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         ret = spi_sync_transfer(spi, &t, 1);
  89
  90         if (ret < 0)
  91                 return ret;
  92
  93         return be16_to_cpu(val) & AD5504_RES_MASK;
  94 }
  95
  96 static int ad5504_read_raw(struct iio_dev *indio_dev,
  97                            struct iio_chan_spec const *chan,
  98                            int *val,
  99                            int *val2,
 100                            long m)
 101 {
 102         struct ad5504_state *st = iio_priv(indio_dev);
 103         unsigned long scale_uv;
 104         int ret;
 105
 106         switch (m) {
 107         case IIO_CHAN_INFO_RAW:
 108                 ret = ad5504_spi_read(st->spi, chan->address);
 109                 if (ret < 0)
 110                         return ret;
 111
 112                 *val = ret;
 113
 114                 return IIO_VAL_INT;
 115         case IIO_CHAN_INFO_SCALE:
 116                 scale_uv = (st->vref_mv * 1000) >> chan->scan_type.realbits;
 117                 *val =  scale_uv / 1000;
 118                 *val2 = (scale_uv % 1000) * 1000;
 119                 return IIO_VAL_INT_PLUS_MICRO;
 120
 121         }
 122         return -EINVAL;
 123 }
 124
 125 static int ad5504_write_raw(struct iio_dev *indio_dev,
 126                                struct iio_chan_spec const *chan,
 127                                int val,
 128                                int val2,
 129                                long mask)
 130 {
 131         struct ad5504_state *st = iio_priv(indio_dev);
 132         int ret;
 133
 134         switch (mask) {
 135         case IIO_CHAN_INFO_RAW:
 136                 if (val >= (1 << chan->scan_type.realbits) || val < 0)
 137                         return -EINVAL;
 138
 139                 return ad5504_spi_write(st->spi, chan->address, val);
 140         default:
 141                 ret = -EINVAL;
 142         }
 143
 144         return -EINVAL;
 145 }
 146
 147 static const char * const ad5504_powerdown_modes[] = {
 148         "20kohm_to_gnd",
 149         "three_state",
 150 };
 151
 152 static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
 153         const struct iio_chan_spec *chan)
 154 {
 155         struct ad5504_state *st = iio_priv(indio_dev);
 156
 157         return st->pwr_down_mode;
 158 }
 159
 160 static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
 161         const struct iio_chan_spec *chan, unsigned int mode)
 162 {
 163         struct ad5504_state *st = iio_priv(indio_dev);
 164
 165         st->pwr_down_mode = mode;
 166
 167         return 0;
 168 }
 169
 170 static const struct iio_enum ad5504_powerdown_mode_enum = {
 171         .items = ad5504_powerdown_modes,
 172         .num_items = ARRAY_SIZE(ad5504_powerdown_modes),
 173         .get = ad5504_get_powerdown_mode,
 174         .set = ad5504_set_powerdown_mode,
 175 };
 176
 177 static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
 178         uintptr_t private, const struct iio_chan_spec *chan, char *buf)
 179 {
 180         struct ad5504_state *st = iio_priv(indio_dev);
 181
 182         return sprintf(buf, "%d\n",
 183                         !(st->pwr_down_mask & (1 << chan->channel)));
 184 }
 185
 186 static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
 187         uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
 188         size_t len)
 189 {
 190         bool pwr_down;
 191         int ret;
 192         struct ad5504_state *st = iio_priv(indio_dev);
 193
 194         ret = strtobool(buf, &pwr_down);
 195         if (ret)
 196                 return ret;
 197
 198         if (pwr_down)
 199                 st->pwr_down_mask |= (1 << chan->channel);
 200         else
 201                 st->pwr_down_mask &= ~(1 << chan->channel);
 202
 203         ret = ad5504_spi_write(st->spi, AD5504_ADDR_CTRL,
 204                                 AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) |
 205                                 AD5504_DAC_PWR(st->pwr_down_mask));
 206
 207         /* writes to the CTRL register must be followed by a NOOP */
 208         ad5504_spi_write(st->spi, AD5504_ADDR_NOOP, 0);
 209
 210         return ret ? ret : len;
 211 }
 212
 213 static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
 214 static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");
 215
 216 static struct attribute *ad5504_ev_attributes[] = {
 217         &iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
 218         &iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
 219         NULL,
 220 };
 221
 222 static struct attribute_group ad5504_ev_attribute_group = {
 223         .attrs = ad5504_ev_attributes,
 224         .name = "events",
 225 };
 226
 227 static irqreturn_t ad5504_event_handler(int irq, void *private)
 228 {
 229         iio_push_event(private,
 230                        IIO_UNMOD_EVENT_CODE(IIO_TEMP,
 231                                             0,
 232                                             IIO_EV_TYPE_THRESH,
 233                                             IIO_EV_DIR_RISING),
 234                        iio_get_time_ns());
 235
 236         return IRQ_HANDLED;
 237 }
 238
 239 static const struct iio_info ad5504_info = {
 240         .write_raw = ad5504_write_raw,
 241         .read_raw = ad5504_read_raw,
 242         .event_attrs = &ad5504_ev_attribute_group,
 243         .driver_module = THIS_MODULE,
 244 };
 245
 246 static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
 247         {
 248                 .name = "powerdown",
 249                 .read = ad5504_read_dac_powerdown,
 250                 .write = ad5504_write_dac_powerdown,
 251         },
 252         IIO_ENUM("powerdown_mode", true, &ad5504_powerdown_mode_enum),
 253         IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum),
 254         { },
 255 };
 256
 257 #define AD5504_CHANNEL(_chan) { \
 258         .type = IIO_VOLTAGE, \
 259         .indexed = 1, \
 260         .output = 1, \
 261         .channel = (_chan), \
 262         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 263         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 264         .address = AD5504_ADDR_DAC(_chan), \
 265         .scan_type = IIO_ST('u', 12, 16, 0), \
 266         .ext_info = ad5504_ext_info, \
 267 }
 268
 269 static const struct iio_chan_spec ad5504_channels[] = {
 270         AD5504_CHANNEL(0),
 271         AD5504_CHANNEL(1),
 272         AD5504_CHANNEL(2),
 273         AD5504_CHANNEL(3),
 274 };
 275
 276 static int ad5504_probe(struct spi_device *spi)
 277 {
 278         struct ad5504_platform_data *pdata = spi->dev.platform_data;
 279         struct iio_dev *indio_dev;
 280         struct ad5504_state *st;
 281         struct regulator *reg;
 282         int ret, voltage_uv = 0;
 283
 284         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 285         if (!indio_dev)
 286                 return -ENOMEM;
 287         reg = devm_regulator_get(&spi->dev, "vcc");
 288         if (!IS_ERR(reg)) {
 289                 ret = regulator_enable(reg);
 290                 if (ret)
 291                         return ret;
 292
 293                 ret = regulator_get_voltage(reg);
 294                 if (ret < 0)
 295                         goto error_disable_reg;
 296
 297                 voltage_uv = ret;
 298         }
 299
 300         spi_set_drvdata(spi, indio_dev);
 301         st = iio_priv(indio_dev);
 302         if (voltage_uv)
 303                 st->vref_mv = voltage_uv / 1000;
 304         else if (pdata)
 305                 st->vref_mv = pdata->vref_mv;
 306         else
 307                 dev_warn(&spi->dev, "reference voltage unspecified\n");
 308
 309         st->reg = reg;
 310         st->spi = spi;
 311         indio_dev->dev.parent = &spi->dev;
 312         indio_dev->name = spi_get_device_id(st->spi)->name;
 313         indio_dev->info = &ad5504_info;
 314         if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
 315                 indio_dev->num_channels = 1;
 316         else
 317                 indio_dev->num_channels = 4;
 318         indio_dev->channels = ad5504_channels;
 319         indio_dev->modes = INDIO_DIRECT_MODE;
 320
 321         if (spi->irq) {
 322                 ret = devm_request_threaded_irq(&spi->dev, spi->irq,
 323                                            NULL,
 324                                            &ad5504_event_handler,
 325                                            IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 326                                            spi_get_device_id(st->spi)->name,
 327                                            indio_dev);
 328                 if (ret)
 329                         goto error_disable_reg;
 330         }
 331
 332         ret = iio_device_register(indio_dev);
 333         if (ret)
 334                 goto error_disable_reg;
 335
 336         return 0;
 337
 338 error_disable_reg:
 339         if (!IS_ERR(reg))
 340                 regulator_disable(reg);
 341
 342         return ret;
 343 }
 344
 345 static int ad5504_remove(struct spi_device *spi)
 346 {
 347         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 348         struct ad5504_state *st = iio_priv(indio_dev);
 349
 350         iio_device_unregister(indio_dev);
 351
 352         if (!IS_ERR(st->reg))
 353                 regulator_disable(st->reg);
 354
 355         return 0;
 356 }
 357
 358 static const struct spi_device_id ad5504_id[] = {
 359         {"ad5504", ID_AD5504},
 360         {"ad5501", ID_AD5501},
 361         {}
 362 };
 363 MODULE_DEVICE_TABLE(spi, ad5504_id);
 364
 365 static struct spi_driver ad5504_driver = {
 366         .driver = {
 367                    .name = "ad5504",
 368                    .owner = THIS_MODULE,
 369                    },
 370         .probe = ad5504_probe,
 371         .remove = ad5504_remove,
 372         .id_table = ad5504_id,
 373 };
 374 module_spi_driver(ad5504_driver);
 375
 376 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 377 MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
 378 MODULE_LICENSE("GPL v2");