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// SPDX-License-Identifier: GPL-2.0-only
/*
* ti-dac082s085.c - Texas Instruments 8/10/12-bit 2/4-channel DAC driver
*
* Copyright (C) 2017 KUNBUS GmbH
*
* http://www.ti.com/lit/ds/symlink/dac082s085.pdf
* http://www.ti.com/lit/ds/symlink/dac102s085.pdf
* http://www.ti.com/lit/ds/symlink/dac122s085.pdf
* http://www.ti.com/lit/ds/symlink/dac084s085.pdf
* http://www.ti.com/lit/ds/symlink/dac104s085.pdf
* http://www.ti.com/lit/ds/symlink/dac124s085.pdf
*/
#include <linux/iio/iio.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
enum { dual_8bit, dual_10bit, dual_12bit, quad_8bit, quad_10bit, quad_12bit };
struct ti_dac_spec {
u8 num_channels;
u8 resolution;
};
static const struct ti_dac_spec ti_dac_spec[] = {
[dual_8bit] = { .num_channels = 2, .resolution = 8 },
[dual_10bit] = { .num_channels = 2, .resolution = 10 },
[dual_12bit] = { .num_channels = 2, .resolution = 12 },
[quad_8bit] = { .num_channels = 4, .resolution = 8 },
[quad_10bit] = { .num_channels = 4, .resolution = 10 },
[quad_12bit] = { .num_channels = 4, .resolution = 12 },
};
/**
* struct ti_dac_chip - TI DAC chip
* @lock: protects write sequences
* @vref: regulator generating Vref
* @mesg: SPI message to perform a write
* @xfer: SPI transfer used by @mesg
* @val: cached value of each output
* @powerdown: whether the chip is powered down
* @powerdown_mode: selected by the user
* @resolution: resolution of the chip
* @buf: buffer for @xfer
*/
struct ti_dac_chip {
struct mutex lock;
struct regulator *vref;
struct spi_message mesg;
struct spi_transfer xfer;
u16 val[4];
bool powerdown;
u8 powerdown_mode;
u8 resolution;
u8 buf[2] ____cacheline_aligned;
};
#define WRITE_NOT_UPDATE(chan) (0x00 | (chan) << 6)
#define WRITE_AND_UPDATE(chan) (0x10 | (chan) << 6)
#define WRITE_ALL_UPDATE 0x20
#define POWERDOWN(mode) (0x30 | ((mode) + 1) << 6)
static int ti_dac_cmd(struct ti_dac_chip *ti_dac, u8 cmd, u16 val)
{
u8 shift = 12 - ti_dac->resolution;
ti_dac->buf[0] = cmd | (val >> (8 - shift));
ti_dac->buf[1] = (val << shift) & 0xff;
return spi_sync(ti_dac->mesg.spi, &ti_dac->mesg);
}
static const char * const ti_dac_powerdown_modes[] = {
"2.5kohm_to_gnd", "100kohm_to_gnd", "three_state",
};
static int ti_dac_get_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
return ti_dac->powerdown_mode;
}
static int ti_dac_set_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
unsigned int mode)
{
struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
int ret = 0;
if (ti_dac->powerdown_mode == mode)
return 0;
mutex_lock(&ti_dac->lock);
if (ti_dac->powerdown) {
ret = ti_dac_cmd(ti_dac, POWERDOWN(mode), 0);
if (ret)
goto out;
}
ti_dac->powerdown_mode = mode;
out:
mutex_unlock(&ti_dac->lock);
return ret;
}
static const struct iio_enum ti_dac_powerdown_mode = {
.items = ti_dac_powerdown_modes,
.num_items = ARRAY_SIZE(ti_dac_powerdown_modes),
.get = ti_dac_get_powerdown_mode,
.set = ti_dac_set_powerdown_mode,
};
static ssize_t ti_dac_read_powerdown(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
char *buf)
{
struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
return sprintf(buf, "%d\n", ti_dac->powerdown);
}
static ssize_t ti_dac_write_powerdown(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
const char *buf, size_t len)
{
struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
bool powerdown;
int ret;
ret = strtobool(buf, &powerdown);
if (ret)
return ret;
if (ti_dac->powerdown == powerdown)
return len;
mutex_lock(&ti_dac->lock);
if (powerdown)
ret = ti_dac_cmd(ti_dac, POWERDOWN(ti_dac->powerdown_mode), 0);
else
ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(0), ti_dac->val[0]);
if (!ret)
ti_dac->powerdown = powerdown;
mutex_unlock(&ti_dac->lock);
return ret ? ret : len;
}
static const struct iio_chan_spec_ext_info ti_dac_ext_info[] = {
{
.name = "powerdown",
.read = ti_dac_read_powerdown,
.write = ti_dac_write_powerdown,
.shared = IIO_SHARED_BY_TYPE,
},
IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &ti_dac_powerdown_mode),
IIO_ENUM_AVAILABLE("powerdown_mode", &ti_dac_powerdown_mode),
{ },
};
#define TI_DAC_CHANNEL(chan) { \
.type = IIO_VOLTAGE, \
.channel = (chan), \
.address = (chan), \
.indexed = true, \
.output = true, \
.datasheet_name = (const char[]){ 'A' + (chan), 0 }, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.ext_info = ti_dac_ext_info, \
}
static const struct iio_chan_spec ti_dac_channels[] = {
TI_DAC_CHANNEL(0),
TI_DAC_CHANNEL(1),
TI_DAC_CHANNEL(2),
TI_DAC_CHANNEL(3),
};
static int ti_dac_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
*val = ti_dac->val[chan->channel];
ret = IIO_VAL_INT;
break;
case IIO_CHAN_INFO_SCALE:
ret = regulator_get_voltage(ti_dac->vref);
if (ret < 0)
return ret;
*val = ret / 1000;
*val2 = ti_dac->resolution;
ret = IIO_VAL_FRACTIONAL_LOG2;
break;
default:
ret = -EINVAL;
}
return ret;
}
static int ti_dac_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (ti_dac->val[chan->channel] == val)
return 0;
if (val >= (1 << ti_dac->resolution) || val < 0)
return -EINVAL;
if (ti_dac->powerdown)
return -EBUSY;
mutex_lock(&ti_dac->lock);
ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(chan->channel), val);
if (!ret)
ti_dac->val[chan->channel] = val;
mutex_unlock(&ti_dac->lock);
break;
default:
ret = -EINVAL;
}
return ret;
}
static int ti_dac_write_raw_get_fmt(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, long mask)
{
return IIO_VAL_INT;
}
static const struct iio_info ti_dac_info = {
.read_raw = ti_dac_read_raw,
.write_raw = ti_dac_write_raw,
.write_raw_get_fmt = ti_dac_write_raw_get_fmt,
};
static int ti_dac_probe(struct spi_device *spi)
{
struct device *dev = &spi->dev;
const struct ti_dac_spec *spec;
struct ti_dac_chip *ti_dac;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*ti_dac));
if (!indio_dev)
return
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