[deliverable/linux.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 = IIO_CHAN_INFO_RAW_SEPARATE_BIT,
};

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

	indio_dev = iio_allocate_device(sizeof(*st));
	if (indio_dev == NULL) {
		ret = -ENOMEM;
		goto error_ret;
	}
	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 = iio_device_register(indio_dev);
	if (ret)
		goto error_free_dev;

	/* 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;

error_free_dev:
	iio_free_device(indio_dev);
error_ret:
	return ret;
}

static int __devexit ad2s90_remove(struct spi_device *spi)
{
	iio_device_unregister(spi_get_drvdata(spi));
	iio_free_device(spi_get_drvdata(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",
		.owner = THIS_MODULE,
	},
	.probe = ad2s90_probe,
	.remove = __devexit_p(ad2s90_remove),
	.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 = {
199d847a	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,
62465770	58	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT,
199d847a JC	59	};
199d847a JC	60
f46d9f15 GY	61	static int __devinit ad2s90_probe(struct spi_device *spi)
f46d9f15 GY	62	{
58f08b0a	63	struct iio_dev *indio_dev;
f46d9f15 GY	64	struct ad2s90_state *st;
	65	int ret = 0;
	66
58f08b0a JC	67	indio_dev = iio_allocate_device(sizeof(*st));
58f08b0a JC	68	if (indio_dev == NULL) {
f46d9f15 GY	69	ret = -ENOMEM;
	70	goto error_ret;
	71	}
58f08b0a JC	72	st = iio_priv(indio_dev);
58f08b0a JC	73	spi_set_drvdata(spi, indio_dev);
f46d9f15 GY	74
	75	mutex_init(&st->lock);
	76	st->sdev = spi;
58f08b0a JC	77	indio_dev->dev.parent = &spi->dev;
	78	indio_dev->info = &ad2s90_info;
	79	indio_dev->modes = INDIO_DIRECT_MODE;
199d847a JC	80	indio_dev->channels = &ad2s90_chan;
199d847a JC	81	indio_dev->num_channels = 1;
19147f5b	82	indio_dev->name = spi_get_device_id(spi)->name;
f46d9f15	83
72a86ccd	84	ret = iio_device_register(indio_dev);
f46d9f15 GY	85	if (ret)
	86	goto error_free_dev;
	87
	88	/* need 600ns between CS and the first falling edge of SCLK */
	89	spi->max_speed_hz = 830000;
	90	spi->mode = SPI_MODE_3;
	91	spi_setup(spi);
	92
	93	return 0;
	94
	95	error_free_dev:
72a86ccd	96	iio_free_device(indio_dev);
f46d9f15 GY	97	error_ret:
	98	return ret;
	99	}
	100
	101	static int __devexit ad2s90_remove(struct spi_device *spi)
	102	{
58f08b0a	103	iio_device_unregister(spi_get_drvdata(spi));
d2fffd6c	104	iio_free_device(spi_get_drvdata(spi));
f46d9f15 GY	105
	106	return 0;
	107	}
	108
19147f5b JC	109	static const struct spi_device_id ad2s90_id[] = {
	110	{ "ad2s90" },
	111	{}
	112	};
55e4390c	113	MODULE_DEVICE_TABLE(spi, ad2s90_id);
19147f5b	114
f46d9f15 GY	115	static struct spi_driver ad2s90_driver = {
f46d9f15 GY	116	.driver = {
19147f5b	117	.name = "ad2s90",
f46d9f15 GY	118	.owner = THIS_MODULE,
	119	},
	120	.probe = ad2s90_probe,
	121	.remove = __devexit_p(ad2s90_remove),
19147f5b	122	.id_table = ad2s90_id,
f46d9f15	123	};
ae6ae6fe	124	module_spi_driver(ad2s90_driver);
f46d9f15 GY	125
	126	MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
	127	MODULE_DESCRIPTION("Analog Devices AD2S90 Resolver to Digital SPI driver");
	128	MODULE_LICENSE("GPL v2");