drivers/iio/dac/ad5449.c - arm/linux - Git at Google

 /*
  * AD5415, AD5426, AD5429, AD5432, AD5439, AD5443, AD5449 Digital to Analog
  * Converter driver.
  *
  * Copyright 2012 Analog Devices Inc.
  *  Author: Lars-Peter Clausen <lars@metafoo.de>
  *
  * Licensed under the GPL-2.
  */

 #include <linux/device.h>
 #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 <asm/unaligned.h>

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

 #include <linux/platform_data/ad5449.h>

 #define AD5449_MAX_CHANNELS		2
 #define AD5449_MAX_VREFS		2

 #define AD5449_CMD_NOOP			0x0
 #define AD5449_CMD_LOAD_AND_UPDATE(x)	(0x1 + (x) * 3)
 #define AD5449_CMD_READ(x)		(0x2 + (x) * 3)
 #define AD5449_CMD_LOAD(x)		(0x3 + (x) * 3)
 #define AD5449_CMD_CTRL			13

 #define AD5449_CTRL_SDO_OFFSET		10
 #define AD5449_CTRL_DAISY_CHAIN		BIT(9)
 #define AD5449_CTRL_HCLR_TO_MIDSCALE	BIT(8)
 #define AD5449_CTRL_SAMPLE_RISING	BIT(7)

 /**
  * struct ad5449_chip_info - chip specific information
  * @channels:		Channel specification
  * @num_channels:	Number of channels
  * @has_ctrl:		Chip has a control register
  */
 struct ad5449_chip_info {
 	const struct iio_chan_spec *channels;
 	unsigned int num_channels;
 	bool has_ctrl;
 };

 /**
  * struct ad5449 - driver instance specific data
  * @spi:		the SPI device for this driver instance
  * @chip_info:		chip model specific constants, available modes etc
  * @vref_reg:		vref supply regulators
  * @has_sdo:		whether the SDO line is connected
  * @dac_cache:		Cache for the DAC values
  * @data:		spi transfer buffers
  */
 struct ad5449 {
 	struct spi_device		*spi;
 	const struct ad5449_chip_info	*chip_info;
 	struct regulator_bulk_data	vref_reg[AD5449_MAX_VREFS];

 	bool has_sdo;
 	uint16_t dac_cache[AD5449_MAX_CHANNELS];

 	/*
 	 * DMA (thus cache coherency maintenance) requires the
 	 * transfer buffers to live in their own cache lines.
 	 */
 	__be16 data[2] ____cacheline_aligned;
 };

 enum ad5449_type {
 	ID_AD5426,
 	ID_AD5429,
 	ID_AD5432,
 	ID_AD5439,
 	ID_AD5443,
 	ID_AD5449,
 };

 static int ad5449_write(struct iio_dev *indio_dev, unsigned int addr,
 	unsigned int val)
 {
 	struct ad5449 *st = iio_priv(indio_dev);
 	int ret;

 	mutex_lock(&indio_dev->mlock);
 	st->data[0] = cpu_to_be16((addr << 12) | val);
 	ret = spi_write(st->spi, st->data, 2);
 	mutex_unlock(&indio_dev->mlock);

 	return ret;
 }

 static int ad5449_read(struct iio_dev *indio_dev, unsigned int addr,
 	unsigned int *val)
 {
 	struct ad5449 *st = iio_priv(indio_dev);
 	int ret;
 	struct spi_transfer t[] = {
 		{
 			.tx_buf = &st->data[0],
 			.len = 2,
 			.cs_change = 1,
 		}, {
 			.tx_buf = &st->data[1],
 			.rx_buf = &st->data[1],
 			.len = 2,
 		},
 	};

 	mutex_lock(&indio_dev->mlock);
 	st->data[0] = cpu_to_be16(addr << 12);
 	st->data[1] = cpu_to_be16(AD5449_CMD_NOOP);

 	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
 	if (ret < 0)
 		goto out_unlock;

 	*val = be16_to_cpu(st->data[1]);

 out_unlock:
 	mutex_unlock(&indio_dev->mlock);
 	return ret;
 }

 static int ad5449_read_raw(struct iio_dev *indio_dev,
 	struct iio_chan_spec const *chan, int *val, int *val2, long info)
 {
 	struct ad5449 *st = iio_priv(indio_dev);
 	struct regulator_bulk_data *reg;
 	int scale_uv;
 	int ret;

 	switch (info) {
 	case IIO_CHAN_INFO_RAW:
 		if (st->has_sdo) {
 			ret = ad5449_read(indio_dev,
 				AD5449_CMD_READ(chan->address), val);
 			if (ret)
 				return ret;
 			*val &= 0xfff;
 		} else {
 			*val = st->dac_cache[chan->address];
 		}

 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		reg = &st->vref_reg[chan->channel];
 		scale_uv = regulator_get_voltage(reg->consumer);
 		if (scale_uv < 0)
 			return scale_uv;

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

 		return IIO_VAL_FRACTIONAL_LOG2;
 	default:
 		break;
 	}

 	return -EINVAL;
 }

 static int ad5449_write_raw(struct iio_dev *indio_dev,
 	struct iio_chan_spec const *chan, int val, int val2, long info)
 {
 	struct ad5449 *st = iio_priv(indio_dev);
 	int ret;

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

 		ret = ad5449_write(indio_dev,
 			AD5449_CMD_LOAD_AND_UPDATE(chan->address),
 			val << chan->scan_type.shift);
 		if (ret == 0)
 			st->dac_cache[chan->address] = val;
 		break;
 	default:
 		ret = -EINVAL;
 	}

 	return ret;
 }

 static const struct iio_info ad5449_info = {
 	.read_raw = ad5449_read_raw,
 	.write_raw = ad5449_write_raw,
 	.driver_module = THIS_MODULE,
 };

 #define AD5449_CHANNEL(chan, bits) {				\
 	.type = IIO_VOLTAGE,					\
 	.indexed = 1,						\
 	.output = 1,						\
 	.channel = (chan),					\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
 		BIT(IIO_CHAN_INFO_SCALE),			\
 	.address = (chan),					\
 	.scan_type = {						\
 		.sign = 'u',					\
 		.realbits = (bits),				\
 		.storagebits = 16,				\
 		.shift = 12 - (bits),				\
 	},							\
 }

 #define DECLARE_AD5449_CHANNELS(name, bits) \
 const struct iio_chan_spec name[] = { \
 	AD5449_CHANNEL(0, bits), \
 	AD5449_CHANNEL(1, bits), \
 }

 static DECLARE_AD5449_CHANNELS(ad5429_channels, 8);
 static DECLARE_AD5449_CHANNELS(ad5439_channels, 10);
 static DECLARE_AD5449_CHANNELS(ad5449_channels, 12);

 static const struct ad5449_chip_info ad5449_chip_info[] = {
 	[ID_AD5426] = {
 		.channels = ad5429_channels,
 		.num_channels = 1,
 		.has_ctrl = false,
 	},
 	[ID_AD5429] = {
 		.channels = ad5429_channels,
 		.num_channels = 2,
 		.has_ctrl = true,
 	},
 	[ID_AD5432] = {
 		.channels = ad5439_channels,
 		.num_channels = 1,
 		.has_ctrl = false,
 	},
 	[ID_AD5439] = {
 		.channels = ad5439_channels,
 		.num_channels = 2,
 		.has_ctrl = true,
 	},
 	[ID_AD5443] = {
 		.channels = ad5449_channels,
 		.num_channels = 1,
 		.has_ctrl = false,
 	},
 	[ID_AD5449] = {
 		.channels = ad5449_channels,
 		.num_channels = 2,
 		.has_ctrl = true,
 	},
 };

 static const char *ad5449_vref_name(struct ad5449 *st, int n)
 {
 	if (st->chip_info->num_channels == 1)
 		return "VREF";

 	if (n == 0)
 		return "VREFA";
 	else
 		return "VREFB";
 }

 static int ad5449_spi_probe(struct spi_device *spi)
 {
 	struct ad5449_platform_data *pdata = spi->dev.platform_data;
 	const struct spi_device_id *id = spi_get_device_id(spi);
 	struct iio_dev *indio_dev;
 	struct ad5449 *st;
 	unsigned int i;
 	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->chip_info = &ad5449_chip_info[id->driver_data];
 	st->spi = spi;

 	for (i = 0; i < st->chip_info->num_channels; ++i)
 		st->vref_reg[i].supply = ad5449_vref_name(st, i);

 	ret = devm_regulator_bulk_get(&spi->dev, st->chip_info->num_channels,
 				st->vref_reg);
 	if (ret)
 		return ret;

 	ret = regulator_bulk_enable(st->chip_info->num_channels, st->vref_reg);
 	if (ret)
 		return ret;

 	indio_dev->dev.parent = &spi->dev;
 	indio_dev->name = id->name;
 	indio_dev->info = &ad5449_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = st->chip_info->channels;
 	indio_dev->num_channels = st->chip_info->num_channels;

 	if (st->chip_info->has_ctrl) {
 		unsigned int ctrl = 0x00;
 		if (pdata) {
 			if (pdata->hardware_clear_to_midscale)
 				ctrl |= AD5449_CTRL_HCLR_TO_MIDSCALE;
 			ctrl |= pdata->sdo_mode << AD5449_CTRL_SDO_OFFSET;
 			st->has_sdo = pdata->sdo_mode != AD5449_SDO_DISABLED;
 		} else {
 			st->has_sdo = true;
 		}
 		ad5449_write(indio_dev, AD5449_CMD_CTRL, ctrl);
 	}

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

 	return 0;

 error_disable_reg:
 	regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);

 	return ret;
 }

 static int ad5449_spi_remove(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
 	struct ad5449 *st = iio_priv(indio_dev);

 	iio_device_unregister(indio_dev);

 	regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);

 	return 0;
 }

 static const struct spi_device_id ad5449_spi_ids[] = {
 	{ "ad5415", ID_AD5449 },
 	{ "ad5426", ID_AD5426 },
 	{ "ad5429", ID_AD5429 },
 	{ "ad5432", ID_AD5432 },
 	{ "ad5439", ID_AD5439 },
 	{ "ad5443", ID_AD5443 },
 	{ "ad5449", ID_AD5449 },
 	{}
 };
 MODULE_DEVICE_TABLE(spi, ad5449_spi_ids);

 static struct spi_driver ad5449_spi_driver = {
 	.driver = {
 		.name = "ad5449",
 	},
 	.probe = ad5449_spi_probe,
 	.remove = ad5449_spi_remove,
 	.id_table = ad5449_spi_ids,
 };
 module_spi_driver(ad5449_spi_driver);

 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 MODULE_DESCRIPTION("Analog Devices AD5449 and similar DACs");
 MODULE_LICENSE("GPL v2");
	/*
	* AD5415, AD5426, AD5429, AD5432, AD5439, AD5443, AD5449 Digital to Analog
	* Converter driver.
	*
	* Copyright 2012 Analog Devices Inc.
	* Author: Lars-Peter Clausen <lars@metafoo.de>
	*
	* Licensed under the GPL-2.
	*/

	#include <linux/device.h>
	#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 <asm/unaligned.h>

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

	#include <linux/platform_data/ad5449.h>

	#define AD5449_MAX_CHANNELS 2
	#define AD5449_MAX_VREFS 2

	#define AD5449_CMD_NOOP 0x0
	#define AD5449_CMD_LOAD_AND_UPDATE(x) (0x1 + (x) * 3)
	#define AD5449_CMD_READ(x) (0x2 + (x) * 3)
	#define AD5449_CMD_LOAD(x) (0x3 + (x) * 3)
	#define AD5449_CMD_CTRL 13

	#define AD5449_CTRL_SDO_OFFSET 10
	#define AD5449_CTRL_DAISY_CHAIN BIT(9)
	#define AD5449_CTRL_HCLR_TO_MIDSCALE BIT(8)
	#define AD5449_CTRL_SAMPLE_RISING BIT(7)

	/**
	* struct ad5449_chip_info - chip specific information
	* @channels: Channel specification
	* @num_channels: Number of channels
	* @has_ctrl: Chip has a control register
	*/
	struct ad5449_chip_info {
	const struct iio_chan_spec *channels;
	unsigned int num_channels;
	bool has_ctrl;
	};

	/**
	* struct ad5449 - driver instance specific data
	* @spi: the SPI device for this driver instance
	* @chip_info: chip model specific constants, available modes etc
	* @vref_reg: vref supply regulators
	* @has_sdo: whether the SDO line is connected
	* @dac_cache: Cache for the DAC values
	* @data: spi transfer buffers
	*/
	struct ad5449 {
	struct spi_device *spi;
	const struct ad5449_chip_info *chip_info;
	struct regulator_bulk_data vref_reg[AD5449_MAX_VREFS];

	bool has_sdo;
	uint16_t dac_cache[AD5449_MAX_CHANNELS];

	/*
	* DMA (thus cache coherency maintenance) requires the
	* transfer buffers to live in their own cache lines.
	*/
	__be16 data[2] ____cacheline_aligned;
	};

	enum ad5449_type {
	ID_AD5426,
	ID_AD5429,
	ID_AD5432,
	ID_AD5439,
	ID_AD5443,
	ID_AD5449,
	};

	static int ad5449_write(struct iio_dev *indio_dev, unsigned int addr,
	unsigned int val)
	{
	struct ad5449 *st = iio_priv(indio_dev);
	int ret;

	mutex_lock(&indio_dev->mlock);
	st->data[0] = cpu_to_be16((addr << 12) \| val);
	ret = spi_write(st->spi, st->data, 2);
	mutex_unlock(&indio_dev->mlock);

	return ret;
	}

	static int ad5449_read(struct iio_dev *indio_dev, unsigned int addr,
	unsigned int *val)
	{
	struct ad5449 *st = iio_priv(indio_dev);
	int ret;
	struct spi_transfer t[] = {
	{
	.tx_buf = &st->data[0],
	.len = 2,
	.cs_change = 1,
	}, {
	.tx_buf = &st->data[1],
	.rx_buf = &st->data[1],
	.len = 2,
	},
	};

	mutex_lock(&indio_dev->mlock);
	st->data[0] = cpu_to_be16(addr << 12);
	st->data[1] = cpu_to_be16(AD5449_CMD_NOOP);

	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
	if (ret < 0)
	goto out_unlock;

	*val = be16_to_cpu(st->data[1]);

	out_unlock:
	mutex_unlock(&indio_dev->mlock);
	return ret;
	}

	static int ad5449_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const chan, int val, int *val2, long info)
	{
	struct ad5449 *st = iio_priv(indio_dev);
	struct regulator_bulk_data *reg;
	int scale_uv;
	int ret;

	switch (info) {
	case IIO_CHAN_INFO_RAW:
	if (st->has_sdo) {
	ret = ad5449_read(indio_dev,
	AD5449_CMD_READ(chan->address), val);
	if (ret)
	return ret;
	*val &= 0xfff;
	} else {
	*val = st->dac_cache[chan->address];
	}

	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
	reg = &st->vref_reg[chan->channel];
	scale_uv = regulator_get_voltage(reg->consumer);
	if (scale_uv < 0)
	return scale_uv;

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

	return IIO_VAL_FRACTIONAL_LOG2;
	default:
	break;
	}

	return -EINVAL;
	}

	static int ad5449_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan, int val, int val2, long info)
	{
	struct ad5449 *st = iio_priv(indio_dev);
	int ret;

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

	ret = ad5449_write(indio_dev,
	AD5449_CMD_LOAD_AND_UPDATE(chan->address),
	val << chan->scan_type.shift);
	if (ret == 0)
	st->dac_cache[chan->address] = val;
	break;
	default:
	ret = -EINVAL;
	}

	return ret;
	}

	static const struct iio_info ad5449_info = {
	.read_raw = ad5449_read_raw,
	.write_raw = ad5449_write_raw,
	.driver_module = THIS_MODULE,
	};

	#define AD5449_CHANNEL(chan, bits) { \
	.type = IIO_VOLTAGE, \
	.indexed = 1, \
	.output = 1, \
	.channel = (chan), \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \| \
	BIT(IIO_CHAN_INFO_SCALE), \
	.address = (chan), \
	.scan_type = { \
	.sign = 'u', \
	.realbits = (bits), \
	.storagebits = 16, \
	.shift = 12 - (bits), \
	}, \
	}

	#define DECLARE_AD5449_CHANNELS(name, bits) \
	const struct iio_chan_spec name[] = { \
	AD5449_CHANNEL(0, bits), \
	AD5449_CHANNEL(1, bits), \
	}

	static DECLARE_AD5449_CHANNELS(ad5429_channels, 8);
	static DECLARE_AD5449_CHANNELS(ad5439_channels, 10);
	static DECLARE_AD5449_CHANNELS(ad5449_channels, 12);

	static const struct ad5449_chip_info ad5449_chip_info[] = {
	[ID_AD5426] = {
	.channels = ad5429_channels,
	.num_channels = 1,
	.has_ctrl = false,
	},
	[ID_AD5429] = {
	.channels = ad5429_channels,
	.num_channels = 2,
	.has_ctrl = true,
	},
	[ID_AD5432] = {
	.channels = ad5439_channels,
	.num_channels = 1,
	.has_ctrl = false,
	},
	[ID_AD5439] = {
	.channels = ad5439_channels,
	.num_channels = 2,
	.has_ctrl = true,
	},
	[ID_AD5443] = {
	.channels = ad5449_channels,
	.num_channels = 1,
	.has_ctrl = false,
	},
	[ID_AD5449] = {
	.channels = ad5449_channels,
	.num_channels = 2,
	.has_ctrl = true,
	},
	};

	static const char ad5449_vref_name(struct ad5449 st, int n)
	{
	if (st->chip_info->num_channels == 1)
	return "VREF";

	if (n == 0)
	return "VREFA";
	else
	return "VREFB";
	}

	static int ad5449_spi_probe(struct spi_device *spi)
	{
	struct ad5449_platform_data *pdata = spi->dev.platform_data;
	const struct spi_device_id *id = spi_get_device_id(spi);
	struct iio_dev *indio_dev;
	struct ad5449 *st;
	unsigned int i;
	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->chip_info = &ad5449_chip_info[id->driver_data];
	st->spi = spi;

	for (i = 0; i < st->chip_info->num_channels; ++i)
	st->vref_reg[i].supply = ad5449_vref_name(st, i);

	ret = devm_regulator_bulk_get(&spi->dev, st->chip_info->num_channels,
	st->vref_reg);
	if (ret)
	return ret;

	ret = regulator_bulk_enable(st->chip_info->num_channels, st->vref_reg);
	if (ret)
	return ret;

	indio_dev->dev.parent = &spi->dev;
	indio_dev->name = id->name;
	indio_dev->info = &ad5449_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = st->chip_info->channels;
	indio_dev->num_channels = st->chip_info->num_channels;

	if (st->chip_info->has_ctrl) {
	unsigned int ctrl = 0x00;
	if (pdata) {
	if (pdata->hardware_clear_to_midscale)
	ctrl \|= AD5449_CTRL_HCLR_TO_MIDSCALE;
	ctrl \|= pdata->sdo_mode << AD5449_CTRL_SDO_OFFSET;
	st->has_sdo = pdata->sdo_mode != AD5449_SDO_DISABLED;
	} else {
	st->has_sdo = true;
	}
	ad5449_write(indio_dev, AD5449_CMD_CTRL, ctrl);
	}

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

	return 0;

	error_disable_reg:
	regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);

	return ret;
	}

	static int ad5449_spi_remove(struct spi_device *spi)
	{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct ad5449 *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);

	regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);

	return 0;
	}

	static const struct spi_device_id ad5449_spi_ids[] = {
	{ "ad5415", ID_AD5449 },
	{ "ad5426", ID_AD5426 },
	{ "ad5429", ID_AD5429 },
	{ "ad5432", ID_AD5432 },
	{ "ad5439", ID_AD5439 },
	{ "ad5443", ID_AD5443 },
	{ "ad5449", ID_AD5449 },
	{}
	};
	MODULE_DEVICE_TABLE(spi, ad5449_spi_ids);

	static struct spi_driver ad5449_spi_driver = {
	.driver = {
	.name = "ad5449",
	},
	.probe = ad5449_spi_probe,
	.remove = ad5449_spi_remove,
	.id_table = ad5449_spi_ids,
	};
	module_spi_driver(ad5449_spi_driver);

	MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
	MODULE_DESCRIPTION("Analog Devices AD5449 and similar DACs");
	MODULE_LICENSE("GPL v2");