[mirror_ubuntu-bionic-kernel.git] / drivers / staging / iio / resolver / ad2s90.c

/*
 * ad2s90.c simple support for the ADI Resolver to Digital Converters: AD2S90
 *
 * 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/module.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

struct ad2s90_state {
	struct mutex lock;
	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);

	mutex_lock(&st->lock);
	ret = spi_read(st->sdev, st->rx, 2);
	if (ret)
		goto error_ret;
	*val = (((u16)(st->rx[0])) << 4) | ((st->rx[1] & 0xF0) >> 4);

error_ret:
	mutex_unlock(&st->lock);

	return IIO_VAL_INT;
}

static const struct iio_info ad2s90_info = {
	.read_raw = ad2s90_read_raw,
	.driver_module = THIS_MODULE,
};

static const struct iio_chan_spec ad2s90_chan = {
	.type = IIO_ANGL,
	.indexed = 1,
	.channel = 0,
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
};

static int ad2s90_probe(struct spi_device *spi)
{
	struct iio_dev *indio_dev;
	struct ad2s90_state *st;
	int ret = 0;

	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;

	ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
	if (ret)
		return ret;

	/* need 600ns between CS and the first falling edge of SCLK */
	spi->max_speed_hz = 830000;
	spi->mode = SPI_MODE_3;
	spi_setup(spi);

	return 0;
}

static const struct spi_device_id ad2s90_id[] = {
	{ "ad2s90" },
	{}
};
MODULE_DEVICE_TABLE(spi, ad2s90_id);

static struct spi_driver ad2s90_driver = {
	.driver = {
		.name = "ad2s90",
	},
	.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");
Commit	Line	Data
f46d9f15 GY	1	/*
	2	* ad2s90.c simple support for the ADI Resolver to Digital Converters: AD2S90
	3	*
	4	* Copyright (c) 2010-2010 Analog Devices Inc.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	*/
	11	#include <linux/types.h>
	12	#include <linux/mutex.h>
	13	#include <linux/device.h>
	14	#include <linux/spi/spi.h>
	15	#include <linux/slab.h>
	16	#include <linux/sysfs.h>
99c97852	17	#include <linux/module.h>
f46d9f15	18
06458e27 JC	19	#include <linux/iio/iio.h>
06458e27 JC	20	#include <linux/iio/sysfs.h>
f46d9f15	21
f46d9f15 GY	22	struct ad2s90_state {
f46d9f15 GY	23	struct mutex lock;
f46d9f15	24	struct spi_device *sdev;
58f08b0a	25	u8 rx[2] ____cacheline_aligned;
f46d9f15 GY	26	};
f46d9f15 GY	27
199d847a JC	28	static int ad2s90_read_raw(struct iio_dev *indio_dev,
	29	struct iio_chan_spec const *chan,
	30	int *val,
	31	int *val2,
	32	long m)
f46d9f15	33	{
f46d9f15	34	int ret;
199d847a	35	struct ad2s90_state *st = iio_priv(indio_dev);
f46d9f15	36
f46d9f15	37	mutex_lock(&st->lock);
58f08b0a	38	ret = spi_read(st->sdev, st->rx, 2);
f46d9f15 GY	39	if (ret)
f46d9f15 GY	40	goto error_ret;
199d847a JC	41	*val = (((u16)(st->rx[0])) << 4) \| ((st->rx[1] & 0xF0) >> 4);
199d847a JC	42
f46d9f15 GY	43	error_ret:
	44	mutex_unlock(&st->lock);
	45
199d847a	46	return IIO_VAL_INT;
f46d9f15 GY	47	}
f46d9f15 GY	48
6fe8135f	49	static const struct iio_info ad2s90_info = {
67cba026	50	.read_raw = ad2s90_read_raw,
6fe8135f JC	51	.driver_module = THIS_MODULE,
	52	};
	53
199d847a JC	54	static const struct iio_chan_spec ad2s90_chan = {
	55	.type = IIO_ANGL,
	56	.indexed = 1,
	57	.channel = 0,
3589ba99	58	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
199d847a JC	59	};
199d847a JC	60
4ae1c61f	61	static int ad2s90_probe(struct spi_device *spi)
f46d9f15	62	{
58f08b0a	63	struct iio_dev *indio_dev;
f46d9f15 GY	64	struct ad2s90_state *st;
	65	int ret = 0;
	66
6bba7983 SK	67	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
	68	if (!indio_dev)
	69	return -ENOMEM;
58f08b0a JC	70	st = iio_priv(indio_dev);
58f08b0a JC	71	spi_set_drvdata(spi, indio_dev);
f46d9f15 GY	72
	73	mutex_init(&st->lock);
	74	st->sdev = spi;
58f08b0a JC	75	indio_dev->dev.parent = &spi->dev;
	76	indio_dev->info = &ad2s90_info;
	77	indio_dev->modes = INDIO_DIRECT_MODE;
199d847a JC	78	indio_dev->channels = &ad2s90_chan;
199d847a JC	79	indio_dev->num_channels = 1;
19147f5b	80	indio_dev->name = spi_get_device_id(spi)->name;
f46d9f15	81
877cdf91	82	ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
f46d9f15	83	if (ret)
6bba7983	84	return ret;
f46d9f15 GY	85
	86	/* need 600ns between CS and the first falling edge of SCLK */
	87	spi->max_speed_hz = 830000;
	88	spi->mode = SPI_MODE_3;
	89	spi_setup(spi);
	90
	91	return 0;
f46d9f15 GY	92	}
f46d9f15 GY	93
19147f5b JC	94	static const struct spi_device_id ad2s90_id[] = {
	95	{ "ad2s90" },
	96	{}
	97	};
55e4390c	98	MODULE_DEVICE_TABLE(spi, ad2s90_id);
19147f5b	99
f46d9f15 GY	100	static struct spi_driver ad2s90_driver = {
f46d9f15 GY	101	.driver = {
19147f5b	102	.name = "ad2s90",
f46d9f15 GY	103	},
f46d9f15 GY	104	.probe = ad2s90_probe,
19147f5b	105	.id_table = ad2s90_id,
f46d9f15	106	};
ae6ae6fe	107	module_spi_driver(ad2s90_driver);
f46d9f15 GY	108
	109	MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
	110	MODULE_DESCRIPTION("Analog Devices AD2S90 Resolver to Digital SPI driver");
	111	MODULE_LICENSE("GPL v2");