drivers/iio/dac/ad5624r_spi.c

   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
  24 static 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
  46 static 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
  63 static 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
  88 static const char * const ad5624r_powerdown_modes[] = {
  89         "1kohm_to_gnd",
  90         "100kohm_to_gnd",
  91         "three_state"
  92 };
  93
  94 static 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
 102 static 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
 112 static 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
 119 static 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
 128 static 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
 152 static 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
 158 static 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 = { \
 180                 .sign = 'u', \
 181                 .realbits = (_bits), \
 182                 .storagebits = 16, \
 183                 .shift = 16 - (_bits), \
 184         }, \
 185         .ext_info = ad5624r_ext_info, \
 186 }
 187
 188 #define DECLARE_AD5624R_CHANNELS(_name, _bits) \
 189         const struct iio_chan_spec _name##_channels[] = { \
 190                 AD5624R_CHANNEL(0, _bits), \
 191                 AD5624R_CHANNEL(1, _bits), \
 192                 AD5624R_CHANNEL(2, _bits), \
 193                 AD5624R_CHANNEL(3, _bits), \
 194 }
 195
 196 static DECLARE_AD5624R_CHANNELS(ad5624r, 12);
 197 static DECLARE_AD5624R_CHANNELS(ad5644r, 14);
 198 static DECLARE_AD5624R_CHANNELS(ad5664r, 16);
 199
 200 static const struct ad5624r_chip_info ad5624r_chip_info_tbl[] = {
 201         [ID_AD5624R3] = {
 202                 .channels = ad5624r_channels,
 203                 .int_vref_mv = 1250,
 204         },
 205         [ID_AD5624R5] = {
 206                 .channels = ad5624r_channels,
 207                 .int_vref_mv = 2500,
 208         },
 209         [ID_AD5644R3] = {
 210                 .channels = ad5644r_channels,
 211                 .int_vref_mv = 1250,
 212         },
 213         [ID_AD5644R5] = {
 214                 .channels = ad5644r_channels,
 215                 .int_vref_mv = 2500,
 216         },
 217         [ID_AD5664R3] = {
 218                 .channels = ad5664r_channels,
 219                 .int_vref_mv = 1250,
 220         },
 221         [ID_AD5664R5] = {
 222                 .channels = ad5664r_channels,
 223                 .int_vref_mv = 2500,
 224         },
 225 };
 226
 227 static int ad5624r_probe(struct spi_device *spi)
 228 {
 229         struct ad5624r_state *st;
 230         struct iio_dev *indio_dev;
 231         int ret, voltage_uv = 0;
 232
 233         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 234         if (!indio_dev)
 235                 return -ENOMEM;
 236         st = iio_priv(indio_dev);
 237         st->reg = devm_regulator_get(&spi->dev, "vcc");
 238         if (!IS_ERR(st->reg)) {
 239                 ret = regulator_enable(st->reg);
 240                 if (ret)
 241                         return ret;
 242
 243                 ret = regulator_get_voltage(st->reg);
 244                 if (ret < 0)
 245                         goto error_disable_reg;
 246
 247                 voltage_uv = ret;
 248         }
 249
 250         spi_set_drvdata(spi, indio_dev);
 251         st->chip_info =
 252                 &ad5624r_chip_info_tbl[spi_get_device_id(spi)->driver_data];
 253
 254         if (voltage_uv)
 255                 st->vref_mv = voltage_uv / 1000;
 256         else
 257                 st->vref_mv = st->chip_info->int_vref_mv;
 258
 259         st->us = spi;
 260
 261         indio_dev->dev.parent = &spi->dev;
 262         indio_dev->name = spi_get_device_id(spi)->name;
 263         indio_dev->info = &ad5624r_info;
 264         indio_dev->modes = INDIO_DIRECT_MODE;
 265         indio_dev->channels = st->chip_info->channels;
 266         indio_dev->num_channels = AD5624R_DAC_CHANNELS;
 267
 268         ret = ad5624r_spi_write(spi, AD5624R_CMD_INTERNAL_REFER_SETUP, 0,
 269                                 !!voltage_uv, 16);
 270         if (ret)
 271                 goto error_disable_reg;
 272
 273         ret = iio_device_register(indio_dev);
 274         if (ret)
 275                 goto error_disable_reg;
 276
 277         return 0;
 278
 279 error_disable_reg:
 280         if (!IS_ERR(st->reg))
 281                 regulator_disable(st->reg);
 282
 283         return ret;
 284 }
 285
 286 static int ad5624r_remove(struct spi_device *spi)
 287 {
 288         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 289         struct ad5624r_state *st = iio_priv(indio_dev);
 290
 291         iio_device_unregister(indio_dev);
 292         if (!IS_ERR(st->reg))
 293                 regulator_disable(st->reg);
 294
 295         return 0;
 296 }
 297
 298 static const struct spi_device_id ad5624r_id[] = {
 299         {"ad5624r3", ID_AD5624R3},
 300         {"ad5644r3", ID_AD5644R3},
 301         {"ad5664r3", ID_AD5664R3},
 302         {"ad5624r5", ID_AD5624R5},
 303         {"ad5644r5", ID_AD5644R5},
 304         {"ad5664r5", ID_AD5664R5},
 305         {}
 306 };
 307 MODULE_DEVICE_TABLE(spi, ad5624r_id);
 308
 309 static struct spi_driver ad5624r_driver = {
 310         .driver = {
 311                    .name = "ad5624r",
 312                    .owner = THIS_MODULE,
 313                    },
 314         .probe = ad5624r_probe,
 315         .remove = ad5624r_remove,
 316         .id_table = ad5624r_id,
 317 };
 318 module_spi_driver(ad5624r_driver);
 319
 320 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 321 MODULE_DESCRIPTION("Analog Devices AD5624/44/64R DAC spi driver");
 322 MODULE_LICENSE("GPL v2");