iio: dac: add support for ltc1660 (8316cebd) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/iio/dac/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -120,6 +120,16 @@ config AD5624R_SPI
		Say yes here to build support for Analog Devices AD5624R, AD5644R and
		AD5664R converters (DAC). This driver uses the common SPI interface.

		config LTC1660
		tristate "Linear Technology LTC1660/LTC1665 DAC SPI driver"
		depends on SPI
		help
		Say yes here to build support for Linear Technology
		LTC1660 and LTC1665 Digital to Analog Converters.

		To compile this driver as a module, choose M here: the
		module will be called ltc1660.

		config LTC2632
		tristate "Linear Technology LTC2632-12/10/8 DAC spi driver"
		depends on SPI

drivers/iio/dac/Makefile

+1 −0

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		@@ -29,6 +29,7 @@ obj-$(CONFIG_CIO_DAC) += cio-dac.o
		obj-$(CONFIG_DPOT_DAC) += dpot-dac.o
		obj-$(CONFIG_DS4424) += ds4424.o
		obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o
		obj-$(CONFIG_LTC1660) += ltc1660.o
		obj-$(CONFIG_LTC2632) += ltc2632.o
		obj-$(CONFIG_M62332) += m62332.o
		obj-$(CONFIG_MAX517) += max517.o

drivers/iio/dac/ltc1660.c

0 → 100644

+250 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/*
		* Driver for Linear Technology LTC1665/LTC1660, 8 channels DAC
		*
		* Copyright (C) 2018 Marcus Folkesson <marcus.folkesson@gmail.com>
		*/
		#include <linux/bitops.h>
		#include <linux/iio/iio.h>
		#include <linux/iio/sysfs.h>
		#include <linux/init.h>
		#include <linux/module.h>
		#include <linux/regulator/consumer.h>
		#include <linux/regmap.h>
		#include <linux/spi/spi.h>

		#define LTC1660_REG_WAKE 0x0
		#define LTC1660_REG_DAC_A 0x1
		#define LTC1660_REG_DAC_B 0x2
		#define LTC1660_REG_DAC_C 0x3
		#define LTC1660_REG_DAC_D 0x4
		#define LTC1660_REG_DAC_E 0x5
		#define LTC1660_REG_DAC_F 0x6
		#define LTC1660_REG_DAC_G 0x7
		#define LTC1660_REG_DAC_H 0x8
		#define LTC1660_REG_SLEEP 0xe

		#define LTC1660_NUM_CHANNELS 8

		static const struct regmap_config ltc1660_regmap_config = {
		.reg_bits = 4,
		.val_bits = 12,
		};

		enum ltc1660_supported_device_ids {
		ID_LTC1660,
		ID_LTC1665,
		};

		struct ltc1660_priv {
		struct spi_device *spi;
		struct regmap *regmap;
		struct regulator *vref_reg;
		unsigned int value[LTC1660_NUM_CHANNELS];
		unsigned int vref_mv;
		};

		static int ltc1660_read_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan,
		int *val,
		int *val2,
		long mask)
		{
		struct ltc1660_priv *priv = iio_priv(indio_dev);

		switch (mask) {
		case IIO_CHAN_INFO_RAW:
		*val = priv->value[chan->channel];
		return IIO_VAL_INT;
		case IIO_CHAN_INFO_SCALE:
		*val = regulator_get_voltage(priv->vref_reg);
		if (*val < 0) {
		dev_err(&priv->spi->dev, "failed to read vref regulator: %d\n",
		*val);
		return *val;
		}

		/* Convert to mV */
		*val /= 1000;
		*val2 = chan->scan_type.realbits;
		return IIO_VAL_FRACTIONAL_LOG2;
		default:
		return -EINVAL;
		}
		}

		static int ltc1660_write_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan,
		int val,
		int val2,
		long mask)
		{
		struct ltc1660_priv *priv = iio_priv(indio_dev);
		int ret;

		switch (mask) {
		case IIO_CHAN_INFO_RAW:
		if (val2 != 0)
		return -EINVAL;

		if (val < 0 \|\| val > GENMASK(chan->scan_type.realbits - 1, 0))
		return -EINVAL;

		ret = regmap_write(priv->regmap, chan->channel,
		(val << chan->scan_type.shift));
		if (!ret)
		priv->value[chan->channel] = val;

		return ret;
		default:
		return -EINVAL;
		}
		}

		#define LTC1660_CHAN(chan, bits) { \
		.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), \
		.scan_type = { \
		.sign = 'u', \
		.realbits = (bits), \
		.storagebits = 16, \
		.shift = 12 - (bits), \
		}, \
		}

		#define LTC1660_OCTAL_CHANNELS(bits) { \
		LTC1660_CHAN(LTC1660_REG_DAC_A, bits), \
		LTC1660_CHAN(LTC1660_REG_DAC_B, bits), \
		LTC1660_CHAN(LTC1660_REG_DAC_C, bits), \
		LTC1660_CHAN(LTC1660_REG_DAC_D, bits), \
		LTC1660_CHAN(LTC1660_REG_DAC_E, bits), \
		LTC1660_CHAN(LTC1660_REG_DAC_F, bits), \
		LTC1660_CHAN(LTC1660_REG_DAC_G, bits), \
		LTC1660_CHAN(LTC1660_REG_DAC_H, bits), \
		}

		static const struct iio_chan_spec ltc1660_channels[][LTC1660_NUM_CHANNELS] = {
		[ID_LTC1660] = LTC1660_OCTAL_CHANNELS(10),
		[ID_LTC1665] = LTC1660_OCTAL_CHANNELS(8),
		};

		static const struct iio_info ltc1660_info = {
		.read_raw = &ltc1660_read_raw,
		.write_raw = &ltc1660_write_raw,
		};

		static int __maybe_unused ltc1660_suspend(struct device *dev)
		{
		struct ltc1660_priv *priv = iio_priv(spi_get_drvdata(
		to_spi_device(dev)));
		return regmap_write(priv->regmap, LTC1660_REG_SLEEP, 0x00);
		}

		static int __maybe_unused ltc1660_resume(struct device *dev)
		{
		struct ltc1660_priv *priv = iio_priv(spi_get_drvdata(
		to_spi_device(dev)));
		return regmap_write(priv->regmap, LTC1660_REG_WAKE, 0x00);
		}
		static SIMPLE_DEV_PM_OPS(ltc1660_pm_ops, ltc1660_suspend, ltc1660_resume);

		static int ltc1660_probe(struct spi_device *spi)
		{
		struct iio_dev *indio_dev;
		struct ltc1660_priv *priv;
		const struct spi_device_id *id = spi_get_device_id(spi);
		int ret;

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

		priv = iio_priv(indio_dev);
		priv->regmap = devm_regmap_init_spi(spi, &ltc1660_regmap_config);
		if (IS_ERR(priv->regmap)) {
		dev_err(&spi->dev, "failed to register spi regmap %ld\n",
		PTR_ERR(priv->regmap));
		return PTR_ERR(priv->regmap);
		}

		priv->vref_reg = devm_regulator_get(&spi->dev, "vref");
		if (IS_ERR(priv->vref_reg)) {
		dev_err(&spi->dev, "vref regulator not specified\n");
		return PTR_ERR(priv->vref_reg);
		}

		ret = regulator_enable(priv->vref_reg);
		if (ret) {
		dev_err(&spi->dev, "failed to enable vref regulator: %d\n",
		ret);
		return ret;
		}

		priv->spi = spi;
		spi_set_drvdata(spi, indio_dev);
		indio_dev->dev.parent = &spi->dev;
		indio_dev->info = &ltc1660_info;
		indio_dev->modes = INDIO_DIRECT_MODE;
		indio_dev->channels = ltc1660_channels[id->driver_data];
		indio_dev->num_channels = LTC1660_NUM_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_reg;
		}

		return 0;

		error_disable_reg:
		regulator_disable(priv->vref_reg);

		return ret;
		}

		static int ltc1660_remove(struct spi_device *spi)
		{
		struct iio_dev *indio_dev = spi_get_drvdata(spi);
		struct ltc1660_priv *priv = iio_priv(indio_dev);

		iio_device_unregister(indio_dev);
		regulator_disable(priv->vref_reg);

		return 0;
		}

		static const struct of_device_id ltc1660_dt_ids[] = {
		{ .compatible = "lltc,ltc1660", .data = (void *)ID_LTC1660 },
		{ .compatible = "lltc,ltc1665", .data = (void *)ID_LTC1665 },
		{ /* sentinel */ }
		};
		MODULE_DEVICE_TABLE(of, ltc1660_dt_ids);

		static const struct spi_device_id ltc1660_id[] = {
		{"ltc1660", ID_LTC1660},
		{"ltc1665", ID_LTC1665},
		{ /* sentinel */ }
		};
		MODULE_DEVICE_TABLE(spi, ltc1660_id);

		static struct spi_driver ltc1660_driver = {
		.driver = {
		.name = "ltc1660",
		.of_match_table = ltc1660_dt_ids,
		.pm = &ltc1660_pm_ops,
		},
		.probe = ltc1660_probe,
		.remove = ltc1660_remove,
		.id_table = ltc1660_id,
		};
		module_spi_driver(ltc1660_driver);

		MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
		MODULE_DESCRIPTION("Linear Technology LTC1660/LTC1665 DAC");
		MODULE_LICENSE("GPL v2");