blob: f94b69f9c2882025b62d60375556a8a98f1170ba [file] [log] [blame]
/*
* ti-adc161s626.c - Texas Instruments ADC161S626 1-channel differential ADC
*
* ADC Devices Supported:
* adc141s626 - 14-bit ADC
* adc161s626 - 16-bit ADC
*
* Copyright (C) 2016 Matt Ranostay <mranostay@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/spi/spi.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>
#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),
.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),
.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;
u8 read_size;
u8 shift;
u8 buffer[16] ____cacheline_aligned;
};
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: {
__be16 buf;
ret = spi_read(data->spi, (void *) &buf, 2);
if (ret)
return ret;
*val = be16_to_cpu(buf);
break;
}
case 3: {
__be32 buf;
ret = spi_read(data->spi, (void *) &buf, 3);
if (ret)
return ret;
*val = be32_to_cpu(buf) >> 8;
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);
int ret;
ret = ti_adc_read_measurement(data, &indio_dev->channels[0],
(int *) &data->buffer);
if (!ret)
iio_push_to_buffers_with_timestamp(indio_dev,
data->buffer,
iio_get_time_ns(indio_dev));
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;
if (mask != IIO_CHAN_INFO_RAW)
return -EINVAL;
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
ret = ti_adc_read_measurement(data, chan, val);
iio_device_release_direct_mode(indio_dev);
if (!ret)
return IIO_VAL_INT;
return 0;
}
static const struct iio_info ti_adc_info = {
.driver_module = THIS_MODULE,
.read_raw = ti_adc_read_raw,
};
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->dev.parent = &spi->dev;
indio_dev->dev.of_node = spi->dev.of_node;
indio_dev->name = TI_ADC_DRV_NAME;
indio_dev->modes = INDIO_DIRECT_MODE;
spi_set_drvdata(spi, indio_dev);
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;
}
ret = iio_triggered_buffer_setup(indio_dev, NULL,
ti_adc_trigger_handler, NULL);
if (ret)
return ret;
ret = iio_device_register(indio_dev);
if (ret)
goto error_unreg_buffer;
return 0;
error_unreg_buffer:
iio_triggered_buffer_cleanup(indio_dev);
return ret;
}
static int ti_adc_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
return 0;
}
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 = of_match_ptr(ti_adc_dt_ids),
},
.probe = ti_adc_probe,
.remove = ti_adc_remove,
.id_table = ti_adc_id,
};
module_spi_driver(ti_adc_driver);
MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
MODULE_DESCRIPTION("Texas Instruments ADC1x1S 1-channel differential ADC");
MODULE_LICENSE("GPL");