drivers/iio/dac/ad5504.c

   1 /*
   2  * AD5504, AD5501 High Voltage Digital to Analog Converter
   3  *
   4  * Copyright 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 #include <linux/iio/events.h>
  22 #include <linux/iio/dac/ad5504.h>
  23
  24 #define AD5505_BITS                     12
  25 #define AD5504_RES_MASK                 ((1 << (AD5505_BITS)) - 1)
  26
  27 #define AD5504_CMD_READ                 (1 << 15)
  28 #define AD5504_CMD_WRITE                (0 << 15)
  29 #define AD5504_ADDR(addr)               ((addr) << 12)
  30
  31 /* Registers */
  32 #define AD5504_ADDR_NOOP                0
  33 #define AD5504_ADDR_DAC(x)              ((x) + 1)
  34 #define AD5504_ADDR_ALL_DAC             5
  35 #define AD5504_ADDR_CTRL                7
  36
  37 /* Control Register */
  38 #define AD5504_DAC_PWR(ch)              ((ch) << 2)
  39 #define AD5504_DAC_PWRDWN_MODE(mode)    ((mode) << 6)
  40 #define AD5504_DAC_PWRDN_20K            0
  41 #define AD5504_DAC_PWRDN_3STATE         1
  42
  43 /**
  44  * struct ad5446_state - driver instance specific data
  45  * @us:                 spi_device
  46  * @reg:                supply regulator
  47  * @vref_mv:            actual reference voltage used
  48  * @pwr_down_mask       power down mask
  49  * @pwr_down_mode       current power down mode
  50  */
  51
  52 struct ad5504_state {
  53         struct spi_device               *spi;
  54         struct regulator                *reg;
  55         unsigned short                  vref_mv;
  56         unsigned                        pwr_down_mask;
  57         unsigned                        pwr_down_mode;
  58 };
  59
  60 /**
  61  * ad5504_supported_device_ids:
  62  */
  63
  64 enum ad5504_supported_device_ids {
  65         ID_AD5504,
  66         ID_AD5501,
  67 };
  68
  69 static int ad5504_spi_write(struct spi_device *spi, u8 addr, u16 val)
  70 {
  71         u16 tmp = cpu_to_be16(AD5504_CMD_WRITE |
  72                               AD5504_ADDR(addr) |
  73                               (val & AD5504_RES_MASK));
  74
  75         return spi_write(spi, (u8 *)&tmp, 2);
  76 }
  77
  78 static int ad5504_spi_read(struct spi_device *spi, u8 addr)
  79 {
  80         u16 tmp = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr));
  81         u16 val;
  82         int ret;
  83         struct spi_transfer     t = {
  84                         .tx_buf         = &tmp,
  85                         .rx_buf         = &val,
  86                         .len            = 2,
  87                 };
  88         struct spi_message      m;
  89
  90         spi_message_init(&m);
  91         spi_message_add_tail(&t, &m);
  92         ret = spi_sync(spi, &m);
  93
  94         if (ret < 0)
  95                 return ret;
  96
  97         return be16_to_cpu(val) & AD5504_RES_MASK;
  98 }
  99
 100 static int ad5504_read_raw(struct iio_dev *indio_dev,
 101                            struct iio_chan_spec const *chan,
 102                            int *val,
 103                            int *val2,
 104                            long m)
 105 {
 106         struct ad5504_state *st = iio_priv(indio_dev);
 107         unsigned long scale_uv;
 108         int ret;
 109
 110         switch (m) {
 111         case IIO_CHAN_INFO_RAW:
 112                 ret = ad5504_spi_read(st->spi, chan->address);
 113                 if (ret < 0)
 114                         return ret;
 115
 116                 *val = ret;
 117
 118                 return IIO_VAL_INT;
 119         case IIO_CHAN_INFO_SCALE:
 120                 scale_uv = (st->vref_mv * 1000) >> chan->scan_type.realbits;
 121                 *val =  scale_uv / 1000;
 122                 *val2 = (scale_uv % 1000) * 1000;
 123                 return IIO_VAL_INT_PLUS_MICRO;
 124
 125         }
 126         return -EINVAL;
 127 }
 128
 129 static int ad5504_write_raw(struct iio_dev *indio_dev,
 130                                struct iio_chan_spec const *chan,
 131                                int val,
 132                                int val2,
 133                                long mask)
 134 {
 135         struct ad5504_state *st = iio_priv(indio_dev);
 136         int ret;
 137
 138         switch (mask) {
 139         case IIO_CHAN_INFO_RAW:
 140                 if (val >= (1 << chan->scan_type.realbits) || val < 0)
 141                         return -EINVAL;
 142
 143                 return ad5504_spi_write(st->spi, chan->address, val);
 144         default:
 145                 ret = -EINVAL;
 146         }
 147
 148         return -EINVAL;
 149 }
 150
 151 static const char * const ad5504_powerdown_modes[] = {
 152         "20kohm_to_gnd",
 153         "three_state",
 154 };
 155
 156 static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
 157         const struct iio_chan_spec *chan)
 158 {
 159         struct ad5504_state *st = iio_priv(indio_dev);
 160
 161         return st->pwr_down_mode;
 162 }
 163
 164 static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
 165         const struct iio_chan_spec *chan, unsigned int mode)
 166 {
 167         struct ad5504_state *st = iio_priv(indio_dev);
 168
 169         st->pwr_down_mode = mode;
 170
 171         return 0;
 172 }
 173
 174 static const struct iio_enum ad5504_powerdown_mode_enum = {
 175         .items = ad5504_powerdown_modes,
 176         .num_items = ARRAY_SIZE(ad5504_powerdown_modes),
 177         .get = ad5504_get_powerdown_mode,
 178         .set = ad5504_set_powerdown_mode,
 179 };
 180
 181 static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
 182         uintptr_t private, const struct iio_chan_spec *chan, char *buf)
 183 {
 184         struct ad5504_state *st = iio_priv(indio_dev);
 185
 186         return sprintf(buf, "%d\n",
 187                         !(st->pwr_down_mask & (1 << chan->channel)));
 188 }
 189
 190 static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
 191         uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
 192         size_t len)
 193 {
 194         bool pwr_down;
 195         int ret;
 196         struct ad5504_state *st = iio_priv(indio_dev);
 197
 198         ret = strtobool(buf, &pwr_down);
 199         if (ret)
 200                 return ret;
 201
 202         if (pwr_down)
 203                 st->pwr_down_mask |= (1 << chan->channel);
 204         else
 205                 st->pwr_down_mask &= ~(1 << chan->channel);
 206
 207         ret = ad5504_spi_write(st->spi, AD5504_ADDR_CTRL,
 208                                 AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) |
 209                                 AD5504_DAC_PWR(st->pwr_down_mask));
 210
 211         /* writes to the CTRL register must be followed by a NOOP */
 212         ad5504_spi_write(st->spi, AD5504_ADDR_NOOP, 0);
 213
 214         return ret ? ret : len;
 215 }
 216
 217 static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
 218 static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");
 219
 220 static struct attribute *ad5504_ev_attributes[] = {
 221         &iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
 222         &iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
 223         NULL,
 224 };
 225
 226 static struct attribute_group ad5504_ev_attribute_group = {
 227         .attrs = ad5504_ev_attributes,
 228         .name = "events",
 229 };
 230
 231 static irqreturn_t ad5504_event_handler(int irq, void *private)
 232 {
 233         iio_push_event(private,
 234                        IIO_UNMOD_EVENT_CODE(IIO_TEMP,
 235                                             0,
 236                                             IIO_EV_TYPE_THRESH,
 237                                             IIO_EV_DIR_RISING),
 238                        iio_get_time_ns());
 239
 240         return IRQ_HANDLED;
 241 }
 242
 243 static const struct iio_info ad5504_info = {
 244         .write_raw = ad5504_write_raw,
 245         .read_raw = ad5504_read_raw,
 246         .event_attrs = &ad5504_ev_attribute_group,
 247         .driver_module = THIS_MODULE,
 248 };
 249
 250 static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
 251         {
 252                 .name = "powerdown",
 253                 .read = ad5504_read_dac_powerdown,
 254                 .write = ad5504_write_dac_powerdown,
 255         },
 256         IIO_ENUM("powerdown_mode", true, &ad5504_powerdown_mode_enum),
 257         IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum),
 258         { },
 259 };
 260
 261 #define AD5504_CHANNEL(_chan) { \
 262         .type = IIO_VOLTAGE, \
 263         .indexed = 1, \
 264         .output = 1, \
 265         .channel = (_chan), \
 266         .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
 267                      IIO_CHAN_INFO_SCALE_SHARED_BIT, \
 268         .address = AD5504_ADDR_DAC(_chan), \
 269         .scan_type = IIO_ST('u', 12, 16, 0), \
 270         .ext_info = ad5504_ext_info, \
 271 }
 272
 273 static const struct iio_chan_spec ad5504_channels[] = {
 274         AD5504_CHANNEL(0),
 275         AD5504_CHANNEL(1),
 276         AD5504_CHANNEL(2),
 277         AD5504_CHANNEL(3),
 278 };
 279
 280 static int __devinit ad5504_probe(struct spi_device *spi)
 281 {
 282         struct ad5504_platform_data *pdata = spi->dev.platform_data;
 283         struct iio_dev *indio_dev;
 284         struct ad5504_state *st;
 285         struct regulator *reg;
 286         int ret, voltage_uv = 0;
 287
 288         indio_dev = iio_device_alloc(sizeof(*st));
 289         if (indio_dev == NULL) {
 290                 ret = -ENOMEM;
 291                 goto error_ret;
 292         }
 293         reg = regulator_get(&spi->dev, "vcc");
 294         if (!IS_ERR(reg)) {
 295                 ret = regulator_enable(reg);
 296                 if (ret)
 297                         goto error_put_reg;
 298
 299                 ret = regulator_get_voltage(reg);
 300                 if (ret < 0)
 301                         goto error_disable_reg;
 302
 303                 voltage_uv = ret;
 304         }
 305
 306         spi_set_drvdata(spi, indio_dev);
 307         st = iio_priv(indio_dev);
 308         if (voltage_uv)
 309                 st->vref_mv = voltage_uv / 1000;
 310         else if (pdata)
 311                 st->vref_mv = pdata->vref_mv;
 312         else
 313                 dev_warn(&spi->dev, "reference voltage unspecified\n");
 314
 315         st->reg = reg;
 316         st->spi = spi;
 317         indio_dev->dev.parent = &spi->dev;
 318         indio_dev->name = spi_get_device_id(st->spi)->name;
 319         indio_dev->info = &ad5504_info;
 320         if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
 321                 indio_dev->num_channels = 1;
 322         else
 323                 indio_dev->num_channels = 4;
 324         indio_dev->channels = ad5504_channels;
 325         indio_dev->modes = INDIO_DIRECT_MODE;
 326
 327         if (spi->irq) {
 328                 ret = request_threaded_irq(spi->irq,
 329                                            NULL,
 330                                            &ad5504_event_handler,
 331                                            IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 332                                            spi_get_device_id(st->spi)->name,
 333                                            indio_dev);
 334                 if (ret)
 335                         goto error_disable_reg;
 336         }
 337
 338         ret = iio_device_register(indio_dev);
 339         if (ret)
 340                 goto error_free_irq;
 341
 342         return 0;
 343
 344 error_free_irq:
 345         if (spi->irq)
 346                 free_irq(spi->irq, indio_dev);
 347 error_disable_reg:
 348         if (!IS_ERR(reg))
 349                 regulator_disable(reg);
 350 error_put_reg:
 351         if (!IS_ERR(reg))
 352                 regulator_put(reg);
 353
 354         iio_device_free(indio_dev);
 355 error_ret:
 356         return ret;
 357 }
 358
 359 static int __devexit ad5504_remove(struct spi_device *spi)
 360 {
 361         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 362         struct ad5504_state *st = iio_priv(indio_dev);
 363
 364         iio_device_unregister(indio_dev);
 365         if (spi->irq)
 366                 free_irq(spi->irq, indio_dev);
 367
 368         if (!IS_ERR(st->reg)) {
 369                 regulator_disable(st->reg);
 370                 regulator_put(st->reg);
 371         }
 372         iio_device_free(indio_dev);
 373
 374         return 0;
 375 }
 376
 377 static const struct spi_device_id ad5504_id[] = {
 378         {"ad5504", ID_AD5504},
 379         {"ad5501", ID_AD5501},
 380         {}
 381 };
 382 MODULE_DEVICE_TABLE(spi, ad5504_id);
 383
 384 static struct spi_driver ad5504_driver = {
 385         .driver = {
 386                    .name = "ad5504",
 387                    .owner = THIS_MODULE,
 388                    },
 389         .probe = ad5504_probe,
 390         .remove = __devexit_p(ad5504_remove),
 391         .id_table = ad5504_id,
 392 };
 393 module_spi_driver(ad5504_driver);
 394
 395 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 396 MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
 397 MODULE_LICENSE("GPL v2");