered-positive"); cfg->buf_negative = fwnode_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; } 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); st->adc_control &= ~AD7124_ADC_CTRL_MODE_MSK; st->adc_control |= AD7124_ADC_CTRL_MODE(AD_SD_MODE_IDLE); 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); } ret = ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control); if (ret < 0) return ret; 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 = spi_get_device_match_data(spi); 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_parse_channel_config(indio_dev, &spi->dev); 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 const struct spi_device_id ad71124_ids[] = { { "ad7124-4", (kernel_ulong_t)&ad7124_chip_info_tbl[ID_AD7124_4] }, { "ad7124-8", (kernel_ulong_t)&ad7124_chip_info_tbl[ID_AD7124_8] }, { } }; MODULE_DEVICE_TABLE(spi, ad71124_ids); static struct spi_driver ad71124_driver = { .driver = { .name = "ad7124", .of_match_table = ad7124_of_match, }, .probe = ad7124_probe, .id_table = ad71124_ids, }; module_spi_driver(ad71124_driver); MODULE_AUTHOR("Stefan Popa "); MODULE_DESCRIPTION("Analog Devices AD7124 SPI driver"); MODULE_LICENSE("GPL"); MODULE_IMPORT_NS(IIO_AD_SIGMA_DELTA);