378 строки
9.0 KiB
C
378 строки
9.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* TI ADS124S0X chip family driver
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* Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/
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*/
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#include <linux/err.h>
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/slab.h>
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#include <linux/sysfs.h>
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#include <linux/gpio/consumer.h>
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#include <linux/spi/spi.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/iio/sysfs.h>
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#include <asm/unaligned.h>
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/* Commands */
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#define ADS124S08_CMD_NOP 0x00
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#define ADS124S08_CMD_WAKEUP 0x02
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#define ADS124S08_CMD_PWRDWN 0x04
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#define ADS124S08_CMD_RESET 0x06
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#define ADS124S08_CMD_START 0x08
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#define ADS124S08_CMD_STOP 0x0a
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#define ADS124S08_CMD_SYOCAL 0x16
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#define ADS124S08_CMD_SYGCAL 0x17
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#define ADS124S08_CMD_SFOCAL 0x19
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#define ADS124S08_CMD_RDATA 0x12
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#define ADS124S08_CMD_RREG 0x20
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#define ADS124S08_CMD_WREG 0x40
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/* Registers */
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#define ADS124S08_ID_REG 0x00
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#define ADS124S08_STATUS 0x01
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#define ADS124S08_INPUT_MUX 0x02
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#define ADS124S08_PGA 0x03
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#define ADS124S08_DATA_RATE 0x04
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#define ADS124S08_REF 0x05
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#define ADS124S08_IDACMAG 0x06
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#define ADS124S08_IDACMUX 0x07
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#define ADS124S08_VBIAS 0x08
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#define ADS124S08_SYS 0x09
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#define ADS124S08_OFCAL0 0x0a
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#define ADS124S08_OFCAL1 0x0b
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#define ADS124S08_OFCAL2 0x0c
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#define ADS124S08_FSCAL0 0x0d
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#define ADS124S08_FSCAL1 0x0e
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#define ADS124S08_FSCAL2 0x0f
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#define ADS124S08_GPIODAT 0x10
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#define ADS124S08_GPIOCON 0x11
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/* ADS124S0x common channels */
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#define ADS124S08_AIN0 0x00
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#define ADS124S08_AIN1 0x01
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#define ADS124S08_AIN2 0x02
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#define ADS124S08_AIN3 0x03
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#define ADS124S08_AIN4 0x04
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#define ADS124S08_AIN5 0x05
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#define ADS124S08_AINCOM 0x0c
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/* ADS124S08 only channels */
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#define ADS124S08_AIN6 0x06
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#define ADS124S08_AIN7 0x07
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#define ADS124S08_AIN8 0x08
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#define ADS124S08_AIN9 0x09
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#define ADS124S08_AIN10 0x0a
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#define ADS124S08_AIN11 0x0b
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#define ADS124S08_MAX_CHANNELS 12
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#define ADS124S08_POS_MUX_SHIFT 0x04
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#define ADS124S08_INT_REF 0x09
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#define ADS124S08_START_REG_MASK 0x1f
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#define ADS124S08_NUM_BYTES_MASK 0x1f
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#define ADS124S08_START_CONV 0x01
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#define ADS124S08_STOP_CONV 0x00
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enum ads124s_id {
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ADS124S08_ID,
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ADS124S06_ID,
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};
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struct ads124s_chip_info {
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const struct iio_chan_spec *channels;
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unsigned int num_channels;
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};
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struct ads124s_private {
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const struct ads124s_chip_info *chip_info;
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struct gpio_desc *reset_gpio;
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struct spi_device *spi;
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struct mutex lock;
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/*
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* Used to correctly align data.
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* Ensure timestamp is naturally aligned.
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* Note that the full buffer length may not be needed if not
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* all channels are enabled, as long as the alignment of the
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* timestamp is maintained.
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*/
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u32 buffer[ADS124S08_MAX_CHANNELS + sizeof(s64)/sizeof(u32)] __aligned(8);
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u8 data[5] ____cacheline_aligned;
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};
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#define ADS124S08_CHAN(index) \
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{ \
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.type = IIO_VOLTAGE, \
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.indexed = 1, \
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.channel = index, \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.scan_index = index, \
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.scan_type = { \
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.sign = 'u', \
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.realbits = 32, \
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.storagebits = 32, \
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}, \
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}
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static const struct iio_chan_spec ads124s06_channels[] = {
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ADS124S08_CHAN(0),
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ADS124S08_CHAN(1),
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ADS124S08_CHAN(2),
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ADS124S08_CHAN(3),
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ADS124S08_CHAN(4),
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ADS124S08_CHAN(5),
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};
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static const struct iio_chan_spec ads124s08_channels[] = {
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ADS124S08_CHAN(0),
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ADS124S08_CHAN(1),
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ADS124S08_CHAN(2),
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ADS124S08_CHAN(3),
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ADS124S08_CHAN(4),
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ADS124S08_CHAN(5),
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ADS124S08_CHAN(6),
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ADS124S08_CHAN(7),
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ADS124S08_CHAN(8),
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ADS124S08_CHAN(9),
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ADS124S08_CHAN(10),
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ADS124S08_CHAN(11),
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};
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static const struct ads124s_chip_info ads124s_chip_info_tbl[] = {
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[ADS124S08_ID] = {
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.channels = ads124s08_channels,
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.num_channels = ARRAY_SIZE(ads124s08_channels),
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},
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[ADS124S06_ID] = {
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.channels = ads124s06_channels,
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.num_channels = ARRAY_SIZE(ads124s06_channels),
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},
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};
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static int ads124s_write_cmd(struct iio_dev *indio_dev, u8 command)
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{
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struct ads124s_private *priv = iio_priv(indio_dev);
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priv->data[0] = command;
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return spi_write(priv->spi, &priv->data[0], 1);
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}
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static int ads124s_write_reg(struct iio_dev *indio_dev, u8 reg, u8 data)
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{
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struct ads124s_private *priv = iio_priv(indio_dev);
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priv->data[0] = ADS124S08_CMD_WREG | reg;
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priv->data[1] = 0x0;
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priv->data[2] = data;
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return spi_write(priv->spi, &priv->data[0], 3);
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}
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static int ads124s_reset(struct iio_dev *indio_dev)
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{
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struct ads124s_private *priv = iio_priv(indio_dev);
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if (priv->reset_gpio) {
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gpiod_set_value(priv->reset_gpio, 0);
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udelay(200);
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gpiod_set_value(priv->reset_gpio, 1);
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} else {
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return ads124s_write_cmd(indio_dev, ADS124S08_CMD_RESET);
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}
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return 0;
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};
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static int ads124s_read(struct iio_dev *indio_dev, unsigned int chan)
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{
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struct ads124s_private *priv = iio_priv(indio_dev);
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int ret;
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struct spi_transfer t[] = {
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{
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.tx_buf = &priv->data[0],
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.len = 4,
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.cs_change = 1,
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}, {
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.tx_buf = &priv->data[1],
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.rx_buf = &priv->data[1],
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.len = 4,
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},
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};
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priv->data[0] = ADS124S08_CMD_RDATA;
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memset(&priv->data[1], ADS124S08_CMD_NOP, sizeof(priv->data) - 1);
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ret = spi_sync_transfer(priv->spi, t, ARRAY_SIZE(t));
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if (ret < 0)
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return ret;
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return get_unaligned_be24(&priv->data[2]);
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}
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static int ads124s_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 m)
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{
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struct ads124s_private *priv = iio_priv(indio_dev);
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int ret;
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mutex_lock(&priv->lock);
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switch (m) {
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case IIO_CHAN_INFO_RAW:
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ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX,
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chan->channel);
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if (ret) {
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dev_err(&priv->spi->dev, "Set ADC CH failed\n");
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goto out;
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}
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ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV);
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if (ret) {
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dev_err(&priv->spi->dev, "Start conversions failed\n");
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goto out;
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}
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ret = ads124s_read(indio_dev, chan->channel);
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if (ret < 0) {
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dev_err(&priv->spi->dev, "Read ADC failed\n");
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goto out;
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}
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*val = ret;
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ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV);
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if (ret) {
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dev_err(&priv->spi->dev, "Stop conversions failed\n");
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goto out;
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}
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ret = IIO_VAL_INT;
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break;
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default:
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ret = -EINVAL;
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break;
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}
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out:
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mutex_unlock(&priv->lock);
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return ret;
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}
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static const struct iio_info ads124s_info = {
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.read_raw = &ads124s_read_raw,
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};
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static irqreturn_t ads124s_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 ads124s_private *priv = iio_priv(indio_dev);
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int scan_index, j = 0;
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int ret;
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for_each_set_bit(scan_index, indio_dev->active_scan_mask,
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indio_dev->masklength) {
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ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX,
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scan_index);
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if (ret)
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dev_err(&priv->spi->dev, "Set ADC CH failed\n");
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ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV);
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if (ret)
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dev_err(&priv->spi->dev, "Start ADC conversions failed\n");
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priv->buffer[j] = ads124s_read(indio_dev, scan_index);
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ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV);
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if (ret)
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dev_err(&priv->spi->dev, "Stop ADC conversions failed\n");
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j++;
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}
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iio_push_to_buffers_with_timestamp(indio_dev, priv->buffer,
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pf->timestamp);
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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 int ads124s_probe(struct spi_device *spi)
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{
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struct ads124s_private *ads124s_priv;
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struct iio_dev *indio_dev;
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const struct spi_device_id *spi_id = spi_get_device_id(spi);
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int ret;
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*ads124s_priv));
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if (indio_dev == NULL)
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return -ENOMEM;
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ads124s_priv = iio_priv(indio_dev);
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ads124s_priv->reset_gpio = devm_gpiod_get_optional(&spi->dev,
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"reset", GPIOD_OUT_LOW);
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if (IS_ERR(ads124s_priv->reset_gpio))
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dev_info(&spi->dev, "Reset GPIO not defined\n");
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ads124s_priv->chip_info = &ads124s_chip_info_tbl[spi_id->driver_data];
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ads124s_priv->spi = spi;
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indio_dev->name = spi_id->name;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = ads124s_priv->chip_info->channels;
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indio_dev->num_channels = ads124s_priv->chip_info->num_channels;
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indio_dev->info = &ads124s_info;
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mutex_init(&ads124s_priv->lock);
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ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,
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ads124s_trigger_handler, NULL);
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if (ret) {
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dev_err(&spi->dev, "iio triggered buffer setup failed\n");
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return ret;
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}
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ads124s_reset(indio_dev);
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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 ads124s_id[] = {
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{ "ads124s06", ADS124S06_ID },
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{ "ads124s08", ADS124S08_ID },
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{ }
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};
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MODULE_DEVICE_TABLE(spi, ads124s_id);
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static const struct of_device_id ads124s_of_table[] = {
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{ .compatible = "ti,ads124s06" },
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{ .compatible = "ti,ads124s08" },
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{ },
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};
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MODULE_DEVICE_TABLE(of, ads124s_of_table);
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static struct spi_driver ads124s_driver = {
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.driver = {
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.name = "ads124s08",
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.of_match_table = ads124s_of_table,
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},
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.probe = ads124s_probe,
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.id_table = ads124s_id,
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};
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module_spi_driver(ads124s_driver);
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MODULE_AUTHOR("Dan Murphy <dmuprhy@ti.com>");
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MODULE_DESCRIPTION("TI TI_ADS12S0X ADC");
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MODULE_LICENSE("GPL v2");
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