![Peter Meerwald](/assets/img/avatar_default.png)
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net> Acked-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
475 lines
11 KiB
C
475 lines
11 KiB
C
/*
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* AD5760, AD5780, AD5781, AD5790, AD5791 Voltage Output Digital to Analog
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* Converter
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*
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* Copyright 2011 Analog Devices Inc.
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*
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* Licensed under the GPL-2.
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*/
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#include <linux/interrupt.h>
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#include <linux/fs.h>
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/spi/spi.h>
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#include <linux/slab.h>
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#include <linux/sysfs.h>
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#include <linux/regulator/consumer.h>
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#include <linux/module.h>
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#include <linux/bitops.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/dac/ad5791.h>
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#define AD5791_DAC_MASK GENMASK(19, 0)
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#define AD5791_CMD_READ BIT(23)
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#define AD5791_CMD_WRITE 0
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#define AD5791_ADDR(addr) ((addr) << 20)
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/* Registers */
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#define AD5791_ADDR_NOOP 0
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#define AD5791_ADDR_DAC0 1
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#define AD5791_ADDR_CTRL 2
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#define AD5791_ADDR_CLRCODE 3
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#define AD5791_ADDR_SW_CTRL 4
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/* Control Register */
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#define AD5791_CTRL_RBUF BIT(1)
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#define AD5791_CTRL_OPGND BIT(2)
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#define AD5791_CTRL_DACTRI BIT(3)
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#define AD5791_CTRL_BIN2SC BIT(4)
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#define AD5791_CTRL_SDODIS BIT(5)
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#define AD5761_CTRL_LINCOMP(x) ((x) << 6)
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#define AD5791_LINCOMP_0_10 0
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#define AD5791_LINCOMP_10_12 1
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#define AD5791_LINCOMP_12_16 2
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#define AD5791_LINCOMP_16_19 3
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#define AD5791_LINCOMP_19_20 12
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#define AD5780_LINCOMP_0_10 0
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#define AD5780_LINCOMP_10_20 12
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/* Software Control Register */
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#define AD5791_SWCTRL_LDAC BIT(0)
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#define AD5791_SWCTRL_CLR BIT(1)
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#define AD5791_SWCTRL_RESET BIT(2)
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#define AD5791_DAC_PWRDN_6K 0
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#define AD5791_DAC_PWRDN_3STATE 1
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/**
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* struct ad5791_chip_info - chip specific information
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* @get_lin_comp: function pointer to the device specific function
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*/
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struct ad5791_chip_info {
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int (*get_lin_comp) (unsigned int span);
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};
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/**
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* struct ad5791_state - driver instance specific data
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* @spi: spi_device
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* @reg_vdd: positive supply regulator
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* @reg_vss: negative supply regulator
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* @chip_info: chip model specific constants
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* @vref_mv: actual reference voltage used
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* @vref_neg_mv: voltage of the negative supply
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* @pwr_down_mode current power down mode
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*/
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struct ad5791_state {
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struct spi_device *spi;
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struct regulator *reg_vdd;
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struct regulator *reg_vss;
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const struct ad5791_chip_info *chip_info;
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unsigned short vref_mv;
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unsigned int vref_neg_mv;
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unsigned ctrl;
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unsigned pwr_down_mode;
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bool pwr_down;
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union {
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__be32 d32;
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u8 d8[4];
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} data[3] ____cacheline_aligned;
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};
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/**
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* ad5791_supported_device_ids:
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*/
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enum ad5791_supported_device_ids {
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ID_AD5760,
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ID_AD5780,
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ID_AD5781,
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ID_AD5791,
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};
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static int ad5791_spi_write(struct ad5791_state *st, u8 addr, u32 val)
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{
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st->data[0].d32 = cpu_to_be32(AD5791_CMD_WRITE |
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AD5791_ADDR(addr) |
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(val & AD5791_DAC_MASK));
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return spi_write(st->spi, &st->data[0].d8[1], 3);
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}
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static int ad5791_spi_read(struct ad5791_state *st, u8 addr, u32 *val)
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{
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int ret;
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struct spi_transfer xfers[] = {
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{
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.tx_buf = &st->data[0].d8[1],
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.bits_per_word = 8,
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.len = 3,
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.cs_change = 1,
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}, {
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.tx_buf = &st->data[1].d8[1],
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.rx_buf = &st->data[2].d8[1],
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.bits_per_word = 8,
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.len = 3,
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},
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};
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st->data[0].d32 = cpu_to_be32(AD5791_CMD_READ |
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AD5791_ADDR(addr));
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st->data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP));
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ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
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*val = be32_to_cpu(st->data[2].d32);
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return ret;
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}
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static const char * const ad5791_powerdown_modes[] = {
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"6kohm_to_gnd",
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"three_state",
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};
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static int ad5791_get_powerdown_mode(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan)
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{
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struct ad5791_state *st = iio_priv(indio_dev);
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return st->pwr_down_mode;
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}
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static int ad5791_set_powerdown_mode(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan, unsigned int mode)
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{
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struct ad5791_state *st = iio_priv(indio_dev);
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st->pwr_down_mode = mode;
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return 0;
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}
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static const struct iio_enum ad5791_powerdown_mode_enum = {
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.items = ad5791_powerdown_modes,
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.num_items = ARRAY_SIZE(ad5791_powerdown_modes),
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.get = ad5791_get_powerdown_mode,
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.set = ad5791_set_powerdown_mode,
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};
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static ssize_t ad5791_read_dac_powerdown(struct iio_dev *indio_dev,
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uintptr_t private, const struct iio_chan_spec *chan, char *buf)
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{
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struct ad5791_state *st = iio_priv(indio_dev);
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return sprintf(buf, "%d\n", st->pwr_down);
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}
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static ssize_t ad5791_write_dac_powerdown(struct iio_dev *indio_dev,
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uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
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size_t len)
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{
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bool pwr_down;
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int ret;
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struct ad5791_state *st = iio_priv(indio_dev);
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ret = strtobool(buf, &pwr_down);
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if (ret)
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return ret;
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if (!pwr_down) {
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st->ctrl &= ~(AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
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} else {
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if (st->pwr_down_mode == AD5791_DAC_PWRDN_6K)
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st->ctrl |= AD5791_CTRL_OPGND;
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else if (st->pwr_down_mode == AD5791_DAC_PWRDN_3STATE)
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st->ctrl |= AD5791_CTRL_DACTRI;
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}
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st->pwr_down = pwr_down;
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ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl);
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return ret ? ret : len;
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}
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static int ad5791_get_lin_comp(unsigned int span)
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{
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if (span <= 10000)
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return AD5791_LINCOMP_0_10;
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else if (span <= 12000)
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return AD5791_LINCOMP_10_12;
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else if (span <= 16000)
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return AD5791_LINCOMP_12_16;
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else if (span <= 19000)
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return AD5791_LINCOMP_16_19;
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else
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return AD5791_LINCOMP_19_20;
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}
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static int ad5780_get_lin_comp(unsigned int span)
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{
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if (span <= 10000)
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return AD5780_LINCOMP_0_10;
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else
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return AD5780_LINCOMP_10_20;
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}
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static const struct ad5791_chip_info ad5791_chip_info_tbl[] = {
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[ID_AD5760] = {
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.get_lin_comp = ad5780_get_lin_comp,
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},
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[ID_AD5780] = {
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.get_lin_comp = ad5780_get_lin_comp,
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},
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[ID_AD5781] = {
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.get_lin_comp = ad5791_get_lin_comp,
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},
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[ID_AD5791] = {
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.get_lin_comp = ad5791_get_lin_comp,
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},
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};
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static int ad5791_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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struct ad5791_state *st = iio_priv(indio_dev);
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u64 val64;
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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 = ad5791_spi_read(st, chan->address, val);
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if (ret)
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return ret;
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*val &= AD5791_DAC_MASK;
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*val >>= chan->scan_type.shift;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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*val = st->vref_mv;
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*val2 = (1 << chan->scan_type.realbits) - 1;
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return IIO_VAL_FRACTIONAL;
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case IIO_CHAN_INFO_OFFSET:
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val64 = (((u64)st->vref_neg_mv) << chan->scan_type.realbits);
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do_div(val64, st->vref_mv);
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*val = -val64;
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return IIO_VAL_INT;
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default:
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return -EINVAL;
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}
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};
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static const struct iio_chan_spec_ext_info ad5791_ext_info[] = {
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{
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.name = "powerdown",
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.shared = IIO_SHARED_BY_TYPE,
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.read = ad5791_read_dac_powerdown,
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.write = ad5791_write_dac_powerdown,
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},
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IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
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&ad5791_powerdown_mode_enum),
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IIO_ENUM_AVAILABLE("powerdown_mode", &ad5791_powerdown_mode_enum),
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{ },
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};
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#define AD5791_CHAN(bits, _shift) { \
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.type = IIO_VOLTAGE, \
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.output = 1, \
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.indexed = 1, \
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.address = AD5791_ADDR_DAC0, \
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.channel = 0, \
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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_type = { \
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.sign = 'u', \
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.realbits = (bits), \
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.storagebits = 24, \
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.shift = (_shift), \
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}, \
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.ext_info = ad5791_ext_info, \
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}
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static const struct iio_chan_spec ad5791_channels[] = {
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[ID_AD5760] = AD5791_CHAN(16, 4),
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[ID_AD5780] = AD5791_CHAN(18, 2),
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[ID_AD5781] = AD5791_CHAN(18, 2),
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[ID_AD5791] = AD5791_CHAN(20, 0)
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};
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static int ad5791_write_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 mask)
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{
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struct ad5791_state *st = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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val &= GENMASK(chan->scan_type.realbits - 1, 0);
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val <<= chan->scan_type.shift;
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return ad5791_spi_write(st, chan->address, val);
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default:
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return -EINVAL;
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}
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}
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static const struct iio_info ad5791_info = {
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.read_raw = &ad5791_read_raw,
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.write_raw = &ad5791_write_raw,
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.driver_module = THIS_MODULE,
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};
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static int ad5791_probe(struct spi_device *spi)
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{
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struct ad5791_platform_data *pdata = spi->dev.platform_data;
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struct iio_dev *indio_dev;
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struct ad5791_state *st;
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int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
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if (!indio_dev)
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return -ENOMEM;
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st = iio_priv(indio_dev);
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st->reg_vdd = devm_regulator_get(&spi->dev, "vdd");
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if (!IS_ERR(st->reg_vdd)) {
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ret = regulator_enable(st->reg_vdd);
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if (ret)
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return ret;
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ret = regulator_get_voltage(st->reg_vdd);
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if (ret < 0)
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goto error_disable_reg_pos;
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pos_voltage_uv = ret;
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}
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st->reg_vss = devm_regulator_get(&spi->dev, "vss");
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if (!IS_ERR(st->reg_vss)) {
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ret = regulator_enable(st->reg_vss);
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if (ret)
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goto error_disable_reg_pos;
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ret = regulator_get_voltage(st->reg_vss);
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if (ret < 0)
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goto error_disable_reg_neg;
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neg_voltage_uv = ret;
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}
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st->pwr_down = true;
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st->spi = spi;
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if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd)) {
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st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000;
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st->vref_neg_mv = neg_voltage_uv / 1000;
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} else if (pdata) {
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st->vref_mv = pdata->vref_pos_mv + pdata->vref_neg_mv;
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st->vref_neg_mv = pdata->vref_neg_mv;
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} else {
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dev_warn(&spi->dev, "reference voltage unspecified\n");
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}
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ret = ad5791_spi_write(st, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET);
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if (ret)
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goto error_disable_reg_neg;
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st->chip_info = &ad5791_chip_info_tbl[spi_get_device_id(spi)
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->driver_data];
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st->ctrl = AD5761_CTRL_LINCOMP(st->chip_info->get_lin_comp(st->vref_mv))
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| ((pdata && pdata->use_rbuf_gain2) ? 0 : AD5791_CTRL_RBUF) |
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AD5791_CTRL_BIN2SC;
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ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl |
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AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
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if (ret)
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goto error_disable_reg_neg;
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spi_set_drvdata(spi, indio_dev);
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indio_dev->dev.parent = &spi->dev;
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indio_dev->info = &ad5791_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels
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= &ad5791_channels[spi_get_device_id(spi)->driver_data];
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indio_dev->num_channels = 1;
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indio_dev->name = spi_get_device_id(st->spi)->name;
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ret = iio_device_register(indio_dev);
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if (ret)
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goto error_disable_reg_neg;
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return 0;
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error_disable_reg_neg:
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if (!IS_ERR(st->reg_vss))
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regulator_disable(st->reg_vss);
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error_disable_reg_pos:
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if (!IS_ERR(st->reg_vdd))
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regulator_disable(st->reg_vdd);
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return ret;
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}
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static int ad5791_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 ad5791_state *st = iio_priv(indio_dev);
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iio_device_unregister(indio_dev);
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if (!IS_ERR(st->reg_vdd))
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regulator_disable(st->reg_vdd);
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if (!IS_ERR(st->reg_vss))
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regulator_disable(st->reg_vss);
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return 0;
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}
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static const struct spi_device_id ad5791_id[] = {
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{"ad5760", ID_AD5760},
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{"ad5780", ID_AD5780},
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{"ad5781", ID_AD5781},
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{"ad5790", ID_AD5791},
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{"ad5791", ID_AD5791},
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{}
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};
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MODULE_DEVICE_TABLE(spi, ad5791_id);
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static struct spi_driver ad5791_driver = {
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.driver = {
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.name = "ad5791",
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.owner = THIS_MODULE,
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},
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.probe = ad5791_probe,
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.remove = ad5791_remove,
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.id_table = ad5791_id,
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};
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module_spi_driver(ad5791_driver);
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MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
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MODULE_DESCRIPTION("Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC");
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MODULE_LICENSE("GPL v2");
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