[linux.git] / drivers / iio / dac / ad7303.c

/*
 * AD7303 Digital to analog converters driver
 *
 * Copyright 2013 Analog Devices Inc.
 *
 * Licensed under the GPL-2.
 */

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

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

#include <linux/platform_data/ad7303.h>

#define AD7303_CFG_EXTERNAL_VREF BIT(15)
#define AD7303_CFG_POWER_DOWN(ch) BIT(11 + (ch))
#define AD7303_CFG_ADDR_OFFSET	10

#define AD7303_CMD_UPDATE_DAC	(0x3 << 8)

/**
 * struct ad7303_state - driver instance specific data
 * @spi:		the device for this driver instance
 * @config:		cached config register value
 * @dac_cache:		current DAC raw value (chip does not support readback)
 * @data:		spi transfer buffer
 */

struct ad7303_state {
	struct spi_device *spi;
	uint16_t config;
	uint8_t dac_cache[2];

	struct regulator *vdd_reg;
	struct regulator *vref_reg;

	/*
	 * DMA (thus cache coherency maintenance) requires the
	 * transfer buffers to live in their own cache lines.
	 */
	__be16 data ____cacheline_aligned;
};

static int ad7303_write(struct ad7303_state *st, unsigned int chan,
	uint8_t val)
{
	st->data = cpu_to_be16(AD7303_CMD_UPDATE_DAC |
		(chan << AD7303_CFG_ADDR_OFFSET) |
		st->config | val);

	return spi_write(st->spi, &st->data, sizeof(st->data));
}

static ssize_t ad7303_read_dac_powerdown(struct iio_dev *indio_dev,
	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
	struct ad7303_state *st = iio_priv(indio_dev);

	return sprintf(buf, "%d\n", (bool)(st->config &
		AD7303_CFG_POWER_DOWN(chan->channel)));
}

static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev,
	 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
	 size_t len)
{
	struct ad7303_state *st = iio_priv(indio_dev);
	bool pwr_down;
	int ret;

	ret = strtobool(buf, &pwr_down);
	if (ret)
		return ret;

	mutex_lock(&indio_dev->mlock);

	if (pwr_down)
		st->config |= AD7303_CFG_POWER_DOWN(chan->channel);
	else
		st->config &= ~AD7303_CFG_POWER_DOWN(chan->channel);

	/* There is no noop cmd which allows us to only update the powerdown
	 * mode, so just write one of the DAC channels again */
	ad7303_write(st, chan->channel, st->dac_cache[chan->channel]);

	mutex_unlock(&indio_dev->mlock);
	return len;
}

static int ad7303_get_vref(struct ad7303_state *st,
	struct iio_chan_spec const *chan)
{
	int ret;

	if (st->config & AD7303_CFG_EXTERNAL_VREF)
		return regulator_get_voltage(st->vref_reg);

	ret = regulator_get_voltage(st->vdd_reg);
	if (ret < 0)
		return ret;
	return ret / 2;
}

static int ad7303_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan, int *val, int *val2, long info)
{
	struct ad7303_state *st = iio_priv(indio_dev);
	int vref_uv;

	switch (info) {
	case IIO_CHAN_INFO_RAW:
		*val = st->dac_cache[chan->channel];
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		vref_uv = ad7303_get_vref(st, chan);
		if (vref_uv < 0)
			return vref_uv;

		*val = 2 * vref_uv / 1000;
		*val2 = chan->scan_type.realbits;

		return IIO_VAL_FRACTIONAL_LOG2;
	default:
		break;
	}
	return -EINVAL;
}

static int ad7303_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan, int val, int val2, long mask)
{
	struct ad7303_state *st = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (val >= (1 << chan->scan_type.realbits) || val < 0)
			return -EINVAL;

		mutex_lock(&indio_dev->mlock);
		ret = ad7303_write(st, chan->address, val);
		if (ret == 0)
			st->dac_cache[chan->channel] = val;
		mutex_unlock(&indio_dev->mlock);
		break;
	default:
		ret = -EINVAL;
	}

	return ret;
}

static const struct iio_info ad7303_info = {
	.read_raw = ad7303_read_raw,
	.write_raw = ad7303_write_raw,
};

static const struct iio_chan_spec_ext_info ad7303_ext_info[] = {
	{
		.name = "powerdown",
		.read = ad7303_read_dac_powerdown,
		.write = ad7303_write_dac_powerdown,
		.shared = IIO_SEPARATE,
	},
	{ },
};

#define AD7303_CHANNEL(chan) {					\
	.type = IIO_VOLTAGE,					\
	.indexed = 1,						\
	.output = 1,						\
	.channel = (chan),					\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
	.address = (chan),					\
	.scan_type = {						\
		.sign = 'u',					\
		.realbits = 8,					\
		.storagebits = 8,				\
		.shift = 0,					\
	},							\
	.ext_info = ad7303_ext_info,				\
}

static const struct iio_chan_spec ad7303_channels[] = {
	AD7303_CHANNEL(0),
	AD7303_CHANNEL(1),
};

static int ad7303_probe(struct spi_device *spi)
{
	const struct spi_device_id *id = spi_get_device_id(spi);
	struct iio_dev *indio_dev;
	struct ad7303_state *st;
	bool ext_ref;
	int ret;

	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
	if (indio_dev == NULL)
		return -ENOMEM;

	st = iio_priv(indio_dev);
	spi_set_drvdata(spi, indio_dev);

	st->spi = spi;

	st->vdd_reg = devm_regulator_get(&spi->dev, "Vdd");
	if (IS_ERR(st->vdd_reg))
		return PTR_ERR(st->vdd_reg);

	ret = regulator_enable(st->vdd_reg);
	if (ret)
		return ret;

	if (spi->dev.of_node) {
		ext_ref = of_property_read_bool(spi->dev.of_node,
				"REF-supply");
	} else {
		struct ad7303_platform_data *pdata = spi->dev.platform_data;
		if (pdata && pdata->use_external_ref)
			ext_ref = true;
		else
		    ext_ref = false;
	}

	if (ext_ref) {
		st->vref_reg = devm_regulator_get(&spi->dev, "REF");
		if (IS_ERR(st->vref_reg)) {
			ret = PTR_ERR(st->vref_reg);
			goto err_disable_vdd_reg;
		}

		ret = regulator_enable(st->vref_reg);
		if (ret)
			goto err_disable_vdd_reg;

		st->config |= AD7303_CFG_EXTERNAL_VREF;
	}

	indio_dev->dev.parent = &spi->dev;
	indio_dev->name = id->name;
	indio_dev->info = &ad7303_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = ad7303_channels;
	indio_dev->num_channels = ARRAY_SIZE(ad7303_channels);

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

	return 0;

err_disable_vref_reg:
	if (st->vref_reg)
		regulator_disable(st->vref_reg);
err_disable_vdd_reg:
	regulator_disable(st->vdd_reg);
	return ret;
}

static int ad7303_remove(struct spi_device *spi)
{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct ad7303_state *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);

	if (st->vref_reg)
		regulator_disable(st->vref_reg);
	regulator_disable(st->vdd_reg);

	return 0;
}

static const struct of_device_id ad7303_spi_of_match[] = {
	{ .compatible = "adi,ad7303", },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, ad7303_spi_of_match);

static const struct spi_device_id ad7303_spi_ids[] = {
	{ "ad7303", 0 },
	{}
};
MODULE_DEVICE_TABLE(spi, ad7303_spi_ids);

static struct spi_driver ad7303_driver = {
	.driver = {
		.name = "ad7303",
		.of_match_table = of_match_ptr(ad7303_spi_of_match),
	},
	.probe = ad7303_probe,
	.remove = ad7303_remove,
	.id_table = ad7303_spi_ids,
};
module_spi_driver(ad7303_driver);

MODULE_AUTHOR("Lars-Peter Clausen <[email protected]>");
MODULE_DESCRIPTION("Analog Devices AD7303 DAC driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
f8347824 LPC	1	/*
	2	* AD7303 Digital to analog converters driver
	3	*
	4	* Copyright 2013 Analog Devices Inc.
	5	*
	6	* Licensed under the GPL-2.
	7	*/
	8
	9	#include <linux/err.h>
	10	#include <linux/module.h>
	11	#include <linux/kernel.h>
	12	#include <linux/spi/spi.h>
	13	#include <linux/slab.h>
	14	#include <linux/sysfs.h>
	15	#include <linux/regulator/consumer.h>
	16	#include <linux/of.h>
	17
	18	#include <linux/iio/iio.h>
	19	#include <linux/iio/sysfs.h>
	20
	21	#include <linux/platform_data/ad7303.h>
	22
	23	#define AD7303_CFG_EXTERNAL_VREF BIT(15)
	24	#define AD7303_CFG_POWER_DOWN(ch) BIT(11 + (ch))
	25	#define AD7303_CFG_ADDR_OFFSET 10
	26
	27	#define AD7303_CMD_UPDATE_DAC (0x3 << 8)
	28
	29	/**
	30	* struct ad7303_state - driver instance specific data
	31	* @spi: the device for this driver instance
	32	* @config: cached config register value
	33	* @dac_cache: current DAC raw value (chip does not support readback)
	34	* @data: spi transfer buffer
	35	*/
	36
	37	struct ad7303_state {
	38	struct spi_device *spi;
	39	uint16_t config;
	40	uint8_t dac_cache[2];
	41
	42	struct regulator *vdd_reg;
	43	struct regulator *vref_reg;
	44
	45	/*
	46	* DMA (thus cache coherency maintenance) requires the
	47	* transfer buffers to live in their own cache lines.
	48	*/
	49	__be16 data ____cacheline_aligned;
	50	};
	51
	52	static int ad7303_write(struct ad7303_state *st, unsigned int chan,
	53	uint8_t val)
	54	{
	55	st->data = cpu_to_be16(AD7303_CMD_UPDATE_DAC \|
	56	(chan << AD7303_CFG_ADDR_OFFSET) \|
	57	st->config \| val);
	58
	59	return spi_write(st->spi, &st->data, sizeof(st->data));
	60	}
	61
	62	static ssize_t ad7303_read_dac_powerdown(struct iio_dev *indio_dev,
	63	uintptr_t private, const struct iio_chan_spec chan, char buf)
	64	{
65	struct ad7303_state *st = iio_priv(indio_dev);
66
67	return sprintf(buf, "%d\n", (bool)(st->config &
68	AD7303_CFG_POWER_DOWN(chan->channel)));
69	}
70
71	static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev,
72	uintptr_t private, const struct iio_chan_spec chan, const char buf,
73	size_t len)
74	{
75	struct ad7303_state *st = iio_priv(indio_dev);
76	bool pwr_down;
77	int ret;
78
79	ret = strtobool(buf, &pwr_down);
80	if (ret)
81	return ret;
82
83	mutex_lock(&indio_dev->mlock);
84
85	if (pwr_down)
86	st->config \|= AD7303_CFG_POWER_DOWN(chan->channel);
87	else
88	st->config &= ~AD7303_CFG_POWER_DOWN(chan->channel);
89
90	/* There is no noop cmd which allows us to only update the powerdown
91	* mode, so just write one of the DAC channels again */
92	ad7303_write(st, chan->channel, st->dac_cache[chan->channel]);
93
94	mutex_unlock(&indio_dev->mlock);
a04cf55a	95	return len;
f8347824 LPC	96	}
	97
	98	static int ad7303_get_vref(struct ad7303_state *st,
	99	struct iio_chan_spec const *chan)
	100	{
	101	int ret;
	102
	103	if (st->config & AD7303_CFG_EXTERNAL_VREF)
	104	return regulator_get_voltage(st->vref_reg);
	105
	106	ret = regulator_get_voltage(st->vdd_reg);
	107	if (ret < 0)
	108	return ret;
	109	return ret / 2;
	110	}
	111
	112	static int ad7303_read_raw(struct iio_dev *indio_dev,
	113	struct iio_chan_spec const chan, int val, int *val2, long info)
	114	{
	115	struct ad7303_state *st = iio_priv(indio_dev);
	116	int vref_uv;
	117
	118	switch (info) {
	119	case IIO_CHAN_INFO_RAW:
	120	*val = st->dac_cache[chan->channel];
	121	return IIO_VAL_INT;
	122	case IIO_CHAN_INFO_SCALE:
	123	vref_uv = ad7303_get_vref(st, chan);
	124	if (vref_uv < 0)
	125	return vref_uv;
	126
	127	val = 2 vref_uv / 1000;
	128	*val2 = chan->scan_type.realbits;
	129
	130	return IIO_VAL_FRACTIONAL_LOG2;
	131	default:
	132	break;
	133	}
	134	return -EINVAL;
	135	}
	136
	137	static int ad7303_write_raw(struct iio_dev *indio_dev,
	138	struct iio_chan_spec const *chan, int val, int val2, long mask)
	139	{
	140	struct ad7303_state *st = iio_priv(indio_dev);
	141	int ret;
	142
	143	switch (mask) {
	144	case IIO_CHAN_INFO_RAW:
	145	if (val >= (1 << chan->scan_type.realbits) \|\| val < 0)
	146	return -EINVAL;
	147
	148	mutex_lock(&indio_dev->mlock);
	149	ret = ad7303_write(st, chan->address, val);
	150	if (ret == 0)
	151	st->dac_cache[chan->channel] = val;
	152	mutex_unlock(&indio_dev->mlock);
	153	break;
	154	default:
	155	ret = -EINVAL;
	156	}
	157
	158	return ret;
	159	}
160
161	static const struct iio_info ad7303_info = {
162	.read_raw = ad7303_read_raw,
163	.write_raw = ad7303_write_raw,
f8347824 LPC	164	};
	165
	166	static const struct iio_chan_spec_ext_info ad7303_ext_info[] = {
	167	{
	168	.name = "powerdown",
	169	.read = ad7303_read_dac_powerdown,
	170	.write = ad7303_write_dac_powerdown,
3704432f	171	.shared = IIO_SEPARATE,
f8347824 LPC	172	},
	173	{ },
	174	};
	175
	176	#define AD7303_CHANNEL(chan) { \
	177	.type = IIO_VOLTAGE, \
	178	.indexed = 1, \
	179	.output = 1, \
	180	.channel = (chan), \
	181	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	182	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	183	.address = (chan), \
	184	.scan_type = { \
	185	.sign = 'u', \
ce420fd4 PR	186	.realbits = 8, \
	187	.storagebits = 8, \
	188	.shift = 0, \
f8347824 LPC	189	}, \
	190	.ext_info = ad7303_ext_info, \
	191	}
	192
	193	static const struct iio_chan_spec ad7303_channels[] = {
	194	AD7303_CHANNEL(0),
	195	AD7303_CHANNEL(1),
	196	};
	197
	198	static int ad7303_probe(struct spi_device *spi)
	199	{
	200	const struct spi_device_id *id = spi_get_device_id(spi);
	201	struct iio_dev *indio_dev;
	202	struct ad7303_state *st;
	203	bool ext_ref;
	204	int ret;
	205
66e670aa	206	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
f8347824 LPC	207	if (indio_dev == NULL)
	208	return -ENOMEM;
	209
	210	st = iio_priv(indio_dev);
	211	spi_set_drvdata(spi, indio_dev);
	212
	213	st->spi = spi;
	214
66e670aa SK	215	st->vdd_reg = devm_regulator_get(&spi->dev, "Vdd");
	216	if (IS_ERR(st->vdd_reg))
	217	return PTR_ERR(st->vdd_reg);
f8347824 LPC	218
	219	ret = regulator_enable(st->vdd_reg);
	220	if (ret)
66e670aa	221	return ret;
f8347824 LPC	222
	223	if (spi->dev.of_node) {
	224	ext_ref = of_property_read_bool(spi->dev.of_node,
	225	"REF-supply");
	226	} else {
	227	struct ad7303_platform_data *pdata = spi->dev.platform_data;
	228	if (pdata && pdata->use_external_ref)
	229	ext_ref = true;
	230	else
	231	ext_ref = false;
	232	}
	233
	234	if (ext_ref) {
66e670aa	235	st->vref_reg = devm_regulator_get(&spi->dev, "REF");
94fccb78 WY	236	if (IS_ERR(st->vref_reg)) {
94fccb78 WY	237	ret = PTR_ERR(st->vref_reg);
f8347824	238	goto err_disable_vdd_reg;
94fccb78	239	}
f8347824 LPC	240
	241	ret = regulator_enable(st->vref_reg);
	242	if (ret)
66e670aa	243	goto err_disable_vdd_reg;
f8347824 LPC	244
	245	st->config \|= AD7303_CFG_EXTERNAL_VREF;
	246	}
	247
	248	indio_dev->dev.parent = &spi->dev;
	249	indio_dev->name = id->name;
	250	indio_dev->info = &ad7303_info;
	251	indio_dev->modes = INDIO_DIRECT_MODE;
	252	indio_dev->channels = ad7303_channels;
	253	indio_dev->num_channels = ARRAY_SIZE(ad7303_channels);
	254
	255	ret = iio_device_register(indio_dev);
	256	if (ret)
	257	goto err_disable_vref_reg;
	258
	259	return 0;
	260
	261	err_disable_vref_reg:
	262	if (st->vref_reg)
	263	regulator_disable(st->vref_reg);
f8347824 LPC	264	err_disable_vdd_reg:
f8347824 LPC	265	regulator_disable(st->vdd_reg);
f8347824 LPC	266	return ret;
	267	}
	268
	269	static int ad7303_remove(struct spi_device *spi)
	270	{
	271	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	272	struct ad7303_state *st = iio_priv(indio_dev);
	273
	274	iio_device_unregister(indio_dev);
	275
66e670aa	276	if (st->vref_reg)
f8347824	277	regulator_disable(st->vref_reg);
f8347824	278	regulator_disable(st->vdd_reg);
f8347824 LPC	279
	280	return 0;
	281	}
	282
1c00dcd3 JMC	283	static const struct of_device_id ad7303_spi_of_match[] = {
	284	{ .compatible = "adi,ad7303", },
	285	{ /* sentinel */ },
	286	};
	287	MODULE_DEVICE_TABLE(of, ad7303_spi_of_match);
	288
f8347824 LPC	289	static const struct spi_device_id ad7303_spi_ids[] = {
	290	{ "ad7303", 0 },
	291	{}
	292	};
	293	MODULE_DEVICE_TABLE(spi, ad7303_spi_ids);
	294
	295	static struct spi_driver ad7303_driver = {
	296	.driver = {
	297	.name = "ad7303",
1c00dcd3	298	.of_match_table = of_match_ptr(ad7303_spi_of_match),
f8347824 LPC	299	},
	300	.probe = ad7303_probe,
	301	.remove = ad7303_remove,
	302	.id_table = ad7303_spi_ids,
	303	};
	304	module_spi_driver(ad7303_driver);
	305
	306	MODULE_AUTHOR("Lars-Peter Clausen <[email protected]>");
	307	MODULE_DESCRIPTION("Analog Devices AD7303 DAC driver");
	308	MODULE_LICENSE("GPL v2");