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da4d3d6bb9
Before this patch the ad_sigma_delta implementation hardcoded the irq trigger type to low, assuming that all Sigma-Delta ADCs have the same interrupt-type. This patch allows all drivers using the ad_sigma_delta layer to set the irq trigger type to the one specified in the datasheet. Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
378 lines
8.6 KiB
C
378 lines
8.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* AD7170/AD7171 and AD7780/AD7781 SPI ADC driver
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*
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* Copyright 2011 Analog Devices Inc.
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* Copyright 2019 Renato Lui Geh
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*/
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#include <linux/interrupt.h>
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/sysfs.h>
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#include <linux/spi/spi.h>
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#include <linux/regulator/consumer.h>
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#include <linux/err.h>
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#include <linux/sched.h>
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#include <linux/gpio/consumer.h>
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#include <linux/module.h>
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#include <linux/bits.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <linux/iio/adc/ad_sigma_delta.h>
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#define AD7780_RDY BIT(7)
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#define AD7780_FILTER BIT(6)
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#define AD7780_ERR BIT(5)
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#define AD7780_ID1 BIT(4)
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#define AD7780_ID0 BIT(3)
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#define AD7780_GAIN BIT(2)
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#define AD7170_ID 0
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#define AD7171_ID 1
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#define AD7780_ID 1
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#define AD7781_ID 0
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#define AD7780_ID_MASK (AD7780_ID0 | AD7780_ID1)
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#define AD7780_PATTERN_GOOD 1
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#define AD7780_PATTERN_MASK GENMASK(1, 0)
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#define AD7170_PATTERN_GOOD 5
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#define AD7170_PATTERN_MASK GENMASK(2, 0)
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#define AD7780_GAIN_MIDPOINT 64
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#define AD7780_FILTER_MIDPOINT 13350
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static const unsigned int ad778x_gain[2] = { 1, 128 };
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static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 };
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struct ad7780_chip_info {
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struct iio_chan_spec channel;
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unsigned int pattern_mask;
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unsigned int pattern;
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bool is_ad778x;
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};
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struct ad7780_state {
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const struct ad7780_chip_info *chip_info;
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struct regulator *reg;
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struct gpio_desc *powerdown_gpio;
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struct gpio_desc *gain_gpio;
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struct gpio_desc *filter_gpio;
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unsigned int gain;
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unsigned int odr;
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unsigned int int_vref_mv;
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struct ad_sigma_delta sd;
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};
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enum ad7780_supported_device_ids {
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ID_AD7170,
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ID_AD7171,
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ID_AD7780,
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ID_AD7781,
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};
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static struct ad7780_state *ad_sigma_delta_to_ad7780(struct ad_sigma_delta *sd)
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{
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return container_of(sd, struct ad7780_state, sd);
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}
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static int ad7780_set_mode(struct ad_sigma_delta *sigma_delta,
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enum ad_sigma_delta_mode mode)
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{
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struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta);
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unsigned int val;
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switch (mode) {
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case AD_SD_MODE_SINGLE:
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case AD_SD_MODE_CONTINUOUS:
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val = 1;
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break;
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default:
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val = 0;
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break;
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}
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gpiod_set_value(st->powerdown_gpio, val);
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return 0;
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}
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static int ad7780_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val,
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int *val2,
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long m)
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{
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struct ad7780_state *st = iio_priv(indio_dev);
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int voltage_uv;
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switch (m) {
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case IIO_CHAN_INFO_RAW:
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return ad_sigma_delta_single_conversion(indio_dev, chan, val);
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case IIO_CHAN_INFO_SCALE:
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voltage_uv = regulator_get_voltage(st->reg);
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if (voltage_uv < 0)
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return voltage_uv;
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voltage_uv /= 1000;
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*val = voltage_uv * st->gain;
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*val2 = chan->scan_type.realbits - 1;
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st->int_vref_mv = voltage_uv;
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return IIO_VAL_FRACTIONAL_LOG2;
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case IIO_CHAN_INFO_OFFSET:
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*val = -(1 << (chan->scan_type.realbits - 1));
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SAMP_FREQ:
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*val = st->odr;
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return IIO_VAL_INT;
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default:
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break;
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}
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return -EINVAL;
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}
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static int ad7780_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val,
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int val2,
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long m)
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{
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struct ad7780_state *st = iio_priv(indio_dev);
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const struct ad7780_chip_info *chip_info = st->chip_info;
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unsigned long long vref;
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unsigned int full_scale, gain;
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if (!chip_info->is_ad778x)
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return -EINVAL;
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switch (m) {
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case IIO_CHAN_INFO_SCALE:
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if (val != 0)
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return -EINVAL;
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vref = st->int_vref_mv * 1000000LL;
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full_scale = 1 << (chip_info->channel.scan_type.realbits - 1);
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gain = DIV_ROUND_CLOSEST_ULL(vref, full_scale);
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gain = DIV_ROUND_CLOSEST(gain, val2);
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st->gain = gain;
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if (gain < AD7780_GAIN_MIDPOINT)
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gain = 0;
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else
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gain = 1;
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gpiod_set_value(st->gain_gpio, gain);
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break;
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case IIO_CHAN_INFO_SAMP_FREQ:
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if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)
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val = 0;
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else
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val = 1;
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st->odr = ad778x_odr_avail[val];
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gpiod_set_value(st->filter_gpio, val);
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break;
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default:
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break;
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}
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return 0;
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}
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static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
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unsigned int raw_sample)
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{
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struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta);
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const struct ad7780_chip_info *chip_info = st->chip_info;
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if ((raw_sample & AD7780_ERR) ||
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((raw_sample & chip_info->pattern_mask) != chip_info->pattern))
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return -EIO;
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if (chip_info->is_ad778x) {
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st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
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st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER];
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}
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return 0;
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}
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static const struct ad_sigma_delta_info ad7780_sigma_delta_info = {
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.set_mode = ad7780_set_mode,
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.postprocess_sample = ad7780_postprocess_sample,
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.has_registers = false,
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.irq_flags = IRQF_TRIGGER_LOW,
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};
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#define AD7780_CHANNEL(bits, wordsize) \
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AD_SD_CHANNEL(1, 0, 0, bits, 32, (wordsize) - (bits))
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#define AD7170_CHANNEL(bits, wordsize) \
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AD_SD_CHANNEL_NO_SAMP_FREQ(1, 0, 0, bits, 32, (wordsize) - (bits))
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static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
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[ID_AD7170] = {
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.channel = AD7170_CHANNEL(12, 24),
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.pattern = AD7170_PATTERN_GOOD,
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.pattern_mask = AD7170_PATTERN_MASK,
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.is_ad778x = false,
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},
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[ID_AD7171] = {
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.channel = AD7170_CHANNEL(16, 24),
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.pattern = AD7170_PATTERN_GOOD,
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.pattern_mask = AD7170_PATTERN_MASK,
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.is_ad778x = false,
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},
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[ID_AD7780] = {
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.channel = AD7780_CHANNEL(24, 32),
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.pattern = AD7780_PATTERN_GOOD,
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.pattern_mask = AD7780_PATTERN_MASK,
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.is_ad778x = true,
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},
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[ID_AD7781] = {
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.channel = AD7780_CHANNEL(20, 32),
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.pattern = AD7780_PATTERN_GOOD,
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.pattern_mask = AD7780_PATTERN_MASK,
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.is_ad778x = true,
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},
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};
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static const struct iio_info ad7780_info = {
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.read_raw = ad7780_read_raw,
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.write_raw = ad7780_write_raw,
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};
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static int ad7780_init_gpios(struct device *dev, struct ad7780_state *st)
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{
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int ret;
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st->powerdown_gpio = devm_gpiod_get_optional(dev,
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"powerdown",
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GPIOD_OUT_LOW);
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if (IS_ERR(st->powerdown_gpio)) {
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ret = PTR_ERR(st->powerdown_gpio);
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dev_err(dev, "Failed to request powerdown GPIO: %d\n", ret);
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return ret;
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}
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if (!st->chip_info->is_ad778x)
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return 0;
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st->gain_gpio = devm_gpiod_get_optional(dev,
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"adi,gain",
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GPIOD_OUT_HIGH);
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if (IS_ERR(st->gain_gpio)) {
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ret = PTR_ERR(st->gain_gpio);
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dev_err(dev, "Failed to request gain GPIO: %d\n", ret);
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return ret;
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}
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st->filter_gpio = devm_gpiod_get_optional(dev,
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"adi,filter",
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GPIOD_OUT_HIGH);
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if (IS_ERR(st->filter_gpio)) {
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ret = PTR_ERR(st->filter_gpio);
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dev_err(dev, "Failed to request filter GPIO: %d\n", ret);
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return ret;
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}
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return 0;
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}
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static int ad7780_probe(struct spi_device *spi)
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{
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struct ad7780_state *st;
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struct iio_dev *indio_dev;
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int ret;
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
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if (!indio_dev)
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return -ENOMEM;
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st = iio_priv(indio_dev);
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st->gain = 1;
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ad_sd_init(&st->sd, indio_dev, spi, &ad7780_sigma_delta_info);
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st->chip_info =
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&ad7780_chip_info_tbl[spi_get_device_id(spi)->driver_data];
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spi_set_drvdata(spi, indio_dev);
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indio_dev->dev.parent = &spi->dev;
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indio_dev->name = spi_get_device_id(spi)->name;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = &st->chip_info->channel;
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indio_dev->num_channels = 1;
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indio_dev->info = &ad7780_info;
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ret = ad7780_init_gpios(&spi->dev, st);
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if (ret)
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goto error_cleanup_buffer_and_trigger;
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st->reg = devm_regulator_get(&spi->dev, "avdd");
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if (IS_ERR(st->reg))
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return PTR_ERR(st->reg);
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ret = regulator_enable(st->reg);
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if (ret) {
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dev_err(&spi->dev, "Failed to enable specified AVdd supply\n");
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return ret;
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}
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ret = ad_sd_setup_buffer_and_trigger(indio_dev);
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if (ret)
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goto error_disable_reg;
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ret = iio_device_register(indio_dev);
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if (ret)
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goto error_cleanup_buffer_and_trigger;
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return 0;
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error_cleanup_buffer_and_trigger:
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ad_sd_cleanup_buffer_and_trigger(indio_dev);
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error_disable_reg:
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regulator_disable(st->reg);
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return ret;
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}
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static int ad7780_remove(struct spi_device *spi)
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{
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struct iio_dev *indio_dev = spi_get_drvdata(spi);
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struct ad7780_state *st = iio_priv(indio_dev);
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iio_device_unregister(indio_dev);
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ad_sd_cleanup_buffer_and_trigger(indio_dev);
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regulator_disable(st->reg);
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return 0;
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}
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static const struct spi_device_id ad7780_id[] = {
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{"ad7170", ID_AD7170},
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{"ad7171", ID_AD7171},
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{"ad7780", ID_AD7780},
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{"ad7781", ID_AD7781},
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{}
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};
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MODULE_DEVICE_TABLE(spi, ad7780_id);
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static struct spi_driver ad7780_driver = {
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.driver = {
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.name = "ad7780",
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},
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.probe = ad7780_probe,
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.remove = ad7780_remove,
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.id_table = ad7780_id,
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};
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module_spi_driver(ad7780_driver);
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MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
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MODULE_DESCRIPTION("Analog Devices AD7780 and similar ADCs");
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MODULE_LICENSE("GPL v2");
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