[deliverable/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 ret ? ret : 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,
	.driver_module = THIS_MODULE,
};

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

#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 = iio_device_alloc(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 = regulator_get(&spi->dev, "Vdd");
	if (IS_ERR(st->vdd_reg)) {
		ret = PTR_ERR(st->vdd_reg);
		goto err_free;
	}

	ret = regulator_enable(st->vdd_reg);
	if (ret)
		goto err_put_vdd_reg;

	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 = 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_put_vref_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_put_vref_reg:
	if (st->vref_reg)
		regulator_put(st->vref_reg);
err_disable_vdd_reg:
	regulator_disable(st->vdd_reg);
err_put_vdd_reg:
	regulator_put(st->vdd_reg);
err_free:
	iio_device_free(indio_dev);

	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_put(st->vref_reg);
	}
	regulator_disable(st->vdd_reg);
	regulator_put(st->vdd_reg);

	iio_device_free(indio_dev);

	return 0;
}

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",
		.owner = THIS_MODULE,
	},
	.probe = ad7303_probe,
	.remove = ad7303_remove,
	.id_table = ad7303_spi_ids,
};
module_spi_driver(ad7303_driver);

MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
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);
95	return ret ? ret : len;
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,
164	.driver_module = THIS_MODULE,
165	};
166
167	static const struct iio_chan_spec_ext_info ad7303_ext_info[] = {
168	{
169	.name = "powerdown",
170	.read = ad7303_read_dac_powerdown,
171	.write = ad7303_write_dac_powerdown,
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', \
186	.realbits = '8', \
187	.storagebits = '8', \
188	.shift = '0', \
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
206	indio_dev = iio_device_alloc(sizeof(*st));
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
215	st->vdd_reg = regulator_get(&spi->dev, "Vdd");
216	if (IS_ERR(st->vdd_reg)) {
217	ret = PTR_ERR(st->vdd_reg);
218	goto err_free;
219	}
220
221	ret = regulator_enable(st->vdd_reg);
222	if (ret)
223	goto err_put_vdd_reg;
224
225	if (spi->dev.of_node) {
226	ext_ref = of_property_read_bool(spi->dev.of_node,
227	"REF-supply");
228	} else {
229	struct ad7303_platform_data *pdata = spi->dev.platform_data;
230	if (pdata && pdata->use_external_ref)
231	ext_ref = true;
232	else
233	ext_ref = false;
234	}
235
236	if (ext_ref) {
237	st->vref_reg = regulator_get(&spi->dev, "REF");
94fccb78 WY	238	if (IS_ERR(st->vref_reg)) {
94fccb78 WY	239	ret = PTR_ERR(st->vref_reg);
f8347824	240	goto err_disable_vdd_reg;
94fccb78	241	}
f8347824 LPC	242
	243	ret = regulator_enable(st->vref_reg);
	244	if (ret)
	245	goto err_put_vref_reg;
	246
	247	st->config \|= AD7303_CFG_EXTERNAL_VREF;
	248	}
	249
	250	indio_dev->dev.parent = &spi->dev;
	251	indio_dev->name = id->name;
	252	indio_dev->info = &ad7303_info;
	253	indio_dev->modes = INDIO_DIRECT_MODE;
	254	indio_dev->channels = ad7303_channels;
	255	indio_dev->num_channels = ARRAY_SIZE(ad7303_channels);
	256
	257	ret = iio_device_register(indio_dev);
	258	if (ret)
	259	goto err_disable_vref_reg;
	260
	261	return 0;
	262
	263	err_disable_vref_reg:
	264	if (st->vref_reg)
	265	regulator_disable(st->vref_reg);
	266	err_put_vref_reg:
	267	if (st->vref_reg)
	268	regulator_put(st->vref_reg);
	269	err_disable_vdd_reg:
	270	regulator_disable(st->vdd_reg);
	271	err_put_vdd_reg:
	272	regulator_put(st->vdd_reg);
	273	err_free:
	274	iio_device_free(indio_dev);
	275
	276	return ret;
	277	}
	278
	279	static int ad7303_remove(struct spi_device *spi)
	280	{
	281	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	282	struct ad7303_state *st = iio_priv(indio_dev);
	283
	284	iio_device_unregister(indio_dev);
	285
	286	if (st->vref_reg) {
	287	regulator_disable(st->vref_reg);
	288	regulator_put(st->vref_reg);
	289	}
	290	regulator_disable(st->vdd_reg);
	291	regulator_put(st->vdd_reg);
	292
	293	iio_device_free(indio_dev);
	294
	295	return 0;
	296	}
	297
	298	static const struct spi_device_id ad7303_spi_ids[] = {
	299	{ "ad7303", 0 },
	300	{}
	301	};
	302	MODULE_DEVICE_TABLE(spi, ad7303_spi_ids);
	303
	304	static struct spi_driver ad7303_driver = {
	305	.driver = {
306	.name = "ad7303",
307	.owner = THIS_MODULE,
308	},
309	.probe = ad7303_probe,
310	.remove = ad7303_remove,
311	.id_table = ad7303_spi_ids,
312	};
313	module_spi_driver(ad7303_driver);
314
315	MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
316	MODULE_DESCRIPTION("Analog Devices AD7303 DAC driver");
317	MODULE_LICENSE("GPL v2");