[linux-block.git] / drivers / iio / amplifiers / ad8366.c

/*
 * AD8366 SPI Dual-Digital Variable Gain Amplifier (VGA)
 *
 * Copyright 2012 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/bitrev.h>

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

struct ad8366_state {
	struct spi_device	*spi;
	struct regulator	*reg;
	unsigned char		ch[2];
	/*
	 * DMA (thus cache coherency maintenance) requires the
	 * transfer buffers to live in their own cache lines.
	 */
	unsigned char		data[2] ____cacheline_aligned;
};

static int ad8366_write(struct iio_dev *indio_dev,
			unsigned char ch_a, unsigned char ch_b)
{
	struct ad8366_state *st = iio_priv(indio_dev);
	int ret;

	ch_a = bitrev8(ch_a & 0x3F);
	ch_b = bitrev8(ch_b & 0x3F);

	st->data[0] = ch_b >> 4;
	st->data[1] = (ch_b << 4) | (ch_a >> 2);

	ret = spi_write(st->spi, st->data, ARRAY_SIZE(st->data));
	if (ret < 0)
		dev_err(&indio_dev->dev, "write failed (%d)", ret);

	return ret;
}

static int ad8366_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val,
			   int *val2,
			   long m)
{
	struct ad8366_state *st = iio_priv(indio_dev);
	int ret;
	unsigned code;

	mutex_lock(&indio_dev->mlock);
	switch (m) {
	case IIO_CHAN_INFO_HARDWAREGAIN:
		code = st->ch[chan->channel];

		/* Values in dB */
		code = code * 253 + 4500;
		*val = code / 1000;
		*val2 = (code % 1000) * 1000;

		ret = IIO_VAL_INT_PLUS_MICRO_DB;
		break;
	default:
		ret = -EINVAL;
	}
	mutex_unlock(&indio_dev->mlock);

	return ret;
};

static int ad8366_write_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int val,
			    int val2,
			    long mask)
{
	struct ad8366_state *st = iio_priv(indio_dev);
	unsigned code;
	int ret;

	if (val < 0 || val2 < 0)
		return -EINVAL;

	/* Values in dB */
	code = (((u8)val * 1000) + ((u32)val2 / 1000));

	if (code > 20500 || code < 4500)
		return -EINVAL;

	code = (code - 4500) / 253;

	mutex_lock(&indio_dev->mlock);
	switch (mask) {
	case IIO_CHAN_INFO_HARDWAREGAIN:
		st->ch[chan->channel] = code;
		ret = ad8366_write(indio_dev, st->ch[0], st->ch[1]);
		break;
	default:
		ret = -EINVAL;
	}
	mutex_unlock(&indio_dev->mlock);

	return ret;
}

static const struct iio_info ad8366_info = {
	.read_raw = &ad8366_read_raw,
	.write_raw = &ad8366_write_raw,
};

#define AD8366_CHAN(_channel) {				\
	.type = IIO_VOLTAGE,				\
	.output = 1,					\
	.indexed = 1,					\
	.channel = _channel,				\
	.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),\
}

static const struct iio_chan_spec ad8366_channels[] = {
	AD8366_CHAN(0),
	AD8366_CHAN(1),
};

static int ad8366_probe(struct spi_device *spi)
{
	struct iio_dev *indio_dev;
	struct ad8366_state *st;
	int ret;

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

	st = iio_priv(indio_dev);

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

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

	indio_dev->dev.parent = &spi->dev;
	indio_dev->name = spi_get_device_id(spi)->name;
	indio_dev->info = &ad8366_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = ad8366_channels;
	indio_dev->num_channels = ARRAY_SIZE(ad8366_channels);

	ret = ad8366_write(indio_dev, 0 , 0);
	if (ret < 0)
		goto error_disable_reg;

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

	return 0;

error_disable_reg:
	if (!IS_ERR(st->reg))
		regulator_disable(st->reg);

	return ret;
}

static int ad8366_remove(struct spi_device *spi)
{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct ad8366_state *st = iio_priv(indio_dev);
	struct regulator *reg = st->reg;

	iio_device_unregister(indio_dev);

	if (!IS_ERR(reg))
		regulator_disable(reg);

	return 0;
}

static const struct spi_device_id ad8366_id[] = {
	{"ad8366", 0},
	{}
};
MODULE_DEVICE_TABLE(spi, ad8366_id);

static struct spi_driver ad8366_driver = {
	.driver = {
		.name	= KBUILD_MODNAME,
	},
	.probe		= ad8366_probe,
	.remove		= ad8366_remove,
	.id_table	= ad8366_id,
};

module_spi_driver(ad8366_driver);

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD8366 VGA");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
e71d42e0 MH	1	/*
	2	* AD8366 SPI Dual-Digital Variable Gain Amplifier (VGA)
	3	*
	4	* Copyright 2012 Analog Devices Inc.
	5	*
	6	* Licensed under the GPL-2.
	7	*/
	8
	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/module.h>
	17	#include <linux/bitrev.h>
	18
	19	#include <linux/iio/iio.h>
	20	#include <linux/iio/sysfs.h>
	21
	22	struct ad8366_state {
	23	struct spi_device *spi;
	24	struct regulator *reg;
	25	unsigned char ch[2];
	26	/*
	27	* DMA (thus cache coherency maintenance) requires the
	28	* transfer buffers to live in their own cache lines.
	29	*/
	30	unsigned char data[2] ____cacheline_aligned;
	31	};
	32
	33	static int ad8366_write(struct iio_dev *indio_dev,
ff6f4629	34	unsigned char ch_a, unsigned char ch_b)
e71d42e0 MH	35	{
	36	struct ad8366_state *st = iio_priv(indio_dev);
	37	int ret;
	38
	39	ch_a = bitrev8(ch_a & 0x3F);
	40	ch_b = bitrev8(ch_b & 0x3F);
	41
	42	st->data[0] = ch_b >> 4;
	43	st->data[1] = (ch_b << 4) \| (ch_a >> 2);
	44
	45	ret = spi_write(st->spi, st->data, ARRAY_SIZE(st->data));
	46	if (ret < 0)
	47	dev_err(&indio_dev->dev, "write failed (%d)", ret);
	48
	49	return ret;
	50	}
	51
	52	static int ad8366_read_raw(struct iio_dev *indio_dev,
	53	struct iio_chan_spec const *chan,
	54	int *val,
	55	int *val2,
	56	long m)
	57	{
	58	struct ad8366_state *st = iio_priv(indio_dev);
	59	int ret;
	60	unsigned code;
	61
	62	mutex_lock(&indio_dev->mlock);
	63	switch (m) {
	64	case IIO_CHAN_INFO_HARDWAREGAIN:
	65	code = st->ch[chan->channel];
	66
	67	/* Values in dB */
	68	code = code * 253 + 4500;
	69	*val = code / 1000;
	70	val2 = (code % 1000) 1000;
	71
	72	ret = IIO_VAL_INT_PLUS_MICRO_DB;
	73	break;
	74	default:
	75	ret = -EINVAL;
	76	}
	77	mutex_unlock(&indio_dev->mlock);
	78
	79	return ret;
	80	};
	81
	82	static int ad8366_write_raw(struct iio_dev *indio_dev,
	83	struct iio_chan_spec const *chan,
	84	int val,
	85	int val2,
	86	long mask)
	87	{
	88	struct ad8366_state *st = iio_priv(indio_dev);
	89	unsigned code;
	90	int ret;
	91
	92	if (val < 0 \|\| val2 < 0)
	93	return -EINVAL;
	94
	95	/* Values in dB */
	96	code = (((u8)val * 1000) + ((u32)val2 / 1000));
	97
	98	if (code > 20500 \|\| code < 4500)
99	return -EINVAL;
100
101	code = (code - 4500) / 253;
102
103	mutex_lock(&indio_dev->mlock);
104	switch (mask) {
105	case IIO_CHAN_INFO_HARDWAREGAIN:
106	st->ch[chan->channel] = code;
107	ret = ad8366_write(indio_dev, st->ch[0], st->ch[1]);
108	break;
109	default:
110	ret = -EINVAL;
111	}
112	mutex_unlock(&indio_dev->mlock);
113
114	return ret;
115	}
116
117	static const struct iio_info ad8366_info = {
118	.read_raw = &ad8366_read_raw,
119	.write_raw = &ad8366_write_raw,
e71d42e0 MH	120	};
	121
	122	#define AD8366_CHAN(_channel) { \
	123	.type = IIO_VOLTAGE, \
	124	.output = 1, \
	125	.indexed = 1, \
	126	.channel = _channel, \
b34ec6f3	127	.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),\
e71d42e0 MH	128	}
	129
	130	static const struct iio_chan_spec ad8366_channels[] = {
	131	AD8366_CHAN(0),
	132	AD8366_CHAN(1),
	133	};
	134
fc52692c	135	static int ad8366_probe(struct spi_device *spi)
e71d42e0 MH	136	{
	137	struct iio_dev *indio_dev;
	138	struct ad8366_state *st;
	139	int ret;
	140
36db8c72	141	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
e71d42e0 MH	142	if (indio_dev == NULL)
	143	return -ENOMEM;
	144
	145	st = iio_priv(indio_dev);
	146
36db8c72	147	st->reg = devm_regulator_get(&spi->dev, "vcc");
e71d42e0 MH	148	if (!IS_ERR(st->reg)) {
	149	ret = regulator_enable(st->reg);
	150	if (ret)
36db8c72	151	return ret;
e71d42e0 MH	152	}
	153
	154	spi_set_drvdata(spi, indio_dev);
	155	st->spi = spi;
	156
	157	indio_dev->dev.parent = &spi->dev;
	158	indio_dev->name = spi_get_device_id(spi)->name;
	159	indio_dev->info = &ad8366_info;
	160	indio_dev->modes = INDIO_DIRECT_MODE;
	161	indio_dev->channels = ad8366_channels;
	162	indio_dev->num_channels = ARRAY_SIZE(ad8366_channels);
	163
2636d005 AA	164	ret = ad8366_write(indio_dev, 0 , 0);
	165	if (ret < 0)
	166	goto error_disable_reg;
	167
e71d42e0 MH	168	ret = iio_device_register(indio_dev);
	169	if (ret)
	170	goto error_disable_reg;
	171
e71d42e0 MH	172	return 0;
	173
	174	error_disable_reg:
	175	if (!IS_ERR(st->reg))
	176	regulator_disable(st->reg);
e71d42e0 MH	177
	178	return ret;
	179	}
	180
fc52692c	181	static int ad8366_remove(struct spi_device *spi)
e71d42e0 MH	182	{
	183	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	184	struct ad8366_state *st = iio_priv(indio_dev);
	185	struct regulator *reg = st->reg;
	186
	187	iio_device_unregister(indio_dev);
	188
d3789c3e	189	if (!IS_ERR(reg))
e71d42e0	190	regulator_disable(reg);
e71d42e0	191
e71d42e0 MH	192	return 0;
	193	}
	194
	195	static const struct spi_device_id ad8366_id[] = {
	196	{"ad8366", 0},
	197	{}
	198	};
ed199a11	199	MODULE_DEVICE_TABLE(spi, ad8366_id);
e71d42e0 MH	200
	201	static struct spi_driver ad8366_driver = {
	202	.driver = {
	203	.name = KBUILD_MODNAME,
e71d42e0 MH	204	},
e71d42e0 MH	205	.probe = ad8366_probe,
fc52692c	206	.remove = ad8366_remove,
e71d42e0 MH	207	.id_table = ad8366_id,
	208	};
	209
	210	module_spi_driver(ad8366_driver);
	211
9920ed25	212	MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
e71d42e0 MH	213	MODULE_DESCRIPTION("Analog Devices AD8366 VGA");
e71d42e0 MH	214	MODULE_LICENSE("GPL v2");