v4.19.13 snapshot.
diff --git a/drivers/iio/dac/ad5791.c b/drivers/iio/dac/ad5791.c
new file mode 100644
index 0000000..7569bf6
--- /dev/null
+++ b/drivers/iio/dac/ad5791.c
@@ -0,0 +1,472 @@
+/*
+ * AD5760, AD5780, AD5781, AD5790, AD5791 Voltage Output Digital to Analog
+ * Converter
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/regulator/consumer.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/dac/ad5791.h>
+
+#define AD5791_DAC_MASK GENMASK(19, 0)
+
+#define AD5791_CMD_READ BIT(23)
+#define AD5791_CMD_WRITE 0
+#define AD5791_ADDR(addr) ((addr) << 20)
+
+/* Registers */
+#define AD5791_ADDR_NOOP 0
+#define AD5791_ADDR_DAC0 1
+#define AD5791_ADDR_CTRL 2
+#define AD5791_ADDR_CLRCODE 3
+#define AD5791_ADDR_SW_CTRL 4
+
+/* Control Register */
+#define AD5791_CTRL_RBUF BIT(1)
+#define AD5791_CTRL_OPGND BIT(2)
+#define AD5791_CTRL_DACTRI BIT(3)
+#define AD5791_CTRL_BIN2SC BIT(4)
+#define AD5791_CTRL_SDODIS BIT(5)
+#define AD5761_CTRL_LINCOMP(x) ((x) << 6)
+
+#define AD5791_LINCOMP_0_10 0
+#define AD5791_LINCOMP_10_12 1
+#define AD5791_LINCOMP_12_16 2
+#define AD5791_LINCOMP_16_19 3
+#define AD5791_LINCOMP_19_20 12
+
+#define AD5780_LINCOMP_0_10 0
+#define AD5780_LINCOMP_10_20 12
+
+/* Software Control Register */
+#define AD5791_SWCTRL_LDAC BIT(0)
+#define AD5791_SWCTRL_CLR BIT(1)
+#define AD5791_SWCTRL_RESET BIT(2)
+
+#define AD5791_DAC_PWRDN_6K 0
+#define AD5791_DAC_PWRDN_3STATE 1
+
+/**
+ * struct ad5791_chip_info - chip specific information
+ * @get_lin_comp: function pointer to the device specific function
+ */
+
+struct ad5791_chip_info {
+ int (*get_lin_comp) (unsigned int span);
+};
+
+/**
+ * struct ad5791_state - driver instance specific data
+ * @spi: spi_device
+ * @reg_vdd: positive supply regulator
+ * @reg_vss: negative supply regulator
+ * @chip_info: chip model specific constants
+ * @vref_mv: actual reference voltage used
+ * @vref_neg_mv: voltage of the negative supply
+ * @pwr_down_mode current power down mode
+ */
+
+struct ad5791_state {
+ struct spi_device *spi;
+ struct regulator *reg_vdd;
+ struct regulator *reg_vss;
+ const struct ad5791_chip_info *chip_info;
+ unsigned short vref_mv;
+ unsigned int vref_neg_mv;
+ unsigned ctrl;
+ unsigned pwr_down_mode;
+ bool pwr_down;
+
+ union {
+ __be32 d32;
+ u8 d8[4];
+ } data[3] ____cacheline_aligned;
+};
+
+/**
+ * ad5791_supported_device_ids:
+ */
+
+enum ad5791_supported_device_ids {
+ ID_AD5760,
+ ID_AD5780,
+ ID_AD5781,
+ ID_AD5791,
+};
+
+static int ad5791_spi_write(struct ad5791_state *st, u8 addr, u32 val)
+{
+ st->data[0].d32 = cpu_to_be32(AD5791_CMD_WRITE |
+ AD5791_ADDR(addr) |
+ (val & AD5791_DAC_MASK));
+
+ return spi_write(st->spi, &st->data[0].d8[1], 3);
+}
+
+static int ad5791_spi_read(struct ad5791_state *st, u8 addr, u32 *val)
+{
+ int ret;
+ struct spi_transfer xfers[] = {
+ {
+ .tx_buf = &st->data[0].d8[1],
+ .bits_per_word = 8,
+ .len = 3,
+ .cs_change = 1,
+ }, {
+ .tx_buf = &st->data[1].d8[1],
+ .rx_buf = &st->data[2].d8[1],
+ .bits_per_word = 8,
+ .len = 3,
+ },
+ };
+
+ st->data[0].d32 = cpu_to_be32(AD5791_CMD_READ |
+ AD5791_ADDR(addr));
+ st->data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP));
+
+ ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
+
+ *val = be32_to_cpu(st->data[2].d32);
+
+ return ret;
+}
+
+static const char * const ad5791_powerdown_modes[] = {
+ "6kohm_to_gnd",
+ "three_state",
+};
+
+static int ad5791_get_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct ad5791_state *st = iio_priv(indio_dev);
+
+ return st->pwr_down_mode;
+}
+
+static int ad5791_set_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, unsigned int mode)
+{
+ struct ad5791_state *st = iio_priv(indio_dev);
+
+ st->pwr_down_mode = mode;
+
+ return 0;
+}
+
+static const struct iio_enum ad5791_powerdown_mode_enum = {
+ .items = ad5791_powerdown_modes,
+ .num_items = ARRAY_SIZE(ad5791_powerdown_modes),
+ .get = ad5791_get_powerdown_mode,
+ .set = ad5791_set_powerdown_mode,
+};
+
+static ssize_t ad5791_read_dac_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private, const struct iio_chan_spec *chan, char *buf)
+{
+ struct ad5791_state *st = iio_priv(indio_dev);
+
+ return sprintf(buf, "%d\n", st->pwr_down);
+}
+
+static ssize_t ad5791_write_dac_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
+ size_t len)
+{
+ bool pwr_down;
+ int ret;
+ struct ad5791_state *st = iio_priv(indio_dev);
+
+ ret = strtobool(buf, &pwr_down);
+ if (ret)
+ return ret;
+
+ if (!pwr_down) {
+ st->ctrl &= ~(AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
+ } else {
+ if (st->pwr_down_mode == AD5791_DAC_PWRDN_6K)
+ st->ctrl |= AD5791_CTRL_OPGND;
+ else if (st->pwr_down_mode == AD5791_DAC_PWRDN_3STATE)
+ st->ctrl |= AD5791_CTRL_DACTRI;
+ }
+ st->pwr_down = pwr_down;
+
+ ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl);
+
+ return ret ? ret : len;
+}
+
+static int ad5791_get_lin_comp(unsigned int span)
+{
+ if (span <= 10000)
+ return AD5791_LINCOMP_0_10;
+ else if (span <= 12000)
+ return AD5791_LINCOMP_10_12;
+ else if (span <= 16000)
+ return AD5791_LINCOMP_12_16;
+ else if (span <= 19000)
+ return AD5791_LINCOMP_16_19;
+ else
+ return AD5791_LINCOMP_19_20;
+}
+
+static int ad5780_get_lin_comp(unsigned int span)
+{
+ if (span <= 10000)
+ return AD5780_LINCOMP_0_10;
+ else
+ return AD5780_LINCOMP_10_20;
+}
+static const struct ad5791_chip_info ad5791_chip_info_tbl[] = {
+ [ID_AD5760] = {
+ .get_lin_comp = ad5780_get_lin_comp,
+ },
+ [ID_AD5780] = {
+ .get_lin_comp = ad5780_get_lin_comp,
+ },
+ [ID_AD5781] = {
+ .get_lin_comp = ad5791_get_lin_comp,
+ },
+ [ID_AD5791] = {
+ .get_lin_comp = ad5791_get_lin_comp,
+ },
+};
+
+static int ad5791_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long m)
+{
+ struct ad5791_state *st = iio_priv(indio_dev);
+ u64 val64;
+ int ret;
+
+ switch (m) {
+ case IIO_CHAN_INFO_RAW:
+ ret = ad5791_spi_read(st, chan->address, val);
+ if (ret)
+ return ret;
+ *val &= AD5791_DAC_MASK;
+ *val >>= chan->scan_type.shift;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = st->vref_mv;
+ *val2 = (1 << chan->scan_type.realbits) - 1;
+ return IIO_VAL_FRACTIONAL;
+ case IIO_CHAN_INFO_OFFSET:
+ val64 = (((u64)st->vref_neg_mv) << chan->scan_type.realbits);
+ do_div(val64, st->vref_mv);
+ *val = -val64;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+
+};
+
+static const struct iio_chan_spec_ext_info ad5791_ext_info[] = {
+ {
+ .name = "powerdown",
+ .shared = IIO_SHARED_BY_TYPE,
+ .read = ad5791_read_dac_powerdown,
+ .write = ad5791_write_dac_powerdown,
+ },
+ IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
+ &ad5791_powerdown_mode_enum),
+ IIO_ENUM_AVAILABLE("powerdown_mode", &ad5791_powerdown_mode_enum),
+ { },
+};
+
+#define AD5791_CHAN(bits, _shift) { \
+ .type = IIO_VOLTAGE, \
+ .output = 1, \
+ .indexed = 1, \
+ .address = AD5791_ADDR_DAC0, \
+ .channel = 0, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_OFFSET), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = (bits), \
+ .storagebits = 24, \
+ .shift = (_shift), \
+ }, \
+ .ext_info = ad5791_ext_info, \
+}
+
+static const struct iio_chan_spec ad5791_channels[] = {
+ [ID_AD5760] = AD5791_CHAN(16, 4),
+ [ID_AD5780] = AD5791_CHAN(18, 2),
+ [ID_AD5781] = AD5791_CHAN(18, 2),
+ [ID_AD5791] = AD5791_CHAN(20, 0)
+};
+
+static int ad5791_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val,
+ int val2,
+ long mask)
+{
+ struct ad5791_state *st = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ val &= GENMASK(chan->scan_type.realbits - 1, 0);
+ val <<= chan->scan_type.shift;
+
+ return ad5791_spi_write(st, chan->address, val);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info ad5791_info = {
+ .read_raw = &ad5791_read_raw,
+ .write_raw = &ad5791_write_raw,
+};
+
+static int ad5791_probe(struct spi_device *spi)
+{
+ struct ad5791_platform_data *pdata = spi->dev.platform_data;
+ struct iio_dev *indio_dev;
+ struct ad5791_state *st;
+ int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+ st = iio_priv(indio_dev);
+ st->reg_vdd = devm_regulator_get(&spi->dev, "vdd");
+ if (!IS_ERR(st->reg_vdd)) {
+ ret = regulator_enable(st->reg_vdd);
+ if (ret)
+ return ret;
+
+ ret = regulator_get_voltage(st->reg_vdd);
+ if (ret < 0)
+ goto error_disable_reg_pos;
+
+ pos_voltage_uv = ret;
+ }
+
+ st->reg_vss = devm_regulator_get(&spi->dev, "vss");
+ if (!IS_ERR(st->reg_vss)) {
+ ret = regulator_enable(st->reg_vss);
+ if (ret)
+ goto error_disable_reg_pos;
+
+ ret = regulator_get_voltage(st->reg_vss);
+ if (ret < 0)
+ goto error_disable_reg_neg;
+
+ neg_voltage_uv = ret;
+ }
+
+ st->pwr_down = true;
+ st->spi = spi;
+
+ if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd)) {
+ st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000;
+ st->vref_neg_mv = neg_voltage_uv / 1000;
+ } else if (pdata) {
+ st->vref_mv = pdata->vref_pos_mv + pdata->vref_neg_mv;
+ st->vref_neg_mv = pdata->vref_neg_mv;
+ } else {
+ dev_warn(&spi->dev, "reference voltage unspecified\n");
+ }
+
+ ret = ad5791_spi_write(st, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET);
+ if (ret)
+ goto error_disable_reg_neg;
+
+ st->chip_info = &ad5791_chip_info_tbl[spi_get_device_id(spi)
+ ->driver_data];
+
+
+ st->ctrl = AD5761_CTRL_LINCOMP(st->chip_info->get_lin_comp(st->vref_mv))
+ | ((pdata && pdata->use_rbuf_gain2) ? 0 : AD5791_CTRL_RBUF) |
+ AD5791_CTRL_BIN2SC;
+
+ ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl |
+ AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
+ if (ret)
+ goto error_disable_reg_neg;
+
+ spi_set_drvdata(spi, indio_dev);
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->info = &ad5791_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels
+ = &ad5791_channels[spi_get_device_id(spi)->driver_data];
+ indio_dev->num_channels = 1;
+ indio_dev->name = spi_get_device_id(st->spi)->name;
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_disable_reg_neg;
+
+ return 0;
+
+error_disable_reg_neg:
+ if (!IS_ERR(st->reg_vss))
+ regulator_disable(st->reg_vss);
+error_disable_reg_pos:
+ if (!IS_ERR(st->reg_vdd))
+ regulator_disable(st->reg_vdd);
+ return ret;
+}
+
+static int ad5791_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct ad5791_state *st = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ if (!IS_ERR(st->reg_vdd))
+ regulator_disable(st->reg_vdd);
+
+ if (!IS_ERR(st->reg_vss))
+ regulator_disable(st->reg_vss);
+
+ return 0;
+}
+
+static const struct spi_device_id ad5791_id[] = {
+ {"ad5760", ID_AD5760},
+ {"ad5780", ID_AD5780},
+ {"ad5781", ID_AD5781},
+ {"ad5790", ID_AD5791},
+ {"ad5791", ID_AD5791},
+ {}
+};
+MODULE_DEVICE_TABLE(spi, ad5791_id);
+
+static struct spi_driver ad5791_driver = {
+ .driver = {
+ .name = "ad5791",
+ },
+ .probe = ad5791_probe,
+ .remove = ad5791_remove,
+ .id_table = ad5791_id,
+};
+module_spi_driver(ad5791_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC");
+MODULE_LICENSE("GPL v2");