staging:iio:dac: Add AD5764 driver (68b14d7e) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/staging/iio/dac/Kconfig

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Original line number	Diff line number	Diff line
		@@ -62,6 +62,16 @@ config AD5504
		To compile this driver as a module, choose M here: the
		module will be called ad5504.

		config AD5764
		tristate "Analog Devices AD5764/64R/44/44R DAC driver"
		depends on SPI_MASTER
		help
		Say yes here to build support for Analog Devices AD5764, AD5764R, AD5744,
		AD5744R Digital to Analog Converter.

		To compile this driver as a module, choose M here: the
		module will be called ad5764.

		config AD5791
		tristate "Analog Devices AD5760/AD5780/AD5781/AD5791 DAC SPI driver"
		depends on SPI

drivers/staging/iio/dac/Makefile

+1 −0

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		@@ -8,6 +8,7 @@ obj-$(CONFIG_AD5624R_SPI) += ad5624r_spi.o
		obj-$(CONFIG_AD5064) += ad5064.o
		obj-$(CONFIG_AD5504) += ad5504.o
		obj-$(CONFIG_AD5446) += ad5446.o
		obj-$(CONFIG_AD5764) += ad5764.o
		obj-$(CONFIG_AD5791) += ad5791.o
		obj-$(CONFIG_AD5686) += ad5686.o
		obj-$(CONFIG_MAX517) += max517.o

drivers/staging/iio/dac/ad5764.c

0 → 100644

+393 −0

Original line number	Diff line number	Diff line
		/*
		* Analog devices AD5764, AD5764R, AD5744, AD5744R quad-channel
		* Digital to Analog Converters driver
		*
		* Copyright 2011 Analog Devices Inc.
		*
		* 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 "../iio.h"
		#include "../sysfs.h"
		#include "dac.h"

		#define AD5764_REG_SF_NOP 0x0
		#define AD5764_REG_SF_CONFIG 0x1
		#define AD5764_REG_SF_CLEAR 0x4
		#define AD5764_REG_SF_LOAD 0x5
		#define AD5764_REG_DATA(x) ((2 << 3) \| (x))
		#define AD5764_REG_COARSE_GAIN(x) ((3 << 3) \| (x))
		#define AD5764_REG_FINE_GAIN(x) ((4 << 3) \| (x))
		#define AD5764_REG_OFFSET(x) ((5 << 3) \| (x))

		#define AD5764_NUM_CHANNELS 4

		/**
		* struct ad5764_chip_info - chip specific information
		* @int_vref: Value of the internal reference voltage in uV - 0 if external
		* reference voltage is used
		* @channel channel specification
		*/

		struct ad5764_chip_info {
		unsigned long int_vref;
		const struct iio_chan_spec *channels;
		};

		/**
		* struct ad5764_state - driver instance specific data
		* @spi: spi_device
		* @chip_info: chip info
		* @vref_reg: vref supply regulators
		* @data: spi transfer buffers
		*/

		struct ad5764_state {
		struct spi_device *spi;
		const struct ad5764_chip_info *chip_info;
		struct regulator_bulk_data vref_reg[2];

		/*
		* DMA (thus cache coherency maintenance) requires the
		* transfer buffers to live in their own cache lines.
		*/
		union {
		__be32 d32;
		u8 d8[4];
		} data[2] ____cacheline_aligned;
		};

		enum ad5764_type {
		ID_AD5744,
		ID_AD5744R,
		ID_AD5764,
		ID_AD5764R,
		};

		#define AD5764_CHANNEL(_chan, _bits) { \
		.type = IIO_VOLTAGE, \
		.indexed = 1, \
		.output = 1, \
		.channel = (_chan), \
		.address = (_chan), \
		.info_mask = IIO_CHAN_INFO_OFFSET_SHARED_BIT \| \
		IIO_CHAN_INFO_SCALE_SEPARATE_BIT \| \
		IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT \| \
		IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT, \
		.scan_type = IIO_ST('u', (_bits), 16, 16 - (_bits)) \
		}

		#define DECLARE_AD5764_CHANNELS(_name, _bits) \
		const struct iio_chan_spec _name##_channels[] = { \
		AD5764_CHANNEL(0, (_bits)), \
		AD5764_CHANNEL(1, (_bits)), \
		AD5764_CHANNEL(2, (_bits)), \
		AD5764_CHANNEL(3, (_bits)), \
		};

		static DECLARE_AD5764_CHANNELS(ad5764, 16);
		static DECLARE_AD5764_CHANNELS(ad5744, 14);

		static const struct ad5764_chip_info ad5764_chip_infos[] = {
		[ID_AD5744] = {
		.int_vref = 0,
		.channels = ad5744_channels,
		},
		[ID_AD5744R] = {
		.int_vref = 5000000,
		.channels = ad5744_channels,
		},
		[ID_AD5764] = {
		.int_vref = 0,
		.channels = ad5764_channels,
		},
		[ID_AD5764R] = {
		.int_vref = 5000000,
		.channels = ad5764_channels,
		},
		};

		static int ad5764_write(struct iio_dev *indio_dev, unsigned int reg,
		unsigned int val)
		{
		struct ad5764_state *st = iio_priv(indio_dev);
		int ret;

		mutex_lock(&indio_dev->mlock);
		st->data[0].d32 = cpu_to_be32((reg << 16) \| val);

		ret = spi_write(st->spi, &st->data[0].d8[1], 3);
		mutex_unlock(&indio_dev->mlock);

		return ret;
		}

		static int ad5764_read(struct iio_dev *indio_dev, unsigned int reg,
		unsigned int *val)
		{
		struct ad5764_state *st = iio_priv(indio_dev);
		struct spi_message m;
		int ret;
		struct spi_transfer t[] = {
		{
		.tx_buf = &st->data[0].d8[1],
		.len = 3,
		.cs_change = 1,
		}, {
		.rx_buf = &st->data[1].d8[1],
		.len = 3,
		},
		};

		spi_message_init(&m);
		spi_message_add_tail(&t[0], &m);
		spi_message_add_tail(&t[1], &m);

		mutex_lock(&indio_dev->mlock);

		st->data[0].d32 = cpu_to_be32((1 << 23) \| (reg << 16));

		ret = spi_sync(st->spi, &m);
		if (ret >= 0)
		*val = be32_to_cpu(st->data[1].d32) & 0xffff;

		mutex_unlock(&indio_dev->mlock);

		return ret;
		}

		static int ad5764_chan_info_to_reg(struct iio_chan_spec const *chan, long info)
		{
		switch (info) {
		case 0:
		return AD5764_REG_DATA(chan->address);
		case IIO_CHAN_INFO_CALIBBIAS:
		return AD5764_REG_OFFSET(chan->address);
		case IIO_CHAN_INFO_CALIBSCALE:
		return AD5764_REG_FINE_GAIN(chan->address);
		default:
		break;
		}

		return 0;
		}

		static int ad5764_write_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan, int val, int val2, long info)
		{
		const int max_val = (1 << chan->scan_type.realbits);
		unsigned int reg;

		switch (info) {
		case 0:
		if (val >= max_val \|\| val < 0)
		return -EINVAL;
		val <<= chan->scan_type.shift;
		break;
		case IIO_CHAN_INFO_CALIBBIAS:
		if (val >= 128 \|\| val < -128)
		return -EINVAL;
		break;
		case IIO_CHAN_INFO_CALIBSCALE:
		if (val >= 32 \|\| val < -32)
		return -EINVAL;
		break;
		default:
		return -EINVAL;
		}

		reg = ad5764_chan_info_to_reg(chan, info);
		return ad5764_write(indio_dev, reg, (u16)val);
		}

		static int ad5764_get_channel_vref(struct ad5764_state *st,
		unsigned int channel)
		{
		if (st->chip_info->int_vref)
		return st->chip_info->int_vref;
		else
		return regulator_get_voltage(st->vref_reg[channel / 2].consumer);
		}

		static int ad5764_read_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const chan, int val, int *val2, long info)
		{
		struct ad5764_state *st = iio_priv(indio_dev);
		unsigned long scale_uv;
		unsigned int reg;
		int vref;
		int ret;

		switch (info) {
		case 0:
		reg = AD5764_REG_DATA(chan->address);
		ret = ad5764_read(indio_dev, reg, val);
		if (ret < 0)
		return ret;
		*val >>= chan->scan_type.shift;
		return IIO_VAL_INT;
		case IIO_CHAN_INFO_CALIBBIAS:
		reg = AD5764_REG_OFFSET(chan->address);
		ret = ad5764_read(indio_dev, reg, val);
		if (ret < 0)
		return ret;
		val = sign_extend32(val, 7);
		return IIO_VAL_INT;
		case IIO_CHAN_INFO_CALIBSCALE:
		reg = AD5764_REG_FINE_GAIN(chan->address);
		ret = ad5764_read(indio_dev, reg, val);
		if (ret < 0)
		return ret;
		val = sign_extend32(val, 5);
		return IIO_VAL_INT;
		case IIO_CHAN_INFO_SCALE:
		/* vout = 4 * vref + ((dac_code / 65535) - 0.5) */
		vref = ad5764_get_channel_vref(st, chan->channel);
		if (vref < 0)
		return vref;

		scale_uv = (vref * 4 * 100) >> chan->scan_type.realbits;
		*val = scale_uv / 100000;
		val2 = (scale_uv % 100000) 10;
		return IIO_VAL_INT_PLUS_MICRO;
		case IIO_CHAN_INFO_OFFSET:
		*val = -(1 << chan->scan_type.realbits) / 2;
		return IIO_VAL_INT;
		}

		return -EINVAL;
		}

		static const struct iio_info ad5764_info = {
		.read_raw = ad5764_read_raw,
		.write_raw = ad5764_write_raw,
		.driver_module = THIS_MODULE,
		};

		static int __devinit ad5764_probe(struct spi_device *spi)
		{
		enum ad5764_type type = spi_get_device_id(spi)->driver_data;
		struct iio_dev *indio_dev;
		struct ad5764_state *st;
		int ret;

		indio_dev = iio_allocate_device(sizeof(*st));
		if (indio_dev == NULL) {
		dev_err(&spi->dev, "Failed to allocate iio device\n");
		return -ENOMEM;
		}

		st = iio_priv(indio_dev);
		spi_set_drvdata(spi, indio_dev);

		st->spi = spi;
		st->chip_info = &ad5764_chip_infos[type];

		indio_dev->dev.parent = &spi->dev;
		indio_dev->name = spi_get_device_id(spi)->name;
		indio_dev->info = &ad5764_info;
		indio_dev->modes = INDIO_DIRECT_MODE;
		indio_dev->num_channels = AD5764_NUM_CHANNELS;
		indio_dev->channels = st->chip_info->channels;

		if (st->chip_info->int_vref == 0) {
		st->vref_reg[0].supply = "vrefAB";
		st->vref_reg[1].supply = "vrefCD";

		ret = regulator_bulk_get(&st->spi->dev,
		ARRAY_SIZE(st->vref_reg), st->vref_reg);
		if (ret) {
		dev_err(&spi->dev, "Failed to request vref regulators: %d\n",
		ret);
		goto error_free;
		}

		ret = regulator_bulk_enable(ARRAY_SIZE(st->vref_reg),
		st->vref_reg);
		if (ret) {
		dev_err(&spi->dev, "Failed to enable vref regulators: %d\n",
		ret);
		goto error_free_reg;
		}
		}

		ret = iio_device_register(indio_dev);
		if (ret) {
		dev_err(&spi->dev, "Failed to register iio device: %d\n", ret);
		goto error_disable_reg;
		}

		return 0;

		error_disable_reg:
		if (st->chip_info->int_vref == 0)
		regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg);
		error_free_reg:
		if (st->chip_info->int_vref == 0)
		regulator_bulk_free(ARRAY_SIZE(st->vref_reg), st->vref_reg);
		error_free:
		iio_free_device(indio_dev);

		return ret;
		}

		static int __devexit ad5764_remove(struct spi_device *spi)
		{
		struct iio_dev *indio_dev = spi_get_drvdata(spi);
		struct ad5764_state *st = iio_priv(indio_dev);

		iio_device_unregister(indio_dev);

		if (st->chip_info->int_vref == 0) {
		regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg);
		regulator_bulk_free(ARRAY_SIZE(st->vref_reg), st->vref_reg);
		}

		iio_free_device(indio_dev);

		return 0;
		}

		static const struct spi_device_id ad5764_ids[] = {
		{ "ad5744", ID_AD5744 },
		{ "ad5744r", ID_AD5744R },
		{ "ad5764", ID_AD5764 },
		{ "ad5764r", ID_AD5764R },
		{ }
		};
		MODULE_DEVICE_TABLE(spi, ad5764_ids);

		static struct spi_driver ad5764_driver = {
		.driver = {
		.name = "ad5764",
		.owner = THIS_MODULE,
		},
		.probe = ad5764_probe,
		.remove = __devexit_p(ad5764_remove),
		.id_table = ad5764_ids,
		};

		static int __init ad5764_spi_init(void)
		{
		return spi_register_driver(&ad5764_driver);
		}
		module_init(ad5764_spi_init);

		static void __exit ad5764_spi_exit(void)
		{
		spi_unregister_driver(&ad5764_driver);
		}
		module_exit(ad5764_spi_exit);

		MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
		MODULE_DESCRIPTION("Analog Devices AD5744/AD5744R/AD5764/AD5764R DAC");
		MODULE_LICENSE("GPL v2");