mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-22 00:40:03 +00:00
![Jonathan Cameron](/assets/img/avatar_default.png)
This prevents use of this driver with ACPI via PRP0001 and is an example of an anti pattern I'm trying to remove from IIO. Hence drop from this driver. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20200910173242.621168-24-jic23@kernel.org
206 lines
4.8 KiB
C
206 lines
4.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* ad2s1200.c simple support for the ADI Resolver to Digital Converters:
|
|
* AD2S1200/1205
|
|
*
|
|
* Copyright (c) 2018-2018 David Veenstra <davidjulianveenstra@gmail.com>
|
|
* Copyright (c) 2010-2010 Analog Devices Inc.
|
|
*/
|
|
|
|
#include <linux/bitops.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/device.h>
|
|
#include <linux/gpio/consumer.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mod_devicetable.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/spi/spi.h>
|
|
#include <linux/sysfs.h>
|
|
#include <linux/types.h>
|
|
|
|
#include <linux/iio/iio.h>
|
|
#include <linux/iio/sysfs.h>
|
|
|
|
#define DRV_NAME "ad2s1200"
|
|
|
|
/* input clock on serial interface */
|
|
#define AD2S1200_HZ 8192000
|
|
/* clock period in nano second */
|
|
#define AD2S1200_TSCLK (1000000000 / AD2S1200_HZ)
|
|
|
|
/**
|
|
* struct ad2s1200_state - driver instance specific data.
|
|
* @lock: protects both the GPIO pins and the rx buffer.
|
|
* @sdev: spi device.
|
|
* @sample: GPIO pin SAMPLE.
|
|
* @rdvel: GPIO pin RDVEL.
|
|
* @rx: buffer for spi transfers.
|
|
*/
|
|
struct ad2s1200_state {
|
|
struct mutex lock;
|
|
struct spi_device *sdev;
|
|
struct gpio_desc *sample;
|
|
struct gpio_desc *rdvel;
|
|
__be16 rx ____cacheline_aligned;
|
|
};
|
|
|
|
static int ad2s1200_read_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *chan,
|
|
int *val,
|
|
int *val2,
|
|
long m)
|
|
{
|
|
struct ad2s1200_state *st = iio_priv(indio_dev);
|
|
int ret;
|
|
|
|
switch (m) {
|
|
case IIO_CHAN_INFO_SCALE:
|
|
switch (chan->type) {
|
|
case IIO_ANGL:
|
|
/* 2 * Pi / (2^12 - 1) ~= 0.001534355 */
|
|
*val = 0;
|
|
*val2 = 1534355;
|
|
return IIO_VAL_INT_PLUS_NANO;
|
|
case IIO_ANGL_VEL:
|
|
/* 2 * Pi ~= 6.283185 */
|
|
*val = 6;
|
|
*val2 = 283185;
|
|
return IIO_VAL_INT_PLUS_MICRO;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
break;
|
|
case IIO_CHAN_INFO_RAW:
|
|
mutex_lock(&st->lock);
|
|
gpiod_set_value(st->sample, 0);
|
|
|
|
/* delay (6 * AD2S1200_TSCLK + 20) nano seconds */
|
|
udelay(1);
|
|
gpiod_set_value(st->sample, 1);
|
|
gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL));
|
|
|
|
ret = spi_read(st->sdev, &st->rx, 2);
|
|
if (ret < 0) {
|
|
mutex_unlock(&st->lock);
|
|
return ret;
|
|
}
|
|
|
|
switch (chan->type) {
|
|
case IIO_ANGL:
|
|
*val = be16_to_cpup(&st->rx) >> 4;
|
|
break;
|
|
case IIO_ANGL_VEL:
|
|
*val = sign_extend32(be16_to_cpup(&st->rx) >> 4, 11);
|
|
break;
|
|
default:
|
|
mutex_unlock(&st->lock);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* delay (2 * AD2S1200_TSCLK + 20) ns for sample pulse */
|
|
udelay(1);
|
|
mutex_unlock(&st->lock);
|
|
|
|
return IIO_VAL_INT;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static const struct iio_chan_spec ad2s1200_channels[] = {
|
|
{
|
|
.type = IIO_ANGL,
|
|
.indexed = 1,
|
|
.channel = 0,
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
|
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
|
|
}, {
|
|
.type = IIO_ANGL_VEL,
|
|
.indexed = 1,
|
|
.channel = 0,
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
|
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
|
|
}
|
|
};
|
|
|
|
static const struct iio_info ad2s1200_info = {
|
|
.read_raw = ad2s1200_read_raw,
|
|
};
|
|
|
|
static int ad2s1200_probe(struct spi_device *spi)
|
|
{
|
|
struct ad2s1200_state *st;
|
|
struct iio_dev *indio_dev;
|
|
int ret;
|
|
|
|
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
|
|
if (!indio_dev)
|
|
return -ENOMEM;
|
|
|
|
spi_set_drvdata(spi, indio_dev);
|
|
st = iio_priv(indio_dev);
|
|
mutex_init(&st->lock);
|
|
st->sdev = spi;
|
|
|
|
st->sample = devm_gpiod_get(&spi->dev, "adi,sample", GPIOD_OUT_LOW);
|
|
if (IS_ERR(st->sample)) {
|
|
dev_err(&spi->dev, "Failed to claim SAMPLE gpio: err=%ld\n",
|
|
PTR_ERR(st->sample));
|
|
return PTR_ERR(st->sample);
|
|
}
|
|
|
|
st->rdvel = devm_gpiod_get(&spi->dev, "adi,rdvel", GPIOD_OUT_LOW);
|
|
if (IS_ERR(st->rdvel)) {
|
|
dev_err(&spi->dev, "Failed to claim RDVEL gpio: err=%ld\n",
|
|
PTR_ERR(st->rdvel));
|
|
return PTR_ERR(st->rdvel);
|
|
}
|
|
|
|
indio_dev->info = &ad2s1200_info;
|
|
indio_dev->modes = INDIO_DIRECT_MODE;
|
|
indio_dev->channels = ad2s1200_channels;
|
|
indio_dev->num_channels = ARRAY_SIZE(ad2s1200_channels);
|
|
indio_dev->name = spi_get_device_id(spi)->name;
|
|
|
|
spi->max_speed_hz = AD2S1200_HZ;
|
|
spi->mode = SPI_MODE_3;
|
|
ret = spi_setup(spi);
|
|
|
|
if (ret < 0) {
|
|
dev_err(&spi->dev, "spi_setup failed!\n");
|
|
return ret;
|
|
}
|
|
|
|
return devm_iio_device_register(&spi->dev, indio_dev);
|
|
}
|
|
|
|
static const struct of_device_id ad2s1200_of_match[] = {
|
|
{ .compatible = "adi,ad2s1200", },
|
|
{ .compatible = "adi,ad2s1205", },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, ad2s1200_of_match);
|
|
|
|
static const struct spi_device_id ad2s1200_id[] = {
|
|
{ "ad2s1200" },
|
|
{ "ad2s1205" },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(spi, ad2s1200_id);
|
|
|
|
static struct spi_driver ad2s1200_driver = {
|
|
.driver = {
|
|
.name = DRV_NAME,
|
|
.of_match_table = ad2s1200_of_match,
|
|
},
|
|
.probe = ad2s1200_probe,
|
|
.id_table = ad2s1200_id,
|
|
};
|
|
module_spi_driver(ad2s1200_driver);
|
|
|
|
MODULE_AUTHOR("David Veenstra <davidjulianveenstra@gmail.com>");
|
|
MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
|
|
MODULE_DESCRIPTION("Analog Devices AD2S1200/1205 Resolver to Digital SPI driver");
|
|
MODULE_LICENSE("GPL v2");
|