#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/spi/spi.h>
#include <linux/unaligned.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/regulator/consumer.h>
#define TI_ADC_DRV_NAME "ti-adc161s626"
enum {
TI_ADC141S626,
TI_ADC161S626,
};
static const struct iio_chan_spec ti_adc141s626_channels[] = {
{
.type = IIO_VOLTAGE,
.channel = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET),
.scan_index = 0,
.scan_type = {
.sign = 's',
.realbits = 14,
.storagebits = 16,
},
},
IIO_CHAN_SOFT_TIMESTAMP(1),
};
static const struct iio_chan_spec ti_adc161s626_channels[] = {
{
.type = IIO_VOLTAGE,
.channel = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET),
.scan_index = 0,
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
},
},
IIO_CHAN_SOFT_TIMESTAMP(1),
};
struct ti_adc_data {
struct iio_dev *indio_dev;
struct spi_device *spi;
struct regulator *ref;
u8 read_size;
u8 shift;
u8 buf[3] __aligned(IIO_DMA_MINALIGN);
};
static int ti_adc_read_measurement(struct ti_adc_data *data,
struct iio_chan_spec const *chan, int *val)
{
int ret;
switch (data->read_size) {
case 2:
ret = spi_read(data->spi, data->buf, 2);
if (ret)
return ret;
*val = get_unaligned_be16(data->buf);
break;
case 3:
ret = spi_read(data->spi, data->buf, 3);
if (ret)
return ret;
*val = get_unaligned_be24(data->buf);
break;
default:
return -EINVAL;
}
*val = sign_extend32(*val >> data->shift, chan->scan_type.realbits - 1);
return 0;
}
static irqreturn_t ti_adc_trigger_handler(int irq, void *private)
{
struct iio_poll_func *pf = private;
struct iio_dev *indio_dev = pf->indio_dev;
struct ti_adc_data *data = iio_priv(indio_dev);
struct {
s16 data;
aligned_s64 timestamp;
} scan = { };
int ret, val;
ret = ti_adc_read_measurement(data, &indio_dev->channels[0], &val);
if (ret)
goto exit_notify_done;
scan.data = val;
iio_push_to_buffers_with_timestamp(indio_dev, &scan, iio_get_time_ns(indio_dev));
exit_notify_done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int ti_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct ti_adc_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (!iio_device_claim_direct(indio_dev))
return -EBUSY;
ret = ti_adc_read_measurement(data, chan, val);
iio_device_release_direct(indio_dev);
if (ret)
return ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
ret = regulator_get_voltage(data->ref);
if (ret < 0)
return ret;
*val = ret / 1000;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
*val = 1 << (chan->scan_type.realbits - 1);
return IIO_VAL_INT;
}
return 0;
}
static const struct iio_info ti_adc_info = {
.read_raw = ti_adc_read_raw,
};
static void ti_adc_reg_disable(void *reg)
{
regulator_disable(reg);
}
static int ti_adc_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
struct ti_adc_data *data;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
indio_dev->info = &ti_adc_info;
indio_dev->name = TI_ADC_DRV_NAME;
indio_dev->modes = INDIO_DIRECT_MODE;
data = iio_priv(indio_dev);
data->spi = spi;
switch (spi_get_device_id(spi)->driver_data) {
case TI_ADC141S626:
indio_dev->channels = ti_adc141s626_channels;
indio_dev->num_channels = ARRAY_SIZE(ti_adc141s626_channels);
data->shift = 0;
data->read_size = 2;
break;
case TI_ADC161S626:
indio_dev->channels = ti_adc161s626_channels;
indio_dev->num_channels = ARRAY_SIZE(ti_adc161s626_channels);
data->shift = 6;
data->read_size = 3;
break;
}
data->ref = devm_regulator_get(&spi->dev, "vdda");
if (IS_ERR(data->ref))
return PTR_ERR(data->ref);
ret = regulator_enable(data->ref);
if (ret < 0)
return ret;
ret = devm_add_action_or_reset(&spi->dev, ti_adc_reg_disable,
data->ref);
if (ret)
return ret;
ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,
ti_adc_trigger_handler, NULL);
if (ret)
return ret;
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct of_device_id ti_adc_dt_ids[] = {
{ .compatible = "ti,adc141s626", },
{ .compatible = "ti,adc161s626", },
{ }
};
MODULE_DEVICE_TABLE(of, ti_adc_dt_ids);
static const struct spi_device_id ti_adc_id[] = {
{ "adc141s626", TI_ADC141S626 },
{ "adc161s626", TI_ADC161S626 },
{ }
};
MODULE_DEVICE_TABLE(spi, ti_adc_id);
static struct spi_driver ti_adc_driver = {
.driver = {
.name = TI_ADC_DRV_NAME,
.of_match_table = ti_adc_dt_ids,
},
.probe = ti_adc_probe,
.id_table = ti_adc_id,
};
module_spi_driver(ti_adc_driver);
MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
MODULE_DESCRIPTION("Texas Instruments ADC1x1S 1-channel differential ADC");
MODULE_LICENSE("GPL");
