478 lines
13 KiB
C
478 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* AD7787/AD7788/AD7789/AD7790/AD7791 SPI ADC driver
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*
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* Copyright 2012 Analog Devices Inc.
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* Author: Lars-Peter Clausen <lars@metafoo.de>
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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/delay.h>
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#include <linux/module.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/buffer.h>
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#include <linux/iio/trigger.h>
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#include <linux/iio/trigger_consumer.h>
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#include <linux/iio/triggered_buffer.h>
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#include <linux/iio/adc/ad_sigma_delta.h>
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#include <linux/platform_data/ad7791.h>
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#define AD7791_REG_COMM 0x0 /* For writes */
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#define AD7791_REG_STATUS 0x0 /* For reads */
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#define AD7791_REG_MODE 0x1
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#define AD7791_REG_FILTER 0x2
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#define AD7791_REG_DATA 0x3
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#define AD7791_MODE_CONTINUOUS 0x00
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#define AD7791_MODE_SINGLE 0x02
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#define AD7791_MODE_POWERDOWN 0x03
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#define AD7791_CH_AIN1P_AIN1N 0x00
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#define AD7791_CH_AIN2 0x01
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#define AD7791_CH_AIN1N_AIN1N 0x02
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#define AD7791_CH_AVDD_MONITOR 0x03
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#define AD7791_FILTER_CLK_DIV_1 (0x0 << 4)
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#define AD7791_FILTER_CLK_DIV_2 (0x1 << 4)
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#define AD7791_FILTER_CLK_DIV_4 (0x2 << 4)
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#define AD7791_FILTER_CLK_DIV_8 (0x3 << 4)
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#define AD7791_FILTER_CLK_MASK (0x3 << 4)
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#define AD7791_FILTER_RATE_120 0x0
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#define AD7791_FILTER_RATE_100 0x1
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#define AD7791_FILTER_RATE_33_3 0x2
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#define AD7791_FILTER_RATE_20 0x3
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#define AD7791_FILTER_RATE_16_6 0x4
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#define AD7791_FILTER_RATE_16_7 0x5
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#define AD7791_FILTER_RATE_13_3 0x6
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#define AD7791_FILTER_RATE_9_5 0x7
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#define AD7791_FILTER_RATE_MASK 0x7
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#define AD7791_MODE_BUFFER BIT(1)
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#define AD7791_MODE_UNIPOLAR BIT(2)
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#define AD7791_MODE_BURNOUT BIT(3)
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#define AD7791_MODE_SEL_MASK (0x3 << 6)
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#define AD7791_MODE_SEL(x) ((x) << 6)
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#define __AD7991_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
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_storagebits, _shift, _extend_name, _type, _mask_all) \
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{ \
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.type = (_type), \
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.differential = (_channel2 == -1 ? 0 : 1), \
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.indexed = 1, \
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.channel = (_channel1), \
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.channel2 = (_channel2), \
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.address = (_address), \
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.extend_name = (_extend_name), \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
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BIT(IIO_CHAN_INFO_OFFSET), \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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.info_mask_shared_by_all = _mask_all, \
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.scan_index = (_si), \
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.scan_type = { \
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.sign = 'u', \
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.realbits = (_bits), \
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.storagebits = (_storagebits), \
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.shift = (_shift), \
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.endianness = IIO_BE, \
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}, \
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}
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#define AD7991_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
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_storagebits, _shift) \
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__AD7991_CHANNEL(_si, _channel, _channel, _address, _bits, \
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_storagebits, _shift, "shorted", IIO_VOLTAGE, \
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BIT(IIO_CHAN_INFO_SAMP_FREQ))
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#define AD7991_CHANNEL(_si, _channel, _address, _bits, \
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_storagebits, _shift) \
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__AD7991_CHANNEL(_si, _channel, -1, _address, _bits, \
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_storagebits, _shift, NULL, IIO_VOLTAGE, \
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BIT(IIO_CHAN_INFO_SAMP_FREQ))
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#define AD7991_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
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_storagebits, _shift) \
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__AD7991_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
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_storagebits, _shift, NULL, IIO_VOLTAGE, \
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BIT(IIO_CHAN_INFO_SAMP_FREQ))
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#define AD7991_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \
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_shift) \
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__AD7991_CHANNEL(_si, _channel, -1, _address, _bits, \
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_storagebits, _shift, "supply", IIO_VOLTAGE, \
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BIT(IIO_CHAN_INFO_SAMP_FREQ))
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#define DECLARE_AD7787_CHANNELS(name, bits, storagebits) \
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const struct iio_chan_spec name[] = { \
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AD7991_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \
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(bits), (storagebits), 0), \
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AD7991_CHANNEL(1, 1, AD7791_CH_AIN2, (bits), (storagebits), 0), \
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AD7991_SHORTED_CHANNEL(2, 0, AD7791_CH_AIN1N_AIN1N, \
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(bits), (storagebits), 0), \
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AD7991_SUPPLY_CHANNEL(3, 2, AD7791_CH_AVDD_MONITOR, \
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(bits), (storagebits), 0), \
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IIO_CHAN_SOFT_TIMESTAMP(4), \
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}
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#define DECLARE_AD7791_CHANNELS(name, bits, storagebits) \
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const struct iio_chan_spec name[] = { \
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AD7991_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \
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(bits), (storagebits), 0), \
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AD7991_SHORTED_CHANNEL(1, 0, AD7791_CH_AIN1N_AIN1N, \
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(bits), (storagebits), 0), \
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AD7991_SUPPLY_CHANNEL(2, 1, AD7791_CH_AVDD_MONITOR, \
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(bits), (storagebits), 0), \
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IIO_CHAN_SOFT_TIMESTAMP(3), \
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}
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static DECLARE_AD7787_CHANNELS(ad7787_channels, 24, 32);
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static DECLARE_AD7791_CHANNELS(ad7790_channels, 16, 16);
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static DECLARE_AD7791_CHANNELS(ad7791_channels, 24, 32);
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enum {
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AD7787,
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AD7788,
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AD7789,
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AD7790,
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AD7791,
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};
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enum ad7791_chip_info_flags {
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AD7791_FLAG_HAS_FILTER = (1 << 0),
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AD7791_FLAG_HAS_BUFFER = (1 << 1),
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AD7791_FLAG_HAS_UNIPOLAR = (1 << 2),
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AD7791_FLAG_HAS_BURNOUT = (1 << 3),
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};
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struct ad7791_chip_info {
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const struct iio_chan_spec *channels;
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unsigned int num_channels;
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enum ad7791_chip_info_flags flags;
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};
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static const struct ad7791_chip_info ad7791_chip_infos[] = {
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[AD7787] = {
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.channels = ad7787_channels,
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.num_channels = ARRAY_SIZE(ad7787_channels),
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.flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
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AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT,
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},
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[AD7788] = {
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.channels = ad7790_channels,
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.num_channels = ARRAY_SIZE(ad7790_channels),
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.flags = AD7791_FLAG_HAS_UNIPOLAR,
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},
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[AD7789] = {
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.channels = ad7791_channels,
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.num_channels = ARRAY_SIZE(ad7791_channels),
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.flags = AD7791_FLAG_HAS_UNIPOLAR,
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},
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[AD7790] = {
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.channels = ad7790_channels,
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.num_channels = ARRAY_SIZE(ad7790_channels),
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.flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
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AD7791_FLAG_HAS_BURNOUT,
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},
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[AD7791] = {
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.channels = ad7791_channels,
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.num_channels = ARRAY_SIZE(ad7791_channels),
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.flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
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AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT,
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},
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};
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struct ad7791_state {
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struct ad_sigma_delta sd;
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uint8_t mode;
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uint8_t filter;
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struct regulator *reg;
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const struct ad7791_chip_info *info;
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};
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static const int ad7791_sample_freq_avail[8][2] = {
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[AD7791_FILTER_RATE_120] = { 120, 0 },
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[AD7791_FILTER_RATE_100] = { 100, 0 },
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[AD7791_FILTER_RATE_33_3] = { 33, 300000 },
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[AD7791_FILTER_RATE_20] = { 20, 0 },
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[AD7791_FILTER_RATE_16_6] = { 16, 600000 },
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[AD7791_FILTER_RATE_16_7] = { 16, 700000 },
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[AD7791_FILTER_RATE_13_3] = { 13, 300000 },
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[AD7791_FILTER_RATE_9_5] = { 9, 500000 },
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};
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static struct ad7791_state *ad_sigma_delta_to_ad7791(struct ad_sigma_delta *sd)
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{
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return container_of(sd, struct ad7791_state, sd);
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}
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static int ad7791_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
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{
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ad_sd_set_comm(sd, channel);
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return 0;
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}
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static int ad7791_set_mode(struct ad_sigma_delta *sd,
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enum ad_sigma_delta_mode mode)
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{
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struct ad7791_state *st = ad_sigma_delta_to_ad7791(sd);
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switch (mode) {
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case AD_SD_MODE_CONTINUOUS:
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mode = AD7791_MODE_CONTINUOUS;
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break;
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case AD_SD_MODE_SINGLE:
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mode = AD7791_MODE_SINGLE;
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break;
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case AD_SD_MODE_IDLE:
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case AD_SD_MODE_POWERDOWN:
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mode = AD7791_MODE_POWERDOWN;
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break;
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}
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st->mode &= ~AD7791_MODE_SEL_MASK;
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st->mode |= AD7791_MODE_SEL(mode);
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return ad_sd_write_reg(sd, AD7791_REG_MODE, sizeof(st->mode), st->mode);
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}
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static const struct ad_sigma_delta_info ad7791_sigma_delta_info = {
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.set_channel = ad7791_set_channel,
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.set_mode = ad7791_set_mode,
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.has_registers = true,
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.addr_shift = 4,
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.read_mask = BIT(3),
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.irq_flags = IRQF_TRIGGER_FALLING,
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};
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static int ad7791_read_raw(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan, int *val, int *val2, long info)
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{
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struct ad7791_state *st = iio_priv(indio_dev);
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bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR);
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unsigned int rate;
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switch (info) {
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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_OFFSET:
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/**
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* Unipolar: 0 to VREF
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* Bipolar -VREF to VREF
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**/
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if (unipolar)
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*val = 0;
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else
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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_SCALE:
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/* The monitor channel uses an internal reference. */
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if (chan->address == AD7791_CH_AVDD_MONITOR) {
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/*
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* The signal is attenuated by a factor of 5 and
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* compared against a 1.17V internal reference.
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*/
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*val = 1170 * 5;
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} else {
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int voltage_uv;
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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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*val = voltage_uv / 1000;
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}
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if (unipolar)
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*val2 = chan->scan_type.realbits;
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else
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*val2 = chan->scan_type.realbits - 1;
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return IIO_VAL_FRACTIONAL_LOG2;
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case IIO_CHAN_INFO_SAMP_FREQ:
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rate = st->filter & AD7791_FILTER_RATE_MASK;
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*val = ad7791_sample_freq_avail[rate][0];
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*val2 = ad7791_sample_freq_avail[rate][1];
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return IIO_VAL_INT_PLUS_MICRO;
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}
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return -EINVAL;
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}
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static int ad7791_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan, int val, int val2, long mask)
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{
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struct ad7791_state *st = iio_priv(indio_dev);
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int ret, i;
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ret = iio_device_claim_direct_mode(indio_dev);
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if (ret)
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return ret;
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switch (mask) {
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case IIO_CHAN_INFO_SAMP_FREQ:
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for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) {
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if (ad7791_sample_freq_avail[i][0] == val &&
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ad7791_sample_freq_avail[i][1] == val2)
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break;
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}
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if (i == ARRAY_SIZE(ad7791_sample_freq_avail)) {
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ret = -EINVAL;
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break;
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}
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st->filter &= ~AD7791_FILTER_RATE_MASK;
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st->filter |= i;
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ad_sd_write_reg(&st->sd, AD7791_REG_FILTER,
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sizeof(st->filter),
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st->filter);
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break;
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default:
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ret = -EINVAL;
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}
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iio_device_release_direct_mode(indio_dev);
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return ret;
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}
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static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("120 100 33.3 20 16.7 16.6 13.3 9.5");
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static struct attribute *ad7791_attributes[] = {
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&iio_const_attr_sampling_frequency_available.dev_attr.attr,
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NULL
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};
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static const struct attribute_group ad7791_attribute_group = {
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.attrs = ad7791_attributes,
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};
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static const struct iio_info ad7791_info = {
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.read_raw = &ad7791_read_raw,
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.write_raw = &ad7791_write_raw,
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.attrs = &ad7791_attribute_group,
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.validate_trigger = ad_sd_validate_trigger,
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};
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static const struct iio_info ad7791_no_filter_info = {
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.read_raw = &ad7791_read_raw,
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.write_raw = &ad7791_write_raw,
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.validate_trigger = ad_sd_validate_trigger,
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};
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static int ad7791_setup(struct ad7791_state *st,
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struct ad7791_platform_data *pdata)
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{
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/* Set to poweron-reset default values */
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st->mode = AD7791_MODE_BUFFER;
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st->filter = AD7791_FILTER_RATE_16_6;
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if (!pdata)
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return 0;
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if ((st->info->flags & AD7791_FLAG_HAS_BUFFER) && !pdata->buffered)
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st->mode &= ~AD7791_MODE_BUFFER;
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if ((st->info->flags & AD7791_FLAG_HAS_BURNOUT) &&
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pdata->burnout_current)
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st->mode |= AD7791_MODE_BURNOUT;
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if ((st->info->flags & AD7791_FLAG_HAS_UNIPOLAR) && pdata->unipolar)
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st->mode |= AD7791_MODE_UNIPOLAR;
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return ad_sd_write_reg(&st->sd, AD7791_REG_MODE, sizeof(st->mode),
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st->mode);
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}
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static void ad7791_reg_disable(void *reg)
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{
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regulator_disable(reg);
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}
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static int ad7791_probe(struct spi_device *spi)
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{
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struct ad7791_platform_data *pdata = spi->dev.platform_data;
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struct iio_dev *indio_dev;
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struct ad7791_state *st;
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int ret;
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if (!spi->irq) {
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dev_err(&spi->dev, "Missing IRQ.\n");
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return -ENXIO;
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}
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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->reg = devm_regulator_get(&spi->dev, "refin");
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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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return ret;
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ret = devm_add_action_or_reset(&spi->dev, ad7791_reg_disable, st->reg);
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if (ret)
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return ret;
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st->info = &ad7791_chip_infos[spi_get_device_id(spi)->driver_data];
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ad_sd_init(&st->sd, indio_dev, spi, &ad7791_sigma_delta_info);
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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->info->channels;
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indio_dev->num_channels = st->info->num_channels;
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if (st->info->flags & AD7791_FLAG_HAS_FILTER)
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indio_dev->info = &ad7791_info;
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else
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indio_dev->info = &ad7791_no_filter_info;
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ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
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if (ret)
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return ret;
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ret = ad7791_setup(st, pdata);
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if (ret)
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return ret;
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return devm_iio_device_register(&spi->dev, indio_dev);
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}
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static const struct spi_device_id ad7791_spi_ids[] = {
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{ "ad7787", AD7787 },
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{ "ad7788", AD7788 },
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{ "ad7789", AD7789 },
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{ "ad7790", AD7790 },
|
|
{ "ad7791", AD7791 },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(spi, ad7791_spi_ids);
|
|
|
|
static struct spi_driver ad7791_driver = {
|
|
.driver = {
|
|
.name = "ad7791",
|
|
},
|
|
.probe = ad7791_probe,
|
|
.id_table = ad7791_spi_ids,
|
|
};
|
|
module_spi_driver(ad7791_driver);
|
|
|
|
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
|
|
MODULE_DESCRIPTION("Analog Devices AD7787/AD7788/AD7789/AD7790/AD7791 ADC driver");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_IMPORT_NS(IIO_AD_SIGMA_DELTA);
|