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         unsigned long scale_uv;
  54
  55         switch (m) {
  56         case IIO_CHAN_INFO_SCALE:
  57                 scale_uv = (st->vref_mv * 1000) >> chan->scan_type.realbits;
  58                 *val =  scale_uv / 1000;
  59                 *val2 = (scale_uv % 1000) * 1000;
  60                 return IIO_VAL_INT_PLUS_MICRO;
  61
  62         }
  63         return -EINVAL;
  64 }
  65
  66 static int ad5624r_write_raw(struct iio_dev *indio_dev,
  67                                struct iio_chan_spec const *chan,
  68                                int val,
  69                                int val2,
  70                                long mask)
  71 {
  72         struct ad5624r_state *st = iio_priv(indio_dev);
  73         int ret;
  74
  75         switch (mask) {
  76         case IIO_CHAN_INFO_RAW:
  77                 if (val >= (1 << chan->scan_type.realbits) || val < 0)
  78                         return -EINVAL;
  79
  80                 return ad5624r_spi_write(st->us,
  81                                 AD5624R_CMD_WRITE_INPUT_N_UPDATE_N,
  82                                 chan->address, val,
  83                                 chan->scan_type.shift);
  84         default:
  85                 ret = -EINVAL;
  86         }
  87
  88         return -EINVAL;
  89 }
  90
  91 static const char * const ad5624r_powerdown_modes[] = {
  92         "1kohm_to_gnd",
  93         "100kohm_to_gnd",
  94         "three_state"
  95 };
  96
  97 static int ad5624r_get_powerdown_mode(struct iio_dev *indio_dev,
  98         const struct iio_chan_spec *chan)
  99 {
 100         struct ad5624r_state *st = iio_priv(indio_dev);
 101
 102         return st->pwr_down_mode;
 103 }
 104
 105 static int ad5624r_set_powerdown_mode(struct iio_dev *indio_dev,
 106         const struct iio_chan_spec *chan, unsigned int mode)
 107 {
 108         struct ad5624r_state *st = iio_priv(indio_dev);
 109
 110         st->pwr_down_mode = mode;
 111
 112         return 0;
 113 }
 114
 115 static const struct iio_enum ad5624r_powerdown_mode_enum = {
 116         .items = ad5624r_powerdown_modes,
 117         .num_items = ARRAY_SIZE(ad5624r_powerdown_modes),
 118         .get = ad5624r_get_powerdown_mode,
 119         .set = ad5624r_set_powerdown_mode,
 120 };
 121
 122 static ssize_t ad5624r_read_dac_powerdown(struct iio_dev *indio_dev,
 123         uintptr_t private, const struct iio_chan_spec *chan, char *buf)
 124 {
 125         struct ad5624r_state *st = iio_priv(indio_dev);
 126
 127         return sprintf(buf, "%d\n",
 128                         !!(st->pwr_down_mask & (1 << chan->channel)));
 129 }
 130
 131 static ssize_t ad5624r_write_dac_powerdown(struct iio_dev *indio_dev,
 132         uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
 133         size_t len)
 134 {
 135         bool pwr_down;
 136         int ret;
 137         struct ad5624r_state *st = iio_priv(indio_dev);
 138
 139         ret = strtobool(buf, &pwr_down);
 140         if (ret)
 141                 return ret;
 142
 143         if (pwr_down)
 144                 st->pwr_down_mask |= (1 << chan->channel);
 145         else
 146                 st->pwr_down_mask &= ~(1 << chan->channel);
 147
 148         ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0,
 149                                 (st->pwr_down_mode << 4) |
 150                                 st->pwr_down_mask, 16);
 151
 152         return ret ? ret : len;
 153 }
 154
 155 static const struct iio_info ad5624r_info = {
 156         .write_raw = ad5624r_write_raw,
 157         .read_raw = ad5624r_read_raw,
 158         .driver_module = THIS_MODULE,
 159 };
 160
 161 static const struct iio_chan_spec_ext_info ad5624r_ext_info[] = {
 162         {
 163                 .name = "powerdown",
 164                 .read = ad5624r_read_dac_powerdown,
 165                 .write = ad5624r_write_dac_powerdown,
 166         },
 167         IIO_ENUM("powerdown_mode", true, &ad5624r_powerdown_mode_enum),
 168         IIO_ENUM_AVAILABLE("powerdown_mode", &ad5624r_powerdown_mode_enum),
 169         { },
 170 };
 171
 172 #define AD5624R_CHANNEL(_chan, _bits) { \
 173         .type = IIO_VOLTAGE, \
 174         .indexed = 1, \
 175         .output = 1, \
 176         .channel = (_chan), \
 177         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 178         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 179         .address = (_chan), \
 180         .scan_type = IIO_ST('u', (_bits), 16, 16 - (_bits)), \
 181         .ext_info = ad5624r_ext_info, \
 182 }
 183
 184 #define DECLARE_AD5624R_CHANNELS(_name, _bits) \
 185         const struct iio_chan_spec _name##_channels[] = { \
 186                 AD5624R_CHANNEL(0, _bits), \
 187                 AD5624R_CHANNEL(1, _bits), \
 188                 AD5624R_CHANNEL(2, _bits), \
 189                 AD5624R_CHANNEL(3, _bits), \
 190 }
 191
 192 static DECLARE_AD5624R_CHANNELS(ad5624r, 12);
 193 static DECLARE_AD5624R_CHANNELS(ad5644r, 14);
 194 static DECLARE_AD5624R_CHANNELS(ad5664r, 16);
 195
 196 static const struct ad5624r_chip_info ad5624r_chip_info_tbl[] = {
 197         [ID_AD5624R3] = {
 198                 .channels = ad5624r_channels,
 199                 .int_vref_mv = 1250,
 200         },
 201         [ID_AD5624R5] = {
 202                 .channels = ad5624r_channels,
 203                 .int_vref_mv = 2500,
 204         },
 205         [ID_AD5644R3] = {
 206                 .channels = ad5644r_channels,
 207                 .int_vref_mv = 1250,
 208         },
 209         [ID_AD5644R5] = {
 210                 .channels = ad5644r_channels,
 211                 .int_vref_mv = 2500,
 212         },
 213         [ID_AD5664R3] = {
 214                 .channels = ad5664r_channels,
 215                 .int_vref_mv = 1250,
 216         },
 217         [ID_AD5664R5] = {
 218                 .channels = ad5664r_channels,
 219                 .int_vref_mv = 2500,
 220         },
 221 };
 222
 223 static int ad5624r_probe(struct spi_device *spi)
 224 {
 225         struct ad5624r_state *st;
 226         struct iio_dev *indio_dev;
 227         int ret, voltage_uv = 0;
 228
 229         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 230         if (!indio_dev)
 231                 return -ENOMEM;
 232         st = iio_priv(indio_dev);
 233         st->reg = devm_regulator_get(&spi->dev, "vcc");
 234         if (!IS_ERR(st->reg)) {
 235                 ret = regulator_enable(st->reg);
 236                 if (ret)
 237                         return ret;
 238
 239                 ret = regulator_get_voltage(st->reg);
 240                 if (ret < 0)
 241                         goto error_disable_reg;
 242
 243                 voltage_uv = ret;
 244         }
 245
 246         spi_set_drvdata(spi, indio_dev);
 247         st->chip_info =
 248                 &ad5624r_chip_info_tbl[spi_get_device_id(spi)->driver_data];
 249
 250         if (voltage_uv)
 251                 st->vref_mv = voltage_uv / 1000;
 252         else
 253                 st->vref_mv = st->chip_info->int_vref_mv;
 254
 255         st->us = spi;
 256
 257         indio_dev->dev.parent = &spi->dev;
 258         indio_dev->name = spi_get_device_id(spi)->name;
 259         indio_dev->info = &ad5624r_info;
 260         indio_dev->modes = INDIO_DIRECT_MODE;
 261         indio_dev->channels = st->chip_info->channels;
 262         indio_dev->num_channels = AD5624R_DAC_CHANNELS;
 263
 264         ret = ad5624r_spi_write(spi, AD5624R_CMD_INTERNAL_REFER_SETUP, 0,
 265                                 !!voltage_uv, 16);
 266         if (ret)
 267                 goto error_disable_reg;
 268
 269         ret = iio_device_register(indio_dev);
 270         if (ret)
 271                 goto error_disable_reg;
 272
 273         return 0;
 274
 275 error_disable_reg:
 276         if (!IS_ERR(st->reg))
 277                 regulator_disable(st->reg);
 278
 279         return ret;
 280 }
 281
 282 static int ad5624r_remove(struct spi_device *spi)
 283 {
 284         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 285         struct ad5624r_state *st = iio_priv(indio_dev);
 286
 287         iio_device_unregister(indio_dev);
 288         if (!IS_ERR(st->reg))
 289                 regulator_disable(st->reg);
 290
 291         return 0;
 292 }
 293
 294 static const struct spi_device_id ad5624r_id[] = {
 295         {"ad5624r3", ID_AD5624R3},
 296         {"ad5644r3", ID_AD5644R3},
 297         {"ad5664r3", ID_AD5664R3},
 298         {"ad5624r5", ID_AD5624R5},
 299         {"ad5644r5", ID_AD5644R5},
 300         {"ad5664r5", ID_AD5664R5},
 301         {}
 302 };
 303 MODULE_DEVICE_TABLE(spi, ad5624r_id);
 304
 305 static struct spi_driver ad5624r_driver = {
 306         .driver = {
 307                    .name = "ad5624r",
 308                    .owner = THIS_MODULE,
 309                    },
 310         .probe = ad5624r_probe,
 311         .remove = ad5624r_remove,
 312         .id_table = ad5624r_id,
 313 };
 314 module_spi_driver(ad5624r_driver);
 315
 316 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 317 MODULE_DESCRIPTION("Analog Devices AD5624/44/64R DAC spi driver");
 318 MODULE_LICENSE("GPL v2");