diff options
Diffstat (limited to 'drivers/iio/adc/ti-ads1100.c')
| -rw-r--r-- | drivers/iio/adc/ti-ads1100.c | 188 |
1 files changed, 164 insertions, 24 deletions
diff --git a/drivers/iio/adc/ti-ads1100.c b/drivers/iio/adc/ti-ads1100.c index 9fe8d54cce83..9957c4d813fb 100644 --- a/drivers/iio/adc/ti-ads1100.c +++ b/drivers/iio/adc/ti-ads1100.c @@ -5,7 +5,7 @@ * Copyright (c) 2023, Topic Embedded Products * * Datasheet: https://www.ti.com/lit/gpn/ads1100 - * IIO driver for ADS1100 and ADS1000 ADC 16-bit I2C + * IIO driver for ADS1100 and similar single channel ADC 16-bit I2C */ #include <linux/bitfield.h> @@ -15,10 +15,12 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/i2c.h> +#include <linux/iopoll.h> #include <linux/mutex.h> #include <linux/property.h> #include <linux/pm_runtime.h> #include <linux/regulator/consumer.h> +#include <linux/time.h> #include <linux/units.h> #include <linux/iio/iio.h> @@ -39,17 +41,44 @@ #define ADS1100_SINGLESHOT ADS1100_CFG_SC #define ADS1100_SLEEP_DELAY_MS 2000 +#define ADS1110_INTERNAL_REF_mV 2048 static const int ads1100_data_rate[] = { 128, 32, 16, 8 }; +static const int ads1110_data_rate[] = { 240, 60, 30, 15 }; static const int ads1100_data_rate_bits[] = { 12, 14, 15, 16 }; +/* Timeout based on the minimum sample rate of 8 SPS (7500ms) */ +#define ADS1100_MAX_DRDY_TIMEOUT_US (7500 * USEC_PER_MSEC) + +struct ads1100_config { + const char *name; + const int *available_data_rate_Hz; + const int data_rate_count; + bool has_internal_vref_only; +}; + +static const struct ads1100_config ads1100_config = { + .name = "ads1100", + .available_data_rate_Hz = ads1100_data_rate, + .data_rate_count = ARRAY_SIZE(ads1100_data_rate), + .has_internal_vref_only = false, +}; + +static const struct ads1100_config ads1110_config = { + .name = "ads1110", + .available_data_rate_Hz = ads1110_data_rate, + .data_rate_count = ARRAY_SIZE(ads1110_data_rate), + .has_internal_vref_only = true, +}; + struct ads1100_data { struct i2c_client *client; struct regulator *reg_vdd; struct mutex lock; int scale_avail[2 * 4]; /* 4 gain settings */ + const struct ads1100_config *chip_info; u8 config; - bool supports_data_rate; /* Only the ADS1100 can select the rate */ + bool supports_data_rate; }; static const struct iio_chan_spec ads1100_channel = { @@ -85,6 +114,20 @@ static int ads1100_set_config_bits(struct ads1100_data *data, u8 mask, u8 value) return 0; }; +static int ads1100_get_vref_millivolts(struct ads1100_data *data) +{ + int voltage_uV; + + if (data->chip_info->has_internal_vref_only) + return ADS1110_INTERNAL_REF_mV; + + voltage_uV = regulator_get_voltage(data->reg_vdd); + if (voltage_uV < 0) + return voltage_uV; + + return voltage_uV / (MICRO / MILLI); +} + static int ads1100_data_bits(struct ads1100_data *data) { return ads1100_data_rate_bits[FIELD_GET(ADS1100_DR_MASK, data->config)]; @@ -123,10 +166,86 @@ static int ads1100_get_adc_result(struct ads1100_data *data, int chan, int *val) return 0; } +static int ads1100_conversion_busy(struct ads1100_data *data) +{ + u8 buffer[3]; + int ret; + + ret = i2c_master_recv(data->client, (char *)&buffer, sizeof(buffer)); + if (ret < 0) { + dev_err(&data->client->dev, "I2C read fail: %d\n", ret); + return ret; + } + + return FIELD_GET(ADS1100_CFG_ST_BSY, buffer[2]); +} + +static int ads1100_wait_single_conversion(struct ads1100_data *data) +{ + int data_rate_index = FIELD_GET(ADS1100_DR_MASK, data->config); + int data_rate_Hz = data->chip_info->available_data_rate_Hz[data_rate_index]; + unsigned long poll_us = DIV_ROUND_CLOSEST(USEC_PER_SEC, data_rate_Hz) / 4; + int busy; + int ret; + + ret = readx_poll_timeout(ads1100_conversion_busy, data, + busy, busy <= 0, + poll_us, ADS1100_MAX_DRDY_TIMEOUT_US); + if (busy < 0) + return busy; + + return ret; +} + +static int ads1100_start_single_conversion(struct ads1100_data *data) +{ + u8 config = data->config | ADS1100_CFG_SC; + int ret; + + ret = i2c_master_send(data->client, &config, sizeof(config)); + if (ret < 0) { + dev_err(&data->client->dev, "I2C write fail: %d\n", ret); + return ret; + } + /* Need to wait because of change from continuous to single mode */ + ret = ads1100_wait_single_conversion(data); + if (ret) + return ret; + + config |= ADS1100_CFG_ST_BSY; + + ret = i2c_master_send(data->client, &config, sizeof(config)); + if (ret < 0) { + dev_err(&data->client->dev, "I2C write fail: %d\n", ret); + return ret; + } + + /* No need to cache it, it's status bit */ + data->config = config & ~ADS1100_CFG_ST_BSY; + + return 0; +} + +static int ads1100_poll_data_ready(struct ads1100_data *data) +{ + int ret; + + ret = ads1100_start_single_conversion(data); + if (ret) + return ret; + + ret = ads1100_wait_single_conversion(data); + if (ret) + return ret; + + return ads1100_set_config_bits(data, ADS1100_CFG_SC, ADS1100_CONTINUOUS); +} + static int ads1100_set_scale(struct ads1100_data *data, int val, int val2) { int microvolts; int gain; + int ret; /* With Vdd between 2.7 and 5V, the scale is always below 1 */ if (val) @@ -135,7 +254,12 @@ static int ads1100_set_scale(struct ads1100_data *data, int val, int val2) if (!val2) return -EINVAL; - microvolts = regulator_get_voltage(data->reg_vdd); + PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND(&data->client->dev, pm); + ret = PM_RUNTIME_ACQUIRE_ERR(&pm); + if (ret) + return ret; + + microvolts = ads1100_get_vref_millivolts(data) * (MICRO / MILLI); /* * val2 is in 'micro' units, n = val2 / 1000000 * result must be millivolts, d = microvolts / 1000 @@ -149,32 +273,40 @@ static int ads1100_set_scale(struct ads1100_data *data, int val, int val2) ads1100_set_config_bits(data, ADS1100_PGA_MASK, ffs(gain) - 1); - return 0; + return ads1100_poll_data_ready(data); } static int ads1100_set_data_rate(struct ads1100_data *data, int chan, int rate) { unsigned int i; unsigned int size; + int ret; - size = data->supports_data_rate ? ARRAY_SIZE(ads1100_data_rate) : 1; + size = data->supports_data_rate ? data->chip_info->data_rate_count : 1; for (i = 0; i < size; i++) { - if (ads1100_data_rate[i] == rate) - return ads1100_set_config_bits(data, ADS1100_DR_MASK, - FIELD_PREP(ADS1100_DR_MASK, i)); + if (data->chip_info->available_data_rate_Hz[i] == rate) + break; } - return -EINVAL; -} + if (i == size) + return -EINVAL; -static int ads1100_get_vdd_millivolts(struct ads1100_data *data) -{ - return regulator_get_voltage(data->reg_vdd) / (MICRO / MILLI); + PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND(&data->client->dev, pm); + ret = PM_RUNTIME_ACQUIRE_ERR(&pm); + if (ret) + return ret; + + ret = ads1100_set_config_bits(data, ADS1100_DR_MASK, + FIELD_PREP(ADS1100_DR_MASK, i)); + if (ret) + return ret; + + return ads1100_poll_data_ready(data); } static void ads1100_calc_scale_avail(struct ads1100_data *data) { - int millivolts = ads1100_get_vdd_millivolts(data); + int millivolts = ads1100_get_vref_millivolts(data); unsigned int i; for (i = 0; i < ARRAY_SIZE(data->scale_avail) / 2; i++) { @@ -196,9 +328,9 @@ static int ads1100_read_avail(struct iio_dev *indio_dev, switch (mask) { case IIO_CHAN_INFO_SAMP_FREQ: *type = IIO_VAL_INT; - *vals = ads1100_data_rate; + *vals = data->chip_info->available_data_rate_Hz; if (data->supports_data_rate) - *length = ARRAY_SIZE(ads1100_data_rate); + *length = data->chip_info->data_rate_count; else *length = 1; return IIO_AVAIL_LIST; @@ -218,6 +350,7 @@ static int ads1100_read_raw(struct iio_dev *indio_dev, { int ret; struct ads1100_data *data = iio_priv(indio_dev); + int data_rate_index; guard(mutex)(&data->lock); switch (mask) { @@ -233,12 +366,12 @@ static int ads1100_read_raw(struct iio_dev *indio_dev, return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: /* full-scale is the supply voltage in millivolts */ - *val = ads1100_get_vdd_millivolts(data); + *val = ads1100_get_vref_millivolts(data); *val2 = 15 + FIELD_GET(ADS1100_PGA_MASK, data->config); return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_SAMP_FREQ: - *val = ads1100_data_rate[FIELD_GET(ADS1100_DR_MASK, - data->config)]; + data_rate_index = FIELD_GET(ADS1100_DR_MASK, data->config); + *val = data->chip_info->available_data_rate_Hz[data_rate_index]; return IIO_VAL_INT; default: return -EINVAL; @@ -318,7 +451,12 @@ static int ads1100_probe(struct i2c_client *client) data->client = client; mutex_init(&data->lock); - indio_dev->name = "ads1100"; + data->chip_info = i2c_get_match_data(client); + if (!data->chip_info) + return dev_err_probe(dev, -ENODATA, + "Can't get device data from firmware\n"); + + indio_dev->name = data->chip_info->name; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = &ads1100_channel; indio_dev->num_channels = 1; @@ -400,16 +538,18 @@ static DEFINE_RUNTIME_DEV_PM_OPS(ads1100_pm_ops, NULL); static const struct i2c_device_id ads1100_id[] = { - { .name = "ads1100" }, - { .name = "ads1000" }, + { .name = "ads1000", .driver_data = (kernel_ulong_t)&ads1100_config }, + { .name = "ads1100", .driver_data = (kernel_ulong_t)&ads1100_config }, + { .name = "ads1110", .driver_data = (kernel_ulong_t)&ads1110_config }, { } }; MODULE_DEVICE_TABLE(i2c, ads1100_id); static const struct of_device_id ads1100_of_match[] = { - {.compatible = "ti,ads1100" }, - {.compatible = "ti,ads1000" }, + { .compatible = "ti,ads1000", .data = &ads1100_config }, + { .compatible = "ti,ads1100", .data = &ads1100_config }, + { .compatible = "ti,ads1110", .data = &ads1110_config }, { } }; |