[linux-2.6-block.git] / drivers / staging / iio / accel / kxsd9.c

/*
 * kxsd9.c	simple support for the Kionix KXSD9 3D
 *		accelerometer.
 *
 * Copyright (c) 2008-2009 Jonathan Cameron <jic23@cam.ac.uk>
 *
 * 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.
 *
 * The i2c interface is very similar, so shouldn't be a problem once
 * I have a suitable wire made up.
 *
 * TODO:	Support the motion detector
 *		Uses register address incrementing so could have a
 *		heavily optimized ring buffer access function.
 */

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include <linux/module.h>

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

#define KXSD9_REG_X		0x00
#define KXSD9_REG_Y		0x02
#define KXSD9_REG_Z		0x04
#define KXSD9_REG_AUX		0x06
#define KXSD9_REG_RESET		0x0a
#define KXSD9_REG_CTRL_C	0x0c

#define KXSD9_FS_MASK		0x03

#define KXSD9_REG_CTRL_B	0x0d
#define KXSD9_REG_CTRL_A	0x0e

#define KXSD9_READ(a) (0x80 | (a))
#define KXSD9_WRITE(a) (a)

#define KXSD9_STATE_RX_SIZE 2
#define KXSD9_STATE_TX_SIZE 2
/**
 * struct kxsd9_state - device related storage
 * @buf_lock:	protect the rx and tx buffers.
 * @us:		spi device
 * @rx:		single rx buffer storage
 * @tx:		single tx buffer storage
 **/
struct kxsd9_state {
	struct mutex buf_lock;
	struct spi_device *us;
	u8 rx[KXSD9_STATE_RX_SIZE] ____cacheline_aligned;
	u8 tx[KXSD9_STATE_TX_SIZE];
};

#define KXSD9_SCALE_2G "0.011978"
#define KXSD9_SCALE_4G "0.023927"
#define KXSD9_SCALE_6G "0.035934"
#define KXSD9_SCALE_8G "0.047853"

/* reverse order */
static const int kxsd9_micro_scales[4] = { 47853, 35934, 23927, 11978 };

static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro)
{
	int ret, i;
	struct kxsd9_state *st = iio_priv(indio_dev);
	bool foundit = false;

	for (i = 0; i < 4; i++)
		if (micro == kxsd9_micro_scales[i]) {
			foundit = true;
			break;
		}
	if (!foundit)
		return -EINVAL;

	mutex_lock(&st->buf_lock);
	ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
	if (ret)
		goto error_ret;
	st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C);
	st->tx[1] = (ret & ~KXSD9_FS_MASK) | i;

	ret = spi_write(st->us, st->tx, 2);
error_ret:
	mutex_unlock(&st->buf_lock);
	return ret;
}

static int kxsd9_read(struct iio_dev *indio_dev, u8 address)
{
	struct spi_message msg;
	int ret;
	struct kxsd9_state *st = iio_priv(indio_dev);
	struct spi_transfer xfers[] = {
		{
			.bits_per_word = 8,
			.len = 1,
			.delay_usecs = 200,
			.tx_buf = st->tx,
		}, {
			.bits_per_word = 8,
			.len = 2,
			.rx_buf = st->rx,
		},
	};

	mutex_lock(&st->buf_lock);
	st->tx[0] = KXSD9_READ(address);
	spi_message_init(&msg);
	spi_message_add_tail(&xfers[0], &msg);
	spi_message_add_tail(&xfers[1], &msg);
	ret = spi_sync(st->us, &msg);
	if (ret)
		return ret;
	return (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
}

static IIO_CONST_ATTR(accel_scale_available,
		KXSD9_SCALE_2G " "
		KXSD9_SCALE_4G " "
		KXSD9_SCALE_6G " "
		KXSD9_SCALE_8G);

static struct attribute *kxsd9_attributes[] = {
	&iio_const_attr_accel_scale_available.dev_attr.attr,
	NULL,
};

static int kxsd9_write_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int val,
			   int val2,
			   long mask)
{
	int ret = -EINVAL;

	if (mask == IIO_CHAN_INFO_SCALE) {
		/* Check no integer component */
		if (val)
			return -EINVAL;
		ret = kxsd9_write_scale(indio_dev, val2);
	}

	return ret;
}

static int kxsd9_read_raw(struct iio_dev *indio_dev,
			  struct iio_chan_spec const *chan,
			  int *val, int *val2, long mask)
{
	int ret = -EINVAL;
	struct kxsd9_state *st = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = kxsd9_read(indio_dev, chan->address);
		if (ret < 0)
			goto error_ret;
		*val = ret;
		break;
	case IIO_CHAN_INFO_SCALE:
		ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
		if (ret)
			goto error_ret;
		*val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
		ret = IIO_VAL_INT_PLUS_MICRO;
		break;
	};

error_ret:
	return ret;
};
#define KXSD9_ACCEL_CHAN(axis)						\
	{								\
		.type = IIO_ACCEL,					\
		.modified = 1,						\
		.channel2 = IIO_MOD_##axis,				\
		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |		\
			IIO_CHAN_INFO_SCALE_SHARED_BIT,			\
		.address = KXSD9_REG_##axis,				\
	}

static const struct iio_chan_spec kxsd9_channels[] = {
	KXSD9_ACCEL_CHAN(X), KXSD9_ACCEL_CHAN(Y), KXSD9_ACCEL_CHAN(Z),
	{
		.type = IIO_VOLTAGE,
		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT,
		.indexed = 1,
		.address = KXSD9_REG_AUX,
	}
};

static const struct attribute_group kxsd9_attribute_group = {
	.attrs = kxsd9_attributes,
};

static int __devinit kxsd9_power_up(struct kxsd9_state *st)
{
	int ret;

	st->tx[0] = 0x0d;
	st->tx[1] = 0x40;
	ret = spi_write(st->us, st->tx, 2);
	if (ret)
		return ret;

	st->tx[0] = 0x0c;
	st->tx[1] = 0x9b;
	return spi_write(st->us, st->tx, 2);
};

static const struct iio_info kxsd9_info = {
	.read_raw = &kxsd9_read_raw,
	.write_raw = &kxsd9_write_raw,
	.attrs = &kxsd9_attribute_group,
	.driver_module = THIS_MODULE,
};

static int __devinit kxsd9_probe(struct spi_device *spi)
{
	struct iio_dev *indio_dev;
	struct kxsd9_state *st;
	int ret = 0;

	indio_dev = iio_device_alloc(sizeof(*st));
	if (indio_dev == NULL) {
		ret = -ENOMEM;
		goto error_ret;
	}
	st = iio_priv(indio_dev);
	spi_set_drvdata(spi, indio_dev);

	st->us = spi;
	mutex_init(&st->buf_lock);
	indio_dev->channels = kxsd9_channels;
	indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);
	indio_dev->name = spi_get_device_id(spi)->name;
	indio_dev->dev.parent = &spi->dev;
	indio_dev->info = &kxsd9_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = iio_device_register(indio_dev);
	if (ret)
		goto error_free_dev;

	spi->mode = SPI_MODE_0;
	spi_setup(spi);
	kxsd9_power_up(st);

	return 0;

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

static int __devexit kxsd9_remove(struct spi_device *spi)
{
	iio_device_unregister(spi_get_drvdata(spi));
	iio_device_free(spi_get_drvdata(spi));

	return 0;
}

static const struct spi_device_id kxsd9_id[] = {
	{"kxsd9", 0},
	{ },
};
MODULE_DEVICE_TABLE(spi, kxsd9_id);

static struct spi_driver kxsd9_driver = {
	.driver = {
		.name = "kxsd9",
		.owner = THIS_MODULE,
	},
	.probe = kxsd9_probe,
	.remove = __devexit_p(kxsd9_remove),
	.id_table = kxsd9_id,
};
module_spi_driver(kxsd9_driver);

MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
e435bc19 JC	1	/*
	2	* kxsd9.c simple support for the Kionix KXSD9 3D
	3	* accelerometer.
	4	*
	5	* Copyright (c) 2008-2009 Jonathan Cameron <jic23@cam.ac.uk>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* The i2c interface is very similar, so shouldn't be a problem once
	12	* I have a suitable wire made up.
	13	*
	14	* TODO: Support the motion detector
	15	* Uses register address incrementing so could have a
	16	* heavily optimized ring buffer access function.
	17	*/
	18
e435bc19 JC	19	#include <linux/device.h>
	20	#include <linux/kernel.h>
	21	#include <linux/spi/spi.h>
	22	#include <linux/sysfs.h>
5a0e3ad6	23	#include <linux/slab.h>
99c97852	24	#include <linux/module.h>
e435bc19	25
06458e27 JC	26	#include <linux/iio/iio.h>
06458e27 JC	27	#include <linux/iio/sysfs.h>
e435bc19 JC	28
	29	#define KXSD9_REG_X 0x00
	30	#define KXSD9_REG_Y 0x02
	31	#define KXSD9_REG_Z 0x04
	32	#define KXSD9_REG_AUX 0x06
	33	#define KXSD9_REG_RESET 0x0a
	34	#define KXSD9_REG_CTRL_C 0x0c
	35
e435bc19 JC	36	#define KXSD9_FS_MASK 0x03
	37
	38	#define KXSD9_REG_CTRL_B 0x0d
	39	#define KXSD9_REG_CTRL_A 0x0e
	40
	41	#define KXSD9_READ(a) (0x80 \| (a))
	42	#define KXSD9_WRITE(a) (a)
	43
e435bc19	44	#define KXSD9_STATE_RX_SIZE 2
d34dbee8	45	#define KXSD9_STATE_TX_SIZE 2
e435bc19 JC	46	/**
	47	* struct kxsd9_state - device related storage
	48	* @buf_lock: protect the rx and tx buffers.
e435bc19 JC	49	* @us: spi device
	50	* @rx: single rx buffer storage
	51	* @tx: single tx buffer storage
	52	**/
	53	struct kxsd9_state {
	54	struct mutex buf_lock;
e435bc19	55	struct spi_device *us;
ed0c012b JC	56	u8 rx[KXSD9_STATE_RX_SIZE] ____cacheline_aligned;
ed0c012b JC	57	u8 tx[KXSD9_STATE_TX_SIZE];
e435bc19 JC	58	};
e435bc19 JC	59
d34dbee8 JC	60	#define KXSD9_SCALE_2G "0.011978"
	61	#define KXSD9_SCALE_4G "0.023927"
	62	#define KXSD9_SCALE_6G "0.035934"
	63	#define KXSD9_SCALE_8G "0.047853"
e435bc19	64
d34dbee8 JC	65	/* reverse order */
d34dbee8 JC	66	static const int kxsd9_micro_scales[4] = { 47853, 35934, 23927, 11978 };
e435bc19	67
d34dbee8	68	static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro)
e435bc19	69	{
d34dbee8	70	int ret, i;
ed0c012b	71	struct kxsd9_state *st = iio_priv(indio_dev);
d34dbee8 JC	72	bool foundit = false;
	73
	74	for (i = 0; i < 4; i++)
	75	if (micro == kxsd9_micro_scales[i]) {
	76	foundit = true;
	77	break;
	78	}
	79	if (!foundit)
e435bc19	80	return -EINVAL;
f3fb0011	81
e435bc19	82	mutex_lock(&st->buf_lock);
d34dbee8	83	ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
e435bc19 JC	84	if (ret)
	85	goto error_ret;
	86	st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C);
d34dbee8	87	st->tx[1] = (ret & ~KXSD9_FS_MASK) \| i;
e435bc19	88
d34dbee8	89	ret = spi_write(st->us, st->tx, 2);
e435bc19 JC	90	error_ret:
e435bc19 JC	91	mutex_unlock(&st->buf_lock);
d34dbee8	92	return ret;
e435bc19	93	}
f3fb0011	94
d34dbee8	95	static int kxsd9_read(struct iio_dev *indio_dev, u8 address)
e435bc19 JC	96	{
	97	struct spi_message msg;
	98	int ret;
ed0c012b	99	struct kxsd9_state *st = iio_priv(indio_dev);
e435bc19 JC	100	struct spi_transfer xfers[] = {
	101	{
	102	.bits_per_word = 8,
	103	.len = 1,
e435bc19 JC	104	.delay_usecs = 200,
	105	.tx_buf = st->tx,
	106	}, {
	107	.bits_per_word = 8,
	108	.len = 2,
e435bc19 JC	109	.rx_buf = st->rx,
	110	},
	111	};
	112
	113	mutex_lock(&st->buf_lock);
d34dbee8	114	st->tx[0] = KXSD9_READ(address);
e435bc19 JC	115	spi_message_init(&msg);
	116	spi_message_add_tail(&xfers[0], &msg);
	117	spi_message_add_tail(&xfers[1], &msg);
	118	ret = spi_sync(st->us, &msg);
	119	if (ret)
d34dbee8 JC	120	return ret;
d34dbee8 JC	121	return (((u16)(st->rx[0])) << 8) \| (st->rx[1] & 0xF0);
e435bc19 JC	122	}
e435bc19 JC	123
f3fb0011 JC	124	static IIO_CONST_ATTR(accel_scale_available,
	125	KXSD9_SCALE_2G " "
	126	KXSD9_SCALE_4G " "
	127	KXSD9_SCALE_6G " "
	128	KXSD9_SCALE_8G);
e435bc19 JC	129
e435bc19 JC	130	static struct attribute *kxsd9_attributes[] = {
f3fb0011	131	&iio_const_attr_accel_scale_available.dev_attr.attr,
e435bc19 JC	132	NULL,
	133	};
	134
d34dbee8 JC	135	static int kxsd9_write_raw(struct iio_dev *indio_dev,
	136	struct iio_chan_spec const *chan,
	137	int val,
	138	int val2,
	139	long mask)
	140	{
	141	int ret = -EINVAL;
	142
c8a9f805	143	if (mask == IIO_CHAN_INFO_SCALE) {
d34dbee8 JC	144	/* Check no integer component */
	145	if (val)
	146	return -EINVAL;
	147	ret = kxsd9_write_scale(indio_dev, val2);
	148	}
	149
	150	return ret;
	151	}
	152
	153	static int kxsd9_read_raw(struct iio_dev *indio_dev,
	154	struct iio_chan_spec const *chan,
	155	int val, int val2, long mask)
	156	{
	157	int ret = -EINVAL;
	158	struct kxsd9_state *st = iio_priv(indio_dev);
	159
	160	switch (mask) {
31313fc6	161	case IIO_CHAN_INFO_RAW:
d34dbee8 JC	162	ret = kxsd9_read(indio_dev, chan->address);
	163	if (ret < 0)
	164	goto error_ret;
	165	*val = ret;
	166	break;
c8a9f805	167	case IIO_CHAN_INFO_SCALE:
d34dbee8 JC	168	ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
	169	if (ret)
	170	goto error_ret;
	171	*val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
	172	ret = IIO_VAL_INT_PLUS_MICRO;
	173	break;
	174	};
	175
	176	error_ret:
	177	return ret;
	178	};
	179	#define KXSD9_ACCEL_CHAN(axis) \
	180	{ \
	181	.type = IIO_ACCEL, \
	182	.modified = 1, \
	183	.channel2 = IIO_MOD_##axis, \
31313fc6 JC	184	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT \| \
31313fc6 JC	185	IIO_CHAN_INFO_SCALE_SHARED_BIT, \
d34dbee8 JC	186	.address = KXSD9_REG_##axis, \
	187	}
	188
f4e4b955	189	static const struct iio_chan_spec kxsd9_channels[] = {
d34dbee8 JC	190	KXSD9_ACCEL_CHAN(X), KXSD9_ACCEL_CHAN(Y), KXSD9_ACCEL_CHAN(Z),
d34dbee8 JC	191	{
6835cb6b	192	.type = IIO_VOLTAGE,
31313fc6	193	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT,
d34dbee8 JC	194	.indexed = 1,
	195	.address = KXSD9_REG_AUX,
	196	}
	197	};
	198
e435bc19 JC	199	static const struct attribute_group kxsd9_attribute_group = {
	200	.attrs = kxsd9_attributes,
	201	};
	202
3fd47d44	203	static int __devinit kxsd9_power_up(struct kxsd9_state *st)
e435bc19	204	{
d34dbee8 JC	205	int ret;
d34dbee8 JC	206
3fd47d44	207	st->tx[0] = 0x0d;
3fd47d44	208	st->tx[1] = 0x40;
d34dbee8 JC	209	ret = spi_write(st->us, st->tx, 2);
	210	if (ret)
	211	return ret;
e435bc19	212
d34dbee8 JC	213	st->tx[0] = 0x0c;
	214	st->tx[1] = 0x9b;
	215	return spi_write(st->us, st->tx, 2);
e435bc19 JC	216	};
e435bc19 JC	217
6fe8135f	218	static const struct iio_info kxsd9_info = {
d34dbee8 JC	219	.read_raw = &kxsd9_read_raw,
d34dbee8 JC	220	.write_raw = &kxsd9_write_raw,
6fe8135f JC	221	.attrs = &kxsd9_attribute_group,
	222	.driver_module = THIS_MODULE,
	223	};
	224
e435bc19 JC	225	static int __devinit kxsd9_probe(struct spi_device *spi)
e435bc19 JC	226	{
ed0c012b	227	struct iio_dev *indio_dev;
e435bc19 JC	228	struct kxsd9_state *st;
	229	int ret = 0;
	230
7cbb7537	231	indio_dev = iio_device_alloc(sizeof(*st));
ed0c012b	232	if (indio_dev == NULL) {
e435bc19 JC	233	ret = -ENOMEM;
	234	goto error_ret;
	235	}
ed0c012b JC	236	st = iio_priv(indio_dev);
ed0c012b JC	237	spi_set_drvdata(spi, indio_dev);
e435bc19 JC	238
	239	st->us = spi;
	240	mutex_init(&st->buf_lock);
d34dbee8 JC	241	indio_dev->channels = kxsd9_channels;
	242	indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);
	243	indio_dev->name = spi_get_device_id(spi)->name;
ed0c012b JC	244	indio_dev->dev.parent = &spi->dev;
	245	indio_dev->info = &kxsd9_info;
	246	indio_dev->modes = INDIO_DIRECT_MODE;
	247
	248	ret = iio_device_register(indio_dev);
e435bc19 JC	249	if (ret)
	250	goto error_free_dev;
	251
	252	spi->mode = SPI_MODE_0;
	253	spi_setup(spi);
3fd47d44	254	kxsd9_power_up(st);
e435bc19 JC	255
	256	return 0;
	257
	258	error_free_dev:
7cbb7537	259	iio_device_free(indio_dev);
e435bc19 JC	260	error_ret:
	261	return ret;
	262	}
	263
	264	static int __devexit kxsd9_remove(struct spi_device *spi)
	265	{
ed0c012b	266	iio_device_unregister(spi_get_drvdata(spi));
7cbb7537	267	iio_device_free(spi_get_drvdata(spi));
e435bc19 JC	268
	269	return 0;
	270	}
	271
d34dbee8	272	static const struct spi_device_id kxsd9_id[] = {
55e4390c LPC	273	{"kxsd9", 0},
55e4390c LPC	274	{ },
d34dbee8	275	};
55e4390c	276	MODULE_DEVICE_TABLE(spi, kxsd9_id);
d34dbee8	277
e435bc19 JC	278	static struct spi_driver kxsd9_driver = {
	279	.driver = {
	280	.name = "kxsd9",
	281	.owner = THIS_MODULE,
	282	},
	283	.probe = kxsd9_probe,
	284	.remove = __devexit_p(kxsd9_remove),
d34dbee8	285	.id_table = kxsd9_id,
e435bc19	286	};
ae6ae6fe	287	module_spi_driver(kxsd9_driver);
e435bc19 JC	288
	289	MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
	290	MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
	291	MODULE_LICENSE("GPL v2");