iio: dac: Support ROHM BD79703 DAC (af6aca65) · Commits · git / linux-net

drivers/iio/dac/Kconfig

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		@@ -348,6 +348,14 @@ config AD8801
		To compile this driver as a module choose M here: the module will be called
		ad8801.

		config BD79703
		tristate "ROHM Semiconductor BD79703 DAC driver"
		depends on SPI
		select REGMAP_SPI
		help
		Say yes here to build support for ROHM Semiconductor BD79703 Digital
		to Analog Converter (DAC).

		config CIO_DAC
		tristate "Measurement Computing CIO-DAC IIO driver"
		depends on X86 && (ISA_BUS \|\| PC104)

drivers/iio/dac/Makefile

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		@@ -34,6 +34,7 @@ obj-$(CONFIG_AD8460) += ad8460.o
		obj-$(CONFIG_AD8801) += ad8801.o
		obj-$(CONFIG_AD9739A) += ad9739a.o
		obj-$(CONFIG_ADI_AXI_DAC) += adi-axi-dac.o
		obj-$(CONFIG_BD79703) += rohm-bd79703.o
		obj-$(CONFIG_CIO_DAC) += cio-dac.o
		obj-$(CONFIG_DPOT_DAC) += dpot-dac.o
		obj-$(CONFIG_DS4424) += ds4424.o

drivers/iio/dac/rohm-bd79703.c

0 → 100644

+162 −0

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		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* BD79703 ROHM Digital to Analog converter
		*
		* Copyright (c) 2024, ROHM Semiconductor.
		*/

		#include <linux/bits.h>
		#include <linux/device.h>
		#include <linux/module.h>
		#include <linux/regmap.h>
		#include <linux/regulator/consumer.h>
		#include <linux/spi/spi.h>
		#include <linux/iio/iio.h>

		#define BD79703_MAX_REGISTER 0xf
		#define BD79703_DAC_BITS 8
		#define BD79703_REG_OUT_ALL GENMASK(2, 0)

		/*
		* The BD79703 uses 12-bit SPI commands. First four bits (high bits) define
		* channel(s) which are operated on, and also the mode. The mode can be to set
		* a DAC word only, or set DAC word and output. The data-sheet is not very
		* specific on how a previously set DAC word can be 'taken in to use'. Thus
		* this driver only uses the 'set DAC and output it' -mode.
		*
		* The BD79703 latches last 12-bits when the chip-select is toggled. Thus we
		* can use 16-bit transfers which should be widely supported. To simplify this
		* further, we treat the last 8 bits as a value, and first 8 bits as an
		* address. This allows us to separate channels/mode by address and treat the
		* 8-bit register value as DAC word. The highest 4 bits of address will be
		* discarded when the transfer is latched.
		*/
		static const struct regmap_config bd79703_regmap_config = {
		.reg_bits = 8,
		.val_bits = 8,
		.max_register = BD79703_MAX_REGISTER,
		.cache_type = REGCACHE_RBTREE,
		};

		struct bd79703_data {
		struct regmap *regmap;
		int vfs;
		};

		static int bd79703_read_raw(struct iio_dev *idev,
		struct iio_chan_spec const chan, int val,
		int *val2, long mask)
		{
		struct bd79703_data *data = iio_priv(idev);

		if (mask != IIO_CHAN_INFO_SCALE)
		return -EINVAL;

		*val = data->vfs / 1000;
		*val2 = BD79703_DAC_BITS;

		return IIO_VAL_FRACTIONAL_LOG2;
		}

		static int bd79703_write_raw(struct iio_dev *idev,
		struct iio_chan_spec const *chan, int val,
		int val2, long mask)
		{
		struct bd79703_data *data = iio_priv(idev);

		if (val < 0 \|\| val >= 1 << BD79703_DAC_BITS)
		return -EINVAL;

		return regmap_write(data->regmap, chan->channel + 1, val);
		};

		static const struct iio_info bd79703_info = {
		.read_raw = bd79703_read_raw,
		.write_raw = bd79703_write_raw,
		};

		#define BD79703_CHAN(_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 = (_chan), \
		}

		static const struct iio_chan_spec bd79703_channels[] = {
		BD79703_CHAN(0),
		BD79703_CHAN(1),
		BD79703_CHAN(2),
		BD79703_CHAN(3),
		BD79703_CHAN(4),
		BD79703_CHAN(5),
		};

		static int bd79703_probe(struct spi_device *spi)
		{
		struct device *dev = &spi->dev;
		struct bd79703_data *data;
		struct iio_dev *idev;
		int ret;

		idev = devm_iio_device_alloc(dev, sizeof(*data));
		if (!idev)
		return -ENOMEM;

		data = iio_priv(idev);

		data->regmap = devm_regmap_init_spi(spi, &bd79703_regmap_config);
		if (IS_ERR(data->regmap))
		return dev_err_probe(dev, PTR_ERR(data->regmap),
		"Failed to initialize Regmap\n");

		ret = devm_regulator_get_enable(dev, "vcc");
		if (ret)
		return dev_err_probe(dev, ret, "Failed to enable VCC\n");

		ret = devm_regulator_get_enable_read_voltage(dev, "vfs");
		if (ret < 0)
		return dev_err_probe(dev, ret, "Failed to get Vfs\n");

		data->vfs = ret;
		idev->channels = bd79703_channels;
		idev->num_channels = ARRAY_SIZE(bd79703_channels);
		idev->modes = INDIO_DIRECT_MODE;
		idev->info = &bd79703_info;
		idev->name = "bd79703";

		/* Initialize all to output zero */
		ret = regmap_write(data->regmap, BD79703_REG_OUT_ALL, 0);
		if (ret)
		return ret;

		return devm_iio_device_register(dev, idev);
		}

		static const struct spi_device_id bd79703_id[] = {
		{ "bd79703", },
		{ }
		};
		MODULE_DEVICE_TABLE(spi, bd79703_id);

		static const struct of_device_id bd79703_of_match[] = {
		{ .compatible = "rohm,bd79703", },
		{ }
		};
		MODULE_DEVICE_TABLE(of, bd79703_of_match);

		static struct spi_driver bd79703_driver = {
		.driver = {
		.name = "bd79703",
		.of_match_table = bd79703_of_match,
		},
		.probe = bd79703_probe,
		.id_table = bd79703_id,
		};
		module_spi_driver(bd79703_driver);

		MODULE_AUTHOR("Matti Vaittinen <mazziesaccount@gmail.com>");
		MODULE_DESCRIPTION("ROHM BD79703 DAC driver");
		MODULE_LICENSE("GPL");