364 lines
8.8 KiB
C
364 lines
8.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* ti-dac082s085.c - Texas Instruments 8/10/12-bit 2/4-channel DAC driver
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*
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* Copyright (C) 2017 KUNBUS GmbH
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*
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* https://www.ti.com/lit/ds/symlink/dac082s085.pdf
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* https://www.ti.com/lit/ds/symlink/dac102s085.pdf
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* https://www.ti.com/lit/ds/symlink/dac122s085.pdf
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* https://www.ti.com/lit/ds/symlink/dac084s085.pdf
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* https://www.ti.com/lit/ds/symlink/dac104s085.pdf
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* https://www.ti.com/lit/ds/symlink/dac124s085.pdf
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*/
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#include <linux/iio/iio.h>
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/regulator/consumer.h>
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#include <linux/spi/spi.h>
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enum { dual_8bit, dual_10bit, dual_12bit, quad_8bit, quad_10bit, quad_12bit };
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struct ti_dac_spec {
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u8 num_channels;
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u8 resolution;
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};
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static const struct ti_dac_spec ti_dac_spec[] = {
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[dual_8bit] = { .num_channels = 2, .resolution = 8 },
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[dual_10bit] = { .num_channels = 2, .resolution = 10 },
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[dual_12bit] = { .num_channels = 2, .resolution = 12 },
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[quad_8bit] = { .num_channels = 4, .resolution = 8 },
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[quad_10bit] = { .num_channels = 4, .resolution = 10 },
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[quad_12bit] = { .num_channels = 4, .resolution = 12 },
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};
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/**
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* struct ti_dac_chip - TI DAC chip
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* @lock: protects write sequences
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* @vref: regulator generating Vref
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* @mesg: SPI message to perform a write
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* @xfer: SPI transfer used by @mesg
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* @val: cached value of each output
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* @powerdown: whether the chip is powered down
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* @powerdown_mode: selected by the user
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* @resolution: resolution of the chip
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* @buf: buffer for @xfer
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*/
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struct ti_dac_chip {
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struct mutex lock;
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struct regulator *vref;
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struct spi_message mesg;
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struct spi_transfer xfer;
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u16 val[4];
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bool powerdown;
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u8 powerdown_mode;
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u8 resolution;
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u8 buf[2] ____cacheline_aligned;
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};
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#define WRITE_NOT_UPDATE(chan) (0x00 | (chan) << 6)
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#define WRITE_AND_UPDATE(chan) (0x10 | (chan) << 6)
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#define WRITE_ALL_UPDATE 0x20
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#define POWERDOWN(mode) (0x30 | ((mode) + 1) << 6)
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static int ti_dac_cmd(struct ti_dac_chip *ti_dac, u8 cmd, u16 val)
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{
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u8 shift = 12 - ti_dac->resolution;
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ti_dac->buf[0] = cmd | (val >> (8 - shift));
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ti_dac->buf[1] = (val << shift) & 0xff;
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return spi_sync(ti_dac->mesg.spi, &ti_dac->mesg);
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}
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static const char * const ti_dac_powerdown_modes[] = {
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"2.5kohm_to_gnd", "100kohm_to_gnd", "three_state",
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};
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static int ti_dac_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 ti_dac_chip *ti_dac = iio_priv(indio_dev);
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return ti_dac->powerdown_mode;
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}
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static int ti_dac_set_powerdown_mode(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan,
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unsigned int mode)
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{
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struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
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int ret = 0;
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if (ti_dac->powerdown_mode == mode)
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return 0;
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mutex_lock(&ti_dac->lock);
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if (ti_dac->powerdown) {
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ret = ti_dac_cmd(ti_dac, POWERDOWN(mode), 0);
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if (ret)
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goto out;
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}
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ti_dac->powerdown_mode = mode;
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out:
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mutex_unlock(&ti_dac->lock);
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return ret;
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}
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static const struct iio_enum ti_dac_powerdown_mode = {
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.items = ti_dac_powerdown_modes,
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.num_items = ARRAY_SIZE(ti_dac_powerdown_modes),
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.get = ti_dac_get_powerdown_mode,
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.set = ti_dac_set_powerdown_mode,
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};
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static ssize_t ti_dac_read_powerdown(struct iio_dev *indio_dev,
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uintptr_t private,
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const struct iio_chan_spec *chan,
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char *buf)
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{
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struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
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return sysfs_emit(buf, "%d\n", ti_dac->powerdown);
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}
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static ssize_t ti_dac_write_powerdown(struct iio_dev *indio_dev,
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uintptr_t private,
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const struct iio_chan_spec *chan,
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const char *buf, size_t len)
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{
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struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
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bool powerdown;
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int ret;
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ret = strtobool(buf, &powerdown);
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if (ret)
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return ret;
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if (ti_dac->powerdown == powerdown)
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return len;
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mutex_lock(&ti_dac->lock);
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if (powerdown)
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ret = ti_dac_cmd(ti_dac, POWERDOWN(ti_dac->powerdown_mode), 0);
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else
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ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(0), ti_dac->val[0]);
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if (!ret)
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ti_dac->powerdown = powerdown;
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mutex_unlock(&ti_dac->lock);
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return ret ? ret : len;
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}
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static const struct iio_chan_spec_ext_info ti_dac_ext_info[] = {
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{
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.name = "powerdown",
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.read = ti_dac_read_powerdown,
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.write = ti_dac_write_powerdown,
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.shared = IIO_SHARED_BY_TYPE,
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},
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IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &ti_dac_powerdown_mode),
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IIO_ENUM_AVAILABLE("powerdown_mode", &ti_dac_powerdown_mode),
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{ },
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};
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#define TI_DAC_CHANNEL(chan) { \
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.type = IIO_VOLTAGE, \
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.channel = (chan), \
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.address = (chan), \
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.indexed = true, \
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.output = true, \
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.datasheet_name = (const char[]){ 'A' + (chan), 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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.ext_info = ti_dac_ext_info, \
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}
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static const struct iio_chan_spec ti_dac_channels[] = {
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TI_DAC_CHANNEL(0),
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TI_DAC_CHANNEL(1),
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TI_DAC_CHANNEL(2),
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TI_DAC_CHANNEL(3),
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};
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static int ti_dac_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 mask)
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{
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struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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*val = ti_dac->val[chan->channel];
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ret = IIO_VAL_INT;
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break;
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case IIO_CHAN_INFO_SCALE:
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ret = regulator_get_voltage(ti_dac->vref);
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if (ret < 0)
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return ret;
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*val = ret / 1000;
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*val2 = ti_dac->resolution;
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ret = IIO_VAL_FRACTIONAL_LOG2;
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break;
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default:
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ret = -EINVAL;
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}
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return ret;
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}
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static int ti_dac_write_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 mask)
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{
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struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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if (ti_dac->val[chan->channel] == val)
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return 0;
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if (val >= (1 << ti_dac->resolution) || val < 0)
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return -EINVAL;
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if (ti_dac->powerdown)
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return -EBUSY;
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mutex_lock(&ti_dac->lock);
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ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(chan->channel), val);
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if (!ret)
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ti_dac->val[chan->channel] = val;
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mutex_unlock(&ti_dac->lock);
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break;
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default:
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ret = -EINVAL;
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}
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return ret;
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}
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static int ti_dac_write_raw_get_fmt(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan, long mask)
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{
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return IIO_VAL_INT;
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}
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static const struct iio_info ti_dac_info = {
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.read_raw = ti_dac_read_raw,
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.write_raw = ti_dac_write_raw,
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.write_raw_get_fmt = ti_dac_write_raw_get_fmt,
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};
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static int ti_dac_probe(struct spi_device *spi)
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{
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struct device *dev = &spi->dev;
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const struct ti_dac_spec *spec;
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struct ti_dac_chip *ti_dac;
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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(dev, sizeof(*ti_dac));
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if (!indio_dev)
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return -ENOMEM;
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indio_dev->info = &ti_dac_info;
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indio_dev->name = spi->modalias;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = ti_dac_channels;
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spi_set_drvdata(spi, indio_dev);
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ti_dac = iio_priv(indio_dev);
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ti_dac->xfer.tx_buf = &ti_dac->buf;
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ti_dac->xfer.len = sizeof(ti_dac->buf);
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spi_message_init_with_transfers(&ti_dac->mesg, &ti_dac->xfer, 1);
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ti_dac->mesg.spi = spi;
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spec = &ti_dac_spec[spi_get_device_id(spi)->driver_data];
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indio_dev->num_channels = spec->num_channels;
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ti_dac->resolution = spec->resolution;
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ti_dac->vref = devm_regulator_get(dev, "vref");
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if (IS_ERR(ti_dac->vref))
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return PTR_ERR(ti_dac->vref);
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ret = regulator_enable(ti_dac->vref);
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if (ret < 0)
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return ret;
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mutex_init(&ti_dac->lock);
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ret = ti_dac_cmd(ti_dac, WRITE_ALL_UPDATE, 0);
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if (ret) {
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dev_err(dev, "failed to initialize outputs to 0\n");
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goto err;
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}
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ret = iio_device_register(indio_dev);
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if (ret)
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goto err;
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return 0;
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err:
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mutex_destroy(&ti_dac->lock);
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regulator_disable(ti_dac->vref);
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return ret;
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}
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static int ti_dac_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 ti_dac_chip *ti_dac = iio_priv(indio_dev);
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iio_device_unregister(indio_dev);
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mutex_destroy(&ti_dac->lock);
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regulator_disable(ti_dac->vref);
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return 0;
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}
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static const struct of_device_id ti_dac_of_id[] = {
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{ .compatible = "ti,dac082s085" },
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{ .compatible = "ti,dac102s085" },
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{ .compatible = "ti,dac122s085" },
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{ .compatible = "ti,dac084s085" },
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{ .compatible = "ti,dac104s085" },
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{ .compatible = "ti,dac124s085" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, ti_dac_of_id);
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static const struct spi_device_id ti_dac_spi_id[] = {
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{ "dac082s085", dual_8bit },
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{ "dac102s085", dual_10bit },
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{ "dac122s085", dual_12bit },
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{ "dac084s085", quad_8bit },
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{ "dac104s085", quad_10bit },
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{ "dac124s085", quad_12bit },
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{ }
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};
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MODULE_DEVICE_TABLE(spi, ti_dac_spi_id);
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static struct spi_driver ti_dac_driver = {
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.driver = {
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.name = "ti-dac082s085",
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.of_match_table = ti_dac_of_id,
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},
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.probe = ti_dac_probe,
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.remove = ti_dac_remove,
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.id_table = ti_dac_spi_id,
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};
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module_spi_driver(ti_dac_driver);
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MODULE_AUTHOR("Lukas Wunner <lukas@wunner.de>");
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MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 2/4-channel DAC driver");
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MODULE_LICENSE("GPL v2");
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