mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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460 lines
11 KiB
C
460 lines
11 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Analog Devices AD7768-1 SPI ADC driver
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*
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* Copyright 2017 Analog Devices Inc.
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*/
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#include <linux/bitfield.h>
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#include <linux/clk.h>
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/regulator/consumer.h>
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#include <linux/sysfs.h>
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#include <linux/spi/spi.h>
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#include <linux/iio/buffer.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/trigger.h>
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#include <linux/iio/triggered_buffer.h>
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#include <linux/iio/trigger_consumer.h>
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/* AD7768 registers definition */
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#define AD7768_REG_CHIP_TYPE 0x3
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#define AD7768_REG_PROD_ID_L 0x4
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#define AD7768_REG_PROD_ID_H 0x5
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#define AD7768_REG_CHIP_GRADE 0x6
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#define AD7768_REG_SCRATCH_PAD 0x0A
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#define AD7768_REG_VENDOR_L 0x0C
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#define AD7768_REG_VENDOR_H 0x0D
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#define AD7768_REG_INTERFACE_FORMAT 0x14
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#define AD7768_REG_POWER_CLOCK 0x15
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#define AD7768_REG_ANALOG 0x16
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#define AD7768_REG_ANALOG2 0x17
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#define AD7768_REG_CONVERSION 0x18
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#define AD7768_REG_DIGITAL_FILTER 0x19
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#define AD7768_REG_SINC3_DEC_RATE_MSB 0x1A
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#define AD7768_REG_SINC3_DEC_RATE_LSB 0x1B
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#define AD7768_REG_DUTY_CYCLE_RATIO 0x1C
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#define AD7768_REG_SYNC_RESET 0x1D
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#define AD7768_REG_GPIO_CONTROL 0x1E
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#define AD7768_REG_GPIO_WRITE 0x1F
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#define AD7768_REG_GPIO_READ 0x20
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#define AD7768_REG_OFFSET_HI 0x21
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#define AD7768_REG_OFFSET_MID 0x22
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#define AD7768_REG_OFFSET_LO 0x23
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#define AD7768_REG_GAIN_HI 0x24
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#define AD7768_REG_GAIN_MID 0x25
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#define AD7768_REG_GAIN_LO 0x26
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#define AD7768_REG_SPI_DIAG_ENABLE 0x28
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#define AD7768_REG_ADC_DIAG_ENABLE 0x29
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#define AD7768_REG_DIG_DIAG_ENABLE 0x2A
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#define AD7768_REG_ADC_DATA 0x2C
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#define AD7768_REG_MASTER_STATUS 0x2D
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#define AD7768_REG_SPI_DIAG_STATUS 0x2E
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#define AD7768_REG_ADC_DIAG_STATUS 0x2F
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#define AD7768_REG_DIG_DIAG_STATUS 0x30
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#define AD7768_REG_MCLK_COUNTER 0x31
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/* AD7768_REG_CONVERSION */
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#define AD7768_CONV_MODE_MSK GENMASK(2, 0)
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#define AD7768_CONV_MODE(x) FIELD_PREP(AD7768_CONV_MODE_MSK, x)
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#define AD7768_RD_FLAG_MSK(x) (BIT(6) | ((x) & 0x3F))
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#define AD7768_WR_FLAG_MSK(x) ((x) & 0x3F)
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enum ad7768_conv_mode {
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AD7768_CONTINUOUS,
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AD7768_ONE_SHOT,
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AD7768_SINGLE,
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AD7768_PERIODIC,
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AD7768_STANDBY
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};
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enum ad7768_pwrmode {
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AD7768_ECO_MODE = 0,
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AD7768_MED_MODE = 2,
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AD7768_FAST_MODE = 3
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};
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static const struct iio_chan_spec ad7768_channels[] = {
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{
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.type = IIO_VOLTAGE,
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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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.indexed = 1,
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.channel = 0,
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.scan_index = 0,
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.scan_type = {
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.sign = 'u',
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.realbits = 24,
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.storagebits = 32,
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.shift = 8,
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.endianness = IIO_BE,
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},
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},
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};
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struct ad7768_state {
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struct spi_device *spi;
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struct regulator *vref;
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struct mutex lock;
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struct completion completion;
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struct iio_trigger *trig;
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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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*/
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union {
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__be32 d32;
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u8 d8[2];
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} data ____cacheline_aligned;
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};
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static int ad7768_spi_reg_read(struct ad7768_state *st, unsigned int addr,
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unsigned int len)
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{
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unsigned int shift;
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int ret;
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shift = 32 - (8 * len);
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st->data.d8[0] = AD7768_RD_FLAG_MSK(addr);
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ret = spi_write_then_read(st->spi, st->data.d8, 1,
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&st->data.d32, len);
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if (ret < 0)
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return ret;
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return (be32_to_cpu(st->data.d32) >> shift);
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}
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static int ad7768_spi_reg_write(struct ad7768_state *st,
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unsigned int addr,
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unsigned int val)
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{
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st->data.d8[0] = AD7768_WR_FLAG_MSK(addr);
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st->data.d8[1] = val & 0xFF;
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return spi_write(st->spi, st->data.d8, 2);
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}
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static int ad7768_set_mode(struct ad7768_state *st,
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enum ad7768_conv_mode mode)
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{
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int regval;
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regval = ad7768_spi_reg_read(st, AD7768_REG_CONVERSION, 1);
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if (regval < 0)
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return regval;
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regval &= ~AD7768_CONV_MODE_MSK;
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regval |= AD7768_CONV_MODE(mode);
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return ad7768_spi_reg_write(st, AD7768_REG_CONVERSION, regval);
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}
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static int ad7768_scan_direct(struct iio_dev *indio_dev)
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{
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struct ad7768_state *st = iio_priv(indio_dev);
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int readval, ret;
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reinit_completion(&st->completion);
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ret = ad7768_set_mode(st, AD7768_ONE_SHOT);
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if (ret < 0)
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return ret;
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ret = wait_for_completion_timeout(&st->completion,
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msecs_to_jiffies(1000));
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if (!ret)
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return -ETIMEDOUT;
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readval = ad7768_spi_reg_read(st, AD7768_REG_ADC_DATA, 3);
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if (readval < 0)
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return readval;
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/*
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* Any SPI configuration of the AD7768-1 can only be
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* performed in continuous conversion mode.
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*/
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ret = ad7768_set_mode(st, AD7768_CONTINUOUS);
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if (ret < 0)
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return ret;
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return readval;
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}
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static int ad7768_reg_access(struct iio_dev *indio_dev,
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unsigned int reg,
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unsigned int writeval,
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unsigned int *readval)
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{
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struct ad7768_state *st = iio_priv(indio_dev);
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int ret;
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mutex_lock(&st->lock);
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if (readval) {
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ret = ad7768_spi_reg_read(st, reg, 1);
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if (ret < 0)
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goto err_unlock;
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*readval = ret;
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ret = 0;
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} else {
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ret = ad7768_spi_reg_write(st, reg, writeval);
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}
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err_unlock:
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mutex_unlock(&st->lock);
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return ret;
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}
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static int ad7768_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long info)
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{
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struct ad7768_state *st = iio_priv(indio_dev);
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int scale_uv, ret;
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switch (info) {
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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 = ad7768_scan_direct(indio_dev);
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if (ret >= 0)
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*val = ret;
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iio_device_release_direct_mode(indio_dev);
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if (ret < 0)
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return ret;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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scale_uv = regulator_get_voltage(st->vref);
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if (scale_uv < 0)
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return scale_uv;
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*val = (scale_uv * 2) / 1000;
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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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static const struct iio_info ad7768_info = {
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.read_raw = &ad7768_read_raw,
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.debugfs_reg_access = &ad7768_reg_access,
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};
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static int ad7768_setup(struct ad7768_state *st)
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{
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int ret;
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/*
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* Two writes to the SPI_RESET[1:0] bits are required to initiate
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* a software reset. The bits must first be set to 11, and then
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* to 10. When the sequence is detected, the reset occurs.
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* See the datasheet, page 70.
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*/
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ret = ad7768_spi_reg_write(st, AD7768_REG_SYNC_RESET, 0x3);
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if (ret)
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return ret;
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ret = ad7768_spi_reg_write(st, AD7768_REG_SYNC_RESET, 0x2);
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if (ret)
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return ret;
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/* Set power mode to fast */
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return ad7768_spi_reg_write(st, AD7768_REG_POWER_CLOCK,
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AD7768_FAST_MODE);
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}
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static irqreturn_t ad7768_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 ad7768_state *st = iio_priv(indio_dev);
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int ret;
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mutex_lock(&st->lock);
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ret = spi_read(st->spi, &st->data.d32, 3);
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if (ret < 0)
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goto err_unlock;
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iio_push_to_buffers_with_timestamp(indio_dev, &st->data.d32,
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iio_get_time_ns(indio_dev));
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iio_trigger_notify_done(indio_dev->trig);
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err_unlock:
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mutex_unlock(&st->lock);
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return IRQ_HANDLED;
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}
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static irqreturn_t ad7768_interrupt(int irq, void *dev_id)
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{
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struct iio_dev *indio_dev = dev_id;
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struct ad7768_state *st = iio_priv(indio_dev);
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if (iio_buffer_enabled(indio_dev))
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iio_trigger_poll(st->trig);
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else
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complete(&st->completion);
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return IRQ_HANDLED;
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};
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static int ad7768_buffer_postenable(struct iio_dev *indio_dev)
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{
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struct ad7768_state *st = iio_priv(indio_dev);
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iio_triggered_buffer_postenable(indio_dev);
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/*
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* Write a 1 to the LSB of the INTERFACE_FORMAT register to enter
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* continuous read mode. Subsequent data reads do not require an
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* initial 8-bit write to query the ADC_DATA register.
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*/
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return ad7768_spi_reg_write(st, AD7768_REG_INTERFACE_FORMAT, 0x01);
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}
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static int ad7768_buffer_predisable(struct iio_dev *indio_dev)
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{
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struct ad7768_state *st = iio_priv(indio_dev);
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int ret;
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/*
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* To exit continuous read mode, perform a single read of the ADC_DATA
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* reg (0x2C), which allows further configuration of the device.
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*/
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ret = ad7768_spi_reg_read(st, AD7768_REG_ADC_DATA, 3);
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if (ret < 0)
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return ret;
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return iio_triggered_buffer_predisable(indio_dev);
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}
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static const struct iio_buffer_setup_ops ad7768_buffer_ops = {
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.postenable = &ad7768_buffer_postenable,
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.predisable = &ad7768_buffer_predisable,
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};
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static const struct iio_trigger_ops ad7768_trigger_ops = {
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.validate_device = iio_trigger_validate_own_device,
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};
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static void ad7768_regulator_disable(void *data)
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{
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struct ad7768_state *st = data;
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regulator_disable(st->vref);
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}
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static int ad7768_probe(struct spi_device *spi)
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{
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struct ad7768_state *st;
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struct iio_dev *indio_dev;
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int ret;
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
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if (!indio_dev)
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return -ENOMEM;
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st = iio_priv(indio_dev);
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st->spi = spi;
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st->vref = devm_regulator_get(&spi->dev, "vref");
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if (IS_ERR(st->vref))
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return PTR_ERR(st->vref);
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ret = regulator_enable(st->vref);
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if (ret) {
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dev_err(&spi->dev, "Failed to enable specified vref supply\n");
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return ret;
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}
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ret = devm_add_action_or_reset(&spi->dev, ad7768_regulator_disable, st);
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if (ret)
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return ret;
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spi_set_drvdata(spi, indio_dev);
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mutex_init(&st->lock);
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indio_dev->channels = ad7768_channels;
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indio_dev->num_channels = ARRAY_SIZE(ad7768_channels);
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indio_dev->dev.parent = &spi->dev;
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indio_dev->name = spi_get_device_id(spi)->name;
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indio_dev->info = &ad7768_info;
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indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_TRIGGERED;
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ret = ad7768_setup(st);
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if (ret < 0) {
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dev_err(&spi->dev, "AD7768 setup failed\n");
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return ret;
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}
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st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
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indio_dev->name, indio_dev->id);
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if (!st->trig)
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return -ENOMEM;
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st->trig->ops = &ad7768_trigger_ops;
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st->trig->dev.parent = &spi->dev;
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iio_trigger_set_drvdata(st->trig, indio_dev);
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ret = devm_iio_trigger_register(&spi->dev, st->trig);
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if (ret)
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return ret;
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indio_dev->trig = iio_trigger_get(st->trig);
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init_completion(&st->completion);
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ret = devm_request_irq(&spi->dev, spi->irq,
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|
&ad7768_interrupt,
|
||
|
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
|
||
|
indio_dev->name, indio_dev);
|
||
|
if (ret)
|
||
|
return ret;
|
||
|
|
||
|
ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
|
||
|
&iio_pollfunc_store_time,
|
||
|
&ad7768_trigger_handler,
|
||
|
&ad7768_buffer_ops);
|
||
|
if (ret)
|
||
|
return ret;
|
||
|
|
||
|
return devm_iio_device_register(&spi->dev, indio_dev);
|
||
|
}
|
||
|
|
||
|
static const struct spi_device_id ad7768_id_table[] = {
|
||
|
{ "ad7768-1", 0 },
|
||
|
{}
|
||
|
};
|
||
|
MODULE_DEVICE_TABLE(spi, ad7768_id_table);
|
||
|
|
||
|
static const struct of_device_id ad7768_of_match[] = {
|
||
|
{ .compatible = "adi,ad7768-1" },
|
||
|
{ },
|
||
|
};
|
||
|
MODULE_DEVICE_TABLE(of, ad7768_of_match);
|
||
|
|
||
|
static struct spi_driver ad7768_driver = {
|
||
|
.driver = {
|
||
|
.name = "ad7768-1",
|
||
|
.of_match_table = ad7768_of_match,
|
||
|
},
|
||
|
.probe = ad7768_probe,
|
||
|
.id_table = ad7768_id_table,
|
||
|
};
|
||
|
module_spi_driver(ad7768_driver);
|
||
|
|
||
|
MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
|
||
|
MODULE_DESCRIPTION("Analog Devices AD7768-1 ADC driver");
|
||
|
MODULE_LICENSE("GPL v2");
|