drivers/iio/dac/ad5624r_spi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AD5624R, AD5644R, AD5664R Digital to analog convertors spi driver
   4  *
   5  * Copyright 2010-2011 Analog Devices Inc.
   6  */
   7
   8 #include <linux/interrupt.h>
   9 #include <linux/fs.h>
  10 #include <linux/device.h>
  11 #include <linux/kernel.h>
  12 #include <linux/spi/spi.h>
  13 #include <linux/slab.h>
  14 #include <linux/sysfs.h>
  15 #include <linux/regulator/consumer.h>
  16 #include <linux/module.h>
  17
  18 #include <linux/iio/iio.h>
  19 #include <linux/iio/sysfs.h>
  20
  21 #include "ad5624r.h"
  22
  23 static int ad5624r_spi_write(struct spi_device *spi,
  24                              u8 cmd, u8 addr, u16 val, u8 shift)
  25 {
  26         u32 data;
  27         u8 msg[3];
  28
  29         /*
  30          * The input shift register is 24 bits wide. The first two bits are
  31          * don't care bits. The next three are the command bits, C2 to C0,
  32          * followed by the 3-bit DAC address, A2 to A0, and then the
  33          * 16-, 14-, 12-bit data-word. The data-word comprises the 16-,
  34          * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits,
  35          * for the AD5664R, AD5644R, and AD5624R, respectively.
  36          */
  37         data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << shift);
  38         msg[0] = data >> 16;
  39         msg[1] = data >> 8;
  40         msg[2] = data;
  41
  42         return spi_write(spi, msg, 3);
  43 }
  44
  45 static int ad5624r_read_raw(struct iio_dev *indio_dev,
  46                            struct iio_chan_spec const *chan,
  47                            int *val,
  48                            int *val2,
  49                            long m)
  50 {
  51         struct ad5624r_state *st = iio_priv(indio_dev);
  52
  53         switch (m) {
  54         case IIO_CHAN_INFO_SCALE:
  55                 *val = st->vref_mv;
  56                 *val2 = chan->scan_type.realbits;
  57                 return IIO_VAL_FRACTIONAL_LOG2;
  58         }
  59         return -EINVAL;
  60 }
  61
  62 static int ad5624r_write_raw(struct iio_dev *indio_dev,
  63                                struct iio_chan_spec const *chan,
  64                                int val,
  65                                int val2,
  66                                long mask)
  67 {
  68         struct ad5624r_state *st = iio_priv(indio_dev);
  69
  70         switch (mask) {
  71         case IIO_CHAN_INFO_RAW:
  72                 if (val >= (1 << chan->scan_type.realbits) || val < 0)
  73                         return -EINVAL;
  74
  75                 return ad5624r_spi_write(st->us,
  76                                 AD5624R_CMD_WRITE_INPUT_N_UPDATE_N,
  77                                 chan->address, val,
  78                                 chan->scan_type.shift);
  79         default:
  80                 return -EINVAL;
  81         }
  82 }
  83
  84 static const char * const ad5624r_powerdown_modes[] = {
  85         "1kohm_to_gnd",
  86         "100kohm_to_gnd",
  87         "three_state"
  88 };
  89
  90 static int ad5624r_get_powerdown_mode(struct iio_dev *indio_dev,
  91         const struct iio_chan_spec *chan)
  92 {
  93         struct ad5624r_state *st = iio_priv(indio_dev);
  94
  95         return st->pwr_down_mode;
  96 }
  97
  98 static int ad5624r_set_powerdown_mode(struct iio_dev *indio_dev,
  99         const struct iio_chan_spec *chan, unsigned int mode)
 100 {
 101         struct ad5624r_state *st = iio_priv(indio_dev);
 102
 103         st->pwr_down_mode = mode;
 104
 105         return 0;
 106 }
 107
 108 static const struct iio_enum ad5624r_powerdown_mode_enum = {
 109         .items = ad5624r_powerdown_modes,
 110         .num_items = ARRAY_SIZE(ad5624r_powerdown_modes),
 111         .get = ad5624r_get_powerdown_mode,
 112         .set = ad5624r_set_powerdown_mode,
 113 };
 114
 115 static ssize_t ad5624r_read_dac_powerdown(struct iio_dev *indio_dev,
 116         uintptr_t private, const struct iio_chan_spec *chan, char *buf)
 117 {
 118         struct ad5624r_state *st = iio_priv(indio_dev);
 119
 120         return sprintf(buf, "%d\n",
 121                         !!(st->pwr_down_mask & (1 << chan->channel)));
 122 }
 123
 124 static ssize_t ad5624r_write_dac_powerdown(struct iio_dev *indio_dev,
 125         uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
 126         size_t len)
 127 {
 128         bool pwr_down;
 129         int ret;
 130         struct ad5624r_state *st = iio_priv(indio_dev);
 131
 132         ret = strtobool(buf, &pwr_down);
 133         if (ret)
 134                 return ret;
 135
 136         if (pwr_down)
 137                 st->pwr_down_mask |= (1 << chan->channel);
 138         else
 139                 st->pwr_down_mask &= ~(1 << chan->channel);
 140
 141         ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0,
 142                                 (st->pwr_down_mode << 4) |
 143                                 st->pwr_down_mask, 16);
 144
 145         return ret ? ret : len;
 146 }
 147
 148 static const struct iio_info ad5624r_info = {
 149         .write_raw = ad5624r_write_raw,
 150         .read_raw = ad5624r_read_raw,
 151 };
 152
 153 static const struct iio_chan_spec_ext_info ad5624r_ext_info[] = {
 154         {
 155                 .name = "powerdown",
 156                 .read = ad5624r_read_dac_powerdown,
 157                 .write = ad5624r_write_dac_powerdown,
 158                 .shared = IIO_SEPARATE,
 159         },
 160         IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
 161                  &ad5624r_powerdown_mode_enum),
 162         IIO_ENUM_AVAILABLE("powerdown_mode", &ad5624r_powerdown_mode_enum),
 163         { },
 164 };
 165
 166 #define AD5624R_CHANNEL(_chan, _bits) { \
 167         .type = IIO_VOLTAGE, \
 168         .indexed = 1, \
 169         .output = 1, \
 170         .channel = (_chan), \
 171         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 172         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 173         .address = (_chan), \
 174         .scan_type = { \
 175                 .sign = 'u', \
 176                 .realbits = (_bits), \
 177                 .storagebits = 16, \
 178                 .shift = 16 - (_bits), \
 179         }, \
 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
 191 static DECLARE_AD5624R_CHANNELS(ad5624r, 12);
 192 static DECLARE_AD5624R_CHANNELS(ad5644r, 14);
 193 static DECLARE_AD5624R_CHANNELS(ad5664r, 16);
 194
 195 static 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
 222 static 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
 274 error_disable_reg:
 275         if (!IS_ERR(st->reg))
 276                 regulator_disable(st->reg);
 277
 278         return ret;
 279 }
 280
 281 static 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
 293 static 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 };
 302 MODULE_DEVICE_TABLE(spi, ad5624r_id);
 303
 304 static struct spi_driver ad5624r_driver = {
 305         .driver = {
 306                    .name = "ad5624r",
 307                    },
 308         .probe = ad5624r_probe,
 309         .remove = ad5624r_remove,
 310         .id_table = ad5624r_id,
 311 };
 312 module_spi_driver(ad5624r_driver);
 313
 314 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 315 MODULE_DESCRIPTION("Analog Devices AD5624/44/64R DAC spi driver");
 316 MODULE_LICENSE("GPL v2");