[deliverable/linux.git] / drivers / iio / accel / kxsd9.c

/*
 * kxsd9.c	simple support for the Kionix KXSD9 3D
 *		accelerometer.
 *
 * Copyright (c) 2008-2009 Jonathan Cameron <jic23@kernel.org>
 *
 * 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)
{
	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);
	ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers));
	if (!ret)
		ret = (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
	mutex_unlock(&st->buf_lock);
	return ret;
}

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_separate = BIT(IIO_CHAN_INFO_RAW),		\
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
		.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_separate = BIT(IIO_CHAN_INFO_RAW),
		.indexed = 1,
		.address = KXSD9_REG_AUX,
	}
};

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

static int 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 kxsd9_probe(struct spi_device *spi)
{
	struct iio_dev *indio_dev;
	struct kxsd9_state *st;

	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);

	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;

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

	return iio_device_register(indio_dev);
}

static int kxsd9_remove(struct spi_device *spi)
{
	iio_device_unregister(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",
	},
	.probe = kxsd9_probe,
	.remove = kxsd9_remove,
	.id_table = kxsd9_id,
};
module_spi_driver(kxsd9_driver);

MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
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	*
0f8c9620	5	* Copyright (c) 2008-2009 Jonathan Cameron <jic23@kernel.org>
e435bc19 JC	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	96	{
e435bc19	97	int ret;
ed0c012b	98	struct kxsd9_state *st = iio_priv(indio_dev);
e435bc19 JC	99	struct spi_transfer xfers[] = {
	100	{
	101	.bits_per_word = 8,
	102	.len = 1,
e435bc19 JC	103	.delay_usecs = 200,
	104	.tx_buf = st->tx,
	105	}, {
	106	.bits_per_word = 8,
	107	.len = 2,
e435bc19 JC	108	.rx_buf = st->rx,
	109	},
	110	};
	111
	112	mutex_lock(&st->buf_lock);
d34dbee8	113	st->tx[0] = KXSD9_READ(address);
14543a00	114	ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers));
0ee005c7 FZ	115	if (!ret)
	116	ret = (((u16)(st->rx[0])) << 8) \| (st->rx[1] & 0xF0);
	117	mutex_unlock(&st->buf_lock);
	118	return ret;
e435bc19 JC	119	}
e435bc19 JC	120
f3fb0011 JC	121	static IIO_CONST_ATTR(accel_scale_available,
	122	KXSD9_SCALE_2G " "
	123	KXSD9_SCALE_4G " "
	124	KXSD9_SCALE_6G " "
	125	KXSD9_SCALE_8G);
e435bc19 JC	126
e435bc19 JC	127	static struct attribute *kxsd9_attributes[] = {
f3fb0011	128	&iio_const_attr_accel_scale_available.dev_attr.attr,
e435bc19 JC	129	NULL,
	130	};
	131
d34dbee8 JC	132	static int kxsd9_write_raw(struct iio_dev *indio_dev,
	133	struct iio_chan_spec const *chan,
	134	int val,
	135	int val2,
	136	long mask)
	137	{
	138	int ret = -EINVAL;
	139
c8a9f805	140	if (mask == IIO_CHAN_INFO_SCALE) {
d34dbee8 JC	141	/* Check no integer component */
	142	if (val)
	143	return -EINVAL;
	144	ret = kxsd9_write_scale(indio_dev, val2);
	145	}
	146
	147	return ret;
	148	}
	149
	150	static int kxsd9_read_raw(struct iio_dev *indio_dev,
	151	struct iio_chan_spec const *chan,
	152	int val, int val2, long mask)
	153	{
	154	int ret = -EINVAL;
	155	struct kxsd9_state *st = iio_priv(indio_dev);
	156
	157	switch (mask) {
31313fc6	158	case IIO_CHAN_INFO_RAW:
d34dbee8 JC	159	ret = kxsd9_read(indio_dev, chan->address);
	160	if (ret < 0)
	161	goto error_ret;
	162	*val = ret;
	163	break;
c8a9f805	164	case IIO_CHAN_INFO_SCALE:
d34dbee8 JC	165	ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
	166	if (ret)
	167	goto error_ret;
	168	*val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
	169	ret = IIO_VAL_INT_PLUS_MICRO;
	170	break;
73327b4c	171	}
d34dbee8 JC	172
	173	error_ret:
	174	return ret;
	175	};
	176	#define KXSD9_ACCEL_CHAN(axis) \
	177	{ \
	178	.type = IIO_ACCEL, \
	179	.modified = 1, \
	180	.channel2 = IIO_MOD_##axis, \
2f6bb534 JC	181	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
2f6bb534 JC	182	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
d34dbee8 JC	183	.address = KXSD9_REG_##axis, \
	184	}
	185
f4e4b955	186	static const struct iio_chan_spec kxsd9_channels[] = {
d34dbee8 JC	187	KXSD9_ACCEL_CHAN(X), KXSD9_ACCEL_CHAN(Y), KXSD9_ACCEL_CHAN(Z),
d34dbee8 JC	188	{
6835cb6b	189	.type = IIO_VOLTAGE,
2f6bb534	190	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
d34dbee8 JC	191	.indexed = 1,
	192	.address = KXSD9_REG_AUX,
	193	}
	194	};
	195
e435bc19 JC	196	static const struct attribute_group kxsd9_attribute_group = {
	197	.attrs = kxsd9_attributes,
	198	};
	199
4ae1c61f	200	static int kxsd9_power_up(struct kxsd9_state *st)
e435bc19	201	{
d34dbee8 JC	202	int ret;
d34dbee8 JC	203
3fd47d44	204	st->tx[0] = 0x0d;
3fd47d44	205	st->tx[1] = 0x40;
d34dbee8 JC	206	ret = spi_write(st->us, st->tx, 2);
	207	if (ret)
	208	return ret;
e435bc19	209
d34dbee8 JC	210	st->tx[0] = 0x0c;
	211	st->tx[1] = 0x9b;
	212	return spi_write(st->us, st->tx, 2);
e435bc19 JC	213	};
e435bc19 JC	214
6fe8135f	215	static const struct iio_info kxsd9_info = {
d34dbee8 JC	216	.read_raw = &kxsd9_read_raw,
d34dbee8 JC	217	.write_raw = &kxsd9_write_raw,
6fe8135f JC	218	.attrs = &kxsd9_attribute_group,
	219	.driver_module = THIS_MODULE,
	220	};
	221
4ae1c61f	222	static int kxsd9_probe(struct spi_device *spi)
e435bc19	223	{
ed0c012b	224	struct iio_dev *indio_dev;
e435bc19	225	struct kxsd9_state *st;
e435bc19	226
4ee30933 SK	227	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
	228	if (!indio_dev)
	229	return -ENOMEM;
	230
ed0c012b JC	231	st = iio_priv(indio_dev);
ed0c012b JC	232	spi_set_drvdata(spi, indio_dev);
e435bc19 JC	233
	234	st->us = spi;
	235	mutex_init(&st->buf_lock);
d34dbee8 JC	236	indio_dev->channels = kxsd9_channels;
	237	indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);
	238	indio_dev->name = spi_get_device_id(spi)->name;
ed0c012b JC	239	indio_dev->dev.parent = &spi->dev;
	240	indio_dev->info = &kxsd9_info;
	241	indio_dev->modes = INDIO_DIRECT_MODE;
	242
e435bc19 JC	243	spi->mode = SPI_MODE_0;
e435bc19 JC	244	spi_setup(spi);
3fd47d44	245	kxsd9_power_up(st);
e435bc19	246
dcf5272c	247	return iio_device_register(indio_dev);
e435bc19 JC	248	}
e435bc19 JC	249
447d4f29	250	static int kxsd9_remove(struct spi_device *spi)
e435bc19	251	{
ed0c012b	252	iio_device_unregister(spi_get_drvdata(spi));
e435bc19 JC	253
	254	return 0;
	255	}
	256
d34dbee8	257	static const struct spi_device_id kxsd9_id[] = {
55e4390c LPC	258	{"kxsd9", 0},
55e4390c LPC	259	{ },
d34dbee8	260	};
55e4390c	261	MODULE_DEVICE_TABLE(spi, kxsd9_id);
d34dbee8	262
e435bc19 JC	263	static struct spi_driver kxsd9_driver = {
	264	.driver = {
	265	.name = "kxsd9",
e435bc19 JC	266	},
e435bc19 JC	267	.probe = kxsd9_probe,
e543acf0	268	.remove = kxsd9_remove,
d34dbee8	269	.id_table = kxsd9_id,
e435bc19	270	};
ae6ae6fe	271	module_spi_driver(kxsd9_driver);
e435bc19	272
0f8c9620	273	MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
e435bc19 JC	274	MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
e435bc19 JC	275	MODULE_LICENSE("GPL v2");