167 lines
3.9 KiB
C
167 lines
3.9 KiB
C
|
/*
|
||
|
* ad2s1200.c simple support for the ADI Resolver to Digital Converters:
|
||
|
* AD2S1200/1205
|
||
|
*
|
||
|
* Copyright (c) 2010-2010 Analog Devices Inc.
|
||
|
*
|
||
|
* This program is free software; you can redistribute it and/or modify
|
||
|
* it under the terms of the GNU General Public License version 2 as
|
||
|
* published by the Free Software Foundation.
|
||
|
*
|
||
|
*/
|
||
|
#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/delay.h>
|
||
|
#include <linux/gpio.h>
|
||
|
#include <linux/module.h>
|
||
|
#include <linux/bitops.h>
|
||
|
|
||
|
#include <linux/iio/iio.h>
|
||
|
#include <linux/iio/sysfs.h>
|
||
|
|
||
|
#define DRV_NAME "ad2s1200"
|
||
|
|
||
|
/* input pin sample and rdvel is controlled by driver */
|
||
|
#define AD2S1200_PN 2
|
||
|
|
||
|
/* input clock on serial interface */
|
||
|
#define AD2S1200_HZ 8192000
|
||
|
/* clock period in nano second */
|
||
|
#define AD2S1200_TSCLK (1000000000 / AD2S1200_HZ)
|
||
|
|
||
|
struct ad2s1200_state {
|
||
|
struct mutex lock;
|
||
|
struct spi_device *sdev;
|
||
|
int sample;
|
||
|
int rdvel;
|
||
|
u8 rx[2] ____cacheline_aligned;
|
||
|
};
|
||
|
|
||
|
static int ad2s1200_read_raw(struct iio_dev *indio_dev,
|
||
|
struct iio_chan_spec const *chan,
|
||
|
int *val,
|
||
|
int *val2,
|
||
|
long m)
|
||
|
{
|
||
|
int ret = 0;
|
||
|
s16 vel;
|
||
|
struct ad2s1200_state *st = iio_priv(indio_dev);
|
||
|
|
||
|
mutex_lock(&st->lock);
|
||
|
gpio_set_value(st->sample, 0);
|
||
|
/* delay (6 * AD2S1200_TSCLK + 20) nano seconds */
|
||
|
udelay(1);
|
||
|
gpio_set_value(st->sample, 1);
|
||
|
gpio_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 = (((u16)(st->rx[0])) << 4) | ((st->rx[1] & 0xF0) >> 4);
|
||
|
break;
|
||
|
case IIO_ANGL_VEL:
|
||
|
vel = (((s16)(st->rx[0])) << 4) | ((st->rx[1] & 0xF0) >> 4);
|
||
|
vel = sign_extend32(vel, 11);
|
||
|
*val = vel;
|
||
|
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;
|
||
|
}
|
||
|
|
||
|
static const struct iio_chan_spec ad2s1200_channels[] = {
|
||
|
{
|
||
|
.type = IIO_ANGL,
|
||
|
.indexed = 1,
|
||
|
.channel = 0,
|
||
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
|
||
|
}, {
|
||
|
.type = IIO_ANGL_VEL,
|
||
|
.indexed = 1,
|
||
|
.channel = 0,
|
||
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
|
||
|
}
|
||
|
};
|
||
|
|
||
|
static const struct iio_info ad2s1200_info = {
|
||
|
.read_raw = ad2s1200_read_raw,
|
||
|
.driver_module = THIS_MODULE,
|
||
|
};
|
||
|
|
||
|
static int ad2s1200_probe(struct spi_device *spi)
|
||
|
{
|
||
|
struct ad2s1200_state *st;
|
||
|
struct iio_dev *indio_dev;
|
||
|
int pn, ret = 0;
|
||
|
unsigned short *pins = spi->dev.platform_data;
|
||
|
|
||
|
for (pn = 0; pn < AD2S1200_PN; pn++) {
|
||
|
ret = devm_gpio_request_one(&spi->dev, pins[pn], GPIOF_DIR_OUT,
|
||
|
DRV_NAME);
|
||
|
if (ret) {
|
||
|
dev_err(&spi->dev, "request gpio pin %d failed\n",
|
||
|
pins[pn]);
|
||
|
return 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 = pins[0];
|
||
|
st->rdvel = pins[1];
|
||
|
|
||
|
indio_dev->dev.parent = &spi->dev;
|
||
|
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;
|
||
|
|
||
|
ret = devm_iio_device_register(&spi->dev, indio_dev);
|
||
|
if (ret)
|
||
|
return ret;
|
||
|
|
||
|
spi->max_speed_hz = AD2S1200_HZ;
|
||
|
spi->mode = SPI_MODE_3;
|
||
|
spi_setup(spi);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
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,
|
||
|
},
|
||
|
.probe = ad2s1200_probe,
|
||
|
.id_table = ad2s1200_id,
|
||
|
};
|
||
|
module_spi_driver(ad2s1200_driver);
|
||
|
|
||
|
MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
|
||
|
MODULE_DESCRIPTION("Analog Devices AD2S1200/1205 Resolver to Digital SPI driver");
|
||
|
MODULE_LICENSE("GPL v2");
|