--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Analog Devices AD5766, AD5767
+ * Digital to Analog Converters driver
+ * Copyright 2019-2020 Analog Devices Inc.
+ */
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <asm/unaligned.h>
+
+#define AD5766_UPPER_WORD_SPI_MASK GENMASK(31, 16)
+#define AD5766_LOWER_WORD_SPI_MASK GENMASK(15, 0)
+#define AD5766_DITHER_SOURCE_MASK(ch) GENMASK(((2 * ch) + 1), (2 * ch))
+#define AD5766_DITHER_SOURCE(ch, source) BIT((ch * 2) + source)
+#define AD5766_DITHER_SCALE_MASK(x) AD5766_DITHER_SOURCE_MASK(x)
+#define AD5766_DITHER_SCALE(ch, scale) (scale << (ch * 2))
+#define AD5766_DITHER_ENABLE_MASK(ch) BIT(ch)
+#define AD5766_DITHER_ENABLE(ch, state) ((!state) << ch)
+#define AD5766_DITHER_INVERT_MASK(ch) BIT(ch)
+#define AD5766_DITHER_INVERT(ch, state) (state << ch)
+
+#define AD5766_CMD_NOP_MUX_OUT 0x00
+#define AD5766_CMD_SDO_CNTRL 0x01
+#define AD5766_CMD_WR_IN_REG(x) (0x10 | ((x) & GENMASK(3, 0)))
+#define AD5766_CMD_WR_DAC_REG(x) (0x20 | ((x) & GENMASK(3, 0)))
+#define AD5766_CMD_SW_LDAC 0x30
+#define AD5766_CMD_SPAN_REG 0x40
+#define AD5766_CMD_WR_PWR_DITHER 0x51
+#define AD5766_CMD_WR_DAC_REG_ALL 0x60
+#define AD5766_CMD_SW_FULL_RESET 0x70
+#define AD5766_CMD_READBACK_REG(x) (0x80 | ((x) & GENMASK(3, 0)))
+#define AD5766_CMD_DITHER_SIG_1 0x90
+#define AD5766_CMD_DITHER_SIG_2 0xA0
+#define AD5766_CMD_INV_DITHER 0xB0
+#define AD5766_CMD_DITHER_SCALE_1 0xC0
+#define AD5766_CMD_DITHER_SCALE_2 0xD0
+
+#define AD5766_FULL_RESET_CODE 0x1234
+
+enum ad5766_type {
+ ID_AD5766,
+ ID_AD5767,
+};
+
+enum ad5766_voltage_range {
+ AD5766_VOLTAGE_RANGE_M20V_0V,
+ AD5766_VOLTAGE_RANGE_M16V_to_0V,
+ AD5766_VOLTAGE_RANGE_M10V_to_0V,
+ AD5766_VOLTAGE_RANGE_M12V_to_14V,
+ AD5766_VOLTAGE_RANGE_M16V_to_10V,
+ AD5766_VOLTAGE_RANGE_M10V_to_6V,
+ AD5766_VOLTAGE_RANGE_M5V_to_5V,
+ AD5766_VOLTAGE_RANGE_M10V_to_10V,
+};
+
+/**
+ * struct ad5766_chip_info - chip specific information
+ * @num_channels: number of channels
+ * @channels: channel specification
+ */
+struct ad5766_chip_info {
+ unsigned int num_channels;
+ const struct iio_chan_spec *channels;
+};
+
+enum {
+ AD5766_DITHER_ENABLE,
+ AD5766_DITHER_INVERT,
+ AD5766_DITHER_SOURCE,
+};
+
+/*
+ * Dither signal can also be scaled.
+ * Available dither scale strings corresponding to "dither_scale" field in
+ * "struct ad5766_state".
+ */
+static const char * const ad5766_dither_scales[] = {
+ "1",
+ "0.75",
+ "0.5",
+ "0.25",
+};
+
+/**
+ * struct ad5766_state - driver instance specific data
+ * @spi: SPI device
+ * @lock: Lock used to restrict concurent access to SPI device
+ * @chip_info: Chip model specific constants
+ * @gpio_reset: Reset GPIO, used to reset the device
+ * @crt_range: Current selected output range
+ * @dither_enable: Power enable bit for each channel dither block (for
+ * example, D15 = DAC 15,D8 = DAC 8, and D0 = DAC 0)
+ * 0 - Normal operation, 1 - Power down
+ * @dither_invert: Inverts the dither signal applied to the selected DAC
+ * outputs
+ * @dither_source: Selects between 2 possible sources:
+ * 1: N0, 2: N1
+ * Two bits are used for each channel
+ * @dither_scale: Two bits are used for each of the 16 channels:
+ * 0: 1 SCALING, 1: 0.75 SCALING, 2: 0.5 SCALING,
+ * 3: 0.25 SCALING.
+ * @data: SPI transfer buffers
+ */
+struct ad5766_state {
+ struct spi_device *spi;
+ struct mutex lock;
+ const struct ad5766_chip_info *chip_info;
+ struct gpio_desc *gpio_reset;
+ enum ad5766_voltage_range crt_range;
+ u16 dither_enable;
+ u16 dither_invert;
+ u32 dither_source;
+ u32 dither_scale;
+ union {
+ u32 d32;
+ u16 w16[2];
+ u8 b8[4];
+ } data[3] ____cacheline_aligned;
+};
+
+struct ad5766_span_tbl {
+ int min;
+ int max;
+};
+
+static const struct ad5766_span_tbl ad5766_span_tbl[] = {
+ [AD5766_VOLTAGE_RANGE_M20V_0V] = {-20, 0},
+ [AD5766_VOLTAGE_RANGE_M16V_to_0V] = {-16, 0},
+ [AD5766_VOLTAGE_RANGE_M10V_to_0V] = {-10, 0},
+ [AD5766_VOLTAGE_RANGE_M12V_to_14V] = {-12, 14},
+ [AD5766_VOLTAGE_RANGE_M16V_to_10V] = {-16, 10},
+ [AD5766_VOLTAGE_RANGE_M10V_to_6V] = {-10, 6},
+ [AD5766_VOLTAGE_RANGE_M5V_to_5V] = {-5, 5},
+ [AD5766_VOLTAGE_RANGE_M10V_to_10V] = {-10, 10},
+};
+
+static int __ad5766_spi_read(struct ad5766_state *st, u8 dac, int *val)
+{
+ int ret;
+ struct spi_transfer xfers[] = {
+ {
+ .tx_buf = &st->data[0].d32,
+ .bits_per_word = 8,
+ .len = 3,
+ .cs_change = 1,
+ }, {
+ .tx_buf = &st->data[1].d32,
+ .rx_buf = &st->data[2].d32,
+ .bits_per_word = 8,
+ .len = 3,
+ },
+ };
+
+ st->data[0].d32 = AD5766_CMD_READBACK_REG(dac);
+ st->data[1].d32 = AD5766_CMD_NOP_MUX_OUT;
+
+ ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
+ if (ret)
+ return ret;
+
+ *val = st->data[2].w16[1];
+
+ return ret;
+}
+
+static int __ad5766_spi_write(struct ad5766_state *st, u8 command, u16 data)
+{
+ st->data[0].b8[0] = command;
+ put_unaligned_be16(data, &st->data[0].b8[1]);
+
+ return spi_write(st->spi, &st->data[0].b8[0], 3);
+}
+
+static int ad5766_read(struct iio_dev *indio_dev, u8 dac, int *val)
+{
+ struct ad5766_state *st = iio_priv(indio_dev);
+ int ret;
+
+ mutex_lock(&st->lock);
+ ret = __ad5766_spi_read(st, dac, val);
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+
+static int ad5766_write(struct iio_dev *indio_dev, u8 dac, u16 data)
+{
+ struct ad5766_state *st = iio_priv(indio_dev);
+ int ret;
+
+ mutex_lock(&st->lock);
+ ret = __ad5766_spi_write(st, AD5766_CMD_WR_DAC_REG(dac), data);
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+
+static int ad5766_reset(struct ad5766_state *st)
+{
+ int ret;
+
+ if (st->gpio_reset) {
+ gpiod_set_value_cansleep(st->gpio_reset, 1);
+ ndelay(100); /* t_reset >= 100ns */
+ gpiod_set_value_cansleep(st->gpio_reset, 0);
+ } else {
+ ret = __ad5766_spi_write(st, AD5766_CMD_SW_FULL_RESET,
+ AD5766_FULL_RESET_CODE);
+ if (ret < 0)
+ return ret;
+ }
+
+ /*
+ * Minimum time between a reset and the subsequent successful write is
+ * typically 25 ns
+ */
+ ndelay(25);
+
+ return 0;
+}
+
+static int ad5766_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long m)
+{
+ struct ad5766_state *st = iio_priv(indio_dev);
+ int ret;
+
+ switch (m) {
+ case IIO_CHAN_INFO_RAW:
+ ret = ad5766_read(indio_dev, chan->address, val);
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = ad5766_span_tbl[st->crt_range].min;
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = ad5766_span_tbl[st->crt_range].max -
+ ad5766_span_tbl[st->crt_range].min;
+ *val2 = st->chip_info->channels[0].scan_type.realbits;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad5766_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val,
+ int val2,
+ long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ {
+ const int max_val = GENMASK(chan->scan_type.realbits - 1, 0);
+
+ if (val > max_val || val < 0)
+ return -EINVAL;
+ val <<= chan->scan_type.shift;
+ return ad5766_write(indio_dev, chan->address, val);
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info ad5766_info = {
+ .read_raw = ad5766_read_raw,
+ .write_raw = ad5766_write_raw,
+};
+
+static int ad5766_get_dither_source(struct iio_dev *dev,
+ const struct iio_chan_spec *chan)
+{
+ struct ad5766_state *st = iio_priv(dev);
+ u32 source;
+
+ source = st->dither_source & AD5766_DITHER_SOURCE_MASK(chan->channel);
+ source = source >> (chan->channel * 2);
+ source -= 1;
+
+ return source;
+}
+
+static int ad5766_set_dither_source(struct iio_dev *dev,
+ const struct iio_chan_spec *chan,
+ unsigned int source)
+{
+ struct ad5766_state *st = iio_priv(dev);
+ uint16_t val;
+ int ret;
+
+ st->dither_source &= ~AD5766_DITHER_SOURCE_MASK(chan->channel);
+ st->dither_source |= AD5766_DITHER_SOURCE(chan->channel, source);
+
+ val = FIELD_GET(AD5766_LOWER_WORD_SPI_MASK, st->dither_source);
+ ret = ad5766_write(dev, AD5766_CMD_DITHER_SIG_1, val);
+ if (ret)
+ return ret;
+
+ val = FIELD_GET(AD5766_UPPER_WORD_SPI_MASK, st->dither_source);
+
+ return ad5766_write(dev, AD5766_CMD_DITHER_SIG_2, val);
+}
+
+static int ad5766_get_dither_scale(struct iio_dev *dev,
+ const struct iio_chan_spec *chan)
+{
+ struct ad5766_state *st = iio_priv(dev);
+ u32 scale;
+
+ scale = st->dither_scale & AD5766_DITHER_SCALE_MASK(chan->channel);
+
+ return (scale >> (chan->channel * 2));
+}
+
+static int ad5766_set_dither_scale(struct iio_dev *dev,
+ const struct iio_chan_spec *chan,
+ unsigned int scale)
+{
+ int ret;
+ struct ad5766_state *st = iio_priv(dev);
+ uint16_t val;
+
+ st->dither_scale &= ~AD5766_DITHER_SCALE_MASK(chan->channel);
+ st->dither_scale |= AD5766_DITHER_SCALE(chan->channel, scale);
+
+ val = FIELD_GET(AD5766_LOWER_WORD_SPI_MASK, st->dither_scale);
+ ret = ad5766_write(dev, AD5766_CMD_DITHER_SCALE_1, val);
+ if (ret)
+ return ret;
+ val = FIELD_GET(AD5766_UPPER_WORD_SPI_MASK, st->dither_scale);
+
+ return ad5766_write(dev, AD5766_CMD_DITHER_SCALE_2, val);
+}
+
+static const struct iio_enum ad5766_dither_scale_enum = {
+ .items = ad5766_dither_scales,
+ .num_items = ARRAY_SIZE(ad5766_dither_scales),
+ .set = ad5766_set_dither_scale,
+ .get = ad5766_get_dither_scale,
+};
+
+static ssize_t ad5766_read_ext(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ char *buf)
+{
+ struct ad5766_state *st = iio_priv(indio_dev);
+
+ switch (private) {
+ case AD5766_DITHER_ENABLE:
+ return sprintf(buf, "%u\n",
+ !(st->dither_enable & BIT(chan->channel)));
+ break;
+ case AD5766_DITHER_INVERT:
+ return sprintf(buf, "%u\n",
+ !!(st->dither_invert & BIT(chan->channel)));
+ break;
+ case AD5766_DITHER_SOURCE:
+ return sprintf(buf, "%d\n",
+ ad5766_get_dither_source(indio_dev, chan));
+ default:
+ return -EINVAL;
+ }
+}
+
+static ssize_t ad5766_write_ext(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ const char *buf, size_t len)
+{
+ struct ad5766_state *st = iio_priv(indio_dev);
+ bool readin;
+ int ret;
+
+ ret = kstrtobool(buf, &readin);
+ if (ret)
+ return ret;
+
+ switch (private) {
+ case AD5766_DITHER_ENABLE:
+ st->dither_enable &= ~AD5766_DITHER_ENABLE_MASK(chan->channel);
+ st->dither_enable |= AD5766_DITHER_ENABLE(chan->channel,
+ readin);
+ ret = ad5766_write(indio_dev, AD5766_CMD_WR_PWR_DITHER,
+ st->dither_enable);
+ break;
+ case AD5766_DITHER_INVERT:
+ st->dither_invert &= ~AD5766_DITHER_INVERT_MASK(chan->channel);
+ st->dither_invert |= AD5766_DITHER_INVERT(chan->channel,
+ readin);
+ ret = ad5766_write(indio_dev, AD5766_CMD_INV_DITHER,
+ st->dither_invert);
+ break;
+ case AD5766_DITHER_SOURCE:
+ ret = ad5766_set_dither_source(indio_dev, chan, readin);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return ret ? ret : len;
+}
+
+#define _AD5766_CHAN_EXT_INFO(_name, _what, _shared) { \
+ .name = _name, \
+ .read = ad5766_read_ext, \
+ .write = ad5766_write_ext, \
+ .private = _what, \
+ .shared = _shared, \
+}
+
+#define IIO_ENUM_AVAILABLE_SHARED(_name, _shared, _e) \
+{ \
+ .name = (_name "_available"), \
+ .shared = _shared, \
+ .read = iio_enum_available_read, \
+ .private = (uintptr_t)(_e), \
+}
+
+static const struct iio_chan_spec_ext_info ad5766_ext_info[] = {
+
+ _AD5766_CHAN_EXT_INFO("dither_enable", AD5766_DITHER_ENABLE,
+ IIO_SEPARATE),
+ _AD5766_CHAN_EXT_INFO("dither_invert", AD5766_DITHER_INVERT,
+ IIO_SEPARATE),
+ _AD5766_CHAN_EXT_INFO("dither_source", AD5766_DITHER_SOURCE,
+ IIO_SEPARATE),
+ IIO_ENUM("dither_scale", IIO_SEPARATE, &ad5766_dither_scale_enum),
+ IIO_ENUM_AVAILABLE_SHARED("dither_scale",
+ IIO_SEPARATE,
+ &ad5766_dither_scale_enum),
+ {}
+};
+
+#define AD576x_CHANNEL(_chan, _bits) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .output = 1, \
+ .channel = (_chan), \
+ .address = (_chan), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = (_bits), \
+ .storagebits = 16, \
+ .shift = 16 - (_bits), \
+ }, \
+ .ext_info = ad5766_ext_info, \
+}
+
+#define DECLARE_AD576x_CHANNELS(_name, _bits) \
+const struct iio_chan_spec _name[] = { \
+ AD576x_CHANNEL(0, (_bits)), \
+ AD576x_CHANNEL(1, (_bits)), \
+ AD576x_CHANNEL(2, (_bits)), \
+ AD576x_CHANNEL(3, (_bits)), \
+ AD576x_CHANNEL(4, (_bits)), \
+ AD576x_CHANNEL(5, (_bits)), \
+ AD576x_CHANNEL(6, (_bits)), \
+ AD576x_CHANNEL(7, (_bits)), \
+ AD576x_CHANNEL(8, (_bits)), \
+ AD576x_CHANNEL(9, (_bits)), \
+ AD576x_CHANNEL(10, (_bits)), \
+ AD576x_CHANNEL(11, (_bits)), \
+ AD576x_CHANNEL(12, (_bits)), \
+ AD576x_CHANNEL(13, (_bits)), \
+ AD576x_CHANNEL(14, (_bits)), \
+ AD576x_CHANNEL(15, (_bits)), \
+}
+
+static DECLARE_AD576x_CHANNELS(ad5766_channels, 16);
+static DECLARE_AD576x_CHANNELS(ad5767_channels, 12);
+
+static const struct ad5766_chip_info ad5766_chip_infos[] = {
+ [ID_AD5766] = {
+ .num_channels = ARRAY_SIZE(ad5766_channels),
+ .channels = ad5766_channels,
+ },
+ [ID_AD5767] = {
+ .num_channels = ARRAY_SIZE(ad5767_channels),
+ .channels = ad5767_channels,
+ },
+};
+
+static int ad5766_get_output_range(struct ad5766_state *st)
+{
+ int i, ret, min, max, tmp[2];
+
+ ret = device_property_read_u32_array(&st->spi->dev,
+ "output-range-voltage",
+ tmp, 2);
+ if (ret)
+ return ret;
+
+ min = tmp[0] / 1000;
+ max = tmp[1] / 1000;
+ for (i = 0; i < ARRAY_SIZE(ad5766_span_tbl); i++) {
+ if (ad5766_span_tbl[i].min != min ||
+ ad5766_span_tbl[i].max != max)
+ continue;
+
+ st->crt_range = i;
+
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int ad5766_default_setup(struct ad5766_state *st)
+{
+ uint16_t val;
+ int ret, i;
+
+ /* Always issue a reset before writing to the span register. */
+ ret = ad5766_reset(st);
+ if (ret)
+ return ret;
+
+ ret = ad5766_get_output_range(st);
+ if (ret)
+ return ret;
+
+ /* Dither power down */
+ st->dither_enable = GENMASK(15, 0);
+ ret = __ad5766_spi_write(st, AD5766_CMD_WR_PWR_DITHER,
+ st->dither_enable);
+ if (ret)
+ return ret;
+
+ st->dither_source = 0;
+ for (i = 0; i < ARRAY_SIZE(ad5766_channels); i++)
+ st->dither_source |= AD5766_DITHER_SOURCE(i, 0);
+ val = FIELD_GET(AD5766_LOWER_WORD_SPI_MASK, st->dither_source);
+ ret = __ad5766_spi_write(st, AD5766_CMD_DITHER_SIG_1, val);
+ if (ret)
+ return ret;
+
+ val = FIELD_GET(AD5766_UPPER_WORD_SPI_MASK, st->dither_source);
+ ret = __ad5766_spi_write(st, AD5766_CMD_DITHER_SIG_2, val);
+ if (ret)
+ return ret;
+
+ st->dither_scale = 0;
+ val = FIELD_GET(AD5766_LOWER_WORD_SPI_MASK, st->dither_scale);
+ ret = __ad5766_spi_write(st, AD5766_CMD_DITHER_SCALE_1, val);
+ if (ret)
+ return ret;
+
+ val = FIELD_GET(AD5766_UPPER_WORD_SPI_MASK, st->dither_scale);
+ ret = __ad5766_spi_write(st, AD5766_CMD_DITHER_SCALE_2, val);
+ if (ret)
+ return ret;
+
+ st->dither_invert = 0;
+ ret = __ad5766_spi_write(st, AD5766_CMD_INV_DITHER, st->dither_invert);
+ if (ret)
+ return ret;
+
+ return __ad5766_spi_write(st, AD5766_CMD_SPAN_REG, st->crt_range);
+}
+
+static int ad5766_probe(struct spi_device *spi)
+{
+ enum ad5766_type type;
+ struct iio_dev *indio_dev;
+ struct ad5766_state *st;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ mutex_init(&st->lock);
+
+ st->spi = spi;
+ type = spi_get_device_id(spi)->driver_data;
+ st->chip_info = &ad5766_chip_infos[type];
+
+ indio_dev->channels = st->chip_info->channels;
+ indio_dev->num_channels = st->chip_info->num_channels;
+ indio_dev->info = &ad5766_info;
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->dev.of_node = spi->dev.of_node;
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(st->gpio_reset))
+ return PTR_ERR(st->gpio_reset);
+
+ ret = ad5766_default_setup(st);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct of_device_id ad5766_dt_match[] = {
+ { .compatible = "adi,ad5766" },
+ { .compatible = "adi,ad5767" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, ad5766_dt_match);
+
+static const struct spi_device_id ad5766_spi_ids[] = {
+ { "ad5766", ID_AD5766 },
+ { "ad5767", ID_AD5767 },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, ad5766_spi_ids);
+
+static struct spi_driver ad5766_driver = {
+ .driver = {
+ .name = "ad5766",
+ .of_match_table = ad5766_dt_match,
+ },
+ .probe = ad5766_probe,
+ .id_table = ad5766_spi_ids,
+};
+module_spi_driver(ad5766_driver);
+
+MODULE_AUTHOR("Denis-Gabriel Gheorghescu <denis.gheorghescu@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD5766/AD5767 DACs");
+MODULE_LICENSE("GPL v2");
projects / platform / kernel / linux-rpi.git / commitdiff