467 lines
13 KiB
C
467 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Analog Devices AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
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* TI ADC081S/ADC101S/ADC121S 8/10/12-bit SPI ADC driver
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*
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* Copyright 2010 Analog Devices Inc.
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*/
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#include <linux/bitops.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/gpio/consumer.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/bitops.h>
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#include <linux/delay.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_consumer.h>
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#include <linux/iio/triggered_buffer.h>
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struct ad7476_state;
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struct ad7476_chip_info {
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unsigned int int_vref_mv;
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struct iio_chan_spec channel[2];
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void (*reset)(struct ad7476_state *);
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void (*conversion_pre_op)(struct ad7476_state *st);
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void (*conversion_post_op)(struct ad7476_state *st);
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bool has_vref;
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bool has_vdrive;
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bool convstart_required;
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};
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struct ad7476_state {
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struct spi_device *spi;
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const struct ad7476_chip_info *chip_info;
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struct gpio_desc *convst_gpio;
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struct spi_transfer xfer;
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struct spi_message msg;
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struct iio_chan_spec channel[2];
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int scale_mv;
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/*
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* DMA (thus cache coherency maintenance) may require the
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* transfer buffers to live in their own cache lines.
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* Make the buffer large enough for one 16 bit sample and one 64 bit
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* aligned 64 bit timestamp.
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*/
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unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)] __aligned(IIO_DMA_MINALIGN);
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};
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static void ad7091_convst(struct ad7476_state *st)
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{
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if (!st->convst_gpio)
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return;
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gpiod_set_value_cansleep(st->convst_gpio, 0);
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udelay(1); /* CONVST pulse width: 10 ns min */
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gpiod_set_value_cansleep(st->convst_gpio, 1);
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udelay(1); /* Conversion time: 650 ns max */
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}
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static void bd79105_convst_disable(struct ad7476_state *st)
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{
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gpiod_set_value_cansleep(st->convst_gpio, 0);
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}
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static void bd79105_convst_enable(struct ad7476_state *st)
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{
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gpiod_set_value_cansleep(st->convst_gpio, 1);
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/* Worst case, 2790 ns required for conversion */
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ndelay(2790);
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}
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static irqreturn_t ad7476_trigger_handler(int irq, void *p)
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{
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struct iio_poll_func *pf = p;
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struct iio_dev *indio_dev = pf->indio_dev;
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struct ad7476_state *st = iio_priv(indio_dev);
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int b_sent;
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if (st->chip_info->conversion_pre_op)
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st->chip_info->conversion_pre_op(st);
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b_sent = spi_sync(st->spi, &st->msg);
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if (b_sent < 0)
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goto done;
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iio_push_to_buffers_with_ts(indio_dev, st->data, sizeof(st->data),
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iio_get_time_ns(indio_dev));
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done:
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if (st->chip_info->conversion_post_op)
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st->chip_info->conversion_post_op(st);
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iio_trigger_notify_done(indio_dev->trig);
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return IRQ_HANDLED;
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}
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static void ad7091_reset(struct ad7476_state *st)
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{
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/* Any transfers with 8 scl cycles will reset the device */
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spi_read(st->spi, st->data, 1);
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}
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static int ad7476_scan_direct(struct ad7476_state *st)
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{
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int ret;
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if (st->chip_info->conversion_pre_op)
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st->chip_info->conversion_pre_op(st);
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ret = spi_sync(st->spi, &st->msg);
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if (ret)
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return ret;
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if (st->chip_info->conversion_post_op)
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st->chip_info->conversion_post_op(st);
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return be16_to_cpup((__be16 *)st->data);
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}
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static int ad7476_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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int ret;
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struct ad7476_state *st = iio_priv(indio_dev);
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switch (m) {
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case IIO_CHAN_INFO_RAW:
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if (!iio_device_claim_direct(indio_dev))
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return -EBUSY;
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ret = ad7476_scan_direct(st);
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iio_device_release_direct(indio_dev);
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if (ret < 0)
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return ret;
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*val = (ret >> chan->scan_type.shift) &
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GENMASK(chan->scan_type.realbits - 1, 0);
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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*val = st->scale_mv;
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*val2 = chan->scan_type.realbits;
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return IIO_VAL_FRACTIONAL_LOG2;
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}
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return -EINVAL;
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}
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#define _AD7476_CHAN(bits, _shift, _info_mask_sep) \
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{ \
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.type = IIO_VOLTAGE, \
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.indexed = 1, \
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.info_mask_separate = _info_mask_sep, \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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.scan_type = { \
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.sign = 'u', \
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.realbits = (bits), \
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.storagebits = 16, \
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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 ADC081S_CHAN(bits) _AD7476_CHAN((bits), 12 - (bits), \
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BIT(IIO_CHAN_INFO_RAW))
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#define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \
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BIT(IIO_CHAN_INFO_RAW))
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#define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \
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BIT(IIO_CHAN_INFO_RAW))
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#define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0)
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#define ADS786X_CHAN(bits) _AD7476_CHAN((bits), 12 - (bits), \
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BIT(IIO_CHAN_INFO_RAW))
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static const struct ad7476_chip_info ad7091_chip_info = {
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.channel[0] = AD7091R_CHAN(12),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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.conversion_pre_op = ad7091_convst,
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.reset = ad7091_reset,
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};
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static const struct ad7476_chip_info ad7091r_chip_info = {
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.channel[0] = AD7091R_CHAN(12),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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.conversion_pre_op = ad7091_convst,
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.int_vref_mv = 2500,
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.has_vref = true,
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.reset = ad7091_reset,
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};
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static const struct ad7476_chip_info ad7273_chip_info = {
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.channel[0] = AD7940_CHAN(10),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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.has_vref = true,
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};
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static const struct ad7476_chip_info ad7274_chip_info = {
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.channel[0] = AD7940_CHAN(12),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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.has_vref = true,
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};
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static const struct ad7476_chip_info ad7276_chip_info = {
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.channel[0] = AD7940_CHAN(12),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info ad7277_chip_info = {
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.channel[0] = AD7940_CHAN(10),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info ad7278_chip_info = {
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.channel[0] = AD7940_CHAN(8),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info ad7466_chip_info = {
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.channel[0] = AD7476_CHAN(12),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info ad7467_chip_info = {
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.channel[0] = AD7476_CHAN(10),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info ad7468_chip_info = {
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.channel[0] = AD7476_CHAN(8),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info ad7475_chip_info = {
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.channel[0] = AD7476_CHAN(12),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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.has_vref = true,
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.has_vdrive = true,
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};
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static const struct ad7476_chip_info ad7495_chip_info = {
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.channel[0] = AD7476_CHAN(12),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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.int_vref_mv = 2500,
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.has_vdrive = true,
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};
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static const struct ad7476_chip_info ad7940_chip_info = {
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.channel[0] = AD7940_CHAN(14),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info adc081s_chip_info = {
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.channel[0] = ADC081S_CHAN(8),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info adc101s_chip_info = {
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.channel[0] = ADC081S_CHAN(10),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info adc121s_chip_info = {
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.channel[0] = ADC081S_CHAN(12),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info ads7866_chip_info = {
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.channel[0] = ADS786X_CHAN(12),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info ads7867_chip_info = {
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.channel[0] = ADS786X_CHAN(10),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info ads7868_chip_info = {
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.channel[0] = ADS786X_CHAN(8),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static const struct ad7476_chip_info ltc2314_14_chip_info = {
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.channel[0] = AD7940_CHAN(14),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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.has_vref = true,
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};
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static const struct ad7476_chip_info bd79105_chip_info = {
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.channel[0] = AD7091R_CHAN(16),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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/*
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* The BD79105 starts ADC data conversion when the CONVSTART line is
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* set HIGH. The CONVSTART must be kept HIGH until the data has been
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* read from the ADC.
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*/
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.conversion_pre_op = bd79105_convst_enable,
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.conversion_post_op = bd79105_convst_disable,
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/* BD79105 won't do conversion without convstart */
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.convstart_required = true,
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.has_vref = true,
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.has_vdrive = true,
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};
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static const struct iio_info ad7476_info = {
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.read_raw = &ad7476_read_raw,
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};
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static int ad7476_probe(struct spi_device *spi)
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{
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struct ad7476_state *st;
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struct iio_dev *indio_dev;
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unsigned int i;
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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->chip_info = spi_get_device_match_data(spi);
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if (!st->chip_info)
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return -ENODEV;
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/* Use VCC for reference voltage if vref / internal vref aren't used */
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if (!st->chip_info->int_vref_mv && !st->chip_info->has_vref) {
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ret = devm_regulator_get_enable_read_voltage(&spi->dev, "vcc");
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if (ret < 0)
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return ret;
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st->scale_mv = ret / 1000;
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} else {
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ret = devm_regulator_get_enable(&spi->dev, "vcc");
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if (ret < 0)
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return ret;
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}
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if (st->chip_info->has_vref) {
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ret = devm_regulator_get_enable_read_voltage(&spi->dev, "vref");
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if (ret < 0) {
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/* Vref is optional if a device has an internal reference */
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if (!st->chip_info->int_vref_mv || ret != -ENODEV)
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return ret;
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} else {
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st->scale_mv = ret / 1000;
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}
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}
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if (!st->scale_mv)
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st->scale_mv = st->chip_info->int_vref_mv;
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if (st->chip_info->has_vdrive) {
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ret = devm_regulator_get_enable(&spi->dev, "vdrive");
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if (ret)
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return ret;
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}
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st->convst_gpio = devm_gpiod_get_optional(&spi->dev,
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"adi,conversion-start",
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GPIOD_OUT_LOW);
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if (IS_ERR(st->convst_gpio))
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return PTR_ERR(st->convst_gpio);
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if (st->chip_info->convstart_required && !st->convst_gpio)
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return dev_err_probe(&spi->dev, -EINVAL, "No convstart GPIO\n");
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/*
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* This will never happen. Unless someone changes the channel specs
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* in this driver. And if someone does, without changing the loop
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* below, then we'd better immediately produce a big fat error, before
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* the change proceeds from that developer's table.
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*/
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static_assert(ARRAY_SIZE(st->channel) == ARRAY_SIZE(st->chip_info->channel));
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for (i = 0; i < ARRAY_SIZE(st->channel); i++) {
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st->channel[i] = st->chip_info->channel[i];
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if (st->convst_gpio)
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__set_bit(IIO_CHAN_INFO_RAW,
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&st->channel[i].info_mask_separate);
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}
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st->spi = spi;
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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->channel;
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indio_dev->num_channels = ARRAY_SIZE(st->channel);
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indio_dev->info = &ad7476_info;
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/* Setup default message */
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st->xfer.rx_buf = &st->data;
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st->xfer.len = indio_dev->channels[0].scan_type.storagebits / 8;
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spi_message_init(&st->msg);
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spi_message_add_tail(&st->xfer, &st->msg);
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ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,
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&ad7476_trigger_handler, NULL);
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if (ret)
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return ret;
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if (st->chip_info->reset)
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st->chip_info->reset(st);
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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 ad7476_id[] = {
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{ "ad7091", (kernel_ulong_t)&ad7091_chip_info },
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{ "ad7091r", (kernel_ulong_t)&ad7091r_chip_info },
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{ "ad7273", (kernel_ulong_t)&ad7273_chip_info },
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{ "ad7274", (kernel_ulong_t)&ad7274_chip_info },
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{ "ad7276", (kernel_ulong_t)&ad7276_chip_info },
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{ "ad7277", (kernel_ulong_t)&ad7277_chip_info },
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{ "ad7278", (kernel_ulong_t)&ad7278_chip_info },
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{ "ad7466", (kernel_ulong_t)&ad7466_chip_info },
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{ "ad7467", (kernel_ulong_t)&ad7467_chip_info },
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{ "ad7468", (kernel_ulong_t)&ad7468_chip_info },
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{ "ad7475", (kernel_ulong_t)&ad7475_chip_info },
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{ "ad7476", (kernel_ulong_t)&ad7466_chip_info },
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{ "ad7476a", (kernel_ulong_t)&ad7466_chip_info },
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{ "ad7477", (kernel_ulong_t)&ad7467_chip_info },
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{ "ad7477a", (kernel_ulong_t)&ad7467_chip_info },
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{ "ad7478", (kernel_ulong_t)&ad7468_chip_info },
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{ "ad7478a", (kernel_ulong_t)&ad7468_chip_info },
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{ "ad7495", (kernel_ulong_t)&ad7495_chip_info },
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{ "ad7910", (kernel_ulong_t)&ad7467_chip_info },
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{ "ad7920", (kernel_ulong_t)&ad7466_chip_info },
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{ "ad7940", (kernel_ulong_t)&ad7940_chip_info },
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{ "adc081s", (kernel_ulong_t)&adc081s_chip_info },
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{ "adc101s", (kernel_ulong_t)&adc101s_chip_info },
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{ "adc121s", (kernel_ulong_t)&adc121s_chip_info },
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{ "ads7866", (kernel_ulong_t)&ads7866_chip_info },
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{ "ads7867", (kernel_ulong_t)&ads7867_chip_info },
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{ "ads7868", (kernel_ulong_t)&ads7868_chip_info },
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{ "bd79105", (kernel_ulong_t)&bd79105_chip_info },
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/*
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* The ROHM BU79100G is identical to the TI's ADS7866 from the software
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* point of view. The binding document mandates the ADS7866 to be
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* marked as a fallback for the BU79100G, but we still need the SPI ID
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|
* here to make the module loading work.
|
|
*/
|
|
{ "bu79100g", (kernel_ulong_t)&ads7866_chip_info },
|
|
{ "ltc2314-14", (kernel_ulong_t)<c2314_14_chip_info },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(spi, ad7476_id);
|
|
|
|
static struct spi_driver ad7476_driver = {
|
|
.driver = {
|
|
.name = "ad7476",
|
|
},
|
|
.probe = ad7476_probe,
|
|
.id_table = ad7476_id,
|
|
};
|
|
module_spi_driver(ad7476_driver);
|
|
|
|
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
|
|
MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs");
|
|
MODULE_LICENSE("GPL v2");
|