[deliverable/linux.git] / drivers / staging / iio / adc / ad7298_core.c

/*
 * AD7298 SPI ADC driver
 *
 * Copyright 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/delay.h>

#include "../iio.h"
#include "../sysfs.h"
#include "../ring_generic.h"
#include "adc.h"

#include "ad7298.h"

static struct iio_chan_spec ad7298_channels[] = {
	IIO_CHAN(IIO_TEMP, 0, 1, 0, NULL, 0, 0,
		 (1 << IIO_CHAN_INFO_SCALE_SEPARATE),
		 9, AD7298_CH_TEMP, IIO_ST('s', 32, 32, 0), 0),
	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 0, 0,
		 (1 << IIO_CHAN_INFO_SCALE_SHARED),
		 0, 0, IIO_ST('u', 12, 16, 0), 0),
	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 1, 0,
		 (1 << IIO_CHAN_INFO_SCALE_SHARED),
		 1, 1, IIO_ST('u', 12, 16, 0), 0),
	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 2, 0,
		 (1 << IIO_CHAN_INFO_SCALE_SHARED),
		 2, 2, IIO_ST('u', 12, 16, 0), 0),
	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 3, 0,
		 (1 << IIO_CHAN_INFO_SCALE_SHARED),
		 3, 3, IIO_ST('u', 12, 16, 0), 0),
	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 4, 0,
		 (1 << IIO_CHAN_INFO_SCALE_SHARED),
		 4, 4, IIO_ST('u', 12, 16, 0), 0),
	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 5, 0,
		 (1 << IIO_CHAN_INFO_SCALE_SHARED),
		 5, 5, IIO_ST('u', 12, 16, 0), 0),
	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 6, 0,
		 (1 << IIO_CHAN_INFO_SCALE_SHARED),
		 6, 6, IIO_ST('u', 12, 16, 0), 0),
	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 7, 0,
		 (1 << IIO_CHAN_INFO_SCALE_SHARED),
		 7, 7, IIO_ST('u', 12, 16, 0), 0),
	IIO_CHAN_SOFT_TIMESTAMP(8),
};

static int ad7298_scan_direct(struct ad7298_state *st, unsigned ch)
{
	int ret;
	st->tx_buf[0] = cpu_to_be16(AD7298_WRITE | st->ext_ref |
				   (AD7298_CH(0) >> ch));

	ret = spi_sync(st->spi, &st->scan_single_msg);
	if (ret)
		return ret;

	return be16_to_cpu(st->rx_buf[0]);
}

static int ad7298_scan_temp(struct ad7298_state *st, int *val)
{
	int tmp, ret;

	tmp = cpu_to_be16(AD7298_WRITE | AD7298_TSENSE |
			  AD7298_TAVG | st->ext_ref);

	ret = spi_write(st->spi, (u8 *)&tmp, 2);
	if (ret)
		return ret;

	tmp = 0;

	ret = spi_write(st->spi, (u8 *)&tmp, 2);
	if (ret)
		return ret;

	usleep_range(101, 1000); /* sleep > 100us */

	ret = spi_read(st->spi, (u8 *)&tmp, 2);
	if (ret)
		return ret;

	tmp = be16_to_cpu(tmp) & RES_MASK(AD7298_BITS);

	/*
	 * One LSB of the ADC corresponds to 0.25 deg C.
	 * The temperature reading is in 12-bit twos complement format
	 */

	if (tmp & (1 << (AD7298_BITS - 1))) {
		tmp = (4096 - tmp) * 250;
		tmp -= (2 * tmp);

	} else {
		tmp *= 250; /* temperature in milli degrees Celsius */
	}

	*val = tmp;

	return 0;
}

static int ad7298_read_raw(struct iio_dev *dev_info,
			   struct iio_chan_spec const *chan,
			   int *val,
			   int *val2,
			   long m)
{
	int ret;
	struct ad7298_state *st = dev_info->dev_data;
	unsigned int scale_uv;

	switch (m) {
	case 0:
		mutex_lock(&dev_info->mlock);
		if (iio_ring_enabled(dev_info)) {
			if (chan->address == AD7298_CH_TEMP)
				ret = -ENODEV;
			else
				ret = ad7298_scan_from_ring(st, chan->address);
		} else {
			if (chan->address == AD7298_CH_TEMP)
				ret = ad7298_scan_temp(st, val);
			else
				ret = ad7298_scan_direct(st, chan->address);
		}
		mutex_unlock(&dev_info->mlock);

		if (ret < 0)
			return ret;

		if (chan->address != AD7298_CH_TEMP)
			*val = ret & RES_MASK(AD7298_BITS);

		return IIO_VAL_INT;
	case (1 << IIO_CHAN_INFO_SCALE_SHARED):
		scale_uv = (st->int_vref_mv * 1000) >> AD7298_BITS;
		*val =  scale_uv / 1000;
		*val2 = (scale_uv % 1000) * 1000;
		return IIO_VAL_INT_PLUS_MICRO;
	case (1 << IIO_CHAN_INFO_SCALE_SEPARATE):
		*val =  1;
		*val2 = 0;
		return IIO_VAL_INT_PLUS_MICRO;
	}
	return -EINVAL;
}

static int __devinit ad7298_probe(struct spi_device *spi)
{
	struct ad7298_platform_data *pdata = spi->dev.platform_data;
	struct ad7298_state *st;
	int ret;

	st = kzalloc(sizeof(*st), GFP_KERNEL);
	if (st == NULL) {
		ret = -ENOMEM;
		goto error_ret;
	}

	st->reg = regulator_get(&spi->dev, "vcc");
	if (!IS_ERR(st->reg)) {
		ret = regulator_enable(st->reg);
		if (ret)
			goto error_put_reg;
	}

	spi_set_drvdata(spi, st);

	st->spi = spi;

	st->indio_dev = iio_allocate_device(0);
	if (st->indio_dev == NULL) {
		ret = -ENOMEM;
		goto error_disable_reg;
	}

	st->indio_dev->name = spi_get_device_id(spi)->name;
	st->indio_dev->dev.parent = &spi->dev;
	st->indio_dev->dev_data = (void *)(st);
	st->indio_dev->driver_module = THIS_MODULE;
	st->indio_dev->modes = INDIO_DIRECT_MODE;
	st->indio_dev->channels = ad7298_channels;
	st->indio_dev->num_channels = ARRAY_SIZE(ad7298_channels);
	st->indio_dev->read_raw = &ad7298_read_raw;

	/* Setup default message */

	st->scan_single_xfer[0].tx_buf = &st->tx_buf[0];
	st->scan_single_xfer[0].len = 2;
	st->scan_single_xfer[0].cs_change = 1;
	st->scan_single_xfer[1].tx_buf = &st->tx_buf[1];
	st->scan_single_xfer[1].len = 2;
	st->scan_single_xfer[1].cs_change = 1;
	st->scan_single_xfer[2].rx_buf = &st->rx_buf[0];
	st->scan_single_xfer[2].len = 2;

	spi_message_init(&st->scan_single_msg);
	spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg);
	spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
	spi_message_add_tail(&st->scan_single_xfer[2], &st->scan_single_msg);

	if (pdata && pdata->vref_mv) {
		st->int_vref_mv = pdata->vref_mv;
		st->ext_ref = AD7298_EXTREF;
	} else {
		st->int_vref_mv = AD7298_INTREF_mV;
	}

	ret = ad7298_register_ring_funcs_and_init(st->indio_dev);
	if (ret)
		goto error_free_device;

	ret = iio_device_register(st->indio_dev);
	if (ret)
		goto error_free_device;

	ret = iio_ring_buffer_register_ex(st->indio_dev->ring, 0,
					  &ad7298_channels[1], /* skip temp0 */
					  ARRAY_SIZE(ad7298_channels) - 1);
	if (ret)
		goto error_cleanup_ring;
	return 0;

error_cleanup_ring:
	ad7298_ring_cleanup(st->indio_dev);
	iio_device_unregister(st->indio_dev);
error_free_device:
	iio_free_device(st->indio_dev);
error_disable_reg:
	if (!IS_ERR(st->reg))
		regulator_disable(st->reg);
error_put_reg:
	if (!IS_ERR(st->reg))
		regulator_put(st->reg);
	kfree(st);
error_ret:
	return ret;
}

static int __devexit ad7298_remove(struct spi_device *spi)
{
	struct ad7298_state *st = spi_get_drvdata(spi);
	struct iio_dev *indio_dev = st->indio_dev;

	iio_ring_buffer_unregister(indio_dev->ring);
	ad7298_ring_cleanup(indio_dev);
	iio_device_unregister(indio_dev);
	if (!IS_ERR(st->reg)) {
		regulator_disable(st->reg);
		regulator_put(st->reg);
	}
	kfree(st);
	return 0;
}

static const struct spi_device_id ad7298_id[] = {
	{"ad7298", 0},
	{}
};

static struct spi_driver ad7298_driver = {
	.driver = {
		.name	= "ad7298",
		.bus	= &spi_bus_type,
		.owner	= THIS_MODULE,
	},
	.probe		= ad7298_probe,
	.remove		= __devexit_p(ad7298_remove),
	.id_table	= ad7298_id,
};

static int __init ad7298_init(void)
{
	return spi_register_driver(&ad7298_driver);
}
module_init(ad7298_init);

static void __exit ad7298_exit(void)
{
	spi_unregister_driver(&ad7298_driver);
}
module_exit(ad7298_exit);

MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD7298 ADC");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("spi:ad7298");
Commit	Line	Data
7c31b984 MH	1	/*
	2	* AD7298 SPI ADC driver
	3	*
	4	* Copyright 2011 Analog Devices Inc.
	5	*
	6	* Licensed under the GPL-2.
	7	*/
	8
7c31b984 MH	9	#include <linux/device.h>
	10	#include <linux/kernel.h>
	11	#include <linux/slab.h>
	12	#include <linux/sysfs.h>
	13	#include <linux/spi/spi.h>
	14	#include <linux/regulator/consumer.h>
	15	#include <linux/err.h>
	16	#include <linux/delay.h>
	17
	18	#include "../iio.h"
	19	#include "../sysfs.h"
	20	#include "../ring_generic.h"
	21	#include "adc.h"
	22
	23	#include "ad7298.h"
	24
01a99e18 MH	25	static struct iio_chan_spec ad7298_channels[] = {
	26	IIO_CHAN(IIO_TEMP, 0, 1, 0, NULL, 0, 0,
	27	(1 << IIO_CHAN_INFO_SCALE_SEPARATE),
	28	9, AD7298_CH_TEMP, IIO_ST('s', 32, 32, 0), 0),
	29	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 0, 0,
	30	(1 << IIO_CHAN_INFO_SCALE_SHARED),
	31	0, 0, IIO_ST('u', 12, 16, 0), 0),
	32	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 1, 0,
	33	(1 << IIO_CHAN_INFO_SCALE_SHARED),
	34	1, 1, IIO_ST('u', 12, 16, 0), 0),
	35	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 2, 0,
	36	(1 << IIO_CHAN_INFO_SCALE_SHARED),
	37	2, 2, IIO_ST('u', 12, 16, 0), 0),
	38	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 3, 0,
	39	(1 << IIO_CHAN_INFO_SCALE_SHARED),
	40	3, 3, IIO_ST('u', 12, 16, 0), 0),
	41	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 4, 0,
	42	(1 << IIO_CHAN_INFO_SCALE_SHARED),
	43	4, 4, IIO_ST('u', 12, 16, 0), 0),
	44	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 5, 0,
	45	(1 << IIO_CHAN_INFO_SCALE_SHARED),
	46	5, 5, IIO_ST('u', 12, 16, 0), 0),
	47	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 6, 0,
	48	(1 << IIO_CHAN_INFO_SCALE_SHARED),
	49	6, 6, IIO_ST('u', 12, 16, 0), 0),
	50	IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 7, 0,
	51	(1 << IIO_CHAN_INFO_SCALE_SHARED),
	52	7, 7, IIO_ST('u', 12, 16, 0), 0),
	53	IIO_CHAN_SOFT_TIMESTAMP(8),
	54	};
	55
7c31b984 MH	56	static int ad7298_scan_direct(struct ad7298_state *st, unsigned ch)
	57	{
	58	int ret;
	59	st->tx_buf[0] = cpu_to_be16(AD7298_WRITE \| st->ext_ref \|
	60	(AD7298_CH(0) >> ch));
	61
	62	ret = spi_sync(st->spi, &st->scan_single_msg);
	63	if (ret)
	64	return ret;
	65
	66	return be16_to_cpu(st->rx_buf[0]);
	67	}
	68
01a99e18	69	static int ad7298_scan_temp(struct ad7298_state st, int val)
7c31b984	70	{
01a99e18	71	int tmp, ret;
7c31b984	72
01a99e18 MH	73	tmp = cpu_to_be16(AD7298_WRITE \| AD7298_TSENSE \|
01a99e18 MH	74	AD7298_TAVG \| st->ext_ref);
7c31b984	75
01a99e18 MH	76	ret = spi_write(st->spi, (u8 *)&tmp, 2);
01a99e18 MH	77	if (ret)
7c31b984 MH	78	return ret;
7c31b984 MH	79
01a99e18	80	tmp = 0;
7c31b984	81
01a99e18 MH	82	ret = spi_write(st->spi, (u8 *)&tmp, 2);
	83	if (ret)
	84	return ret;
7c31b984	85
7c31b984	86	usleep_range(101, 1000); /* sleep > 100us */
01a99e18 MH	87
	88	ret = spi_read(st->spi, (u8 *)&tmp, 2);
	89	if (ret)
	90	return ret;
7c31b984 MH	91
	92	tmp = be16_to_cpu(tmp) & RES_MASK(AD7298_BITS);
	93
	94	/*
	95	* One LSB of the ADC corresponds to 0.25 deg C.
	96	* The temperature reading is in 12-bit twos complement format
	97	*/
	98
	99	if (tmp & (1 << (AD7298_BITS - 1))) {
	100	tmp = (4096 - tmp) * 250;
	101	tmp -= (2 * tmp);
	102
	103	} else {
	104	tmp = 250; / temperature in milli degrees Celsius */
	105	}
	106
01a99e18	107	*val = tmp;
7c31b984	108
01a99e18 MH	109	return 0;
01a99e18 MH	110	}
7c31b984	111
01a99e18 MH	112	static int ad7298_read_raw(struct iio_dev *dev_info,
	113	struct iio_chan_spec const *chan,
	114	int *val,
	115	int *val2,
	116	long m)
7c31b984	117	{
01a99e18 MH	118	int ret;
	119	struct ad7298_state *st = dev_info->dev_data;
	120	unsigned int scale_uv;
	121
	122	switch (m) {
	123	case 0:
	124	mutex_lock(&dev_info->mlock);
	125	if (iio_ring_enabled(dev_info)) {
	126	if (chan->address == AD7298_CH_TEMP)
	127	ret = -ENODEV;
	128	else
	129	ret = ad7298_scan_from_ring(st, chan->address);
	130	} else {
	131	if (chan->address == AD7298_CH_TEMP)
	132	ret = ad7298_scan_temp(st, val);
	133	else
	134	ret = ad7298_scan_direct(st, chan->address);
	135	}
	136	mutex_unlock(&dev_info->mlock);
	137
	138	if (ret < 0)
	139	return ret;
	140
	141	if (chan->address != AD7298_CH_TEMP)
	142	*val = ret & RES_MASK(AD7298_BITS);
	143
	144	return IIO_VAL_INT;
	145	case (1 << IIO_CHAN_INFO_SCALE_SHARED):
	146	scale_uv = (st->int_vref_mv * 1000) >> AD7298_BITS;
	147	*val = scale_uv / 1000;
	148	val2 = (scale_uv % 1000) 1000;
	149	return IIO_VAL_INT_PLUS_MICRO;
	150	case (1 << IIO_CHAN_INFO_SCALE_SEPARATE):
	151	*val = 1;
	152	*val2 = 0;
	153	return IIO_VAL_INT_PLUS_MICRO;
	154	}
	155	return -EINVAL;
7c31b984	156	}
7c31b984 MH	157
	158	static int __devinit ad7298_probe(struct spi_device *spi)
	159	{
	160	struct ad7298_platform_data *pdata = spi->dev.platform_data;
	161	struct ad7298_state *st;
	162	int ret;
	163
	164	st = kzalloc(sizeof(*st), GFP_KERNEL);
	165	if (st == NULL) {
	166	ret = -ENOMEM;
	167	goto error_ret;
	168	}
	169
	170	st->reg = regulator_get(&spi->dev, "vcc");
	171	if (!IS_ERR(st->reg)) {
	172	ret = regulator_enable(st->reg);
	173	if (ret)
	174	goto error_put_reg;
	175	}
	176
	177	spi_set_drvdata(spi, st);
	178
7c31b984 MH	179	st->spi = spi;
7c31b984 MH	180
6f7c8ee5	181	st->indio_dev = iio_allocate_device(0);
7c31b984 MH	182	if (st->indio_dev == NULL) {
	183	ret = -ENOMEM;
	184	goto error_disable_reg;
	185	}
	186
845bd12a	187	st->indio_dev->name = spi_get_device_id(spi)->name;
7c31b984	188	st->indio_dev->dev.parent = &spi->dev;
7c31b984 MH	189	st->indio_dev->dev_data = (void *)(st);
	190	st->indio_dev->driver_module = THIS_MODULE;
	191	st->indio_dev->modes = INDIO_DIRECT_MODE;
01a99e18 MH	192	st->indio_dev->channels = ad7298_channels;
	193	st->indio_dev->num_channels = ARRAY_SIZE(ad7298_channels);
	194	st->indio_dev->read_raw = &ad7298_read_raw;
7c31b984 MH	195
	196	/* Setup default message */
	197
	198	st->scan_single_xfer[0].tx_buf = &st->tx_buf[0];
	199	st->scan_single_xfer[0].len = 2;
	200	st->scan_single_xfer[0].cs_change = 1;
	201	st->scan_single_xfer[1].tx_buf = &st->tx_buf[1];
	202	st->scan_single_xfer[1].len = 2;
	203	st->scan_single_xfer[1].cs_change = 1;
	204	st->scan_single_xfer[2].rx_buf = &st->rx_buf[0];
	205	st->scan_single_xfer[2].len = 2;
	206
	207	spi_message_init(&st->scan_single_msg);
	208	spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg);
	209	spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
	210	spi_message_add_tail(&st->scan_single_xfer[2], &st->scan_single_msg);
	211
	212	if (pdata && pdata->vref_mv) {
	213	st->int_vref_mv = pdata->vref_mv;
	214	st->ext_ref = AD7298_EXTREF;
	215	} else {
	216	st->int_vref_mv = AD7298_INTREF_mV;
	217	}
	218
	219	ret = ad7298_register_ring_funcs_and_init(st->indio_dev);
	220	if (ret)
	221	goto error_free_device;
	222
	223	ret = iio_device_register(st->indio_dev);
	224	if (ret)
	225	goto error_free_device;
	226
01a99e18 MH	227	ret = iio_ring_buffer_register_ex(st->indio_dev->ring, 0,
	228	&ad7298_channels[1], /* skip temp0 */
	229	ARRAY_SIZE(ad7298_channels) - 1);
7c31b984 MH	230	if (ret)
	231	goto error_cleanup_ring;
	232	return 0;
	233
	234	error_cleanup_ring:
	235	ad7298_ring_cleanup(st->indio_dev);
	236	iio_device_unregister(st->indio_dev);
	237	error_free_device:
	238	iio_free_device(st->indio_dev);
	239	error_disable_reg:
	240	if (!IS_ERR(st->reg))
	241	regulator_disable(st->reg);
	242	error_put_reg:
	243	if (!IS_ERR(st->reg))
	244	regulator_put(st->reg);
	245	kfree(st);
	246	error_ret:
	247	return ret;
	248	}
	249
	250	static int __devexit ad7298_remove(struct spi_device *spi)
	251	{
	252	struct ad7298_state *st = spi_get_drvdata(spi);
	253	struct iio_dev *indio_dev = st->indio_dev;
	254
	255	iio_ring_buffer_unregister(indio_dev->ring);
	256	ad7298_ring_cleanup(indio_dev);
	257	iio_device_unregister(indio_dev);
	258	if (!IS_ERR(st->reg)) {
	259	regulator_disable(st->reg);
	260	regulator_put(st->reg);
	261	}
	262	kfree(st);
	263	return 0;
	264	}
	265
	266	static const struct spi_device_id ad7298_id[] = {
	267	{"ad7298", 0},
	268	{}
	269	};
	270
	271	static struct spi_driver ad7298_driver = {
	272	.driver = {
	273	.name = "ad7298",
	274	.bus = &spi_bus_type,
	275	.owner = THIS_MODULE,
	276	},
	277	.probe = ad7298_probe,
	278	.remove = __devexit_p(ad7298_remove),
	279	.id_table = ad7298_id,
	280	};
	281
	282	static int __init ad7298_init(void)
	283	{
	284	return spi_register_driver(&ad7298_driver);
	285	}
	286	module_init(ad7298_init);
	287
	288	static void __exit ad7298_exit(void)
	289	{
	290	spi_unregister_driver(&ad7298_driver);
	291	}
	292	module_exit(ad7298_exit);
	293
294	MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
295	MODULE_DESCRIPTION("Analog Devices AD7298 ADC");
296	MODULE_LICENSE("GPL v2");
297	MODULE_ALIAS("spi:ad7298");