mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 18:14:07 +08:00
iio: dac: Add support for external reference voltage through the regulator framework.
Signed-off-by: Silvan Murer <silvan.murer@gmail.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
parent
0f6a2165af
commit
9ff1d5009f
@ -12,12 +12,26 @@ Required properties:
|
||||
Property rules described in Documentation/devicetree/bindings/spi/spi-bus.txt
|
||||
apply. In particular, "reg" and "spi-max-frequency" properties must be given.
|
||||
|
||||
Optional properties:
|
||||
- vref-supply: Phandle to the external reference voltage supply. This should
|
||||
only be set if there is an external reference voltage connected to the VREF
|
||||
pin. If the property is not set the internal reference is used.
|
||||
|
||||
Example:
|
||||
|
||||
vref: regulator-vref {
|
||||
compatible = "regulator-fixed";
|
||||
regulator-name = "vref-ltc2632";
|
||||
regulator-min-microvolt = <1250000>;
|
||||
regulator-max-microvolt = <1250000>;
|
||||
regulator-always-on;
|
||||
};
|
||||
|
||||
spi_master {
|
||||
dac: ltc2632@0 {
|
||||
compatible = "lltc,ltc2632-l12";
|
||||
reg = <0>; /* CS0 */
|
||||
spi-max-frequency = <1000000>;
|
||||
vref-supply = <&vref>; /* optional */
|
||||
};
|
||||
};
|
||||
|
@ -2,6 +2,7 @@
|
||||
* LTC2632 Digital to analog convertors spi driver
|
||||
*
|
||||
* Copyright 2017 Maxime Roussin-Bélanger
|
||||
* expanded by Silvan Murer <silvan.murer@gmail.com>
|
||||
*
|
||||
* Licensed under the GPL-2.
|
||||
*/
|
||||
@ -10,6 +11,7 @@
|
||||
#include <linux/spi/spi.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/iio/iio.h>
|
||||
#include <linux/regulator/consumer.h>
|
||||
|
||||
#define LTC2632_DAC_CHANNELS 2
|
||||
|
||||
@ -28,7 +30,7 @@
|
||||
/**
|
||||
* struct ltc2632_chip_info - chip specific information
|
||||
* @channels: channel spec for the DAC
|
||||
* @vref_mv: reference voltage
|
||||
* @vref_mv: internal reference voltage
|
||||
*/
|
||||
struct ltc2632_chip_info {
|
||||
const struct iio_chan_spec *channels;
|
||||
@ -39,10 +41,14 @@ struct ltc2632_chip_info {
|
||||
* struct ltc2632_state - driver instance specific data
|
||||
* @spi_dev: pointer to the spi_device struct
|
||||
* @powerdown_cache_mask used to show current channel powerdown state
|
||||
* @vref_mv used reference voltage (internal or external)
|
||||
* @vref_reg regulator for the reference voltage
|
||||
*/
|
||||
struct ltc2632_state {
|
||||
struct spi_device *spi_dev;
|
||||
unsigned int powerdown_cache_mask;
|
||||
int vref_mv;
|
||||
struct regulator *vref_reg;
|
||||
};
|
||||
|
||||
enum ltc2632_supported_device_ids {
|
||||
@ -90,7 +96,7 @@ static int ltc2632_read_raw(struct iio_dev *indio_dev,
|
||||
|
||||
switch (m) {
|
||||
case IIO_CHAN_INFO_SCALE:
|
||||
*val = chip_info->vref_mv;
|
||||
*val = st->vref_mv;
|
||||
*val2 = chan->scan_type.realbits;
|
||||
return IIO_VAL_FRACTIONAL_LOG2;
|
||||
}
|
||||
@ -246,6 +252,45 @@ static int ltc2632_probe(struct spi_device *spi)
|
||||
chip_info = (struct ltc2632_chip_info *)
|
||||
spi_get_device_id(spi)->driver_data;
|
||||
|
||||
st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
|
||||
if (PTR_ERR(st->vref_reg) == -ENODEV) {
|
||||
/* use internal reference voltage */
|
||||
st->vref_reg = NULL;
|
||||
st->vref_mv = chip_info->vref_mv;
|
||||
|
||||
ret = ltc2632_spi_write(spi, LTC2632_CMD_INTERNAL_REFER,
|
||||
0, 0, 0);
|
||||
if (ret) {
|
||||
dev_err(&spi->dev,
|
||||
"Set internal reference command failed, %d\n",
|
||||
ret);
|
||||
return ret;
|
||||
}
|
||||
} else if (IS_ERR(st->vref_reg)) {
|
||||
dev_err(&spi->dev,
|
||||
"Error getting voltage reference regulator\n");
|
||||
return PTR_ERR(st->vref_reg);
|
||||
} else {
|
||||
/* use external reference voltage */
|
||||
ret = regulator_enable(st->vref_reg);
|
||||
if (ret) {
|
||||
dev_err(&spi->dev,
|
||||
"enable reference regulator failed, %d\n",
|
||||
ret);
|
||||
return ret;
|
||||
}
|
||||
st->vref_mv = regulator_get_voltage(st->vref_reg) / 1000;
|
||||
|
||||
ret = ltc2632_spi_write(spi, LTC2632_CMD_EXTERNAL_REFER,
|
||||
0, 0, 0);
|
||||
if (ret) {
|
||||
dev_err(&spi->dev,
|
||||
"Set external reference command failed, %d\n",
|
||||
ret);
|
||||
return ret;
|
||||
}
|
||||
}
|
||||
|
||||
indio_dev->dev.parent = &spi->dev;
|
||||
indio_dev->name = dev_of_node(&spi->dev) ? dev_of_node(&spi->dev)->name
|
||||
: spi_get_device_id(spi)->name;
|
||||
@ -254,14 +299,20 @@ static int ltc2632_probe(struct spi_device *spi)
|
||||
indio_dev->channels = chip_info->channels;
|
||||
indio_dev->num_channels = LTC2632_DAC_CHANNELS;
|
||||
|
||||
ret = ltc2632_spi_write(spi, LTC2632_CMD_INTERNAL_REFER, 0, 0, 0);
|
||||
if (ret) {
|
||||
dev_err(&spi->dev,
|
||||
"Set internal reference command failed, %d\n", ret);
|
||||
return ret;
|
||||
}
|
||||
return iio_device_register(indio_dev);
|
||||
}
|
||||
|
||||
return devm_iio_device_register(&spi->dev, indio_dev);
|
||||
static int ltc2632_remove(struct spi_device *spi)
|
||||
{
|
||||
struct iio_dev *indio_dev = spi_get_drvdata(spi);
|
||||
struct ltc2632_state *st = iio_priv(indio_dev);
|
||||
|
||||
iio_device_unregister(indio_dev);
|
||||
|
||||
if (st->vref_reg)
|
||||
regulator_disable(st->vref_reg);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const struct spi_device_id ltc2632_id[] = {
|
||||
@ -305,6 +356,7 @@ static struct spi_driver ltc2632_driver = {
|
||||
.of_match_table = of_match_ptr(ltc2632_of_match),
|
||||
},
|
||||
.probe = ltc2632_probe,
|
||||
.remove = ltc2632_remove,
|
||||
.id_table = ltc2632_id,
|
||||
};
|
||||
module_spi_driver(ltc2632_driver);
|
||||
|
Loading…
Reference in New Issue
Block a user