Orange Pi5 kernel

// 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->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");