The AD5766/AD5767 are 16-channel, 16-bit/12-bit, voltage output dense DACs
Digital-to-Analog converters.

This change adds support for these DACs.

Link: 
https://www.analog.com/media/en/technical-documentation/data-sheets/ad5766-5767.pdf

Signed-off-by: Cristian Pop <[email protected]>
---
 Changes in v2:
        -Remove forward declarations, arrange code
        -New ABI docs
        -Move "max_val" scope in case
        -Remove blank line
        -Use bitfield operations, where posible
        -Change declaration type to int of:
                int             scale_avail[AD5766_VOLTAGE_RANGE_MAX][2];
                int             offset_avail[AD5766_VOLTAGE_RANGE_MAX][2];
        -Move initialization down to just above where it is used: 
                "type = spi_get_device_id(spi)->driver_data;"

 drivers/iio/dac/ad5766.c | 758 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 758 insertions(+)
 create mode 100644 drivers/iio/dac/ad5766.c

diff --git a/drivers/iio/dac/ad5766.c b/drivers/iio/dac/ad5766.c
new file mode 100644
index 000000000000..e6d24a41bd4e
--- /dev/null
+++ b/drivers/iio/dac/ad5766.c
@@ -0,0 +1,758 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Analog Devices AD5766, AD5767
+ * Digital to Analog Converters driver
+ *
+ * Copyright 2019-2020 Analog Devices Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/iio/iio.h>
+#include <linux/bitfield.h>
+
+#define AD5766_UPPER_WORD_SPI_MASK             GENMASK(31, 16)
+#define AD5766_LOWER_WORD_SPI_MASK             GENMASK(15, 0)
+#define AD5766_DITHER_SOURCE_MASK(x)           GENMASK(((2 * x) + 1), (2 * x))
+#define AD5766_DITHER_SCALE_MASK(x)            AD5766_DITHER_SOURCE_MASK(x)
+
+#define AD5766_CMD_NOP_MUX_OUT                 0x00
+#define AD5766_CMD_SDO_CNTRL                   0x01
+#define AD5766_CMD_WR_IN_REG(x)                        (0x10 | ((x) & 0xF))
+#define AD5766_CMD_WR_DAC_REG(x)               (0x20 | ((x) & 0xF))
+#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) & 0xF))
+#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,
+       AD5766_VOLTAGE_RANGE_MAX,
+};
+
+/**
+ * struct ad5766_chip_info - chip specific information
+ * @num_channels:      number of channels
+ * @channel:           channel specification
+ */
+struct ad5766_chip_info {
+       unsigned int                    num_channels;
+       const struct iio_chan_spec      *channels;
+};
+
+enum {
+       AD5766_DITHER_PWR,
+       AD5766_DITHER_INVERT
+};
+
+/*
+ * External dither signal can be composed with the DAC output, if activated.
+ * The dither signals are applied to the N0 and N1 input pins.
+ * Dither source for each of the channel can be selected by writing to
+ * "dither_source",a 32 bit variable and two bits are used for each of the 16
+ * channels: 0: NO_DITHER, 1: N0, 2: N1.
+ * This variable holds available dither source strings.
+ */
+static const char * const ad5766_dither_sources[] = {
+       "NO_DITHER",
+       "N0",
+       "N1",
+};
+
+/*
+ * Dither signal can also be scaled.
+ * Available dither scale strings coresponding to "dither_scale" field in
+ * "struct ad5766_state".
+ * "dither_scale" is a 32 bit variable and two bits are used for each of the 16
+ * channels: 0: NO_SCALING, 1: 75%_SCALING, 2: 50%_SCALING, 3: 25%_SCALING.
+ */
+static const char * const ad5766_dither_scales[] = {
+       "NO_SCALING",
+       "75%_SCALING",
+       "50%_SCALING",
+       "25%_SCALING",
+};
+
+/**
+ * struct ad5766_state - driver instance specific data
+ * @spi:               SPI device
+ * @lock:              Mutex lock
+ * @chip_info:         Chip model specific constants
+ * @gpio_reset:                Reset GPIO, used to reset the device
+ * @crt_range:         Current selected output range
+ * @cached_offset:     Cached range coresponding to the selected offset
+ * @dither_power_ctrl: Power-down 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 3 possible sources:
+ *                     0: No dither, 1: N0, 2: N1
+ *                     Two bits are used for each channel
+ * @dither_scale:      Selects between 4 possible scales:
+ *                     0: No scale, 1: 75%, 2: 50%, 3: 25%
+ *                     Two bits are used for each channel
+ * @scale_avail:       Scale available table
+ * @offset_avail:      Offest available table
+ * @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;
+       enum ad5766_voltage_range       cached_offset;
+       u16             dither_power_ctrl;
+       u16             dither_invert;
+       u32             dither_source;
+       u32             dither_scale;
+       int             scale_avail[AD5766_VOLTAGE_RANGE_MAX][2];
+       int             offset_avail[AD5766_VOLTAGE_RANGE_MAX][2];
+       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] = {
+               .min = -20,
+               .max = 0,
+       },
+       [AD5766_VOLTAGE_RANGE_M16V_to_0V] = {
+               .min = -16,
+               .max = 0,
+       },
+       [AD5766_VOLTAGE_RANGE_M10V_to_0V] = {
+               .min = -10,
+               .max = 0,
+       },
+       [AD5766_VOLTAGE_RANGE_M12V_to_14V] = {
+               .min = -12,
+               .max = 14,
+       },
+       [AD5766_VOLTAGE_RANGE_M16V_to_10V] = {
+               .min = -16,
+               .max = 10,
+       },
+       [AD5766_VOLTAGE_RANGE_M10V_to_6V] = {
+               .min = -10,
+               .max = 6,
+       },
+       [AD5766_VOLTAGE_RANGE_M5V_to_5V] = {
+               .min = -5,
+               .max = 5,
+       },
+       [AD5766_VOLTAGE_RANGE_M10V_to_10V] = {
+               .min = -10,
+               .max = 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;
+       st->data[0].b8[1] = (data & 0xFF00) >> 8;
+       st->data[0].b8[2] = (data & 0x00FF) >> 0;
+
+       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 = 0;
+
+       if (st->gpio_reset) {
+               gpiod_set_value_cansleep(st->gpio_reset, 0);
+               ndelay(100); /* t_reset >= 100ns */
+               gpiod_set_value_cansleep(st->gpio_reset, 1);
+       } 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_default_setup(struct ad5766_state *st,
+       enum ad5766_voltage_range range)
+{
+       int ret;
+       uint16_t val;
+
+       /* Always issue a software reset before writing to the span register. */
+       ret = ad5766_reset(st);
+       if (ret)
+               return ret;
+
+       ret = _ad5766_spi_write(st, AD5766_CMD_SPAN_REG, range);
+       if (ret)
+               return ret;
+
+       st->crt_range = range;
+       st->cached_offset = range;
+
+       st->dither_power_ctrl = 0;
+       ret = _ad5766_spi_write(st, AD5766_CMD_WR_PWR_DITHER,
+                            st->dither_power_ctrl);
+       if (ret)
+               return ret;
+
+       st->dither_source = 0;
+       val = FIELD_GET(AD5766_LOWER_WORD_SPI_MASK, st->dither_source);
+       ret = _ad5766_spi_write(st, AD5766_CMD_DITHER_SIG_1,
+                         st->dither_source & 0xFFFF);
+       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 0;
+}
+
+static int ad5766_set_offset(struct ad5766_state *st, int val, int val2)
+{
+       int i;
+       s32 (*tbl)[AD5766_VOLTAGE_RANGE_MAX][2] = &(st->offset_avail);
+
+       for (i = 0; i < AD5766_VOLTAGE_RANGE_MAX; i++) {
+               if ((*tbl)[i][0] == val && (*tbl)[i][1] == val2) {
+                       st->cached_offset = i;
+                       return 0;
+               }
+       }
+
+       return -EINVAL;
+}
+
+static int ad5766_set_scale(struct ad5766_state *st, int val, int val2)
+{
+       int i;
+       enum ad5766_voltage_range offset_idx = st->cached_offset;
+       s32 (*offset_tbl)[AD5766_VOLTAGE_RANGE_MAX][2] = &(st->offset_avail);
+       s32 (*scale_tbl)[AD5766_VOLTAGE_RANGE_MAX][2] = &(st->scale_avail);
+
+       for (i = 0; i < AD5766_VOLTAGE_RANGE_MAX; i++) {
+               if ((*scale_tbl)[i][0] != val || (*scale_tbl)[i][1] != val2)
+                       continue;
+
+               if ((*offset_tbl)[i][0] != (*offset_tbl)[offset_idx][0] ||
+                       (*offset_tbl)[i][1] != (*offset_tbl)[offset_idx][1])
+                       continue;
+
+               return ad5766_default_setup(st, i);
+       }
+
+       return -EINVAL;
+}
+
+static int ad5766_read_avail(struct iio_dev *indio_dev,
+                                struct iio_chan_spec const *chan,
+                                const int **vals, int *type, int *length,
+                                long mask)
+{
+       struct ad5766_state *st = iio_priv(indio_dev);
+
+       switch (mask) {
+       case IIO_CHAN_INFO_SCALE:
+               *vals = (const int *)st->scale_avail;
+               *type = IIO_VAL_INT_PLUS_MICRO;
+               /* Values are stored in a 2D matrix  */
+               *length = AD5766_VOLTAGE_RANGE_MAX * 2;
+
+               return IIO_AVAIL_LIST;
+       case IIO_CHAN_INFO_OFFSET:
+               *vals = (const int *)st->offset_avail;
+               *type = IIO_VAL_INT_PLUS_MICRO;
+               /* Values are stored in a 2D matrix  */
+               *length = AD5766_VOLTAGE_RANGE_MAX * 2;
+
+               return IIO_AVAIL_LIST;
+       default:
+               return -EINVAL;
+       }
+}
+
+static int ad5766_read_raw(struct iio_dev *indio_dev,
+                          struct iio_chan_spec const *chan,
+                          int *val,
+                          int *val2,
+                          long m)
+{
+       int ret;
+       struct ad5766_state *st = iio_priv(indio_dev);
+
+       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_SCALE:
+               *val = st->scale_avail[st->crt_range][0];
+               *val2 = st->scale_avail[st->crt_range][1];
+
+               return IIO_VAL_INT_PLUS_MICRO;
+
+       case IIO_CHAN_INFO_OFFSET:
+               *val = st->offset_avail[st->crt_range][0];
+               *val2 = st->offset_avail[st->crt_range][1];
+
+               return IIO_VAL_INT_PLUS_MICRO;
+       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)
+{
+       struct ad5766_state *st = iio_priv(indio_dev);
+
+       switch (info) {
+       case IIO_CHAN_INFO_RAW:
+       {
+               const int max_val = (1 << chan->scan_type.realbits);
+
+               if (val >= max_val || val < 0)
+                       return -EINVAL;
+               val <<= chan->scan_type.shift;
+               return ad5766_write(indio_dev, chan->address, val);
+       }
+       case IIO_CHAN_INFO_OFFSET:
+               return ad5766_set_offset(st, val, val2);
+       case IIO_CHAN_INFO_SCALE:
+               return ad5766_set_scale(st, val, val2);
+       default:
+               return -EINVAL;
+       }
+}
+
+static const struct iio_info ad5766_info = {
+       .read_raw = ad5766_read_raw,
+       .write_raw = ad5766_write_raw,
+       .read_avail = ad5766_read_avail,
+};
+
+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);
+
+       return (source >> chan->channel * 2);
+}
+
+static int ad5766_set_dither_source(struct iio_dev *dev,
+                         const struct iio_chan_spec *chan,
+                         unsigned int mode)
+{
+       int ret;
+       struct ad5766_state *st = iio_priv(dev);
+       uint16_t val;
+
+       st->dither_source &= ~AD5766_DITHER_SOURCE_MASK(chan->channel);
+       st->dither_source |= (mode << (chan->channel * 2));
+
+       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 const struct iio_enum ad5766_dither_source_enum = {
+       .items = ad5766_dither_sources,
+       .num_items = ARRAY_SIZE(ad5766_dither_sources),
+       .set = ad5766_set_dither_source,
+       .get = ad5766_get_dither_source,
+};
+
+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 |= (scale << (chan->channel * 2));
+
+       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)
+{
+       int ret;
+       struct ad5766_state *st = iio_priv(indio_dev);
+
+       switch ((u32)private) {
+       case AD5766_DITHER_PWR:
+               return sprintf(buf, "%u\n", 0x01 &
+                              ~(st->dither_power_ctrl >> chan->channel));
+               break;
+       case AD5766_DITHER_INVERT:
+               return sprintf(buf, "%u\n", 0x01 &
+                              (st->dither_invert >> chan->channel));
+               break;
+       default:
+               ret = -EINVAL;
+               break;
+       }
+
+       return ret;
+}
+
+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)
+{
+       bool readin;
+       int ret;
+       struct ad5766_state *st = iio_priv(indio_dev);
+
+       ret = kstrtobool(buf, &readin);
+       if (ret)
+               return ret;
+
+       switch ((u32)private) {
+       case AD5766_DITHER_PWR:
+               ret = kstrtobool(buf, &readin);
+               if (ret)
+                       break;
+               readin = !readin;
+               st->dither_power_ctrl = (st->dither_power_ctrl &
+                                        ~BIT(chan->channel)) |
+                                        (readin << chan->channel);
+               ret = ad5766_write(indio_dev, AD5766_CMD_WR_PWR_DITHER,
+                            st->dither_power_ctrl);
+               break;
+       case AD5766_DITHER_INVERT:
+               st->dither_invert = (st->dither_invert &
+                                               ~BIT(chan->channel)) |
+                                               (readin << chan->channel);
+               ret = ad5766_write(indio_dev, AD5766_CMD_INV_DITHER,
+                               st->dither_power_ctrl);
+               break;
+       default:
+               ret = -EINVAL;
+               break;
+       }
+
+       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, \
+}
+
+static const struct iio_chan_spec_ext_info ad5766_ext_info[] = {
+
+       _AD5766_CHAN_EXT_INFO("dither_pwr", AD5766_DITHER_PWR, IIO_SEPARATE),
+       _AD5766_CHAN_EXT_INFO("dither_invert", AD5766_DITHER_INVERT,
+                             IIO_SEPARATE),
+       IIO_ENUM("dither_source", IIO_SEPARATE, &ad5766_dither_source_enum),
+       IIO_ENUM_AVAILABLE_SHARED("dither_source",
+                                 IIO_SEPARATE,
+                                 &ad5766_dither_source_enum),
+       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),                               \
+       .info_mask_shared_by_type_available =                           \
+               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 void ad5766_init_scale_tables(struct ad5766_state *st)
+{
+       int i;
+       s32 denom;
+       s64 offset;
+       u64 scale;
+       u8 realbits = st->chip_info->channels[0].scan_type.realbits;
+
+       for (i = 0; i < AD5766_VOLTAGE_RANGE_MAX; i++) {
+               offset = (1 << realbits) * ad5766_span_tbl[i].min;
+               denom = ad5766_span_tbl[i].max - ad5766_span_tbl[i].min;
+               offset = div_s64(offset * 1000000, denom);
+               st->offset_avail[i][0] = div_s64(offset, 1000000);
+               div_s64_rem(offset, 1000000, &st->offset_avail[i][1]);
+
+               scale = ad5766_span_tbl[i].max - ad5766_span_tbl[i].min;
+               scale = div_u64((scale * 1000000000), (1 << realbits));
+               st->scale_avail[i][0] = (int)div_u64(scale, 1000000);
+               div_s64_rem(scale, 1000000, &st->scale_avail[i][1]);
+       }
+}
+
+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_HIGH);
+
+       ad5766_init_scale_tables(st);
+
+       ret = ad5766_default_setup(st, AD5766_VOLTAGE_RANGE_M5V_to_5V);
+       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 <[email protected]>");
+MODULE_DESCRIPTION("Analog Devices AD5766/AD5767 DACs");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1

Reply via email to