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