drivers/iio/dac/ad5504.c - arm/linux - Git at Google

 /*
  * AD5504, AD5501 High Voltage Digital to Analog Converter
  *
  * Copyright 2011 Analog Devices Inc.
  *
  * Licensed under the GPL-2.
  */

 #include <linux/interrupt.h>
 #include <linux/fs.h>
 #include <linux/device.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/module.h>
 #include <linux/bitops.h>

 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/events.h>
 #include <linux/iio/dac/ad5504.h>

 #define AD5504_RES_MASK			GENMASK(11, 0)
 #define AD5504_CMD_READ			BIT(15)
 #define AD5504_CMD_WRITE		0
 #define AD5504_ADDR(addr)		((addr) << 12)

 /* Registers */
 #define AD5504_ADDR_NOOP		0
 #define AD5504_ADDR_DAC(x)		((x) + 1)
 #define AD5504_ADDR_ALL_DAC		5
 #define AD5504_ADDR_CTRL		7

 /* Control Register */
 #define AD5504_DAC_PWR(ch)		((ch) << 2)
 #define AD5504_DAC_PWRDWN_MODE(mode)	((mode) << 6)
 #define AD5504_DAC_PWRDN_20K		0
 #define AD5504_DAC_PWRDN_3STATE		1

 /**
  * struct ad5446_state - driver instance specific data
  * @spi:			spi_device
  * @reg:		supply regulator
  * @vref_mv:		actual reference voltage used
  * @pwr_down_mask	power down mask
  * @pwr_down_mode	current power down mode
  * @data:		transfer buffer
  */
 struct ad5504_state {
 	struct spi_device		*spi;
 	struct regulator		*reg;
 	unsigned short			vref_mv;
 	unsigned			pwr_down_mask;
 	unsigned			pwr_down_mode;

 	__be16				data[2] ____cacheline_aligned;
 };

 /**
  * ad5504_supported_device_ids:
  */

 enum ad5504_supported_device_ids {
 	ID_AD5504,
 	ID_AD5501,
 };

 static int ad5504_spi_write(struct ad5504_state *st, u8 addr, u16 val)
 {
 	st->data[0] = cpu_to_be16(AD5504_CMD_WRITE | AD5504_ADDR(addr) |
 			      (val & AD5504_RES_MASK));

 	return spi_write(st->spi, &st->data[0], 2);
 }

 static int ad5504_spi_read(struct ad5504_state *st, u8 addr)
 {
 	int ret;
 	struct spi_transfer t = {
 	    .tx_buf = &st->data[0],
 	    .rx_buf = &st->data[1],
 	    .len = 2,
 	};

 	st->data[0] = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr));
 	ret = spi_sync_transfer(st->spi, &t, 1);
 	if (ret < 0)
 		return ret;

 	return be16_to_cpu(st->data[1]) & AD5504_RES_MASK;
 }

 static int ad5504_read_raw(struct iio_dev *indio_dev,
 			   struct iio_chan_spec const *chan,
 			   int *val,
 			   int *val2,
 			   long m)
 {
 	struct ad5504_state *st = iio_priv(indio_dev);
 	int ret;

 	switch (m) {
 	case IIO_CHAN_INFO_RAW:
 		ret = ad5504_spi_read(st, chan->address);
 		if (ret < 0)
 			return ret;

 		*val = ret;

 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		*val = st->vref_mv;
 		*val2 = chan->scan_type.realbits;
 		return IIO_VAL_FRACTIONAL_LOG2;
 	}
 	return -EINVAL;
 }

 static int ad5504_write_raw(struct iio_dev *indio_dev,
 			       struct iio_chan_spec const *chan,
 			       int val,
 			       int val2,
 			       long mask)
 {
 	struct ad5504_state *st = iio_priv(indio_dev);

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

 		return ad5504_spi_write(st, chan->address, val);
 	default:
 		return -EINVAL;
 	}
 }

 static const char * const ad5504_powerdown_modes[] = {
 	"20kohm_to_gnd",
 	"three_state",
 };

 static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
 	const struct iio_chan_spec *chan)
 {
 	struct ad5504_state *st = iio_priv(indio_dev);

 	return st->pwr_down_mode;
 }

 static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
 	const struct iio_chan_spec *chan, unsigned int mode)
 {
 	struct ad5504_state *st = iio_priv(indio_dev);

 	st->pwr_down_mode = mode;

 	return 0;
 }

 static const struct iio_enum ad5504_powerdown_mode_enum = {
 	.items = ad5504_powerdown_modes,
 	.num_items = ARRAY_SIZE(ad5504_powerdown_modes),
 	.get = ad5504_get_powerdown_mode,
 	.set = ad5504_set_powerdown_mode,
 };

 static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
 	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
 {
 	struct ad5504_state *st = iio_priv(indio_dev);

 	return sprintf(buf, "%d\n",
 			!(st->pwr_down_mask & (1 << chan->channel)));
 }

 static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
 	uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
 	size_t len)
 {
 	bool pwr_down;
 	int ret;
 	struct ad5504_state *st = iio_priv(indio_dev);

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

 	if (pwr_down)
 		st->pwr_down_mask |= (1 << chan->channel);
 	else
 		st->pwr_down_mask &= ~(1 << chan->channel);

 	ret = ad5504_spi_write(st, AD5504_ADDR_CTRL,
 				AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) |
 				AD5504_DAC_PWR(st->pwr_down_mask));

 	/* writes to the CTRL register must be followed by a NOOP */
 	ad5504_spi_write(st, AD5504_ADDR_NOOP, 0);

 	return ret ? ret : len;
 }

 static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
 static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");

 static struct attribute *ad5504_ev_attributes[] = {
 	&iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
 	&iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
 	NULL,
 };

 static const struct attribute_group ad5504_ev_attribute_group = {
 	.attrs = ad5504_ev_attributes,
 };

 static irqreturn_t ad5504_event_handler(int irq, void *private)
 {
 	iio_push_event(private,
 		       IIO_UNMOD_EVENT_CODE(IIO_TEMP,
 					    0,
 					    IIO_EV_TYPE_THRESH,
 					    IIO_EV_DIR_RISING),
 		       iio_get_time_ns(private));

 	return IRQ_HANDLED;
 }

 static const struct iio_info ad5504_info = {
 	.write_raw = ad5504_write_raw,
 	.read_raw = ad5504_read_raw,
 	.event_attrs = &ad5504_ev_attribute_group,
 	.driver_module = THIS_MODULE,
 };

 static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
 	{
 		.name = "powerdown",
 		.read = ad5504_read_dac_powerdown,
 		.write = ad5504_write_dac_powerdown,
 		.shared = IIO_SEPARATE,
 	},
 	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
 		 &ad5504_powerdown_mode_enum),
 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum),
 	{ },
 };

 #define AD5504_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 = AD5504_ADDR_DAC(_chan), \
 	.scan_type = { \
 		.sign = 'u', \
 		.realbits = 12, \
 		.storagebits = 16, \
 	}, \
 	.ext_info = ad5504_ext_info, \
 }

 static const struct iio_chan_spec ad5504_channels[] = {
 	AD5504_CHANNEL(0),
 	AD5504_CHANNEL(1),
 	AD5504_CHANNEL(2),
 	AD5504_CHANNEL(3),
 };

 static int ad5504_probe(struct spi_device *spi)
 {
 	struct ad5504_platform_data *pdata = spi->dev.platform_data;
 	struct iio_dev *indio_dev;
 	struct ad5504_state *st;
 	struct regulator *reg;
 	int ret, voltage_uv = 0;

 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 	if (!indio_dev)
 		return -ENOMEM;
 	reg = devm_regulator_get(&spi->dev, "vcc");
 	if (!IS_ERR(reg)) {
 		ret = regulator_enable(reg);
 		if (ret)
 			return ret;

 		ret = regulator_get_voltage(reg);
 		if (ret < 0)
 			goto error_disable_reg;

 		voltage_uv = ret;
 	}

 	spi_set_drvdata(spi, indio_dev);
 	st = iio_priv(indio_dev);
 	if (voltage_uv)
 		st->vref_mv = voltage_uv / 1000;
 	else if (pdata)
 		st->vref_mv = pdata->vref_mv;
 	else
 		dev_warn(&spi->dev, "reference voltage unspecified\n");

 	st->reg = reg;
 	st->spi = spi;
 	indio_dev->dev.parent = &spi->dev;
 	indio_dev->name = spi_get_device_id(st->spi)->name;
 	indio_dev->info = &ad5504_info;
 	if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
 		indio_dev->num_channels = 1;
 	else
 		indio_dev->num_channels = 4;
 	indio_dev->channels = ad5504_channels;
 	indio_dev->modes = INDIO_DIRECT_MODE;

 	if (spi->irq) {
 		ret = devm_request_threaded_irq(&spi->dev, spi->irq,
 					   NULL,
 					   &ad5504_event_handler,
 					   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 					   spi_get_device_id(st->spi)->name,
 					   indio_dev);
 		if (ret)
 			goto error_disable_reg;
 	}

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

 	return 0;

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

 	return ret;
 }

 static int ad5504_remove(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
 	struct ad5504_state *st = iio_priv(indio_dev);

 	iio_device_unregister(indio_dev);

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

 	return 0;
 }

 static const struct spi_device_id ad5504_id[] = {
 	{"ad5504", ID_AD5504},
 	{"ad5501", ID_AD5501},
 	{}
 };
 MODULE_DEVICE_TABLE(spi, ad5504_id);

 static struct spi_driver ad5504_driver = {
 	.driver = {
 		   .name = "ad5504",
 		   },
 	.probe = ad5504_probe,
 	.remove = ad5504_remove,
 	.id_table = ad5504_id,
 };
 module_spi_driver(ad5504_driver);

 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
 MODULE_LICENSE("GPL v2");
	/*
	* AD5504, AD5501 High Voltage Digital to Analog Converter
	*
	* Copyright 2011 Analog Devices Inc.
	*
	* Licensed under the GPL-2.
	*/

	#include <linux/interrupt.h>
	#include <linux/fs.h>
	#include <linux/device.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/module.h>
	#include <linux/bitops.h>

	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/events.h>
	#include <linux/iio/dac/ad5504.h>

	#define AD5504_RES_MASK GENMASK(11, 0)
	#define AD5504_CMD_READ BIT(15)
	#define AD5504_CMD_WRITE 0
	#define AD5504_ADDR(addr) ((addr) << 12)

	/* Registers */
	#define AD5504_ADDR_NOOP 0
	#define AD5504_ADDR_DAC(x) ((x) + 1)
	#define AD5504_ADDR_ALL_DAC 5
	#define AD5504_ADDR_CTRL 7

	/* Control Register */
	#define AD5504_DAC_PWR(ch) ((ch) << 2)
	#define AD5504_DAC_PWRDWN_MODE(mode) ((mode) << 6)
	#define AD5504_DAC_PWRDN_20K 0
	#define AD5504_DAC_PWRDN_3STATE 1

	/**
	* struct ad5446_state - driver instance specific data
	* @spi: spi_device
	* @reg: supply regulator
	* @vref_mv: actual reference voltage used
	* @pwr_down_mask power down mask
	* @pwr_down_mode current power down mode
	* @data: transfer buffer
	*/
	struct ad5504_state {
	struct spi_device *spi;
	struct regulator *reg;
	unsigned short vref_mv;
	unsigned pwr_down_mask;
	unsigned pwr_down_mode;

	__be16 data[2] ____cacheline_aligned;
	};

	/**
	* ad5504_supported_device_ids:
	*/

	enum ad5504_supported_device_ids {
	ID_AD5504,
	ID_AD5501,
	};

	static int ad5504_spi_write(struct ad5504_state *st, u8 addr, u16 val)
	{
	st->data[0] = cpu_to_be16(AD5504_CMD_WRITE \| AD5504_ADDR(addr) \|
	(val & AD5504_RES_MASK));

	return spi_write(st->spi, &st->data[0], 2);
	}

	static int ad5504_spi_read(struct ad5504_state *st, u8 addr)
	{
	int ret;
	struct spi_transfer t = {
	.tx_buf = &st->data[0],
	.rx_buf = &st->data[1],
	.len = 2,
	};

	st->data[0] = cpu_to_be16(AD5504_CMD_READ \| AD5504_ADDR(addr));
	ret = spi_sync_transfer(st->spi, &t, 1);
	if (ret < 0)
	return ret;

	return be16_to_cpu(st->data[1]) & AD5504_RES_MASK;
	}

	static int ad5504_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int *val,
	int *val2,
	long m)
	{
	struct ad5504_state *st = iio_priv(indio_dev);
	int ret;

	switch (m) {
	case IIO_CHAN_INFO_RAW:
	ret = ad5504_spi_read(st, chan->address);
	if (ret < 0)
	return ret;

	*val = ret;

	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
	*val = st->vref_mv;
	*val2 = chan->scan_type.realbits;
	return IIO_VAL_FRACTIONAL_LOG2;
	}
	return -EINVAL;
	}

	static int ad5504_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val,
	int val2,
	long mask)
	{
	struct ad5504_state *st = iio_priv(indio_dev);

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

	return ad5504_spi_write(st, chan->address, val);
	default:
	return -EINVAL;
	}
	}

	static const char * const ad5504_powerdown_modes[] = {
	"20kohm_to_gnd",
	"three_state",
	};

	static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan)
	{
	struct ad5504_state *st = iio_priv(indio_dev);

	return st->pwr_down_mode;
	}

	static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan, unsigned int mode)
	{
	struct ad5504_state *st = iio_priv(indio_dev);

	st->pwr_down_mode = mode;

	return 0;
	}

	static const struct iio_enum ad5504_powerdown_mode_enum = {
	.items = ad5504_powerdown_modes,
	.num_items = ARRAY_SIZE(ad5504_powerdown_modes),
	.get = ad5504_get_powerdown_mode,
	.set = ad5504_set_powerdown_mode,
	};

	static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
	uintptr_t private, const struct iio_chan_spec chan, char buf)
	{
	struct ad5504_state *st = iio_priv(indio_dev);

	return sprintf(buf, "%d\n",
	!(st->pwr_down_mask & (1 << chan->channel)));
	}

	static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
	uintptr_t private, const struct iio_chan_spec chan, const char buf,
	size_t len)
	{
	bool pwr_down;
	int ret;
	struct ad5504_state *st = iio_priv(indio_dev);

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

	if (pwr_down)
	st->pwr_down_mask \|= (1 << chan->channel);
	else
	st->pwr_down_mask &= ~(1 << chan->channel);

	ret = ad5504_spi_write(st, AD5504_ADDR_CTRL,
	AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) \|
	AD5504_DAC_PWR(st->pwr_down_mask));

	/* writes to the CTRL register must be followed by a NOOP */
	ad5504_spi_write(st, AD5504_ADDR_NOOP, 0);

	return ret ? ret : len;
	}

	static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
	static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");

	static struct attribute *ad5504_ev_attributes[] = {
	&iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
	&iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
	NULL,
	};

	static const struct attribute_group ad5504_ev_attribute_group = {
	.attrs = ad5504_ev_attributes,
	};

	static irqreturn_t ad5504_event_handler(int irq, void *private)
	{
	iio_push_event(private,
	IIO_UNMOD_EVENT_CODE(IIO_TEMP,
	0,
	IIO_EV_TYPE_THRESH,
	IIO_EV_DIR_RISING),
	iio_get_time_ns(private));

	return IRQ_HANDLED;
	}

	static const struct iio_info ad5504_info = {
	.write_raw = ad5504_write_raw,
	.read_raw = ad5504_read_raw,
	.event_attrs = &ad5504_ev_attribute_group,
	.driver_module = THIS_MODULE,
	};

	static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
	{
	.name = "powerdown",
	.read = ad5504_read_dac_powerdown,
	.write = ad5504_write_dac_powerdown,
	.shared = IIO_SEPARATE,
	},
	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
	&ad5504_powerdown_mode_enum),
	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum),
	{ },
	};

	#define AD5504_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 = AD5504_ADDR_DAC(_chan), \
	.scan_type = { \
	.sign = 'u', \
	.realbits = 12, \
	.storagebits = 16, \
	}, \
	.ext_info = ad5504_ext_info, \
	}

	static const struct iio_chan_spec ad5504_channels[] = {
	AD5504_CHANNEL(0),
	AD5504_CHANNEL(1),
	AD5504_CHANNEL(2),
	AD5504_CHANNEL(3),
	};

	static int ad5504_probe(struct spi_device *spi)
	{
	struct ad5504_platform_data *pdata = spi->dev.platform_data;
	struct iio_dev *indio_dev;
	struct ad5504_state *st;
	struct regulator *reg;
	int ret, voltage_uv = 0;

	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
	if (!indio_dev)
	return -ENOMEM;
	reg = devm_regulator_get(&spi->dev, "vcc");
	if (!IS_ERR(reg)) {
	ret = regulator_enable(reg);
	if (ret)
	return ret;

	ret = regulator_get_voltage(reg);
	if (ret < 0)
	goto error_disable_reg;

	voltage_uv = ret;
	}

	spi_set_drvdata(spi, indio_dev);
	st = iio_priv(indio_dev);
	if (voltage_uv)
	st->vref_mv = voltage_uv / 1000;
	else if (pdata)
	st->vref_mv = pdata->vref_mv;
	else
	dev_warn(&spi->dev, "reference voltage unspecified\n");

	st->reg = reg;
	st->spi = spi;
	indio_dev->dev.parent = &spi->dev;
	indio_dev->name = spi_get_device_id(st->spi)->name;
	indio_dev->info = &ad5504_info;
	if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
	indio_dev->num_channels = 1;
	else
	indio_dev->num_channels = 4;
	indio_dev->channels = ad5504_channels;
	indio_dev->modes = INDIO_DIRECT_MODE;

	if (spi->irq) {
	ret = devm_request_threaded_irq(&spi->dev, spi->irq,
	NULL,
	&ad5504_event_handler,
	IRQF_TRIGGER_FALLING \| IRQF_ONESHOT,
	spi_get_device_id(st->spi)->name,
	indio_dev);
	if (ret)
	goto error_disable_reg;
	}

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

	return 0;

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

	return ret;
	}

	static int ad5504_remove(struct spi_device *spi)
	{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct ad5504_state *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);

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

	return 0;
	}

	static const struct spi_device_id ad5504_id[] = {
	{"ad5504", ID_AD5504},
	{"ad5501", ID_AD5501},
	{}
	};
	MODULE_DEVICE_TABLE(spi, ad5504_id);

	static struct spi_driver ad5504_driver = {
	.driver = {
	.name = "ad5504",
	},
	.probe = ad5504_probe,
	.remove = ad5504_remove,
	.id_table = ad5504_id,
	};
	module_spi_driver(ad5504_driver);

	MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
	MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
	MODULE_LICENSE("GPL v2");