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494 lines
13 KiB
494 lines
13 KiB
// 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 <[email protected]> |
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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_LOW, |
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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 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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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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spi_set_drvdata(spi, indio_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->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 = 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 = ad7791_setup(st, pdata); |
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if (ret) |
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goto error_remove_trigger; |
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ret = iio_device_register(indio_dev); |
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if (ret) |
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goto error_remove_trigger; |
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return 0; |
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error_remove_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 ad7791_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 ad7791_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 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 }, |
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{ "ad7791", AD7791 }, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(spi, ad7791_spi_ids); |
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static struct spi_driver ad7791_driver = { |
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.driver = { |
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.name = "ad7791", |
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}, |
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.probe = ad7791_probe, |
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.remove = ad7791_remove, |
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.id_table = ad7791_spi_ids, |
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}; |
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module_spi_driver(ad7791_driver); |
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MODULE_AUTHOR("Lars-Peter Clausen <[email protected]>"); |
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MODULE_DESCRIPTION("Analog Devices AD7787/AD7788/AD7789/AD7790/AD7791 ADC driver"); |
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MODULE_LICENSE("GPL v2");
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