// SPDX-License-Identifier: GPL-2.0-only /* * Texas Instruments ADS1119 ADC driver. * * Copyright 2024 Toradex */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define ADS1119_CMD_RESET 0x06 #define ADS1119_CMD_POWERDOWN 0x02 #define ADS1119_CMD_START_SYNC 0x08 #define ADS1119_CMD_RDATA 0x10 #define ADS1119_CMD_RREG_CONFIG 0x20 #define ADS1119_CMD_RREG_STATUS 0x24 #define ADS1119_CMD_WREG 0x40 #define ADS1119_CMD_RREG(reg) (0x20 | (reg) << 2) /* Config register */ #define ADS1119_REG_CONFIG 0x00 #define ADS1119_CONFIG_VREF_FIELD BIT(0) #define ADS1119_CONFIG_CM_FIELD BIT(1) #define ADS1119_CONFIG_DR_FIELD GENMASK(3, 2) #define ADS1119_CONFIG_GAIN_FIELD BIT(4) #define ADS1119_CONFIG_MUX_FIELD GENMASK(7, 5) #define ADS1119_VREF_INTERNAL 0 #define ADS1119_VREF_EXTERNAL 1 #define ADS1119_VREF_INTERNAL_VAL 2048000 #define ADS1119_CM_SINGLE 0 #define ADS1119_CM_CONTINUOUS 1 #define ADS1119_DR_20_SPS 0 #define ADS1119_DR_90_SPS 1 #define ADS1119_DR_330_SPS 2 #define ADS1119_DR_1000_SPS 3 #define ADS1119_GAIN_1 0 #define ADS1119_GAIN_4 1 #define ADS1119_MUX_AIN0_AIN1 0 #define ADS1119_MUX_AIN2_AIN3 1 #define ADS1119_MUX_AIN1_AIN2 2 #define ADS1119_MUX_AIN0 3 #define ADS1119_MUX_AIN1 4 #define ADS1119_MUX_AIN2 5 #define ADS1119_MUX_AIN3 6 #define ADS1119_MUX_SHORTED 7 /* Status register */ #define ADS1119_REG_STATUS 0x01 #define ADS1119_STATUS_DRDY_FIELD BIT(7) #define ADS1119_DEFAULT_GAIN 1 #define ADS1119_DEFAULT_DATARATE 20 #define ADS1119_SUSPEND_DELAY 2000 /* Timeout based on the minimum sample rate of 20 SPS (50000us) */ #define ADS1119_MAX_DRDY_TIMEOUT 85000 #define ADS1119_MAX_CHANNELS 7 #define ADS1119_MAX_SINGLE_CHANNELS 4 struct ads1119_channel_config { int gain; int datarate; int mux; }; struct ads1119_state { struct completion completion; struct i2c_client *client; struct gpio_desc *reset_gpio; struct iio_trigger *trig; struct ads1119_channel_config *channels_cfg; unsigned int num_channels_cfg; unsigned int cached_config; int vref_uV; }; static const char * const ads1119_power_supplies[] = { "avdd", "dvdd" }; static const int ads1119_available_datarates[] = { 20, 90, 330, 1000, }; static const int ads1119_available_gains[] = { 1, 1, 1, 4, }; static int ads1119_upd_cfg_reg(struct ads1119_state *st, unsigned int fields, unsigned int val) { unsigned int config = st->cached_config; int ret; config &= ~fields; config |= val; ret = i2c_smbus_write_byte_data(st->client, ADS1119_CMD_WREG, config); if (ret) return ret; st->cached_config = config; return 0; } static bool ads1119_data_ready(struct ads1119_state *st) { int status; status = i2c_smbus_read_byte_data(st->client, ADS1119_CMD_RREG_STATUS); if (status < 0) return false; return FIELD_GET(ADS1119_STATUS_DRDY_FIELD, status); } static int ads1119_reset(struct ads1119_state *st) { st->cached_config = 0; if (!st->reset_gpio) return i2c_smbus_write_byte(st->client, ADS1119_CMD_RESET); gpiod_set_value_cansleep(st->reset_gpio, 1); udelay(1); gpiod_set_value_cansleep(st->reset_gpio, 0); udelay(1); return 0; } static int ads1119_set_conv_mode(struct ads1119_state *st, bool continuous) { unsigned int mode; if (continuous) mode = ADS1119_CM_CONTINUOUS; else mode = ADS1119_CM_SINGLE; return ads1119_upd_cfg_reg(st, ADS1119_CONFIG_CM_FIELD, FIELD_PREP(ADS1119_CONFIG_CM_FIELD, mode)); } static int ads1119_get_hw_gain(int gain) { if (gain == 4) return ADS1119_GAIN_4; else return ADS1119_GAIN_1; } static int ads1119_get_hw_datarate(int datarate) { switch (datarate) { case 90: return ADS1119_DR_90_SPS; case 330: return ADS1119_DR_330_SPS; case 1000: return ADS1119_DR_1000_SPS; case 20: default: return ADS1119_DR_20_SPS; } } static int ads1119_configure_channel(struct ads1119_state *st, int mux, int gain, int datarate) { int ret; ret = ads1119_upd_cfg_reg(st, ADS1119_CONFIG_MUX_FIELD, FIELD_PREP(ADS1119_CONFIG_MUX_FIELD, mux)); if (ret) return ret; ret = ads1119_upd_cfg_reg(st, ADS1119_CONFIG_GAIN_FIELD, FIELD_PREP(ADS1119_CONFIG_GAIN_FIELD, ads1119_get_hw_gain(gain))); if (ret) return ret; return ads1119_upd_cfg_reg(st, ADS1119_CONFIG_DR_FIELD, FIELD_PREP(ADS1119_CONFIG_DR_FIELD, ads1119_get_hw_datarate(datarate))); } static int ads1119_poll_data_ready(struct ads1119_state *st, struct iio_chan_spec const *chan) { unsigned int datarate = st->channels_cfg[chan->address].datarate; unsigned long wait_time; bool data_ready; /* Poll 5 times more than the data rate */ wait_time = DIV_ROUND_CLOSEST(MICRO, 5 * datarate); return read_poll_timeout(ads1119_data_ready, data_ready, data_ready, wait_time, ADS1119_MAX_DRDY_TIMEOUT, false, st); } static int ads1119_read_data(struct ads1119_state *st, struct iio_chan_spec const *chan, unsigned int *val) { unsigned int timeout; int ret = 0; timeout = msecs_to_jiffies(ADS1119_MAX_DRDY_TIMEOUT); if (!st->client->irq) { ret = ads1119_poll_data_ready(st, chan); if (ret) return ret; } else if (!wait_for_completion_timeout(&st->completion, timeout)) { return -ETIMEDOUT; } ret = i2c_smbus_read_word_swapped(st->client, ADS1119_CMD_RDATA); if (ret < 0) return ret; *val = ret; return 0; } static int ads1119_single_conversion(struct ads1119_state *st, struct iio_chan_spec const *chan, int *val, bool calib_offset) { struct device *dev = &st->client->dev; int mux = st->channels_cfg[chan->address].mux; int gain = st->channels_cfg[chan->address].gain; int datarate = st->channels_cfg[chan->address].datarate; unsigned int sample; int ret; if (calib_offset) mux = ADS1119_MUX_SHORTED; ret = pm_runtime_resume_and_get(dev); if (ret) goto pdown; ret = ads1119_configure_channel(st, mux, gain, datarate); if (ret) goto pdown; ret = i2c_smbus_write_byte(st->client, ADS1119_CMD_START_SYNC); if (ret) goto pdown; ret = ads1119_read_data(st, chan, &sample); if (ret) goto pdown; *val = sign_extend32(sample, chan->scan_type.realbits - 1); ret = IIO_VAL_INT; pdown: pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); return ret; } static int ads1119_validate_datarate(struct ads1119_state *st, int datarate) { switch (datarate) { case 20: case 90: case 330: case 1000: return datarate; default: return -EINVAL; } } static int ads1119_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, const int **vals, int *type, int *length, long mask) { switch (mask) { case IIO_CHAN_INFO_SCALE: *type = IIO_VAL_FRACTIONAL; *vals = ads1119_available_gains; *length = ARRAY_SIZE(ads1119_available_gains); return IIO_AVAIL_LIST; case IIO_CHAN_INFO_SAMP_FREQ: *type = IIO_VAL_INT; *vals = ads1119_available_datarates; *length = ARRAY_SIZE(ads1119_available_datarates); return IIO_AVAIL_LIST; default: return -EINVAL; } } static int ads1119_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct ads1119_state *st = iio_priv(indio_dev); unsigned int index = chan->address; if (index >= st->num_channels_cfg) return -EINVAL; switch (mask) { case IIO_CHAN_INFO_RAW: iio_device_claim_direct_scoped(return -EBUSY, indio_dev) return ads1119_single_conversion(st, chan, val, false); unreachable(); case IIO_CHAN_INFO_OFFSET: iio_device_claim_direct_scoped(return -EBUSY, indio_dev) return ads1119_single_conversion(st, chan, val, true); unreachable(); case IIO_CHAN_INFO_SCALE: *val = st->vref_uV / 1000; *val /= st->channels_cfg[index].gain; *val2 = chan->scan_type.realbits - 1; return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_SAMP_FREQ: *val = st->channels_cfg[index].datarate; return IIO_VAL_INT; default: return -EINVAL; } } static int ads1119_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct ads1119_state *st = iio_priv(indio_dev); unsigned int index = chan->address; int ret; if (index >= st->num_channels_cfg) return -EINVAL; switch (mask) { case IIO_CHAN_INFO_SCALE: ret = MICRO / ((val * MICRO) + val2); if (ret != 1 && ret != 4) return -EINVAL; st->channels_cfg[index].gain = ret; return 0; case IIO_CHAN_INFO_SAMP_FREQ: ret = ads1119_validate_datarate(st, val); if (ret < 0) return ret; st->channels_cfg[index].datarate = ret; return 0; default: return -EINVAL; } } static int ads1119_debugfs_reg_access(struct iio_dev *indio_dev, unsigned int reg, unsigned int writeval, unsigned int *readval) { struct ads1119_state *st = iio_priv(indio_dev); int ret; if (reg > ADS1119_REG_STATUS) return -EINVAL; if (readval) { ret = i2c_smbus_read_byte_data(st->client, ADS1119_CMD_RREG(reg)); if (ret < 0) return ret; *readval = ret; return 0; } if (reg > ADS1119_REG_CONFIG) return -EINVAL; return i2c_smbus_write_byte_data(st->client, ADS1119_CMD_WREG, writeval); } static const struct iio_info ads1119_info = { .read_avail = ads1119_read_avail, .read_raw = ads1119_read_raw, .write_raw = ads1119_write_raw, .debugfs_reg_access = ads1119_debugfs_reg_access, }; static int ads1119_triggered_buffer_preenable(struct iio_dev *indio_dev) { struct ads1119_state *st = iio_priv(indio_dev); struct device *dev = &st->client->dev; unsigned int index; int ret; index = find_first_bit(indio_dev->active_scan_mask, iio_get_masklength(indio_dev)); ret = ads1119_set_conv_mode(st, true); if (ret) return ret; ret = ads1119_configure_channel(st, st->channels_cfg[index].mux, st->channels_cfg[index].gain, st->channels_cfg[index].datarate); if (ret) return ret; ret = pm_runtime_resume_and_get(dev); if (ret) return ret; return i2c_smbus_write_byte(st->client, ADS1119_CMD_START_SYNC); } static int ads1119_triggered_buffer_postdisable(struct iio_dev *indio_dev) { struct ads1119_state *st = iio_priv(indio_dev); struct device *dev = &st->client->dev; int ret; ret = ads1119_set_conv_mode(st, false); if (ret) return ret; pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); return 0; } static const struct iio_buffer_setup_ops ads1119_buffer_setup_ops = { .preenable = ads1119_triggered_buffer_preenable, .postdisable = ads1119_triggered_buffer_postdisable, .validate_scan_mask = &iio_validate_scan_mask_onehot, }; static const struct iio_trigger_ops ads1119_trigger_ops = { .validate_device = &iio_trigger_validate_own_device, }; static irqreturn_t ads1119_irq_handler(int irq, void *dev_id) { struct iio_dev *indio_dev = dev_id; struct ads1119_state *st = iio_priv(indio_dev); if (iio_buffer_enabled(indio_dev) && iio_trigger_using_own(indio_dev)) iio_trigger_poll(indio_dev->trig); else complete(&st->completion); return IRQ_HANDLED; } static irqreturn_t ads1119_trigger_handler(int irq, void *private) { struct iio_poll_func *pf = private; struct iio_dev *indio_dev = pf->indio_dev; struct ads1119_state *st = iio_priv(indio_dev); struct { unsigned int sample; s64 timestamp __aligned(8); } scan; unsigned int index; int ret; if (!iio_trigger_using_own(indio_dev)) { index = find_first_bit(indio_dev->active_scan_mask, iio_get_masklength(indio_dev)); ret = ads1119_poll_data_ready(st, &indio_dev->channels[index]); if (ret) { dev_err(&st->client->dev, "Failed to poll data on trigger (%d)\n", ret); goto done; } } ret = i2c_smbus_read_word_swapped(st->client, ADS1119_CMD_RDATA); if (ret < 0) { dev_err(&st->client->dev, "Failed to read data on trigger (%d)\n", ret); goto done; } scan.sample = ret; iio_push_to_buffers_with_timestamp(indio_dev, &scan, iio_get_time_ns(indio_dev)); done: iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static int ads1119_init(struct ads1119_state *st, bool vref_external) { int ret; ret = ads1119_reset(st); if (ret) return ret; if (vref_external) return ads1119_upd_cfg_reg(st, ADS1119_CONFIG_VREF_FIELD, FIELD_PREP(ADS1119_CONFIG_VREF_FIELD, ADS1119_VREF_EXTERNAL)); return 0; } static int ads1119_map_analog_inputs_mux(int ain_pos, int ain_neg, bool differential) { if (ain_pos >= ADS1119_MAX_SINGLE_CHANNELS) return -EINVAL; if (!differential) return ADS1119_MUX_AIN0 + ain_pos; if (ain_pos == 0 && ain_neg == 1) return ADS1119_MUX_AIN0_AIN1; else if (ain_pos == 1 && ain_neg == 2) return ADS1119_MUX_AIN1_AIN2; else if (ain_pos == 2 && ain_neg == 3) return ADS1119_MUX_AIN2_AIN3; return -EINVAL; } static int ads1119_alloc_and_config_channels(struct iio_dev *indio_dev) { const struct iio_chan_spec ads1119_channel = (const struct iio_chan_spec) { .type = IIO_VOLTAGE, .indexed = 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), .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_SAMP_FREQ), .scan_type = { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_CPU, }, }; const struct iio_chan_spec ads1119_ts = IIO_CHAN_SOFT_TIMESTAMP(0); struct ads1119_state *st = iio_priv(indio_dev); struct iio_chan_spec *iio_channels, *chan; struct device *dev = &st->client->dev; unsigned int num_channels, i; bool differential; u32 ain[2]; int ret; st->num_channels_cfg = device_get_child_node_count(dev); if (st->num_channels_cfg > ADS1119_MAX_CHANNELS) return dev_err_probe(dev, -EINVAL, "Too many channels %d, max is %d\n", st->num_channels_cfg, ADS1119_MAX_CHANNELS); st->channels_cfg = devm_kcalloc(dev, st->num_channels_cfg, sizeof(*st->channels_cfg), GFP_KERNEL); if (!st->channels_cfg) return -ENOMEM; /* Allocate one more iio channel for the timestamp */ num_channels = st->num_channels_cfg + 1; iio_channels = devm_kcalloc(dev, num_channels, sizeof(*iio_channels), GFP_KERNEL); if (!iio_channels) return -ENOMEM; i = 0; device_for_each_child_node_scoped(dev, child) { chan = &iio_channels[i]; differential = fwnode_property_present(child, "diff-channels"); if (differential) ret = fwnode_property_read_u32_array(child, "diff-channels", ain, 2); else ret = fwnode_property_read_u32(child, "single-channel", &ain[0]); if (ret) return dev_err_probe(dev, ret, "Failed to get channel property\n"); ret = ads1119_map_analog_inputs_mux(ain[0], ain[1], differential); if (ret < 0) return dev_err_probe(dev, ret, "Invalid channel value\n"); st->channels_cfg[i].mux = ret; st->channels_cfg[i].gain = ADS1119_DEFAULT_GAIN; st->channels_cfg[i].datarate = ADS1119_DEFAULT_DATARATE; *chan = ads1119_channel; chan->channel = ain[0]; chan->address = i; chan->scan_index = i; if (differential) { chan->channel2 = ain[1]; chan->differential = 1; } dev_dbg(dev, "channel: index %d, mux %d\n", i, st->channels_cfg[i].mux); i++; } iio_channels[i] = ads1119_ts; iio_channels[i].address = i; iio_channels[i].scan_index = i; indio_dev->channels = iio_channels; indio_dev->num_channels = num_channels; return 0; } static void ads1119_powerdown(void *data) { struct ads1119_state *st = data; i2c_smbus_write_byte(st->client, ADS1119_CMD_POWERDOWN); } static int ads1119_probe(struct i2c_client *client) { struct iio_dev *indio_dev; struct ads1119_state *st; struct device *dev = &client->dev; bool vref_external = true; int ret; indio_dev = devm_iio_device_alloc(dev, sizeof(*st)); if (!indio_dev) return dev_err_probe(dev, -ENOMEM, "Failed to allocate IIO device\n"); st = iio_priv(indio_dev); st->client = client; indio_dev->name = "ads1119"; indio_dev->info = &ads1119_info; indio_dev->modes = INDIO_DIRECT_MODE; i2c_set_clientdata(client, indio_dev); ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(ads1119_power_supplies), ads1119_power_supplies); if (ret) return dev_err_probe(dev, ret, "Failed to get and enable supplies\n"); st->vref_uV = devm_regulator_get_enable_read_voltage(dev, "vref"); if (st->vref_uV == -ENODEV) { vref_external = false; st->vref_uV = ADS1119_VREF_INTERNAL_VAL; } else if (st->vref_uV < 0) { return dev_err_probe(dev, st->vref_uV, "Failed to get vref\n"); } st->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); if (IS_ERR(st->reset_gpio)) return dev_err_probe(dev, PTR_ERR(st->reset_gpio), "Failed to get reset gpio\n"); ret = ads1119_alloc_and_config_channels(indio_dev); if (ret) return ret; init_completion(&st->completion); ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, ads1119_trigger_handler, &ads1119_buffer_setup_ops); if (ret) return dev_err_probe(dev, ret, "Failed to setup IIO buffer\n"); if (client->irq > 0) { ret = devm_request_threaded_irq(dev, client->irq, ads1119_irq_handler, NULL, IRQF_ONESHOT, "ads1119", indio_dev); if (ret) return dev_err_probe(dev, ret, "Failed to allocate irq\n"); st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name, iio_device_id(indio_dev)); if (!st->trig) return dev_err_probe(dev, -ENOMEM, "Failed to allocate IIO trigger\n"); st->trig->ops = &ads1119_trigger_ops; iio_trigger_set_drvdata(st->trig, indio_dev); ret = devm_iio_trigger_register(dev, st->trig); if (ret) return dev_err_probe(dev, ret, "Failed to register IIO trigger\n"); } ret = ads1119_init(st, vref_external); if (ret) return dev_err_probe(dev, ret, "Failed to initialize device\n"); pm_runtime_set_autosuspend_delay(dev, ADS1119_SUSPEND_DELAY); pm_runtime_use_autosuspend(dev); pm_runtime_mark_last_busy(dev); pm_runtime_set_active(dev); ret = devm_pm_runtime_enable(dev); if (ret) return dev_err_probe(dev, ret, "Failed to enable pm runtime\n"); ret = devm_add_action_or_reset(dev, ads1119_powerdown, st); if (ret) return dev_err_probe(dev, ret, "Failed to add powerdown action\n"); return devm_iio_device_register(dev, indio_dev); } static int ads1119_runtime_suspend(struct device *dev) { struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); struct ads1119_state *st = iio_priv(indio_dev); return i2c_smbus_write_byte(st->client, ADS1119_CMD_POWERDOWN); } /* * The ADS1119 does not require a resume function because it automatically * powers on after a reset. * After a power down command, the ADS1119 can still communicate but turns off * its analog parts. To resume from power down, the device will power up again * upon receiving a start/sync command. */ static DEFINE_RUNTIME_DEV_PM_OPS(ads1119_pm_ops, ads1119_runtime_suspend, NULL, NULL); static const struct of_device_id __maybe_unused ads1119_of_match[] = { { .compatible = "ti,ads1119" }, { } }; MODULE_DEVICE_TABLE(of, ads1119_of_match); static const struct i2c_device_id ads1119_id[] = { { "ads1119" }, { } }; MODULE_DEVICE_TABLE(i2c, ads1119_id); static struct i2c_driver ads1119_driver = { .driver = { .name = "ads1119", .of_match_table = ads1119_of_match, .pm = pm_ptr(&ads1119_pm_ops), }, .probe = ads1119_probe, .id_table = ads1119_id, }; module_i2c_driver(ads1119_driver); MODULE_AUTHOR("João Paulo Gonçalves "); MODULE_DESCRIPTION("Texas Instruments ADS1119 ADC Driver"); MODULE_LICENSE("GPL");