mirror of https://gitee.com/openkylin/linux.git
251 lines
6.1 KiB
C
251 lines
6.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Driver for Linear Technology LTC1665/LTC1660, 8 channels DAC
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*
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* Copyright (C) 2018 Marcus Folkesson <marcus.folkesson@gmail.com>
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*/
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#include <linux/bitops.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/regulator/consumer.h>
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#include <linux/regmap.h>
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#include <linux/spi/spi.h>
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#define LTC1660_REG_WAKE 0x0
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#define LTC1660_REG_DAC_A 0x1
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#define LTC1660_REG_DAC_B 0x2
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#define LTC1660_REG_DAC_C 0x3
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#define LTC1660_REG_DAC_D 0x4
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#define LTC1660_REG_DAC_E 0x5
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#define LTC1660_REG_DAC_F 0x6
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#define LTC1660_REG_DAC_G 0x7
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#define LTC1660_REG_DAC_H 0x8
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#define LTC1660_REG_SLEEP 0xe
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#define LTC1660_NUM_CHANNELS 8
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static const struct regmap_config ltc1660_regmap_config = {
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.reg_bits = 4,
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.val_bits = 12,
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};
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enum ltc1660_supported_device_ids {
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ID_LTC1660,
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ID_LTC1665,
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};
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struct ltc1660_priv {
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struct spi_device *spi;
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struct regmap *regmap;
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struct regulator *vref_reg;
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unsigned int value[LTC1660_NUM_CHANNELS];
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unsigned int vref_mv;
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};
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static int ltc1660_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val,
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int *val2,
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long mask)
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{
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struct ltc1660_priv *priv = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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*val = priv->value[chan->channel];
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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*val = regulator_get_voltage(priv->vref_reg);
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if (*val < 0) {
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dev_err(&priv->spi->dev, "failed to read vref regulator: %d\n",
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*val);
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return *val;
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}
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/* Convert to mV */
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*val /= 1000;
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*val2 = chan->scan_type.realbits;
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return IIO_VAL_FRACTIONAL_LOG2;
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default:
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return -EINVAL;
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}
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}
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static int ltc1660_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val,
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int val2,
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long mask)
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{
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struct ltc1660_priv *priv = iio_priv(indio_dev);
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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if (val2 != 0)
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return -EINVAL;
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if (val < 0 || val > GENMASK(chan->scan_type.realbits - 1, 0))
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return -EINVAL;
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ret = regmap_write(priv->regmap, chan->channel,
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(val << chan->scan_type.shift));
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if (!ret)
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priv->value[chan->channel] = val;
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return ret;
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default:
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return -EINVAL;
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}
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}
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#define LTC1660_CHAN(chan, bits) { \
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.type = IIO_VOLTAGE, \
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.indexed = 1, \
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.output = 1, \
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.channel = chan, \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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.scan_type = { \
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.sign = 'u', \
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.realbits = (bits), \
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.storagebits = 16, \
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.shift = 12 - (bits), \
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}, \
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}
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#define LTC1660_OCTAL_CHANNELS(bits) { \
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LTC1660_CHAN(LTC1660_REG_DAC_A, bits), \
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LTC1660_CHAN(LTC1660_REG_DAC_B, bits), \
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LTC1660_CHAN(LTC1660_REG_DAC_C, bits), \
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LTC1660_CHAN(LTC1660_REG_DAC_D, bits), \
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LTC1660_CHAN(LTC1660_REG_DAC_E, bits), \
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LTC1660_CHAN(LTC1660_REG_DAC_F, bits), \
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LTC1660_CHAN(LTC1660_REG_DAC_G, bits), \
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LTC1660_CHAN(LTC1660_REG_DAC_H, bits), \
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}
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static const struct iio_chan_spec ltc1660_channels[][LTC1660_NUM_CHANNELS] = {
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[ID_LTC1660] = LTC1660_OCTAL_CHANNELS(10),
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[ID_LTC1665] = LTC1660_OCTAL_CHANNELS(8),
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};
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static const struct iio_info ltc1660_info = {
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.read_raw = <c1660_read_raw,
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.write_raw = <c1660_write_raw,
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};
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static int __maybe_unused ltc1660_suspend(struct device *dev)
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{
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struct ltc1660_priv *priv = iio_priv(spi_get_drvdata(
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to_spi_device(dev)));
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return regmap_write(priv->regmap, LTC1660_REG_SLEEP, 0x00);
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}
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static int __maybe_unused ltc1660_resume(struct device *dev)
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{
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struct ltc1660_priv *priv = iio_priv(spi_get_drvdata(
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to_spi_device(dev)));
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return regmap_write(priv->regmap, LTC1660_REG_WAKE, 0x00);
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}
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static SIMPLE_DEV_PM_OPS(ltc1660_pm_ops, ltc1660_suspend, ltc1660_resume);
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static int ltc1660_probe(struct spi_device *spi)
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{
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struct iio_dev *indio_dev;
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struct ltc1660_priv *priv;
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const struct spi_device_id *id = spi_get_device_id(spi);
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int ret;
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*priv));
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if (indio_dev == NULL)
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return -ENOMEM;
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priv = iio_priv(indio_dev);
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priv->regmap = devm_regmap_init_spi(spi, <c1660_regmap_config);
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if (IS_ERR(priv->regmap)) {
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dev_err(&spi->dev, "failed to register spi regmap %ld\n",
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PTR_ERR(priv->regmap));
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return PTR_ERR(priv->regmap);
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}
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priv->vref_reg = devm_regulator_get(&spi->dev, "vref");
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if (IS_ERR(priv->vref_reg)) {
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dev_err(&spi->dev, "vref regulator not specified\n");
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return PTR_ERR(priv->vref_reg);
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}
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ret = regulator_enable(priv->vref_reg);
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if (ret) {
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dev_err(&spi->dev, "failed to enable vref regulator: %d\n",
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ret);
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return ret;
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}
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priv->spi = spi;
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spi_set_drvdata(spi, indio_dev);
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indio_dev->dev.parent = &spi->dev;
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indio_dev->info = <c1660_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = ltc1660_channels[id->driver_data];
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indio_dev->num_channels = LTC1660_NUM_CHANNELS;
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indio_dev->name = id->name;
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ret = iio_device_register(indio_dev);
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if (ret) {
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dev_err(&spi->dev, "failed to register iio device: %d\n",
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ret);
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goto error_disable_reg;
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}
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return 0;
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error_disable_reg:
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regulator_disable(priv->vref_reg);
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return ret;
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}
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static int ltc1660_remove(struct spi_device *spi)
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{
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struct iio_dev *indio_dev = spi_get_drvdata(spi);
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struct ltc1660_priv *priv = iio_priv(indio_dev);
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iio_device_unregister(indio_dev);
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regulator_disable(priv->vref_reg);
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return 0;
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}
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static const struct of_device_id ltc1660_dt_ids[] = {
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{ .compatible = "lltc,ltc1660", .data = (void *)ID_LTC1660 },
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{ .compatible = "lltc,ltc1665", .data = (void *)ID_LTC1665 },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, ltc1660_dt_ids);
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static const struct spi_device_id ltc1660_id[] = {
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{"ltc1660", ID_LTC1660},
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{"ltc1665", ID_LTC1665},
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(spi, ltc1660_id);
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static struct spi_driver ltc1660_driver = {
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.driver = {
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.name = "ltc1660",
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.of_match_table = ltc1660_dt_ids,
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.pm = <c1660_pm_ops,
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},
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.probe = ltc1660_probe,
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.remove = ltc1660_remove,
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.id_table = ltc1660_id,
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};
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module_spi_driver(ltc1660_driver);
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MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
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MODULE_DESCRIPTION("Linear Technology LTC1660/LTC1665 DAC");
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MODULE_LICENSE("GPL v2");
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