| // 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_LOW, |
| }; |
| |
| #define AD7780_CHANNEL(bits, wordsize) \ |
| AD_SD_CHANNEL(1, 0, 0, bits, 32, (wordsize) - (bits)) |
| #define AD7170_CHANNEL(bits, wordsize) \ |
| AD_SD_CHANNEL_NO_SAMP_FREQ(1, 0, 0, bits, 32, (wordsize) - (bits)) |
| |
| 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->dev.parent = &spi->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) |
| goto error_cleanup_buffer_and_trigger; |
| |
| 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"); |