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336 lines
7.5 KiB
336 lines
7.5 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* ti-dac7311.c - Texas Instruments 8/10/12-bit 1-channel DAC driver |
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* |
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* Copyright (C) 2018 CMC NV |
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* |
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* https://www.ti.com/lit/ds/symlink/dac7311.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/regulator/consumer.h> |
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#include <linux/spi/spi.h> |
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enum { |
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ID_DAC5311 = 0, |
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ID_DAC6311, |
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ID_DAC7311, |
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}; |
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enum { |
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POWER_1KOHM_TO_GND = 0, |
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POWER_100KOHM_TO_GND, |
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POWER_TRI_STATE, |
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}; |
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struct ti_dac_spec { |
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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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[ID_DAC5311] = { .resolution = 8 }, |
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[ID_DAC6311] = { .resolution = 10 }, |
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[ID_DAC7311] = { .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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* @spi: SPI device to send data to the device |
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* @val: cached value |
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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 transfer data |
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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_device *spi; |
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u16 val; |
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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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static u8 ti_dac_get_power(struct ti_dac_chip *ti_dac, bool powerdown) |
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{ |
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if (powerdown) |
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return ti_dac->powerdown_mode + 1; |
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return 0; |
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} |
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static int ti_dac_cmd(struct ti_dac_chip *ti_dac, u8 power, u16 val) |
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{ |
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u8 shift = 14 - ti_dac->resolution; |
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ti_dac->buf[0] = (val << shift) & 0xFF; |
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ti_dac->buf[1] = (power << 6) | (val >> (8 - shift)); |
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return spi_write(ti_dac->spi, ti_dac->buf, 2); |
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} |
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static const char * const ti_dac_powerdown_modes[] = { |
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"1kohm_to_gnd", |
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"100kohm_to_gnd", |
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"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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ti_dac->powerdown_mode = mode; |
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return 0; |
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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 sprintf(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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u8 power; |
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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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power = ti_dac_get_power(ti_dac, powerdown); |
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mutex_lock(&ti_dac->lock); |
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ret = ti_dac_cmd(ti_dac, power, 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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.output = true, \ |
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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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}; |
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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; |
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return IIO_VAL_INT; |
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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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return IIO_VAL_FRACTIONAL_LOG2; |
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} |
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return -EINVAL; |
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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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u8 power = ti_dac_get_power(ti_dac, ti_dac->powerdown); |
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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 == 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, power, val); |
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if (!ret) |
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ti_dac->val = 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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dev_err(dev, "can not allocate iio device\n"); |
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return -ENOMEM; |
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} |
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spi->mode = SPI_MODE_1; |
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spi->bits_per_word = 16; |
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spi_setup(spi); |
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indio_dev->info = &ti_dac_info; |
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indio_dev->name = spi_get_device_id(spi)->name; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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indio_dev->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->powerdown = false; |
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ti_dac->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 = 1; |
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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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dev_err(dev, "error to get regulator\n"); |
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return PTR_ERR(ti_dac->vref); |
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} |
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ret = regulator_enable(ti_dac->vref); |
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if (ret < 0) { |
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dev_err(dev, "can not enable regulator\n"); |
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return ret; |
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} |
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mutex_init(&ti_dac->lock); |
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ret = iio_device_register(indio_dev); |
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if (ret) { |
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dev_err(dev, "fail to register iio device: %d\n", ret); |
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goto err; |
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} |
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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,dac5311" }, |
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{ .compatible = "ti,dac6311" }, |
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{ .compatible = "ti,dac7311" }, |
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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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{ "dac5311", ID_DAC5311 }, |
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{ "dac6311", ID_DAC6311 }, |
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{ "dac7311", ID_DAC7311 }, |
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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-dac7311", |
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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("Charles-Antoine Couret <[email protected]>"); |
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MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1-channel DAC driver"); |
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MODULE_LICENSE("GPL v2");
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