iio: adc: Add driver for the TI ADS8344 A/DC chips
This adds support for the Texas Instruments ADS8344 ADC chip. This chip has a 16-bit 8-Channel ADC and is access directly through SPI. Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Gregory CLEMENT
Jonathan Cameron
parent
65c7a3d2cf
commit
8dd2d7c0fe
@ -979,6 +979,16 @@ config TI_ADS7950
|
||||
To compile this driver as a module, choose M here: the
|
||||
module will be called ti-ads7950.
|
||||
|
||||
config TI_ADS8344
|
||||
tristate "Texas Instruments ADS8344"
|
||||
depends on SPI && OF
|
||||
help
|
||||
If you say yes here you get support for Texas Instruments ADS8344
|
||||
ADC chips
|
||||
|
||||
This driver can also be built as a module. If so, the module will be
|
||||
called ti-ads8344.
|
||||
|
||||
config TI_ADS8688
|
||||
tristate "Texas Instruments ADS8688"
|
||||
depends on SPI && OF
|
||||
|
||||
@ -88,6 +88,7 @@ obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
|
||||
obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o
|
||||
obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
|
||||
obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o
|
||||
obj-$(CONFIG_TI_ADS8344) += ti-ads8344.o
|
||||
obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
|
||||
obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o
|
||||
obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
|
||||
|
||||
204
drivers/iio/adc/ti-ads8344.c
Normal file
204
drivers/iio/adc/ti-ads8344.c
Normal file
@ -0,0 +1,204 @@
|
||||
// SPDX-License-Identifier: GPL-2.0+
|
||||
/*
|
||||
* ADS8344 16-bit 8-Channel ADC driver
|
||||
*
|
||||
* Author: Gregory CLEMENT <gregory.clement@bootlin.com>
|
||||
*
|
||||
* Datasheet: http://www.ti.com/lit/ds/symlink/ads8344.pdf
|
||||
*/
|
||||
|
||||
#include <linux/delay.h>
|
||||
#include <linux/iio/buffer.h>
|
||||
#include <linux/iio/iio.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/regulator/consumer.h>
|
||||
#include <linux/spi/spi.h>
|
||||
|
||||
#define ADS8344_START BIT(7)
|
||||
#define ADS8344_SINGLE_END BIT(2)
|
||||
#define ADS8344_CHANNEL(channel) ((channel) << 4)
|
||||
#define ADS8344_CLOCK_INTERNAL 0x2 /* PD1 = 1 and PD0 = 0 */
|
||||
|
||||
struct ads8344 {
|
||||
struct spi_device *spi;
|
||||
struct regulator *reg;
|
||||
/*
|
||||
* Lock protecting access to adc->tx_buff and rx_buff,
|
||||
* especially from concurrent read on sysfs file.
|
||||
*/
|
||||
struct mutex lock;
|
||||
|
||||
u8 tx_buf ____cacheline_aligned;
|
||||
u16 rx_buf;
|
||||
};
|
||||
|
||||
#define ADS8344_VOLTAGE_CHANNEL(chan, si) \
|
||||
{ \
|
||||
.type = IIO_VOLTAGE, \
|
||||
.indexed = 1, \
|
||||
.channel = chan, \
|
||||
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
|
||||
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
|
||||
}
|
||||
|
||||
#define ADS8344_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si) \
|
||||
{ \
|
||||
.type = IIO_VOLTAGE, \
|
||||
.indexed = 1, \
|
||||
.channel = (chan1), \
|
||||
.channel2 = (chan2), \
|
||||
.differential = 1, \
|
||||
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
|
||||
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
|
||||
}
|
||||
|
||||
static const struct iio_chan_spec ads8344_channels[] = {
|
||||
ADS8344_VOLTAGE_CHANNEL(0, 0),
|
||||
ADS8344_VOLTAGE_CHANNEL(1, 4),
|
||||
ADS8344_VOLTAGE_CHANNEL(2, 1),
|
||||
ADS8344_VOLTAGE_CHANNEL(3, 5),
|
||||
ADS8344_VOLTAGE_CHANNEL(4, 2),
|
||||
ADS8344_VOLTAGE_CHANNEL(5, 6),
|
||||
ADS8344_VOLTAGE_CHANNEL(6, 3),
|
||||
ADS8344_VOLTAGE_CHANNEL(7, 7),
|
||||
ADS8344_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
|
||||
ADS8344_VOLTAGE_CHANNEL_DIFF(2, 3, 9),
|
||||
ADS8344_VOLTAGE_CHANNEL_DIFF(4, 5, 10),
|
||||
ADS8344_VOLTAGE_CHANNEL_DIFF(6, 7, 11),
|
||||
ADS8344_VOLTAGE_CHANNEL_DIFF(1, 0, 12),
|
||||
ADS8344_VOLTAGE_CHANNEL_DIFF(3, 2, 13),
|
||||
ADS8344_VOLTAGE_CHANNEL_DIFF(5, 4, 14),
|
||||
ADS8344_VOLTAGE_CHANNEL_DIFF(7, 6, 15),
|
||||
};
|
||||
|
||||
static int ads8344_adc_conversion(struct ads8344 *adc, int channel,
|
||||
bool differential)
|
||||
{
|
||||
struct spi_device *spi = adc->spi;
|
||||
int ret;
|
||||
|
||||
adc->tx_buf = ADS8344_START;
|
||||
if (!differential)
|
||||
adc->tx_buf |= ADS8344_SINGLE_END;
|
||||
adc->tx_buf |= ADS8344_CHANNEL(channel);
|
||||
adc->tx_buf |= ADS8344_CLOCK_INTERNAL;
|
||||
|
||||
ret = spi_write(spi, &adc->tx_buf, 1);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
udelay(9);
|
||||
|
||||
ret = spi_read(spi, &adc->rx_buf, 2);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
return adc->rx_buf;
|
||||
}
|
||||
|
||||
static int ads8344_read_raw(struct iio_dev *iio,
|
||||
struct iio_chan_spec const *channel, int *value,
|
||||
int *shift, long mask)
|
||||
{
|
||||
struct ads8344 *adc = iio_priv(iio);
|
||||
|
||||
switch (mask) {
|
||||
case IIO_CHAN_INFO_RAW:
|
||||
mutex_lock(&adc->lock);
|
||||
*value = ads8344_adc_conversion(adc, channel->scan_index,
|
||||
channel->differential);
|
||||
mutex_unlock(&adc->lock);
|
||||
if (*value < 0)
|
||||
return *value;
|
||||
|
||||
return IIO_VAL_INT;
|
||||
case IIO_CHAN_INFO_SCALE:
|
||||
*value = regulator_get_voltage(adc->reg);
|
||||
if (*value < 0)
|
||||
return *value;
|
||||
|
||||
/* convert regulator output voltage to mV */
|
||||
*value /= 1000;
|
||||
*shift = 16;
|
||||
|
||||
return IIO_VAL_FRACTIONAL_LOG2;
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
}
|
||||
|
||||
static const struct iio_info ads8344_info = {
|
||||
.read_raw = ads8344_read_raw,
|
||||
};
|
||||
|
||||
static int ads8344_probe(struct spi_device *spi)
|
||||
{
|
||||
struct iio_dev *indio_dev;
|
||||
struct ads8344 *adc;
|
||||
int ret;
|
||||
|
||||
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
|
||||
if (!indio_dev)
|
||||
return -ENOMEM;
|
||||
|
||||
adc = iio_priv(indio_dev);
|
||||
adc->spi = spi;
|
||||
mutex_init(&adc->lock);
|
||||
|
||||
indio_dev->name = dev_name(&spi->dev);
|
||||
indio_dev->dev.parent = &spi->dev;
|
||||
indio_dev->dev.of_node = spi->dev.of_node;
|
||||
indio_dev->info = &ads8344_info;
|
||||
indio_dev->modes = INDIO_DIRECT_MODE;
|
||||
indio_dev->channels = ads8344_channels;
|
||||
indio_dev->num_channels = ARRAY_SIZE(ads8344_channels);
|
||||
|
||||
adc->reg = devm_regulator_get(&spi->dev, "vref");
|
||||
if (IS_ERR(adc->reg))
|
||||
return PTR_ERR(adc->reg);
|
||||
|
||||
ret = regulator_enable(adc->reg);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
spi_set_drvdata(spi, indio_dev);
|
||||
|
||||
ret = iio_device_register(indio_dev);
|
||||
if (ret) {
|
||||
regulator_disable(adc->reg);
|
||||
return ret;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ads8344_remove(struct spi_device *spi)
|
||||
{
|
||||
struct iio_dev *indio_dev = spi_get_drvdata(spi);
|
||||
struct ads8344 *adc = iio_priv(indio_dev);
|
||||
|
||||
iio_device_unregister(indio_dev);
|
||||
regulator_disable(adc->reg);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const struct of_device_id ads8344_of_match[] = {
|
||||
{ .compatible = "ti,ads8344", },
|
||||
{}
|
||||
};
|
||||
MODULE_DEVICE_TABLE(of, ads8344_of_match);
|
||||
|
||||
static struct spi_driver ads8344_driver = {
|
||||
.driver = {
|
||||
.name = "ads8344",
|
||||
.of_match_table = ads8344_of_match,
|
||||
},
|
||||
.probe = ads8344_probe,
|
||||
.remove = ads8344_remove,
|
||||
};
|
||||
module_spi_driver(ads8344_driver);
|
||||
|
||||
MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@bootlin.com>");
|
||||
MODULE_DESCRIPTION("ADS8344 driver");
|
||||
MODULE_LICENSE("GPL");
|
||||
Loading…
Reference in New Issue
Block a user