diff options
Diffstat (limited to 'drivers/iio/adc/ad7780.c')
| -rw-r--r-- | drivers/iio/adc/ad7780.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad7780.c b/drivers/iio/adc/ad7780.c new file mode 100644 index 000000000..c70048bc7 --- /dev/null +++ b/drivers/iio/adc/ad7780.c @@ -0,0 +1,395 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * AD7170/AD7171 and AD7780/AD7781 SPI ADC driver + * + * Copyright 2011 Analog Devices Inc. + * Copyright 2019 Renato Lui Geh + */ + +#include <linux/interrupt.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/spi/spi.h> +#include <linux/regulator/consumer.h> +#include <linux/err.h> +#include <linux/sched.h> +#include <linux/gpio/consumer.h> +#include <linux/module.h> +#include <linux/bits.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/adc/ad_sigma_delta.h> + +#define AD7780_RDY BIT(7) +#define AD7780_FILTER BIT(6) +#define AD7780_ERR BIT(5) +#define AD7780_ID1 BIT(4) +#define AD7780_ID0 BIT(3) +#define AD7780_GAIN BIT(2) + +#define AD7170_ID 0 +#define AD7171_ID 1 +#define AD7780_ID 1 +#define AD7781_ID 0 + +#define AD7780_ID_MASK (AD7780_ID0 | AD7780_ID1) + +#define AD7780_PATTERN_GOOD 1 +#define AD7780_PATTERN_MASK GENMASK(1, 0) + +#define AD7170_PATTERN_GOOD 5 +#define AD7170_PATTERN_MASK GENMASK(2, 0) + +#define AD7780_GAIN_MIDPOINT 64 +#define AD7780_FILTER_MIDPOINT 13350 + +static const unsigned int ad778x_gain[2] = { 1, 128 }; +static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 }; + +struct ad7780_chip_info { + struct iio_chan_spec channel; + unsigned int pattern_mask; + unsigned int pattern; + bool is_ad778x; +}; + +struct ad7780_state { + const struct ad7780_chip_info *chip_info; + struct regulator *reg; + struct gpio_desc *powerdown_gpio; + struct gpio_desc *gain_gpio; + struct gpio_desc *filter_gpio; + unsigned int gain; + unsigned int odr; + unsigned int int_vref_mv; + + struct ad_sigma_delta sd; +}; + +enum ad7780_supported_device_ids { + ID_AD7170, + ID_AD7171, + ID_AD7780, + ID_AD7781, +}; + +static struct ad7780_state *ad_sigma_delta_to_ad7780(struct ad_sigma_delta *sd) +{ + return container_of(sd, struct ad7780_state, sd); +} + +static int ad7780_set_mode(struct ad_sigma_delta *sigma_delta, + enum ad_sigma_delta_mode mode) +{ + struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta); + unsigned int val; + + switch (mode) { + case AD_SD_MODE_SINGLE: + case AD_SD_MODE_CONTINUOUS: + val = 1; + break; + default: + val = 0; + break; + } + + gpiod_set_value(st->powerdown_gpio, val); + + return 0; +} + +static int ad7780_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long m) +{ + struct ad7780_state *st = iio_priv(indio_dev); + int voltage_uv; + + switch (m) { + case IIO_CHAN_INFO_RAW: + return ad_sigma_delta_single_conversion(indio_dev, chan, val); + case IIO_CHAN_INFO_SCALE: + voltage_uv = regulator_get_voltage(st->reg); + if (voltage_uv < 0) + return voltage_uv; + voltage_uv /= 1000; + *val = voltage_uv * st->gain; + *val2 = chan->scan_type.realbits - 1; + st->int_vref_mv = voltage_uv; + return IIO_VAL_FRACTIONAL_LOG2; + case IIO_CHAN_INFO_OFFSET: + *val = -(1 << (chan->scan_type.realbits - 1)); + return IIO_VAL_INT; + case IIO_CHAN_INFO_SAMP_FREQ: + *val = st->odr; + return IIO_VAL_INT; + default: + break; + } + + return -EINVAL; +} + +static int ad7780_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, + int val2, + long m) +{ + struct ad7780_state *st = iio_priv(indio_dev); + const struct ad7780_chip_info *chip_info = st->chip_info; + unsigned long long vref; + unsigned int full_scale, gain; + + if (!chip_info->is_ad778x) + return -EINVAL; + + switch (m) { + case IIO_CHAN_INFO_SCALE: + if (val != 0) + return -EINVAL; + + vref = st->int_vref_mv * 1000000LL; + full_scale = 1 << (chip_info->channel.scan_type.realbits - 1); + gain = DIV_ROUND_CLOSEST_ULL(vref, full_scale); + gain = DIV_ROUND_CLOSEST(gain, val2); + st->gain = gain; + if (gain < AD7780_GAIN_MIDPOINT) + gain = 0; + else + gain = 1; + gpiod_set_value(st->gain_gpio, gain); + break; + case IIO_CHAN_INFO_SAMP_FREQ: + if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT) + val = 0; + else + val = 1; + st->odr = ad778x_odr_avail[val]; + gpiod_set_value(st->filter_gpio, val); + break; + default: + break; + } + + return 0; +} + +static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta, + unsigned int raw_sample) +{ + struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta); + const struct ad7780_chip_info *chip_info = st->chip_info; + + if ((raw_sample & AD7780_ERR) || + ((raw_sample & chip_info->pattern_mask) != chip_info->pattern)) + return -EIO; + + if (chip_info->is_ad778x) { + st->gain = ad778x_gain[raw_sample & AD7780_GAIN]; + st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER]; + } + + return 0; +} + +static const struct ad_sigma_delta_info ad7780_sigma_delta_info = { + .set_mode = ad7780_set_mode, + .postprocess_sample = ad7780_postprocess_sample, + .has_registers = false, + .irq_flags = IRQF_TRIGGER_FALLING, +}; + +#define _AD7780_CHANNEL(_bits, _wordsize, _mask_all) \ +{ \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = 0, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_OFFSET), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_shared_by_all = _mask_all, \ + .scan_index = 1, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = (_bits), \ + .storagebits = 32, \ + .shift = (_wordsize) - (_bits), \ + .endianness = IIO_BE, \ + }, \ +} + +#define AD7780_CHANNEL(_bits, _wordsize) \ + _AD7780_CHANNEL(_bits, _wordsize, BIT(IIO_CHAN_INFO_SAMP_FREQ)) +#define AD7170_CHANNEL(_bits, _wordsize) \ + _AD7780_CHANNEL(_bits, _wordsize, 0) + +static const struct ad7780_chip_info ad7780_chip_info_tbl[] = { + [ID_AD7170] = { + .channel = AD7170_CHANNEL(12, 24), + .pattern = AD7170_PATTERN_GOOD, + .pattern_mask = AD7170_PATTERN_MASK, + .is_ad778x = false, + }, + [ID_AD7171] = { + .channel = AD7170_CHANNEL(16, 24), + .pattern = AD7170_PATTERN_GOOD, + .pattern_mask = AD7170_PATTERN_MASK, + .is_ad778x = false, + }, + [ID_AD7780] = { + .channel = AD7780_CHANNEL(24, 32), + .pattern = AD7780_PATTERN_GOOD, + .pattern_mask = AD7780_PATTERN_MASK, + .is_ad778x = true, + }, + [ID_AD7781] = { + .channel = AD7780_CHANNEL(20, 32), + .pattern = AD7780_PATTERN_GOOD, + .pattern_mask = AD7780_PATTERN_MASK, + .is_ad778x = true, + }, +}; + +static const struct iio_info ad7780_info = { + .read_raw = ad7780_read_raw, + .write_raw = ad7780_write_raw, +}; + +static int ad7780_init_gpios(struct device *dev, struct ad7780_state *st) +{ + int ret; + + st->powerdown_gpio = devm_gpiod_get_optional(dev, + "powerdown", + GPIOD_OUT_LOW); + if (IS_ERR(st->powerdown_gpio)) { + ret = PTR_ERR(st->powerdown_gpio); + dev_err(dev, "Failed to request powerdown GPIO: %d\n", ret); + return ret; + } + + if (!st->chip_info->is_ad778x) + return 0; + + + st->gain_gpio = devm_gpiod_get_optional(dev, + "adi,gain", + GPIOD_OUT_HIGH); + if (IS_ERR(st->gain_gpio)) { + ret = PTR_ERR(st->gain_gpio); + dev_err(dev, "Failed to request gain GPIO: %d\n", ret); + return ret; + } + + st->filter_gpio = devm_gpiod_get_optional(dev, + "adi,filter", + GPIOD_OUT_HIGH); + if (IS_ERR(st->filter_gpio)) { + ret = PTR_ERR(st->filter_gpio); + dev_err(dev, "Failed to request filter GPIO: %d\n", ret); + return ret; + } + + return 0; +} + +static int ad7780_probe(struct spi_device *spi) +{ + struct ad7780_state *st; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + st->gain = 1; + + ad_sd_init(&st->sd, indio_dev, spi, &ad7780_sigma_delta_info); + + st->chip_info = + &ad7780_chip_info_tbl[spi_get_device_id(spi)->driver_data]; + + spi_set_drvdata(spi, indio_dev); + + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = &st->chip_info->channel; + indio_dev->num_channels = 1; + indio_dev->info = &ad7780_info; + + ret = ad7780_init_gpios(&spi->dev, st); + if (ret) + return ret; + + st->reg = devm_regulator_get(&spi->dev, "avdd"); + if (IS_ERR(st->reg)) + return PTR_ERR(st->reg); + + ret = regulator_enable(st->reg); + if (ret) { + dev_err(&spi->dev, "Failed to enable specified AVdd supply\n"); + return ret; + } + + ret = ad_sd_setup_buffer_and_trigger(indio_dev); + if (ret) + goto error_disable_reg; + + ret = iio_device_register(indio_dev); + if (ret) + goto error_cleanup_buffer_and_trigger; + + return 0; + +error_cleanup_buffer_and_trigger: + ad_sd_cleanup_buffer_and_trigger(indio_dev); +error_disable_reg: + regulator_disable(st->reg); + + return ret; +} + +static int ad7780_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + struct ad7780_state *st = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + ad_sd_cleanup_buffer_and_trigger(indio_dev); + + regulator_disable(st->reg); + + return 0; +} + +static const struct spi_device_id ad7780_id[] = { + {"ad7170", ID_AD7170}, + {"ad7171", ID_AD7171}, + {"ad7780", ID_AD7780}, + {"ad7781", ID_AD7781}, + {} +}; +MODULE_DEVICE_TABLE(spi, ad7780_id); + +static struct spi_driver ad7780_driver = { + .driver = { + .name = "ad7780", + }, + .probe = ad7780_probe, + .remove = ad7780_remove, + .id_table = ad7780_id, +}; +module_spi_driver(ad7780_driver); + +MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>"); +MODULE_DESCRIPTION("Analog Devices AD7780 and similar ADCs"); +MODULE_LICENSE("GPL v2"); |