mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-24 05:04:00 +08:00
9564c7a492
Move ad2s90 resolver driver out of staging to the main tree. Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Victor Colombo <victorcolombo@gmail.com> Acked-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
132 lines
3.0 KiB
C
132 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* ad2s90.c simple support for the ADI Resolver to Digital Converters: AD2S90
|
|
*
|
|
* Copyright (c) 2010-2010 Analog Devices Inc.
|
|
*/
|
|
#include <linux/types.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/device.h>
|
|
#include <linux/spi/spi.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/sysfs.h>
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/iio/iio.h>
|
|
#include <linux/iio/sysfs.h>
|
|
|
|
/*
|
|
* Although chip's max frequency is 2Mhz, it needs 600ns between CS and the
|
|
* first falling edge of SCLK, so frequency should be at most 1 / (2 * 6e-7)
|
|
*/
|
|
#define AD2S90_MAX_SPI_FREQ_HZ 830000
|
|
|
|
struct ad2s90_state {
|
|
struct mutex lock; /* lock to protect rx buffer */
|
|
struct spi_device *sdev;
|
|
u8 rx[2] ____cacheline_aligned;
|
|
};
|
|
|
|
static int ad2s90_read_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *chan,
|
|
int *val,
|
|
int *val2,
|
|
long m)
|
|
{
|
|
int ret;
|
|
struct ad2s90_state *st = iio_priv(indio_dev);
|
|
|
|
if (chan->type != IIO_ANGL)
|
|
return -EINVAL;
|
|
|
|
switch (m) {
|
|
case IIO_CHAN_INFO_SCALE:
|
|
/* 2 * Pi / 2^12 */
|
|
*val = 6283; /* mV */
|
|
*val2 = 12;
|
|
return IIO_VAL_FRACTIONAL_LOG2;
|
|
case IIO_CHAN_INFO_RAW:
|
|
mutex_lock(&st->lock);
|
|
ret = spi_read(st->sdev, st->rx, 2);
|
|
if (ret < 0) {
|
|
mutex_unlock(&st->lock);
|
|
return ret;
|
|
}
|
|
*val = (((u16)(st->rx[0])) << 4) | ((st->rx[1] & 0xF0) >> 4);
|
|
|
|
mutex_unlock(&st->lock);
|
|
|
|
return IIO_VAL_INT;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static const struct iio_info ad2s90_info = {
|
|
.read_raw = ad2s90_read_raw,
|
|
};
|
|
|
|
static const struct iio_chan_spec ad2s90_chan = {
|
|
.type = IIO_ANGL,
|
|
.indexed = 1,
|
|
.channel = 0,
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
|
|
};
|
|
|
|
static int ad2s90_probe(struct spi_device *spi)
|
|
{
|
|
struct iio_dev *indio_dev;
|
|
struct ad2s90_state *st;
|
|
|
|
if (spi->max_speed_hz > AD2S90_MAX_SPI_FREQ_HZ) {
|
|
dev_err(&spi->dev, "SPI CLK, %d Hz exceeds %d Hz\n",
|
|
spi->max_speed_hz, AD2S90_MAX_SPI_FREQ_HZ);
|
|
return -EINVAL;
|
|
}
|
|
|
|
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
|
|
if (!indio_dev)
|
|
return -ENOMEM;
|
|
st = iio_priv(indio_dev);
|
|
spi_set_drvdata(spi, indio_dev);
|
|
|
|
mutex_init(&st->lock);
|
|
st->sdev = spi;
|
|
indio_dev->dev.parent = &spi->dev;
|
|
indio_dev->info = &ad2s90_info;
|
|
indio_dev->modes = INDIO_DIRECT_MODE;
|
|
indio_dev->channels = &ad2s90_chan;
|
|
indio_dev->num_channels = 1;
|
|
indio_dev->name = spi_get_device_id(spi)->name;
|
|
|
|
return devm_iio_device_register(indio_dev->dev.parent, indio_dev);
|
|
}
|
|
|
|
static const struct of_device_id ad2s90_of_match[] = {
|
|
{ .compatible = "adi,ad2s90", },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(of, ad2s90_of_match);
|
|
|
|
static const struct spi_device_id ad2s90_id[] = {
|
|
{ "ad2s90" },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(spi, ad2s90_id);
|
|
|
|
static struct spi_driver ad2s90_driver = {
|
|
.driver = {
|
|
.name = "ad2s90",
|
|
.of_match_table = ad2s90_of_match,
|
|
},
|
|
.probe = ad2s90_probe,
|
|
.id_table = ad2s90_id,
|
|
};
|
|
module_spi_driver(ad2s90_driver);
|
|
|
|
MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
|
|
MODULE_DESCRIPTION("Analog Devices AD2S90 Resolver to Digital SPI driver");
|
|
MODULE_LICENSE("GPL v2");
|