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363 lines
8.8 KiB
363 lines
8.8 KiB
// 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 <[email protected]>"); |
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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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