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513 lines
13 KiB
513 lines
13 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* AD7266/65 SPI ADC driver |
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* |
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* Copyright 2012 Analog Devices Inc. |
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*/ |
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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/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/gpio/consumer.h> |
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#include <linux/module.h> |
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#include <linux/interrupt.h> |
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#include <linux/iio/iio.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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#include <linux/platform_data/ad7266.h> |
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struct ad7266_state { |
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struct spi_device *spi; |
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struct regulator *reg; |
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unsigned long vref_mv; |
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struct spi_transfer single_xfer[3]; |
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struct spi_message single_msg; |
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enum ad7266_range range; |
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enum ad7266_mode mode; |
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bool fixed_addr; |
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struct gpio_desc *gpios[3]; |
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/* |
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* DMA (thus cache coherency maintenance) requires the |
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* transfer buffers to live in their own cache lines. |
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* The buffer needs to be large enough to hold two samples (4 bytes) and |
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* the naturally aligned timestamp (8 bytes). |
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*/ |
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struct { |
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__be16 sample[2]; |
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s64 timestamp; |
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} data ____cacheline_aligned; |
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}; |
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static int ad7266_wakeup(struct ad7266_state *st) |
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{ |
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/* Any read with >= 2 bytes will wake the device */ |
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return spi_read(st->spi, &st->data.sample[0], 2); |
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} |
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static int ad7266_powerdown(struct ad7266_state *st) |
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{ |
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/* Any read with < 2 bytes will powerdown the device */ |
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return spi_read(st->spi, &st->data.sample[0], 1); |
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} |
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static int ad7266_preenable(struct iio_dev *indio_dev) |
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{ |
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struct ad7266_state *st = iio_priv(indio_dev); |
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return ad7266_wakeup(st); |
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} |
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static int ad7266_postdisable(struct iio_dev *indio_dev) |
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{ |
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struct ad7266_state *st = iio_priv(indio_dev); |
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return ad7266_powerdown(st); |
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} |
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static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = { |
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.preenable = &ad7266_preenable, |
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.postdisable = &ad7266_postdisable, |
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}; |
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static irqreturn_t ad7266_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 ad7266_state *st = iio_priv(indio_dev); |
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int ret; |
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ret = spi_read(st->spi, st->data.sample, 4); |
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if (ret == 0) { |
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iio_push_to_buffers_with_timestamp(indio_dev, &st->data, |
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pf->timestamp); |
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} |
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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 ad7266_select_input(struct ad7266_state *st, unsigned int nr) |
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{ |
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unsigned int i; |
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if (st->fixed_addr) |
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return; |
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switch (st->mode) { |
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case AD7266_MODE_SINGLE_ENDED: |
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nr >>= 1; |
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break; |
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case AD7266_MODE_PSEUDO_DIFF: |
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nr |= 1; |
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break; |
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case AD7266_MODE_DIFF: |
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nr &= ~1; |
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break; |
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} |
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for (i = 0; i < 3; ++i) |
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gpiod_set_value(st->gpios[i], (bool)(nr & BIT(i))); |
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} |
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static int ad7266_update_scan_mode(struct iio_dev *indio_dev, |
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const unsigned long *scan_mask) |
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{ |
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struct ad7266_state *st = iio_priv(indio_dev); |
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unsigned int nr = find_first_bit(scan_mask, indio_dev->masklength); |
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ad7266_select_input(st, nr); |
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return 0; |
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} |
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static int ad7266_read_single(struct ad7266_state *st, int *val, |
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unsigned int address) |
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{ |
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int ret; |
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ad7266_select_input(st, address); |
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ret = spi_sync(st->spi, &st->single_msg); |
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*val = be16_to_cpu(st->data.sample[address % 2]); |
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return ret; |
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} |
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static int ad7266_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, int *val, int *val2, long m) |
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{ |
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struct ad7266_state *st = iio_priv(indio_dev); |
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unsigned long scale_mv; |
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int ret; |
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switch (m) { |
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case IIO_CHAN_INFO_RAW: |
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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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ret = ad7266_read_single(st, val, chan->address); |
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iio_device_release_direct_mode(indio_dev); |
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*val = (*val >> 2) & 0xfff; |
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if (chan->scan_type.sign == 's') |
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*val = sign_extend32(*val, 11); |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_SCALE: |
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scale_mv = st->vref_mv; |
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if (st->mode == AD7266_MODE_DIFF) |
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scale_mv *= 2; |
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if (st->range == AD7266_RANGE_2VREF) |
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scale_mv *= 2; |
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*val = scale_mv; |
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*val2 = chan->scan_type.realbits; |
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return IIO_VAL_FRACTIONAL_LOG2; |
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case IIO_CHAN_INFO_OFFSET: |
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if (st->range == AD7266_RANGE_2VREF && |
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st->mode != AD7266_MODE_DIFF) |
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*val = 2048; |
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else |
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*val = 0; |
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return IIO_VAL_INT; |
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} |
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return -EINVAL; |
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} |
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#define AD7266_CHAN(_chan, _sign) { \ |
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.type = IIO_VOLTAGE, \ |
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.indexed = 1, \ |
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.channel = (_chan), \ |
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.address = (_chan), \ |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ |
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| BIT(IIO_CHAN_INFO_OFFSET), \ |
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.scan_index = (_chan), \ |
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.scan_type = { \ |
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.sign = (_sign), \ |
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.realbits = 12, \ |
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.storagebits = 16, \ |
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.shift = 2, \ |
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.endianness = IIO_BE, \ |
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}, \ |
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} |
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#define AD7266_DECLARE_SINGLE_ENDED_CHANNELS(_name, _sign) \ |
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const struct iio_chan_spec ad7266_channels_##_name[] = { \ |
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AD7266_CHAN(0, (_sign)), \ |
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AD7266_CHAN(1, (_sign)), \ |
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AD7266_CHAN(2, (_sign)), \ |
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AD7266_CHAN(3, (_sign)), \ |
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AD7266_CHAN(4, (_sign)), \ |
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AD7266_CHAN(5, (_sign)), \ |
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AD7266_CHAN(6, (_sign)), \ |
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AD7266_CHAN(7, (_sign)), \ |
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AD7266_CHAN(8, (_sign)), \ |
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AD7266_CHAN(9, (_sign)), \ |
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AD7266_CHAN(10, (_sign)), \ |
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AD7266_CHAN(11, (_sign)), \ |
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IIO_CHAN_SOFT_TIMESTAMP(13), \ |
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} |
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#define AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(_name, _sign) \ |
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const struct iio_chan_spec ad7266_channels_##_name##_fixed[] = { \ |
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AD7266_CHAN(0, (_sign)), \ |
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AD7266_CHAN(1, (_sign)), \ |
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IIO_CHAN_SOFT_TIMESTAMP(2), \ |
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} |
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static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(u, 'u'); |
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static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(s, 's'); |
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static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(u, 'u'); |
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static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(s, 's'); |
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#define AD7266_CHAN_DIFF(_chan, _sign) { \ |
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.type = IIO_VOLTAGE, \ |
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.indexed = 1, \ |
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.channel = (_chan) * 2, \ |
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.channel2 = (_chan) * 2 + 1, \ |
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.address = (_chan), \ |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ |
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| BIT(IIO_CHAN_INFO_OFFSET), \ |
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.scan_index = (_chan), \ |
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.scan_type = { \ |
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.sign = _sign, \ |
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.realbits = 12, \ |
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.storagebits = 16, \ |
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.shift = 2, \ |
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.endianness = IIO_BE, \ |
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}, \ |
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.differential = 1, \ |
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} |
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#define AD7266_DECLARE_DIFF_CHANNELS(_name, _sign) \ |
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const struct iio_chan_spec ad7266_channels_diff_##_name[] = { \ |
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AD7266_CHAN_DIFF(0, (_sign)), \ |
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AD7266_CHAN_DIFF(1, (_sign)), \ |
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AD7266_CHAN_DIFF(2, (_sign)), \ |
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AD7266_CHAN_DIFF(3, (_sign)), \ |
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AD7266_CHAN_DIFF(4, (_sign)), \ |
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AD7266_CHAN_DIFF(5, (_sign)), \ |
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IIO_CHAN_SOFT_TIMESTAMP(6), \ |
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} |
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static AD7266_DECLARE_DIFF_CHANNELS(s, 's'); |
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static AD7266_DECLARE_DIFF_CHANNELS(u, 'u'); |
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#define AD7266_DECLARE_DIFF_CHANNELS_FIXED(_name, _sign) \ |
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const struct iio_chan_spec ad7266_channels_diff_fixed_##_name[] = { \ |
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AD7266_CHAN_DIFF(0, (_sign)), \ |
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AD7266_CHAN_DIFF(1, (_sign)), \ |
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IIO_CHAN_SOFT_TIMESTAMP(2), \ |
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} |
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static AD7266_DECLARE_DIFF_CHANNELS_FIXED(s, 's'); |
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static AD7266_DECLARE_DIFF_CHANNELS_FIXED(u, 'u'); |
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static const struct iio_info ad7266_info = { |
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.read_raw = &ad7266_read_raw, |
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.update_scan_mode = &ad7266_update_scan_mode, |
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}; |
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static const unsigned long ad7266_available_scan_masks[] = { |
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0x003, |
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0x00c, |
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0x030, |
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0x0c0, |
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0x300, |
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0xc00, |
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0x000, |
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}; |
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static const unsigned long ad7266_available_scan_masks_diff[] = { |
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0x003, |
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0x00c, |
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0x030, |
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0x000, |
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}; |
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static const unsigned long ad7266_available_scan_masks_fixed[] = { |
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0x003, |
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0x000, |
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}; |
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struct ad7266_chan_info { |
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const struct iio_chan_spec *channels; |
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unsigned int num_channels; |
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const unsigned long *scan_masks; |
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}; |
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#define AD7266_CHAN_INFO_INDEX(_differential, _signed, _fixed) \ |
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(((_differential) << 2) | ((_signed) << 1) | ((_fixed) << 0)) |
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static const struct ad7266_chan_info ad7266_chan_infos[] = { |
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[AD7266_CHAN_INFO_INDEX(0, 0, 0)] = { |
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.channels = ad7266_channels_u, |
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.num_channels = ARRAY_SIZE(ad7266_channels_u), |
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.scan_masks = ad7266_available_scan_masks, |
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}, |
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[AD7266_CHAN_INFO_INDEX(0, 0, 1)] = { |
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.channels = ad7266_channels_u_fixed, |
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.num_channels = ARRAY_SIZE(ad7266_channels_u_fixed), |
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.scan_masks = ad7266_available_scan_masks_fixed, |
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}, |
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[AD7266_CHAN_INFO_INDEX(0, 1, 0)] = { |
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.channels = ad7266_channels_s, |
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.num_channels = ARRAY_SIZE(ad7266_channels_s), |
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.scan_masks = ad7266_available_scan_masks, |
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}, |
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[AD7266_CHAN_INFO_INDEX(0, 1, 1)] = { |
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.channels = ad7266_channels_s_fixed, |
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.num_channels = ARRAY_SIZE(ad7266_channels_s_fixed), |
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.scan_masks = ad7266_available_scan_masks_fixed, |
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}, |
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[AD7266_CHAN_INFO_INDEX(1, 0, 0)] = { |
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.channels = ad7266_channels_diff_u, |
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.num_channels = ARRAY_SIZE(ad7266_channels_diff_u), |
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.scan_masks = ad7266_available_scan_masks_diff, |
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}, |
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[AD7266_CHAN_INFO_INDEX(1, 0, 1)] = { |
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.channels = ad7266_channels_diff_fixed_u, |
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.num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_u), |
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.scan_masks = ad7266_available_scan_masks_fixed, |
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}, |
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[AD7266_CHAN_INFO_INDEX(1, 1, 0)] = { |
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.channels = ad7266_channels_diff_s, |
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.num_channels = ARRAY_SIZE(ad7266_channels_diff_s), |
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.scan_masks = ad7266_available_scan_masks_diff, |
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}, |
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[AD7266_CHAN_INFO_INDEX(1, 1, 1)] = { |
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.channels = ad7266_channels_diff_fixed_s, |
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.num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_s), |
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.scan_masks = ad7266_available_scan_masks_fixed, |
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}, |
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}; |
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static void ad7266_init_channels(struct iio_dev *indio_dev) |
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{ |
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struct ad7266_state *st = iio_priv(indio_dev); |
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bool is_differential, is_signed; |
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const struct ad7266_chan_info *chan_info; |
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int i; |
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is_differential = st->mode != AD7266_MODE_SINGLE_ENDED; |
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is_signed = (st->range == AD7266_RANGE_2VREF) | |
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(st->mode == AD7266_MODE_DIFF); |
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i = AD7266_CHAN_INFO_INDEX(is_differential, is_signed, st->fixed_addr); |
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chan_info = &ad7266_chan_infos[i]; |
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indio_dev->channels = chan_info->channels; |
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indio_dev->num_channels = chan_info->num_channels; |
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indio_dev->available_scan_masks = chan_info->scan_masks; |
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indio_dev->masklength = chan_info->num_channels - 1; |
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} |
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static const char * const ad7266_gpio_labels[] = { |
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"ad0", "ad1", "ad2", |
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}; |
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static int ad7266_probe(struct spi_device *spi) |
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{ |
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struct ad7266_platform_data *pdata = spi->dev.platform_data; |
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struct iio_dev *indio_dev; |
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struct ad7266_state *st; |
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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 == NULL) |
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return -ENOMEM; |
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st = iio_priv(indio_dev); |
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st->reg = devm_regulator_get_optional(&spi->dev, "vref"); |
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if (!IS_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 = regulator_get_voltage(st->reg); |
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if (ret < 0) |
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goto error_disable_reg; |
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st->vref_mv = ret / 1000; |
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} else { |
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/* Any other error indicates that the regulator does exist */ |
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if (PTR_ERR(st->reg) != -ENODEV) |
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return PTR_ERR(st->reg); |
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/* Use internal reference */ |
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st->vref_mv = 2500; |
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} |
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if (pdata) { |
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st->fixed_addr = pdata->fixed_addr; |
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st->mode = pdata->mode; |
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st->range = pdata->range; |
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if (!st->fixed_addr) { |
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for (i = 0; i < ARRAY_SIZE(st->gpios); ++i) { |
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st->gpios[i] = devm_gpiod_get(&spi->dev, |
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ad7266_gpio_labels[i], |
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GPIOD_OUT_LOW); |
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if (IS_ERR(st->gpios[i])) { |
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ret = PTR_ERR(st->gpios[i]); |
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goto error_disable_reg; |
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} |
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} |
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} |
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} else { |
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st->fixed_addr = true; |
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st->range = AD7266_RANGE_VREF; |
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st->mode = AD7266_MODE_DIFF; |
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} |
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spi_set_drvdata(spi, indio_dev); |
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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->info = &ad7266_info; |
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ad7266_init_channels(indio_dev); |
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/* wakeup */ |
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st->single_xfer[0].rx_buf = &st->data.sample[0]; |
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st->single_xfer[0].len = 2; |
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st->single_xfer[0].cs_change = 1; |
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/* conversion */ |
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st->single_xfer[1].rx_buf = st->data.sample; |
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st->single_xfer[1].len = 4; |
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st->single_xfer[1].cs_change = 1; |
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/* powerdown */ |
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st->single_xfer[2].tx_buf = &st->data.sample[0]; |
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st->single_xfer[2].len = 1; |
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spi_message_init(&st->single_msg); |
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spi_message_add_tail(&st->single_xfer[0], &st->single_msg); |
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spi_message_add_tail(&st->single_xfer[1], &st->single_msg); |
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spi_message_add_tail(&st->single_xfer[2], &st->single_msg); |
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ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, |
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&ad7266_trigger_handler, &iio_triggered_buffer_setup_ops); |
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if (ret) |
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goto error_disable_reg; |
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ret = iio_device_register(indio_dev); |
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if (ret) |
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goto error_buffer_cleanup; |
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return 0; |
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error_buffer_cleanup: |
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iio_triggered_buffer_cleanup(indio_dev); |
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error_disable_reg: |
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if (!IS_ERR(st->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 ad7266_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 ad7266_state *st = iio_priv(indio_dev); |
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iio_device_unregister(indio_dev); |
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iio_triggered_buffer_cleanup(indio_dev); |
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if (!IS_ERR(st->reg)) |
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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 ad7266_id[] = { |
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{"ad7265", 0}, |
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{"ad7266", 0}, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(spi, ad7266_id); |
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static struct spi_driver ad7266_driver = { |
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.driver = { |
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.name = "ad7266", |
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}, |
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.probe = ad7266_probe, |
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.remove = ad7266_remove, |
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.id_table = ad7266_id, |
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}; |
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module_spi_driver(ad7266_driver); |
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MODULE_AUTHOR("Lars-Peter Clausen <[email protected]>"); |
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MODULE_DESCRIPTION("Analog Devices AD7266/65 ADC"); |
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MODULE_LICENSE("GPL v2");
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