linux/drivers/iio/dac/ad5624r_spi.c
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   1/*
   2 * AD5624R, AD5644R, AD5664R Digital to analog convertors spi driver
   3 *
   4 * Copyright 2010-2011 Analog Devices Inc.
   5 *
   6 * Licensed under the GPL-2.
   7 */
   8
   9#include <linux/interrupt.h>
  10#include <linux/fs.h>
  11#include <linux/device.h>
  12#include <linux/kernel.h>
  13#include <linux/spi/spi.h>
  14#include <linux/slab.h>
  15#include <linux/sysfs.h>
  16#include <linux/regulator/consumer.h>
  17#include <linux/module.h>
  18
  19#include <linux/iio/iio.h>
  20#include <linux/iio/sysfs.h>
  21
  22#include "ad5624r.h"
  23
  24static int ad5624r_spi_write(struct spi_device *spi,
  25                             u8 cmd, u8 addr, u16 val, u8 len)
  26{
  27        u32 data;
  28        u8 msg[3];
  29
  30        /*
  31         * The input shift register is 24 bits wide. The first two bits are
  32         * don't care bits. The next three are the command bits, C2 to C0,
  33         * followed by the 3-bit DAC address, A2 to A0, and then the
  34         * 16-, 14-, 12-bit data-word. The data-word comprises the 16-,
  35         * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits,
  36         * for the AD5664R, AD5644R, and AD5624R, respectively.
  37         */
  38        data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << (16 - len));
  39        msg[0] = data >> 16;
  40        msg[1] = data >> 8;
  41        msg[2] = data;
  42
  43        return spi_write(spi, msg, 3);
  44}
  45
  46static int ad5624r_read_raw(struct iio_dev *indio_dev,
  47                           struct iio_chan_spec const *chan,
  48                           int *val,
  49                           int *val2,
  50                           long m)
  51{
  52        struct ad5624r_state *st = iio_priv(indio_dev);
  53
  54        switch (m) {
  55        case IIO_CHAN_INFO_SCALE:
  56                *val = st->vref_mv;
  57                *val2 = chan->scan_type.realbits;
  58                return IIO_VAL_FRACTIONAL_LOG2;
  59        }
  60        return -EINVAL;
  61}
  62
  63static int ad5624r_write_raw(struct iio_dev *indio_dev,
  64                               struct iio_chan_spec const *chan,
  65                               int val,
  66                               int val2,
  67                               long mask)
  68{
  69        struct ad5624r_state *st = iio_priv(indio_dev);
  70        int ret;
  71
  72        switch (mask) {
  73        case IIO_CHAN_INFO_RAW:
  74                if (val >= (1 << chan->scan_type.realbits) || val < 0)
  75                        return -EINVAL;
  76
  77                return ad5624r_spi_write(st->us,
  78                                AD5624R_CMD_WRITE_INPUT_N_UPDATE_N,
  79                                chan->address, val,
  80                                chan->scan_type.shift);
  81        default:
  82                ret = -EINVAL;
  83        }
  84
  85        return -EINVAL;
  86}
  87
  88static const char * const ad5624r_powerdown_modes[] = {
  89        "1kohm_to_gnd",
  90        "100kohm_to_gnd",
  91        "three_state"
  92};
  93
  94static int ad5624r_get_powerdown_mode(struct iio_dev *indio_dev,
  95        const struct iio_chan_spec *chan)
  96{
  97        struct ad5624r_state *st = iio_priv(indio_dev);
  98
  99        return st->pwr_down_mode;
 100}
 101
 102static int ad5624r_set_powerdown_mode(struct iio_dev *indio_dev,
 103        const struct iio_chan_spec *chan, unsigned int mode)
 104{
 105        struct ad5624r_state *st = iio_priv(indio_dev);
 106
 107        st->pwr_down_mode = mode;
 108
 109        return 0;
 110}
 111
 112static const struct iio_enum ad5624r_powerdown_mode_enum = {
 113        .items = ad5624r_powerdown_modes,
 114        .num_items = ARRAY_SIZE(ad5624r_powerdown_modes),
 115        .get = ad5624r_get_powerdown_mode,
 116        .set = ad5624r_set_powerdown_mode,
 117};
 118
 119static ssize_t ad5624r_read_dac_powerdown(struct iio_dev *indio_dev,
 120        uintptr_t private, const struct iio_chan_spec *chan, char *buf)
 121{
 122        struct ad5624r_state *st = iio_priv(indio_dev);
 123
 124        return sprintf(buf, "%d\n",
 125                        !!(st->pwr_down_mask & (1 << chan->channel)));
 126}
 127
 128static ssize_t ad5624r_write_dac_powerdown(struct iio_dev *indio_dev,
 129        uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
 130        size_t len)
 131{
 132        bool pwr_down;
 133        int ret;
 134        struct ad5624r_state *st = iio_priv(indio_dev);
 135
 136        ret = strtobool(buf, &pwr_down);
 137        if (ret)
 138                return ret;
 139
 140        if (pwr_down)
 141                st->pwr_down_mask |= (1 << chan->channel);
 142        else
 143                st->pwr_down_mask &= ~(1 << chan->channel);
 144
 145        ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0,
 146                                (st->pwr_down_mode << 4) |
 147                                st->pwr_down_mask, 16);
 148
 149        return ret ? ret : len;
 150}
 151
 152static const struct iio_info ad5624r_info = {
 153        .write_raw = ad5624r_write_raw,
 154        .read_raw = ad5624r_read_raw,
 155        .driver_module = THIS_MODULE,
 156};
 157
 158static const struct iio_chan_spec_ext_info ad5624r_ext_info[] = {
 159        {
 160                .name = "powerdown",
 161                .read = ad5624r_read_dac_powerdown,
 162                .write = ad5624r_write_dac_powerdown,
 163                .shared = IIO_SEPARATE,
 164        },
 165        IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
 166                 &ad5624r_powerdown_mode_enum),
 167        IIO_ENUM_AVAILABLE("powerdown_mode", &ad5624r_powerdown_mode_enum),
 168        { },
 169};
 170
 171#define AD5624R_CHANNEL(_chan, _bits) { \
 172        .type = IIO_VOLTAGE, \
 173        .indexed = 1, \
 174        .output = 1, \
 175        .channel = (_chan), \
 176        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 177        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 178        .address = (_chan), \
 179        .scan_type = IIO_ST('u', (_bits), 16, 16 - (_bits)), \
 180        .ext_info = ad5624r_ext_info, \
 181}
 182
 183#define DECLARE_AD5624R_CHANNELS(_name, _bits) \
 184        const struct iio_chan_spec _name##_channels[] = { \
 185                AD5624R_CHANNEL(0, _bits), \
 186                AD5624R_CHANNEL(1, _bits), \
 187                AD5624R_CHANNEL(2, _bits), \
 188                AD5624R_CHANNEL(3, _bits), \
 189}
 190
 191static DECLARE_AD5624R_CHANNELS(ad5624r, 12);
 192static DECLARE_AD5624R_CHANNELS(ad5644r, 14);
 193static DECLARE_AD5624R_CHANNELS(ad5664r, 16);
 194
 195static const struct ad5624r_chip_info ad5624r_chip_info_tbl[] = {
 196        [ID_AD5624R3] = {
 197                .channels = ad5624r_channels,
 198                .int_vref_mv = 1250,
 199        },
 200        [ID_AD5624R5] = {
 201                .channels = ad5624r_channels,
 202                .int_vref_mv = 2500,
 203        },
 204        [ID_AD5644R3] = {
 205                .channels = ad5644r_channels,
 206                .int_vref_mv = 1250,
 207        },
 208        [ID_AD5644R5] = {
 209                .channels = ad5644r_channels,
 210                .int_vref_mv = 2500,
 211        },
 212        [ID_AD5664R3] = {
 213                .channels = ad5664r_channels,
 214                .int_vref_mv = 1250,
 215        },
 216        [ID_AD5664R5] = {
 217                .channels = ad5664r_channels,
 218                .int_vref_mv = 2500,
 219        },
 220};
 221
 222static int ad5624r_probe(struct spi_device *spi)
 223{
 224        struct ad5624r_state *st;
 225        struct iio_dev *indio_dev;
 226        int ret, voltage_uv = 0;
 227
 228        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 229        if (!indio_dev)
 230                return -ENOMEM;
 231        st = iio_priv(indio_dev);
 232        st->reg = devm_regulator_get(&spi->dev, "vcc");
 233        if (!IS_ERR(st->reg)) {
 234                ret = regulator_enable(st->reg);
 235                if (ret)
 236                        return ret;
 237
 238                ret = regulator_get_voltage(st->reg);
 239                if (ret < 0)
 240                        goto error_disable_reg;
 241
 242                voltage_uv = ret;
 243        }
 244
 245        spi_set_drvdata(spi, indio_dev);
 246        st->chip_info =
 247                &ad5624r_chip_info_tbl[spi_get_device_id(spi)->driver_data];
 248
 249        if (voltage_uv)
 250                st->vref_mv = voltage_uv / 1000;
 251        else
 252                st->vref_mv = st->chip_info->int_vref_mv;
 253
 254        st->us = spi;
 255
 256        indio_dev->dev.parent = &spi->dev;
 257        indio_dev->name = spi_get_device_id(spi)->name;
 258        indio_dev->info = &ad5624r_info;
 259        indio_dev->modes = INDIO_DIRECT_MODE;
 260        indio_dev->channels = st->chip_info->channels;
 261        indio_dev->num_channels = AD5624R_DAC_CHANNELS;
 262
 263        ret = ad5624r_spi_write(spi, AD5624R_CMD_INTERNAL_REFER_SETUP, 0,
 264                                !!voltage_uv, 16);
 265        if (ret)
 266                goto error_disable_reg;
 267
 268        ret = iio_device_register(indio_dev);
 269        if (ret)
 270                goto error_disable_reg;
 271
 272        return 0;
 273
 274error_disable_reg:
 275        if (!IS_ERR(st->reg))
 276                regulator_disable(st->reg);
 277
 278        return ret;
 279}
 280
 281static int ad5624r_remove(struct spi_device *spi)
 282{
 283        struct iio_dev *indio_dev = spi_get_drvdata(spi);
 284        struct ad5624r_state *st = iio_priv(indio_dev);
 285
 286        iio_device_unregister(indio_dev);
 287        if (!IS_ERR(st->reg))
 288                regulator_disable(st->reg);
 289
 290        return 0;
 291}
 292
 293static const struct spi_device_id ad5624r_id[] = {
 294        {"ad5624r3", ID_AD5624R3},
 295        {"ad5644r3", ID_AD5644R3},
 296        {"ad5664r3", ID_AD5664R3},
 297        {"ad5624r5", ID_AD5624R5},
 298        {"ad5644r5", ID_AD5644R5},
 299        {"ad5664r5", ID_AD5664R5},
 300        {}
 301};
 302MODULE_DEVICE_TABLE(spi, ad5624r_id);
 303
 304static struct spi_driver ad5624r_driver = {
 305        .driver = {
 306                   .name = "ad5624r",
 307                   .owner = THIS_MODULE,
 308                   },
 309        .probe = ad5624r_probe,
 310        .remove = ad5624r_remove,
 311        .id_table = ad5624r_id,
 312};
 313module_spi_driver(ad5624r_driver);
 314
 315MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 316MODULE_DESCRIPTION("Analog Devices AD5624/44/64R DAC spi driver");
 317MODULE_LICENSE("GPL v2");
 318