iio: dac: AD8801: add Analog Devices AD8801/AD8803 support (7f270bc9) · Commits · jan.koester / Linux

drivers/iio/dac/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -190,6 +190,16 @@ config CIO_DAC
		base port addresses for the devices may be configured via the base
		array module parameter.

		config AD8801
		tristate "Analog Devices AD8801/AD8803 DAC driver"
		depends on SPI_MASTER
		help
		Say yes here to build support for Analog Devices AD8801, AD8803 Digital to
		Analog Converters (DAC).

		To compile this driver as a module choose M here: the module will be called
		ad8801.

		config LPC18XX_DAC
		tristate "NXP LPC18xx DAC driver"
		depends on ARCH_LPC18XX \|\| COMPILE_TEST

drivers/iio/dac/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@ obj-$(CONFIG_AD5764) += ad5764.o
		obj-$(CONFIG_AD5791) += ad5791.o
		obj-$(CONFIG_AD5686) += ad5686.o
		obj-$(CONFIG_AD7303) += ad7303.o
		obj-$(CONFIG_AD8801) += ad8801.o
		obj-$(CONFIG_CIO_DAC) += cio-dac.o
		obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o
		obj-$(CONFIG_M62332) += m62332.o

drivers/iio/dac/ad8801.c

0 → 100644

+239 −0

Original line number	Diff line number	Diff line
		/*
		* IIO DAC driver for Analog Devices AD8801 DAC
		*
		* Copyright (C) 2016 Gwenhael Goavec-Merou
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License, version 2, as
		* published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it will be useful, but
		* WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
		* General Public License for more details.
		*
		*/

		#include <linux/iio/iio.h>
		#include <linux/module.h>
		#include <linux/regulator/consumer.h>
		#include <linux/spi/spi.h>
		#include <linux/sysfs.h>

		#define AD8801_CFG_ADDR_OFFSET 8

		enum ad8801_device_ids {
		ID_AD8801,
		ID_AD8803,
		};

		struct ad8801_state {
		struct spi_device *spi;
		unsigned char dac_cache[8]; /* Value write on each channel */
		unsigned int vrefh_mv;
		unsigned int vrefl_mv;
		struct regulator *vrefh_reg;
		struct regulator *vrefl_reg;

		__be16 data ____cacheline_aligned;
		};

		static int ad8801_spi_write(struct ad8801_state *state,
		u8 channel, unsigned char value)
		{
		state->data = cpu_to_be16((channel << AD8801_CFG_ADDR_OFFSET) \| value);
		return spi_write(state->spi, &state->data, sizeof(state->data));
		}

		static int ad8801_write_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan, int val, int val2, long mask)
		{
		struct ad8801_state *state = iio_priv(indio_dev);
		int ret;

		switch (mask) {
		case IIO_CHAN_INFO_RAW:
		if (val >= 256 \|\| val < 0)
		return -EINVAL;

		ret = ad8801_spi_write(state, chan->channel, val);
		if (ret == 0)
		state->dac_cache[chan->channel] = val;
		break;
		default:
		ret = -EINVAL;
		}

		return ret;
		}

		static int ad8801_read_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const chan, int val, int *val2, long info)
		{
		struct ad8801_state *state = iio_priv(indio_dev);

		switch (info) {
		case IIO_CHAN_INFO_RAW:
		*val = state->dac_cache[chan->channel];
		return IIO_VAL_INT;
		case IIO_CHAN_INFO_SCALE:
		*val = state->vrefh_mv - state->vrefl_mv;
		*val2 = 8;
		return IIO_VAL_FRACTIONAL_LOG2;
		case IIO_CHAN_INFO_OFFSET:
		*val = state->vrefl_mv;
		return IIO_VAL_INT;
		default:
		return -EINVAL;
		}

		return -EINVAL;
		}

		static const struct iio_info ad8801_info = {
		.read_raw = ad8801_read_raw,
		.write_raw = ad8801_write_raw,
		.driver_module = THIS_MODULE,
		};

		#define AD8801_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) \| \
		BIT(IIO_CHAN_INFO_OFFSET), \
		}

		static const struct iio_chan_spec ad8801_channels[] = {
		AD8801_CHANNEL(0),
		AD8801_CHANNEL(1),
		AD8801_CHANNEL(2),
		AD8801_CHANNEL(3),
		AD8801_CHANNEL(4),
		AD8801_CHANNEL(5),
		AD8801_CHANNEL(6),
		AD8801_CHANNEL(7),
		};

		static int ad8801_probe(struct spi_device *spi)
		{
		struct iio_dev *indio_dev;
		struct ad8801_state *state;
		const struct spi_device_id *id;
		int ret;

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

		state = iio_priv(indio_dev);
		state->spi = spi;
		id = spi_get_device_id(spi);

		state->vrefh_reg = devm_regulator_get(&spi->dev, "vrefh");
		if (IS_ERR(state->vrefh_reg)) {
		dev_err(&spi->dev, "Vrefh regulator not specified\n");
		return PTR_ERR(state->vrefh_reg);
		}

		ret = regulator_enable(state->vrefh_reg);
		if (ret) {
		dev_err(&spi->dev, "Failed to enable vrefh regulator: %d\n",
		ret);
		return ret;
		}

		ret = regulator_get_voltage(state->vrefh_reg);
		if (ret < 0) {
		dev_err(&spi->dev, "Failed to read vrefh regulator: %d\n",
		ret);
		goto error_disable_vrefh_reg;
		}
		state->vrefh_mv = ret / 1000;

		if (id->driver_data == ID_AD8803) {
		state->vrefl_reg = devm_regulator_get(&spi->dev, "vrefl");
		if (IS_ERR(state->vrefl_reg)) {
		dev_err(&spi->dev, "Vrefl regulator not specified\n");
		ret = PTR_ERR(state->vrefl_reg);
		goto error_disable_vrefh_reg;
		}

		ret = regulator_enable(state->vrefl_reg);
		if (ret) {
		dev_err(&spi->dev, "Failed to enable vrefl regulator: %d\n",
		ret);
		goto error_disable_vrefh_reg;
		}

		ret = regulator_get_voltage(state->vrefl_reg);
		if (ret < 0) {
		dev_err(&spi->dev, "Failed to read vrefl regulator: %d\n",
		ret);
		goto error_disable_vrefl_reg;
		}
		state->vrefl_mv = ret / 1000;
		} else {
		state->vrefl_mv = 0;
		state->vrefl_reg = NULL;
		}

		spi_set_drvdata(spi, indio_dev);
		indio_dev->dev.parent = &spi->dev;
		indio_dev->info = &ad8801_info;
		indio_dev->modes = INDIO_DIRECT_MODE;
		indio_dev->channels = ad8801_channels;
		indio_dev->num_channels = ARRAY_SIZE(ad8801_channels);
		indio_dev->name = id->name;

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

		return 0;

		error_disable_vrefl_reg:
		if (state->vrefl_reg)
		regulator_disable(state->vrefl_reg);
		error_disable_vrefh_reg:
		regulator_disable(state->vrefh_reg);
		return ret;
		}

		static int ad8801_remove(struct spi_device *spi)
		{
		struct iio_dev *indio_dev = spi_get_drvdata(spi);
		struct ad8801_state *state = iio_priv(indio_dev);

		iio_device_unregister(indio_dev);
		if (state->vrefl_reg)
		regulator_disable(state->vrefl_reg);
		regulator_disable(state->vrefh_reg);

		return 0;
		}

		static const struct spi_device_id ad8801_ids[] = {
		{"ad8801", ID_AD8801},
		{"ad8803", ID_AD8803},
		{}
		};
		MODULE_DEVICE_TABLE(spi, ad8801_ids);

		static struct spi_driver ad8801_driver = {
		.driver = {
		.name = "ad8801",
		},
		.probe = ad8801_probe,
		.remove = ad8801_remove,
		.id_table = ad8801_ids,
		};
		module_spi_driver(ad8801_driver);

		MODULE_AUTHOR("Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>");
		MODULE_DESCRIPTION("Analog Devices AD8801/AD8803 DAC");
		MODULE_LICENSE("GPL v2");