drivers/iio/adc/ad7476.c - arm/linux-arm64-legacy - Git at Google

 /*
  * AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
  *
  * Copyright 2010 Analog Devices Inc.
  *
  * Licensed under the GPL-2 or later.
  */

 #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/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>

 #define RES_MASK(bits)	((1 << (bits)) - 1)

 struct ad7476_state;

 struct ad7476_chip_info {
 	unsigned int			int_vref_uv;
 	struct iio_chan_spec		channel[2];
 	void (*reset)(struct ad7476_state *);
 };

 struct ad7476_state {
 	struct spi_device		*spi;
 	const struct ad7476_chip_info	*chip_info;
 	struct regulator		*reg;
 	struct spi_transfer		xfer;
 	struct spi_message		msg;
 	/*
 	 * DMA (thus cache coherency maintenance) requires the
 	 * transfer buffers to live in their own cache lines.
 	 * Make the buffer large enough for one 16 bit sample and one 64 bit
 	 * aligned 64 bit timestamp.
 	 */
 	unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)]
 			____cacheline_aligned;
 };

 enum ad7476_supported_device_ids {
 	ID_AD7091R,
 	ID_AD7276,
 	ID_AD7277,
 	ID_AD7278,
 	ID_AD7466,
 	ID_AD7467,
 	ID_AD7468,
 	ID_AD7495,
 	ID_AD7940,
 };

 static irqreturn_t ad7476_trigger_handler(int irq, void  *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct ad7476_state *st = iio_priv(indio_dev);
 	int b_sent;

 	b_sent = spi_sync(st->spi, &st->msg);
 	if (b_sent < 0)
 		goto done;

 	iio_push_to_buffers_with_timestamp(indio_dev, st->data,
 		iio_get_time_ns());
 done:
 	iio_trigger_notify_done(indio_dev->trig);

 	return IRQ_HANDLED;
 }

 static void ad7091_reset(struct ad7476_state *st)
 {
 	/* Any transfers with 8 scl cycles will reset the device */
 	spi_read(st->spi, st->data, 1);
 }

 static int ad7476_scan_direct(struct ad7476_state *st)
 {
 	int ret;

 	ret = spi_sync(st->spi, &st->msg);
 	if (ret)
 		return ret;

 	return be16_to_cpup((__be16 *)st->data);
 }

 static int ad7476_read_raw(struct iio_dev *indio_dev,
 			   struct iio_chan_spec const *chan,
 			   int *val,
 			   int *val2,
 			   long m)
 {
 	int ret;
 	struct ad7476_state *st = iio_priv(indio_dev);
 	int scale_uv;

 	switch (m) {
 	case IIO_CHAN_INFO_RAW:
 		mutex_lock(&indio_dev->mlock);
 		if (iio_buffer_enabled(indio_dev))
 			ret = -EBUSY;
 		else
 			ret = ad7476_scan_direct(st);
 		mutex_unlock(&indio_dev->mlock);

 		if (ret < 0)
 			return ret;
 		*val = (ret >> st->chip_info->channel[0].scan_type.shift) &
 			RES_MASK(st->chip_info->channel[0].scan_type.realbits);
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		if (!st->chip_info->int_vref_uv) {
 			scale_uv = regulator_get_voltage(st->reg);
 			if (scale_uv < 0)
 				return scale_uv;
 		} else {
 			scale_uv = st->chip_info->int_vref_uv;
 		}
 		*val = scale_uv / 1000;
 		*val2 = chan->scan_type.realbits;
 		return IIO_VAL_FRACTIONAL_LOG2;
 	}
 	return -EINVAL;
 }

 #define _AD7476_CHAN(bits, _shift, _info_mask_sep)		\
 	{							\
 	.type = IIO_VOLTAGE,					\
 	.indexed = 1,						\
 	.info_mask_separate = _info_mask_sep,			\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
 	.scan_type = {						\
 		.sign = 'u',					\
 		.realbits = (bits),				\
 		.storagebits = 16,				\
 		.shift = (_shift),				\
 		.endianness = IIO_BE,				\
 	},							\
 }

 #define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \
 		BIT(IIO_CHAN_INFO_RAW))
 #define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \
 		BIT(IIO_CHAN_INFO_RAW))
 #define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0)

 static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
 	[ID_AD7091R] = {
 		.channel[0] = AD7091R_CHAN(12),
 		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
 		.reset = ad7091_reset,
 	},
 	[ID_AD7276] = {
 		.channel[0] = AD7940_CHAN(12),
 		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
 	},
 	[ID_AD7277] = {
 		.channel[0] = AD7940_CHAN(10),
 		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
 	},
 	[ID_AD7278] = {
 		.channel[0] = AD7940_CHAN(8),
 		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
 	},
 	[ID_AD7466] = {
 		.channel[0] = AD7476_CHAN(12),
 		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
 	},
 	[ID_AD7467] = {
 		.channel[0] = AD7476_CHAN(10),
 		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
 	},
 	[ID_AD7468] = {
 		.channel[0] = AD7476_CHAN(8),
 		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
 	},
 	[ID_AD7495] = {
 		.channel[0] = AD7476_CHAN(12),
 		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
 		.int_vref_uv = 2500000,
 	},
 	[ID_AD7940] = {
 		.channel[0] = AD7940_CHAN(14),
 		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
 	},
 };

 static const struct iio_info ad7476_info = {
 	.driver_module = THIS_MODULE,
 	.read_raw = &ad7476_read_raw,
 };

 static int ad7476_probe(struct spi_device *spi)
 {
 	struct ad7476_state *st;
 	struct iio_dev *indio_dev;
 	int ret;

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

 	st = iio_priv(indio_dev);
 	st->chip_info =
 		&ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];

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

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

 	spi_set_drvdata(spi, indio_dev);

 	st->spi = spi;

 	/* Establish that the iio_dev is a child of the spi device */
 	indio_dev->dev.parent = &spi->dev;
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = st->chip_info->channel;
 	indio_dev->num_channels = 2;
 	indio_dev->info = &ad7476_info;
 	/* Setup default message */

 	st->xfer.rx_buf = &st->data;
 	st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8;

 	spi_message_init(&st->msg);
 	spi_message_add_tail(&st->xfer, &st->msg);

 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 			&ad7476_trigger_handler, NULL);
 	if (ret)
 		goto error_disable_reg;

 	if (st->chip_info->reset)
 		st->chip_info->reset(st);

 	ret = iio_device_register(indio_dev);
 	if (ret)
 		goto error_ring_unregister;
 	return 0;

 error_ring_unregister:
 	iio_triggered_buffer_cleanup(indio_dev);
 error_disable_reg:
 	regulator_disable(st->reg);

 	return ret;
 }

 static int ad7476_remove(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
 	struct ad7476_state *st = iio_priv(indio_dev);

 	iio_device_unregister(indio_dev);
 	iio_triggered_buffer_cleanup(indio_dev);
 	regulator_disable(st->reg);

 	return 0;
 }

 static const struct spi_device_id ad7476_id[] = {
 	{"ad7091r", ID_AD7091R},
 	{"ad7273", ID_AD7277},
 	{"ad7274", ID_AD7276},
 	{"ad7276", ID_AD7276},
 	{"ad7277", ID_AD7277},
 	{"ad7278", ID_AD7278},
 	{"ad7466", ID_AD7466},
 	{"ad7467", ID_AD7467},
 	{"ad7468", ID_AD7468},
 	{"ad7475", ID_AD7466},
 	{"ad7476", ID_AD7466},
 	{"ad7476a", ID_AD7466},
 	{"ad7477", ID_AD7467},
 	{"ad7477a", ID_AD7467},
 	{"ad7478", ID_AD7468},
 	{"ad7478a", ID_AD7468},
 	{"ad7495", ID_AD7495},
 	{"ad7910", ID_AD7467},
 	{"ad7920", ID_AD7466},
 	{"ad7940", ID_AD7940},
 	{}
 };
 MODULE_DEVICE_TABLE(spi, ad7476_id);

 static struct spi_driver ad7476_driver = {
 	.driver = {
 		.name	= "ad7476",
 		.owner	= THIS_MODULE,
 	},
 	.probe		= ad7476_probe,
 	.remove		= ad7476_remove,
 	.id_table	= ad7476_id,
 };
 module_spi_driver(ad7476_driver);

 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs");
 MODULE_LICENSE("GPL v2");
	/*
	* AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
	*
	* Copyright 2010 Analog Devices Inc.
	*
	* Licensed under the GPL-2 or later.
	*/

	#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/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/trigger_consumer.h>
	#include <linux/iio/triggered_buffer.h>

	#define RES_MASK(bits) ((1 << (bits)) - 1)

	struct ad7476_state;

	struct ad7476_chip_info {
	unsigned int int_vref_uv;
	struct iio_chan_spec channel[2];
	void (reset)(struct ad7476_state );
	};

	struct ad7476_state {
	struct spi_device *spi;
	const struct ad7476_chip_info *chip_info;
	struct regulator *reg;
	struct spi_transfer xfer;
	struct spi_message msg;
	/*
	* DMA (thus cache coherency maintenance) requires the
	* transfer buffers to live in their own cache lines.
	* Make the buffer large enough for one 16 bit sample and one 64 bit
	* aligned 64 bit timestamp.
	*/
	unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)]
	____cacheline_aligned;
	};

	enum ad7476_supported_device_ids {
	ID_AD7091R,
	ID_AD7276,
	ID_AD7277,
	ID_AD7278,
	ID_AD7466,
	ID_AD7467,
	ID_AD7468,
	ID_AD7495,
	ID_AD7940,
	};

	static irqreturn_t ad7476_trigger_handler(int irq, void *p)
	{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct ad7476_state *st = iio_priv(indio_dev);
	int b_sent;

	b_sent = spi_sync(st->spi, &st->msg);
	if (b_sent < 0)
	goto done;

	iio_push_to_buffers_with_timestamp(indio_dev, st->data,
	iio_get_time_ns());
	done:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
	}

	static void ad7091_reset(struct ad7476_state *st)
	{
	/* Any transfers with 8 scl cycles will reset the device */
	spi_read(st->spi, st->data, 1);
	}

	static int ad7476_scan_direct(struct ad7476_state *st)
	{
	int ret;

	ret = spi_sync(st->spi, &st->msg);
	if (ret)
	return ret;

	return be16_to_cpup((__be16 *)st->data);
	}

	static int ad7476_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int *val,
	int *val2,
	long m)
	{
	int ret;
	struct ad7476_state *st = iio_priv(indio_dev);
	int scale_uv;

	switch (m) {
	case IIO_CHAN_INFO_RAW:
	mutex_lock(&indio_dev->mlock);
	if (iio_buffer_enabled(indio_dev))
	ret = -EBUSY;
	else
	ret = ad7476_scan_direct(st);
	mutex_unlock(&indio_dev->mlock);

	if (ret < 0)
	return ret;
	*val = (ret >> st->chip_info->channel[0].scan_type.shift) &
	RES_MASK(st->chip_info->channel[0].scan_type.realbits);
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
	if (!st->chip_info->int_vref_uv) {
	scale_uv = regulator_get_voltage(st->reg);
	if (scale_uv < 0)
	return scale_uv;
	} else {
	scale_uv = st->chip_info->int_vref_uv;
	}
	*val = scale_uv / 1000;
	*val2 = chan->scan_type.realbits;
	return IIO_VAL_FRACTIONAL_LOG2;
	}
	return -EINVAL;
	}

	#define _AD7476_CHAN(bits, _shift, _info_mask_sep) \
	{ \
	.type = IIO_VOLTAGE, \
	.indexed = 1, \
	.info_mask_separate = _info_mask_sep, \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	.scan_type = { \
	.sign = 'u', \
	.realbits = (bits), \
	.storagebits = 16, \
	.shift = (_shift), \
	.endianness = IIO_BE, \
	}, \
	}

	#define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \
	BIT(IIO_CHAN_INFO_RAW))
	#define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \
	BIT(IIO_CHAN_INFO_RAW))
	#define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0)

	static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
	[ID_AD7091R] = {
	.channel[0] = AD7091R_CHAN(12),
	.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
	.reset = ad7091_reset,
	},
	[ID_AD7276] = {
	.channel[0] = AD7940_CHAN(12),
	.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
	},
	[ID_AD7277] = {
	.channel[0] = AD7940_CHAN(10),
	.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
	},
	[ID_AD7278] = {
	.channel[0] = AD7940_CHAN(8),
	.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
	},
	[ID_AD7466] = {
	.channel[0] = AD7476_CHAN(12),
	.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
	},
	[ID_AD7467] = {
	.channel[0] = AD7476_CHAN(10),
	.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
	},
	[ID_AD7468] = {
	.channel[0] = AD7476_CHAN(8),
	.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
	},
	[ID_AD7495] = {
	.channel[0] = AD7476_CHAN(12),
	.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
	.int_vref_uv = 2500000,
	},
	[ID_AD7940] = {
	.channel[0] = AD7940_CHAN(14),
	.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
	},
	};

	static const struct iio_info ad7476_info = {
	.driver_module = THIS_MODULE,
	.read_raw = &ad7476_read_raw,
	};

	static int ad7476_probe(struct spi_device *spi)
	{
	struct ad7476_state *st;
	struct iio_dev *indio_dev;
	int ret;

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

	st = iio_priv(indio_dev);
	st->chip_info =
	&ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];

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

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

	spi_set_drvdata(spi, indio_dev);

	st->spi = spi;

	/* Establish that the iio_dev is a child of the spi device */
	indio_dev->dev.parent = &spi->dev;
	indio_dev->name = spi_get_device_id(spi)->name;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = st->chip_info->channel;
	indio_dev->num_channels = 2;
	indio_dev->info = &ad7476_info;
	/* Setup default message */

	st->xfer.rx_buf = &st->data;
	st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8;

	spi_message_init(&st->msg);
	spi_message_add_tail(&st->xfer, &st->msg);

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
	&ad7476_trigger_handler, NULL);
	if (ret)
	goto error_disable_reg;

	if (st->chip_info->reset)
	st->chip_info->reset(st);

	ret = iio_device_register(indio_dev);
	if (ret)
	goto error_ring_unregister;
	return 0;

	error_ring_unregister:
	iio_triggered_buffer_cleanup(indio_dev);
	error_disable_reg:
	regulator_disable(st->reg);

	return ret;
	}

	static int ad7476_remove(struct spi_device *spi)
	{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct ad7476_state *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);
	regulator_disable(st->reg);

	return 0;
	}

	static const struct spi_device_id ad7476_id[] = {
	{"ad7091r", ID_AD7091R},
	{"ad7273", ID_AD7277},
	{"ad7274", ID_AD7276},
	{"ad7276", ID_AD7276},
	{"ad7277", ID_AD7277},
	{"ad7278", ID_AD7278},
	{"ad7466", ID_AD7466},
	{"ad7467", ID_AD7467},
	{"ad7468", ID_AD7468},
	{"ad7475", ID_AD7466},
	{"ad7476", ID_AD7466},
	{"ad7476a", ID_AD7466},
	{"ad7477", ID_AD7467},
	{"ad7477a", ID_AD7467},
	{"ad7478", ID_AD7468},
	{"ad7478a", ID_AD7468},
	{"ad7495", ID_AD7495},
	{"ad7910", ID_AD7467},
	{"ad7920", ID_AD7466},
	{"ad7940", ID_AD7940},
	{}
	};
	MODULE_DEVICE_TABLE(spi, ad7476_id);

	static struct spi_driver ad7476_driver = {
	.driver = {
	.name = "ad7476",
	.owner = THIS_MODULE,
	},
	.probe = ad7476_probe,
	.remove = ad7476_remove,
	.id_table = ad7476_id,
	};
	module_spi_driver(ad7476_driver);

	MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
	MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs");
	MODULE_LICENSE("GPL v2");