[linux-2.6-block.git] / drivers / iio / adc / ad7887.c

/*
 * AD7887 SPI ADC driver
 *
 * Copyright 2010-2011 Analog Devices Inc.
 *
 * Licensed under the GPL-2.
 */

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/interrupt.h>

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

#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

#include <linux/platform_data/ad7887.h>

#define AD7887_REF_DIS		(1 << 5) /* on-chip reference disable */
#define AD7887_DUAL		(1 << 4) /* dual-channel mode */
#define AD7887_CH_AIN1		(1 << 3) /* convert on channel 1, DUAL=1 */
#define AD7887_CH_AIN0		(0 << 3) /* convert on channel 0, DUAL=0,1 */
#define AD7887_PM_MODE1		(0)	 /* CS based shutdown */
#define AD7887_PM_MODE2		(1)	 /* full on */
#define AD7887_PM_MODE3		(2)	 /* auto shutdown after conversion */
#define AD7887_PM_MODE4		(3)	 /* standby mode */

enum ad7887_channels {
	AD7887_CH0,
	AD7887_CH0_CH1,
	AD7887_CH1,
};

#define RES_MASK(bits)	((1 << (bits)) - 1)

/**
 * struct ad7887_chip_info - chip specifc information
 * @int_vref_mv:	the internal reference voltage
 * @channel:		channel specification
 */
struct ad7887_chip_info {
	u16				int_vref_mv;
	struct iio_chan_spec		channel[3];
};

struct ad7887_state {
	struct spi_device		*spi;
	const struct ad7887_chip_info	*chip_info;
	struct regulator		*reg;
	struct spi_transfer		xfer[4];
	struct spi_message		msg[3];
	struct spi_message		*ring_msg;
	unsigned char			tx_cmd_buf[4];

	/*
	 * DMA (thus cache coherency maintenance) requires the
	 * transfer buffers to live in their own cache lines.
	 * Buffer needs to be large enough to hold two 16 bit samples and a
	 * 64 bit aligned 64 bit timestamp.
	 */
	unsigned char data[ALIGN(4, sizeof(s64)) + sizeof(s64)]
		____cacheline_aligned;
};

enum ad7887_supported_device_ids {
	ID_AD7887
};

static int ad7887_ring_preenable(struct iio_dev *indio_dev)
{
	struct ad7887_state *st = iio_priv(indio_dev);
	int ret;

	ret = iio_sw_buffer_preenable(indio_dev);
	if (ret < 0)
		return ret;

	/* We know this is a single long so can 'cheat' */
	switch (*indio_dev->active_scan_mask) {
	case (1 << 0):
		st->ring_msg = &st->msg[AD7887_CH0];
		break;
	case (1 << 1):
		st->ring_msg = &st->msg[AD7887_CH1];
		/* Dummy read: push CH1 setting down to hardware */
		spi_sync(st->spi, st->ring_msg);
		break;
	case ((1 << 1) | (1 << 0)):
		st->ring_msg = &st->msg[AD7887_CH0_CH1];
		break;
	}

	return 0;
}

static int ad7887_ring_postdisable(struct iio_dev *indio_dev)
{
	struct ad7887_state *st = iio_priv(indio_dev);

	/* dummy read: restore default CH0 settin */
	return spi_sync(st->spi, &st->msg[AD7887_CH0]);
}

/**
 * ad7887_trigger_handler() bh of trigger launched polling to ring buffer
 *
 * Currently there is no option in this driver to disable the saving of
 * timestamps within the ring.
 **/
static irqreturn_t ad7887_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct ad7887_state *st = iio_priv(indio_dev);
	s64 time_ns;
	int b_sent;

	b_sent = spi_sync(st->spi, st->ring_msg);
	if (b_sent)
		goto done;

	time_ns = iio_get_time_ns();

	if (indio_dev->scan_timestamp)
		memcpy(st->data + indio_dev->scan_bytes - sizeof(s64),
		       &time_ns, sizeof(time_ns));

	iio_push_to_buffers(indio_dev, st->data);
done:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

static const struct iio_buffer_setup_ops ad7887_ring_setup_ops = {
	.preenable = &ad7887_ring_preenable,
	.postenable = &iio_triggered_buffer_postenable,
	.predisable = &iio_triggered_buffer_predisable,
	.postdisable = &ad7887_ring_postdisable,
};

static int ad7887_scan_direct(struct ad7887_state *st, unsigned ch)
{
	int ret = spi_sync(st->spi, &st->msg[ch]);
	if (ret)
		return ret;

	return (st->data[(ch * 2)] << 8) | st->data[(ch * 2) + 1];
}

static int ad7887_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val,
			   int *val2,
			   long m)
{
	int ret;
	struct ad7887_state *st = iio_priv(indio_dev);

	switch (m) {
	case IIO_CHAN_INFO_RAW:
		mutex_lock(&indio_dev->mlock);
		if (iio_buffer_enabled(indio_dev))
			ret = -EBUSY;
		else
			ret = ad7887_scan_direct(st, chan->address);
		mutex_unlock(&indio_dev->mlock);

		if (ret < 0)
			return ret;
		*val = ret >> chan->scan_type.shift;
		*val &= RES_MASK(chan->scan_type.realbits);
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		if (st->reg) {
			*val = regulator_get_voltage(st->reg);
			if (*val < 0)
				return *val;
			*val /= 1000;
		} else {
			*val = st->chip_info->int_vref_mv;
		}

		*val2 = chan->scan_type.realbits;

		return IIO_VAL_FRACTIONAL_LOG2;
	}
	return -EINVAL;
}


static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
	/*
	 * More devices added in future
	 */
	[ID_AD7887] = {
		.channel[0] = {
			.type = IIO_VOLTAGE,
			.indexed = 1,
			.channel = 1,
			.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
			IIO_CHAN_INFO_SCALE_SHARED_BIT,
			.address = 1,
			.scan_index = 1,
			.scan_type = IIO_ST('u', 12, 16, 0),
		},
		.channel[1] = {
			.type = IIO_VOLTAGE,
			.indexed = 1,
			.channel = 0,
			.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
			IIO_CHAN_INFO_SCALE_SHARED_BIT,
			.address = 0,
			.scan_index = 0,
			.scan_type = IIO_ST('u', 12, 16, 0),
		},
		.channel[2] = IIO_CHAN_SOFT_TIMESTAMP(2),
		.int_vref_mv = 2500,
	},
};

static const struct iio_info ad7887_info = {
	.read_raw = &ad7887_read_raw,
	.driver_module = THIS_MODULE,
};

static int ad7887_probe(struct spi_device *spi)
{
	struct ad7887_platform_data *pdata = spi->dev.platform_data;
	struct ad7887_state *st;
	struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st));
	uint8_t mode;
	int ret;

	if (indio_dev == NULL)
		return -ENOMEM;

	st = iio_priv(indio_dev);

	if (!pdata || !pdata->use_onchip_ref) {
		st->reg = regulator_get(&spi->dev, "vref");
		if (IS_ERR(st->reg)) {
			ret = PTR_ERR(st->reg);
			goto error_free;
		}

		ret = regulator_enable(st->reg);
		if (ret)
			goto error_put_reg;
	}

	st->chip_info =
		&ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];

	spi_set_drvdata(spi, indio_dev);
	st->spi = spi;

	/* Estabilish that the iio_dev is a child of the spi device */
	indio_dev->dev.parent = &spi->dev;
	indio_dev->name = spi_get_device_id(spi)->name;
	indio_dev->info = &ad7887_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	/* Setup default message */

	mode = AD7887_PM_MODE4;
	if (!pdata || !pdata->use_onchip_ref)
		mode |= AD7887_REF_DIS;
	if (pdata && pdata->en_dual)
		mode |= AD7887_DUAL;

	st->tx_cmd_buf[0] = AD7887_CH_AIN0 | mode;

	st->xfer[0].rx_buf = &st->data[0];
	st->xfer[0].tx_buf = &st->tx_cmd_buf[0];
	st->xfer[0].len = 2;

	spi_message_init(&st->msg[AD7887_CH0]);
	spi_message_add_tail(&st->xfer[0], &st->msg[AD7887_CH0]);

	if (pdata && pdata->en_dual) {
		st->tx_cmd_buf[2] = AD7887_CH_AIN1 | mode;

		st->xfer[1].rx_buf = &st->data[0];
		st->xfer[1].tx_buf = &st->tx_cmd_buf[2];
		st->xfer[1].len = 2;

		st->xfer[2].rx_buf = &st->data[2];
		st->xfer[2].tx_buf = &st->tx_cmd_buf[0];
		st->xfer[2].len = 2;

		spi_message_init(&st->msg[AD7887_CH0_CH1]);
		spi_message_add_tail(&st->xfer[1], &st->msg[AD7887_CH0_CH1]);
		spi_message_add_tail(&st->xfer[2], &st->msg[AD7887_CH0_CH1]);

		st->xfer[3].rx_buf = &st->data[2];
		st->xfer[3].tx_buf = &st->tx_cmd_buf[2];
		st->xfer[3].len = 2;

		spi_message_init(&st->msg[AD7887_CH1]);
		spi_message_add_tail(&st->xfer[3], &st->msg[AD7887_CH1]);

		indio_dev->channels = st->chip_info->channel;
		indio_dev->num_channels = 3;
	} else {
		indio_dev->channels = &st->chip_info->channel[1];
		indio_dev->num_channels = 2;
	}

	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
			&ad7887_trigger_handler, &ad7887_ring_setup_ops);
	if (ret)
		goto error_disable_reg;

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

	return 0;
error_unregister_ring:
	iio_triggered_buffer_cleanup(indio_dev);
error_disable_reg:
	if (st->reg)
		regulator_disable(st->reg);
error_put_reg:
	if (st->reg)
		regulator_put(st->reg);
error_free:
	iio_device_free(indio_dev);

	return ret;
}

static int ad7887_remove(struct spi_device *spi)
{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct ad7887_state *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);
	if (st->reg) {
		regulator_disable(st->reg);
		regulator_put(st->reg);
	}
	iio_device_free(indio_dev);

	return 0;
}

static const struct spi_device_id ad7887_id[] = {
	{"ad7887", ID_AD7887},
	{}
};
MODULE_DEVICE_TABLE(spi, ad7887_id);

static struct spi_driver ad7887_driver = {
	.driver = {
		.name	= "ad7887",
		.owner	= THIS_MODULE,
	},
	.probe		= ad7887_probe,
	.remove		= ad7887_remove,
	.id_table	= ad7887_id,
};
module_spi_driver(ad7887_driver);

MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD7887 ADC");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
2b4756aa MH	1	/*
	2	* AD7887 SPI ADC driver
	3	*
596d0609	4	* Copyright 2010-2011 Analog Devices Inc.
2b4756aa	5	*
596d0609	6	* Licensed under the GPL-2.
2b4756aa MH	7	*/
2b4756aa MH	8
2b4756aa MH	9	#include <linux/device.h>
	10	#include <linux/kernel.h>
	11	#include <linux/slab.h>
	12	#include <linux/sysfs.h>
2b4756aa MH	13	#include <linux/spi/spi.h>
	14	#include <linux/regulator/consumer.h>
	15	#include <linux/err.h>
99c97852	16	#include <linux/module.h>
65dd3d3d	17	#include <linux/interrupt.h>
2b4756aa	18
06458e27 JC	19	#include <linux/iio/iio.h>
	20	#include <linux/iio/sysfs.h>
	21	#include <linux/iio/buffer.h>
cdf38709	22
65dd3d3d LPC	23	#include <linux/iio/trigger_consumer.h>
65dd3d3d LPC	24	#include <linux/iio/triggered_buffer.h>
2b4756aa	25
4eb3ccf1	26	#include <linux/platform_data/ad7887.h>
2b4756aa	27
65dd3d3d LPC	28	#define AD7887_REF_DIS (1 << 5) /* on-chip reference disable */
	29	#define AD7887_DUAL (1 << 4) /* dual-channel mode */
	30	#define AD7887_CH_AIN1 (1 << 3) /* convert on channel 1, DUAL=1 */
	31	#define AD7887_CH_AIN0 (0 << 3) /* convert on channel 0, DUAL=0,1 */
	32	#define AD7887_PM_MODE1 (0) /* CS based shutdown */
	33	#define AD7887_PM_MODE2 (1) /* full on */
	34	#define AD7887_PM_MODE3 (2) /* auto shutdown after conversion */
	35	#define AD7887_PM_MODE4 (3) /* standby mode */
	36
	37	enum ad7887_channels {
	38	AD7887_CH0,
	39	AD7887_CH0_CH1,
	40	AD7887_CH1,
	41	};
	42
	43	#define RES_MASK(bits) ((1 << (bits)) - 1)
	44
	45	/**
	46	* struct ad7887_chip_info - chip specifc information
	47	* @int_vref_mv: the internal reference voltage
	48	* @channel: channel specification
	49	*/
	50	struct ad7887_chip_info {
	51	u16 int_vref_mv;
	52	struct iio_chan_spec channel[3];
	53	};
	54
	55	struct ad7887_state {
	56	struct spi_device *spi;
	57	const struct ad7887_chip_info *chip_info;
	58	struct regulator *reg;
	59	struct spi_transfer xfer[4];
	60	struct spi_message msg[3];
	61	struct spi_message *ring_msg;
fce7c3ea	62	unsigned char tx_cmd_buf[4];
65dd3d3d LPC	63
	64	/*
	65	* DMA (thus cache coherency maintenance) requires the
	66	* transfer buffers to live in their own cache lines.
	67	* Buffer needs to be large enough to hold two 16 bit samples and a
	68	* 64 bit aligned 64 bit timestamp.
	69	*/
	70	unsigned char data[ALIGN(4, sizeof(s64)) + sizeof(s64)]
	71	____cacheline_aligned;
	72	};
	73
	74	enum ad7887_supported_device_ids {
	75	ID_AD7887
	76	};
	77
	78	static int ad7887_ring_preenable(struct iio_dev *indio_dev)
	79	{
	80	struct ad7887_state *st = iio_priv(indio_dev);
	81	int ret;
	82
	83	ret = iio_sw_buffer_preenable(indio_dev);
	84	if (ret < 0)
	85	return ret;
	86
	87	/* We know this is a single long so can 'cheat' */
	88	switch (*indio_dev->active_scan_mask) {
	89	case (1 << 0):
	90	st->ring_msg = &st->msg[AD7887_CH0];
	91	break;
	92	case (1 << 1):
	93	st->ring_msg = &st->msg[AD7887_CH1];
	94	/* Dummy read: push CH1 setting down to hardware */
	95	spi_sync(st->spi, st->ring_msg);
	96	break;
	97	case ((1 << 1) \| (1 << 0)):
	98	st->ring_msg = &st->msg[AD7887_CH0_CH1];
	99	break;
	100	}
	101
	102	return 0;
	103	}
	104
	105	static int ad7887_ring_postdisable(struct iio_dev *indio_dev)
	106	{
	107	struct ad7887_state *st = iio_priv(indio_dev);
	108
	109	/* dummy read: restore default CH0 settin */
	110	return spi_sync(st->spi, &st->msg[AD7887_CH0]);
	111	}
	112
	113	/**
	114	* ad7887_trigger_handler() bh of trigger launched polling to ring buffer
	115	*
	116	* Currently there is no option in this driver to disable the saving of
	117	* timestamps within the ring.
	118	**/
	119	static irqreturn_t ad7887_trigger_handler(int irq, void *p)
	120	{
	121	struct iio_poll_func *pf = p;
	122	struct iio_dev *indio_dev = pf->indio_dev;
	123	struct ad7887_state *st = iio_priv(indio_dev);
	124	s64 time_ns;
	125	int b_sent;
	126
127	b_sent = spi_sync(st->spi, st->ring_msg);
128	if (b_sent)
129	goto done;
130
131	time_ns = iio_get_time_ns();
132
133	if (indio_dev->scan_timestamp)
134	memcpy(st->data + indio_dev->scan_bytes - sizeof(s64),
135	&time_ns, sizeof(time_ns));
136
84b36ce5	137	iio_push_to_buffers(indio_dev, st->data);
65dd3d3d LPC	138	done:
	139	iio_trigger_notify_done(indio_dev->trig);
	140
	141	return IRQ_HANDLED;
	142	}
	143
	144	static const struct iio_buffer_setup_ops ad7887_ring_setup_ops = {
	145	.preenable = &ad7887_ring_preenable,
	146	.postenable = &iio_triggered_buffer_postenable,
	147	.predisable = &iio_triggered_buffer_predisable,
	148	.postdisable = &ad7887_ring_postdisable,
	149	};
	150
2b4756aa MH	151	static int ad7887_scan_direct(struct ad7887_state *st, unsigned ch)
	152	{
	153	int ret = spi_sync(st->spi, &st->msg[ch]);
	154	if (ret)
	155	return ret;
	156
	157	return (st->data[(ch * 2)] << 8) \| st->data[(ch * 2) + 1];
	158	}
	159
84f79ecb	160	static int ad7887_read_raw(struct iio_dev *indio_dev,
596d0609 MH	161	struct iio_chan_spec const *chan,
	162	int *val,
	163	int *val2,
	164	long m)
2b4756aa	165	{
2b4756aa	166	int ret;
84f79ecb	167	struct ad7887_state *st = iio_priv(indio_dev);
2b4756aa	168
596d0609	169	switch (m) {
b11f98ff	170	case IIO_CHAN_INFO_RAW:
84f79ecb JC	171	mutex_lock(&indio_dev->mlock);
84f79ecb JC	172	if (iio_buffer_enabled(indio_dev))
790d8759	173	ret = -EBUSY;
596d0609 MH	174	else
596d0609 MH	175	ret = ad7887_scan_direct(st, chan->address);
84f79ecb	176	mutex_unlock(&indio_dev->mlock);
596d0609 MH	177
	178	if (ret < 0)
	179	return ret;
98efb70a LPC	180	*val = ret >> chan->scan_type.shift;
98efb70a LPC	181	*val &= RES_MASK(chan->scan_type.realbits);
596d0609	182	return IIO_VAL_INT;
c8a9f805	183	case IIO_CHAN_INFO_SCALE:
bf5d2613 LPC	184	if (st->reg) {
	185	*val = regulator_get_voltage(st->reg);
	186	if (*val < 0)
	187	return *val;
	188	*val /= 1000;
	189	} else {
	190	*val = st->chip_info->int_vref_mv;
	191	}
	192
98efb70a	193	*val2 = chan->scan_type.realbits;
bf5d2613 LPC	194
bf5d2613 LPC	195	return IIO_VAL_FRACTIONAL_LOG2;
596d0609 MH	196	}
596d0609 MH	197	return -EINVAL;
2b4756aa MH	198	}
2b4756aa MH	199
2b4756aa MH	200
	201	static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
	202	/*
	203	* More devices added in future
	204	*/
	205	[ID_AD7887] = {
31bf47d5 JC	206	.channel[0] = {
	207	.type = IIO_VOLTAGE,
	208	.indexed = 1,
	209	.channel = 1,
b11f98ff JC	210	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT \|
b11f98ff JC	211	IIO_CHAN_INFO_SCALE_SHARED_BIT,
31bf47d5 JC	212	.address = 1,
	213	.scan_index = 1,
	214	.scan_type = IIO_ST('u', 12, 16, 0),
	215	},
	216	.channel[1] = {
	217	.type = IIO_VOLTAGE,
	218	.indexed = 1,
	219	.channel = 0,
b11f98ff JC	220	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT \|
b11f98ff JC	221	IIO_CHAN_INFO_SCALE_SHARED_BIT,
31bf47d5 JC	222	.address = 0,
	223	.scan_index = 0,
	224	.scan_type = IIO_ST('u', 12, 16, 0),
	225	},
596d0609	226	.channel[2] = IIO_CHAN_SOFT_TIMESTAMP(2),
2b4756aa MH	227	.int_vref_mv = 2500,
	228	},
	229	};
	230
6fe8135f JC	231	static const struct iio_info ad7887_info = {
	232	.read_raw = &ad7887_read_raw,
	233	.driver_module = THIS_MODULE,
	234	};
	235
fc52692c	236	static int ad7887_probe(struct spi_device *spi)
2b4756aa MH	237	{
	238	struct ad7887_platform_data *pdata = spi->dev.platform_data;
	239	struct ad7887_state *st;
7cbb7537	240	struct iio_dev indio_dev = iio_device_alloc(sizeof(st));
fce7c3ea	241	uint8_t mode;
bf5d2613	242	int ret;
2b4756aa	243
f39e086a MH	244	if (indio_dev == NULL)
	245	return -ENOMEM;
	246
	247	st = iio_priv(indio_dev);
2b4756aa	248
bf5d2613 LPC	249	if (!pdata \|\| !pdata->use_onchip_ref) {
	250	st->reg = regulator_get(&spi->dev, "vref");
	251	if (IS_ERR(st->reg)) {
	252	ret = PTR_ERR(st->reg);
	253	goto error_free;
	254	}
	255
2b4756aa MH	256	ret = regulator_enable(st->reg);
	257	if (ret)
	258	goto error_put_reg;
2b4756aa MH	259	}
	260
	261	st->chip_info =
	262	&ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
	263
f39e086a	264	spi_set_drvdata(spi, indio_dev);
2b4756aa MH	265	st->spi = spi;
2b4756aa MH	266
2b4756aa	267	/* Estabilish that the iio_dev is a child of the spi device */
f39e086a MH	268	indio_dev->dev.parent = &spi->dev;
f39e086a MH	269	indio_dev->name = spi_get_device_id(spi)->name;
6fe8135f	270	indio_dev->info = &ad7887_info;
f39e086a	271	indio_dev->modes = INDIO_DIRECT_MODE;
2b4756aa MH	272
	273	/* Setup default message */
	274
fce7c3ea LPC	275	mode = AD7887_PM_MODE4;
	276	if (!pdata \|\| !pdata->use_onchip_ref)
	277	mode \|= AD7887_REF_DIS;
	278	if (pdata && pdata->en_dual)
	279	mode \|= AD7887_DUAL;
	280
	281	st->tx_cmd_buf[0] = AD7887_CH_AIN0 \| mode;
2b4756aa MH	282
	283	st->xfer[0].rx_buf = &st->data[0];
	284	st->xfer[0].tx_buf = &st->tx_cmd_buf[0];
	285	st->xfer[0].len = 2;
	286
	287	spi_message_init(&st->msg[AD7887_CH0]);
	288	spi_message_add_tail(&st->xfer[0], &st->msg[AD7887_CH0]);
	289
	290	if (pdata && pdata->en_dual) {
fce7c3ea	291	st->tx_cmd_buf[2] = AD7887_CH_AIN1 \| mode;
2b4756aa MH	292
	293	st->xfer[1].rx_buf = &st->data[0];
	294	st->xfer[1].tx_buf = &st->tx_cmd_buf[2];
	295	st->xfer[1].len = 2;
	296
	297	st->xfer[2].rx_buf = &st->data[2];
fce7c3ea	298	st->xfer[2].tx_buf = &st->tx_cmd_buf[0];
2b4756aa MH	299	st->xfer[2].len = 2;
	300
	301	spi_message_init(&st->msg[AD7887_CH0_CH1]);
	302	spi_message_add_tail(&st->xfer[1], &st->msg[AD7887_CH0_CH1]);
	303	spi_message_add_tail(&st->xfer[2], &st->msg[AD7887_CH0_CH1]);
	304
fce7c3ea LPC	305	st->xfer[3].rx_buf = &st->data[2];
fce7c3ea LPC	306	st->xfer[3].tx_buf = &st->tx_cmd_buf[2];
2b4756aa MH	307	st->xfer[3].len = 2;
	308
	309	spi_message_init(&st->msg[AD7887_CH1]);
	310	spi_message_add_tail(&st->xfer[3], &st->msg[AD7887_CH1]);
	311
f39e086a MH	312	indio_dev->channels = st->chip_info->channel;
f39e086a MH	313	indio_dev->num_channels = 3;
2b4756aa	314	} else {
f39e086a MH	315	indio_dev->channels = &st->chip_info->channel[1];
f39e086a MH	316	indio_dev->num_channels = 2;
596d0609	317	}
2b4756aa	318
65dd3d3d LPC	319	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
65dd3d3d LPC	320	&ad7887_trigger_handler, &ad7887_ring_setup_ops);
2b4756aa	321	if (ret)
f39e086a	322	goto error_disable_reg;
2b4756aa	323
26d25ae3 JC	324	ret = iio_device_register(indio_dev);
	325	if (ret)
	326	goto error_unregister_ring;
	327
	328	return 0;
	329	error_unregister_ring:
65dd3d3d	330	iio_triggered_buffer_cleanup(indio_dev);
2b4756aa	331	error_disable_reg:
bf5d2613	332	if (st->reg)
2b4756aa MH	333	regulator_disable(st->reg);
2b4756aa MH	334	error_put_reg:
bf5d2613	335	if (st->reg)
2b4756aa	336	regulator_put(st->reg);
bf5d2613	337	error_free:
7cbb7537	338	iio_device_free(indio_dev);
f39e086a	339
2b4756aa MH	340	return ret;
	341	}
	342
fc52692c	343	static int ad7887_remove(struct spi_device *spi)
2b4756aa	344	{
f39e086a MH	345	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	346	struct ad7887_state *st = iio_priv(indio_dev);
	347
d2fffd6c	348	iio_device_unregister(indio_dev);
65dd3d3d	349	iio_triggered_buffer_cleanup(indio_dev);
bf5d2613	350	if (st->reg) {
2b4756aa MH	351	regulator_disable(st->reg);
	352	regulator_put(st->reg);
	353	}
7cbb7537	354	iio_device_free(indio_dev);
f39e086a	355
2b4756aa MH	356	return 0;
	357	}
	358
	359	static const struct spi_device_id ad7887_id[] = {
	360	{"ad7887", ID_AD7887},
	361	{}
	362	};
55e4390c	363	MODULE_DEVICE_TABLE(spi, ad7887_id);
2b4756aa MH	364
	365	static struct spi_driver ad7887_driver = {
	366	.driver = {
	367	.name = "ad7887",
2b4756aa MH	368	.owner = THIS_MODULE,
	369	},
	370	.probe = ad7887_probe,
fc52692c	371	.remove = ad7887_remove,
2b4756aa MH	372	.id_table = ad7887_id,
2b4756aa MH	373	};
ae6ae6fe	374	module_spi_driver(ad7887_driver);
2b4756aa MH	375
	376	MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
	377	MODULE_DESCRIPTION("Analog Devices AD7887 ADC");
	378	MODULE_LICENSE("GPL v2");