#include <linux/iio/iio.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
enum {
ID_DAC5311 = 0,
ID_DAC6311,
ID_DAC7311,
};
enum {
POWER_1KOHM_TO_GND = 0,
POWER_100KOHM_TO_GND,
POWER_TRI_STATE,
};
struct ti_dac_spec {
u8 resolution;
};
static const struct ti_dac_spec ti_dac_spec[] = {
[ID_DAC5311] = { .resolution = 8 },
[ID_DAC6311] = { .resolution = 10 },
[ID_DAC7311] = { .resolution = 12 },
};
struct ti_dac_chip {
struct mutex lock;
struct regulator *vref;
struct spi_device *spi;
u16 val;
bool powerdown;
u8 powerdown_mode;
u8 resolution;
u8 buf[2] __aligned(IIO_DMA_MINALIGN);
};
static u8 ti_dac_get_power(struct ti_dac_chip *ti_dac, bool powerdown)
{
if (powerdown)
return ti_dac->powerdown_mode + 1;
return 0;
}
static int ti_dac_cmd(struct ti_dac_chip *ti_dac, u8 power, u16 val)
{
u8 shift = 14 - ti_dac->resolution;
ti_dac->buf[0] = (val << shift) & 0xFF;
ti_dac->buf[1] = (power << 6) | (val >> (8 - shift));
return spi_write(ti_dac->spi, ti_dac->buf, 2);
}
static const char * const ti_dac_powerdown_modes[] = {
"1kohm_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);
ti_dac->powerdown_mode = mode;
return 0;
}
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 sysfs_emit(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;
u8 power;
int ret;
ret = kstrtobool(buf, &powerdown);
if (ret)
return ret;
power = ti_dac_get_power(ti_dac, powerdown);
mutex_lock(&ti_dac->lock);
ret = ti_dac_cmd(ti_dac, power, 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", IIO_SHARED_BY_TYPE, &ti_dac_powerdown_mode),
{ }
};
#define TI_DAC_CHANNEL(chan) { \
.type = IIO_VOLTAGE, \
.channel = (chan), \
.output = true, \
.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),
};
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;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
ret = regulator_get_voltage(ti_dac->vref);
if (ret < 0)
return ret;
*val = ret / 1000;
*val2 = ti_dac->resolution;
return IIO_VAL_FRACTIONAL_LOG2;
}
return -EINVAL;
}
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);
u8 power = ti_dac_get_power(ti_dac, ti_dac->powerdown);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (ti_dac->val == 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, power, val);
if (!ret)
ti_dac->val = 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 -ENOMEM;
spi->mode = SPI_MODE_1;
spi->bits_per_word = 16;
ret = spi_setup(spi);
if (ret < 0)
return dev_err_probe(dev, ret, "spi_setup failed\n");
indio_dev->info = &ti_dac_info;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = ti_dac_channels;
spi_set_drvdata(spi, indio_dev);
ti_dac = iio_priv(indio_dev);
ti_dac->powerdown = false;
ti_dac->spi = spi;
spec = &ti_dac_spec[spi_get_device_id(spi)->driver_data];
indio_dev->num_channels = 1;
ti_dac->resolution = spec->resolution;
ti_dac->vref = devm_regulator_get(dev, "vref");
if (IS_ERR(ti_dac->vref))
return dev_err_probe(dev, PTR_ERR(ti_dac->vref),
"error to get regulator\n");
ret = regulator_enable(ti_dac->vref);
if (ret < 0) {
dev_err(dev, "can not enable regulator\n");
return ret;
}
mutex_init(&ti_dac->lock);
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(dev, "fail to register iio device: %d\n", ret);
goto err;
}
return 0;
err:
mutex_destroy(&ti_dac->lock);
regulator_disable(ti_dac->vref);
return ret;
}
static void ti_dac_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
mutex_destroy(&ti_dac->lock);
regulator_disable(ti_dac->vref);
}
static const struct of_device_id ti_dac_of_id[] = {
{ .compatible = "ti,dac5311" },
{ .compatible = "ti,dac6311" },
{ .compatible = "ti,dac7311" },
{ }
};
MODULE_DEVICE_TABLE(of, ti_dac_of_id);
static const struct spi_device_id ti_dac_spi_id[] = {
{ "dac5311", ID_DAC5311 },
{ "dac6311", ID_DAC6311 },
{ "dac7311", ID_DAC7311 },
{ }
};
MODULE_DEVICE_TABLE(spi, ti_dac_spi_id);
static struct spi_driver ti_dac_driver = {
.driver = {
.name = "ti-dac7311",
.of_match_table = ti_dac_of_id,
},
.probe = ti_dac_probe,
.remove = ti_dac_remove,
.id_table = ti_dac_spi_id,
};
module_spi_driver(ti_dac_driver);
MODULE_AUTHOR("Charles-Antoine Couret <charles-antoine.couret@essensium.com>");
MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1-channel DAC driver");
MODULE_LICENSE("GPL v2");
