drivers/iio/dac/ad5504.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AD5504, AD5501 High Voltage Digital to Analog Converter
   4  *
   5  * Copyright 2011 Analog Devices Inc.
   6  */
   7
   8 #include <linux/interrupt.h>
   9 #include <linux/fs.h>
  10 #include <linux/device.h>
  11 #include <linux/kernel.h>
  12 #include <linux/spi/spi.h>
  13 #include <linux/slab.h>
  14 #include <linux/sysfs.h>
  15 #include <linux/regulator/consumer.h>
  16 #include <linux/module.h>
  17 #include <linux/bitops.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 AD5504_RES_MASK                 GENMASK(11, 0)
  25 #define AD5504_CMD_READ                 BIT(15)
  26 #define AD5504_CMD_WRITE                0
  27 #define AD5504_ADDR(addr)               ((addr) << 12)
  28
  29 /* Registers */
  30 #define AD5504_ADDR_NOOP                0
  31 #define AD5504_ADDR_DAC(x)              ((x) + 1)
  32 #define AD5504_ADDR_ALL_DAC             5
  33 #define AD5504_ADDR_CTRL                7
  34
  35 /* Control Register */
  36 #define AD5504_DAC_PWR(ch)              ((ch) << 2)
  37 #define AD5504_DAC_PWRDWN_MODE(mode)    ((mode) << 6)
  38 #define AD5504_DAC_PWRDN_20K            0
  39 #define AD5504_DAC_PWRDN_3STATE         1
  40
  41 /**
  42  * struct ad5446_state - driver instance specific data
  43  * @spi:                        spi_device
  44  * @reg:                supply regulator
  45  * @vref_mv:            actual reference voltage used
  46  * @pwr_down_mask       power down mask
  47  * @pwr_down_mode       current power down mode
  48  * @data:               transfer buffer
  49  */
  50 struct ad5504_state {
  51         struct spi_device               *spi;
  52         struct regulator                *reg;
  53         unsigned short                  vref_mv;
  54         unsigned                        pwr_down_mask;
  55         unsigned                        pwr_down_mode;
  56
  57         __be16                          data[2] ____cacheline_aligned;
  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 ad5504_state *st, u8 addr, u16 val)
  70 {
  71         st->data[0] = cpu_to_be16(AD5504_CMD_WRITE | AD5504_ADDR(addr) |
  72                               (val & AD5504_RES_MASK));
  73
  74         return spi_write(st->spi, &st->data[0], 2);
  75 }
  76
  77 static int ad5504_spi_read(struct ad5504_state *st, u8 addr)
  78 {
  79         int ret;
  80         struct spi_transfer t = {
  81             .tx_buf = &st->data[0],
  82             .rx_buf = &st->data[1],
  83             .len = 2,
  84         };
  85
  86         st->data[0] = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr));
  87         ret = spi_sync_transfer(st->spi, &t, 1);
  88         if (ret < 0)
  89                 return ret;
  90
  91         return be16_to_cpu(st->data[1]) & AD5504_RES_MASK;
  92 }
  93
  94 static int ad5504_read_raw(struct iio_dev *indio_dev,
  95                            struct iio_chan_spec const *chan,
  96                            int *val,
  97                            int *val2,
  98                            long m)
  99 {
 100         struct ad5504_state *st = iio_priv(indio_dev);
 101         int ret;
 102
 103         switch (m) {
 104         case IIO_CHAN_INFO_RAW:
 105                 ret = ad5504_spi_read(st, chan->address);
 106                 if (ret < 0)
 107                         return ret;
 108
 109                 *val = ret;
 110
 111                 return IIO_VAL_INT;
 112         case IIO_CHAN_INFO_SCALE:
 113                 *val = st->vref_mv;
 114                 *val2 = chan->scan_type.realbits;
 115                 return IIO_VAL_FRACTIONAL_LOG2;
 116         }
 117         return -EINVAL;
 118 }
 119
 120 static int ad5504_write_raw(struct iio_dev *indio_dev,
 121                                struct iio_chan_spec const *chan,
 122                                int val,
 123                                int val2,
 124                                long mask)
 125 {
 126         struct ad5504_state *st = iio_priv(indio_dev);
 127
 128         switch (mask) {
 129         case IIO_CHAN_INFO_RAW:
 130                 if (val >= (1 << chan->scan_type.realbits) || val < 0)
 131                         return -EINVAL;
 132
 133                 return ad5504_spi_write(st, chan->address, val);
 134         default:
 135                 return -EINVAL;
 136         }
 137 }
 138
 139 static const char * const ad5504_powerdown_modes[] = {
 140         "20kohm_to_gnd",
 141         "three_state",
 142 };
 143
 144 static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
 145         const struct iio_chan_spec *chan)
 146 {
 147         struct ad5504_state *st = iio_priv(indio_dev);
 148
 149         return st->pwr_down_mode;
 150 }
 151
 152 static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
 153         const struct iio_chan_spec *chan, unsigned int mode)
 154 {
 155         struct ad5504_state *st = iio_priv(indio_dev);
 156
 157         st->pwr_down_mode = mode;
 158
 159         return 0;
 160 }
 161
 162 static const struct iio_enum ad5504_powerdown_mode_enum = {
 163         .items = ad5504_powerdown_modes,
 164         .num_items = ARRAY_SIZE(ad5504_powerdown_modes),
 165         .get = ad5504_get_powerdown_mode,
 166         .set = ad5504_set_powerdown_mode,
 167 };
 168
 169 static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
 170         uintptr_t private, const struct iio_chan_spec *chan, char *buf)
 171 {
 172         struct ad5504_state *st = iio_priv(indio_dev);
 173
 174         return sprintf(buf, "%d\n",
 175                         !(st->pwr_down_mask & (1 << chan->channel)));
 176 }
 177
 178 static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
 179         uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
 180         size_t len)
 181 {
 182         bool pwr_down;
 183         int ret;
 184         struct ad5504_state *st = iio_priv(indio_dev);
 185
 186         ret = strtobool(buf, &pwr_down);
 187         if (ret)
 188                 return ret;
 189
 190         if (pwr_down)
 191                 st->pwr_down_mask |= (1 << chan->channel);
 192         else
 193                 st->pwr_down_mask &= ~(1 << chan->channel);
 194
 195         ret = ad5504_spi_write(st, AD5504_ADDR_CTRL,
 196                                 AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) |
 197                                 AD5504_DAC_PWR(st->pwr_down_mask));
 198
 199         /* writes to the CTRL register must be followed by a NOOP */
 200         ad5504_spi_write(st, AD5504_ADDR_NOOP, 0);
 201
 202         return ret ? ret : len;
 203 }
 204
 205 static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
 206 static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");
 207
 208 static struct attribute *ad5504_ev_attributes[] = {
 209         &iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
 210         &iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
 211         NULL,
 212 };
 213
 214 static const struct attribute_group ad5504_ev_attribute_group = {
 215         .attrs = ad5504_ev_attributes,
 216 };
 217
 218 static irqreturn_t ad5504_event_handler(int irq, void *private)
 219 {
 220         iio_push_event(private,
 221                        IIO_UNMOD_EVENT_CODE(IIO_TEMP,
 222                                             0,
 223                                             IIO_EV_TYPE_THRESH,
 224                                             IIO_EV_DIR_RISING),
 225                        iio_get_time_ns(private));
 226
 227         return IRQ_HANDLED;
 228 }
 229
 230 static const struct iio_info ad5504_info = {
 231         .write_raw = ad5504_write_raw,
 232         .read_raw = ad5504_read_raw,
 233         .event_attrs = &ad5504_ev_attribute_group,
 234 };
 235
 236 static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
 237         {
 238                 .name = "powerdown",
 239                 .read = ad5504_read_dac_powerdown,
 240                 .write = ad5504_write_dac_powerdown,
 241                 .shared = IIO_SEPARATE,
 242         },
 243         IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
 244                  &ad5504_powerdown_mode_enum),
 245         IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum),
 246         { },
 247 };
 248
 249 #define AD5504_CHANNEL(_chan) { \
 250         .type = IIO_VOLTAGE, \
 251         .indexed = 1, \
 252         .output = 1, \
 253         .channel = (_chan), \
 254         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 255         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 256         .address = AD5504_ADDR_DAC(_chan), \
 257         .scan_type = { \
 258                 .sign = 'u', \
 259                 .realbits = 12, \
 260                 .storagebits = 16, \
 261         }, \
 262         .ext_info = ad5504_ext_info, \
 263 }
 264
 265 static const struct iio_chan_spec ad5504_channels[] = {
 266         AD5504_CHANNEL(0),
 267         AD5504_CHANNEL(1),
 268         AD5504_CHANNEL(2),
 269         AD5504_CHANNEL(3),
 270 };
 271
 272 static int ad5504_probe(struct spi_device *spi)
 273 {
 274         struct ad5504_platform_data *pdata = spi->dev.platform_data;
 275         struct iio_dev *indio_dev;
 276         struct ad5504_state *st;
 277         struct regulator *reg;
 278         int ret, voltage_uv = 0;
 279
 280         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 281         if (!indio_dev)
 282                 return -ENOMEM;
 283         reg = devm_regulator_get(&spi->dev, "vcc");
 284         if (!IS_ERR(reg)) {
 285                 ret = regulator_enable(reg);
 286                 if (ret)
 287                         return ret;
 288
 289                 ret = regulator_get_voltage(reg);
 290                 if (ret < 0)
 291                         goto error_disable_reg;
 292
 293                 voltage_uv = ret;
 294         }
 295
 296         spi_set_drvdata(spi, indio_dev);
 297         st = iio_priv(indio_dev);
 298         if (voltage_uv)
 299                 st->vref_mv = voltage_uv / 1000;
 300         else if (pdata)
 301                 st->vref_mv = pdata->vref_mv;
 302         else
 303                 dev_warn(&spi->dev, "reference voltage unspecified\n");
 304
 305         st->reg = reg;
 306         st->spi = spi;
 307         indio_dev->dev.parent = &spi->dev;
 308         indio_dev->name = spi_get_device_id(st->spi)->name;
 309         indio_dev->info = &ad5504_info;
 310         if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
 311                 indio_dev->num_channels = 1;
 312         else
 313                 indio_dev->num_channels = 4;
 314         indio_dev->channels = ad5504_channels;
 315         indio_dev->modes = INDIO_DIRECT_MODE;
 316
 317         if (spi->irq) {
 318                 ret = devm_request_threaded_irq(&spi->dev, spi->irq,
 319                                            NULL,
 320                                            &ad5504_event_handler,
 321                                            IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 322                                            spi_get_device_id(st->spi)->name,
 323                                            indio_dev);
 324                 if (ret)
 325                         goto error_disable_reg;
 326         }
 327
 328         ret = iio_device_register(indio_dev);
 329         if (ret)
 330                 goto error_disable_reg;
 331
 332         return 0;
 333
 334 error_disable_reg:
 335         if (!IS_ERR(reg))
 336                 regulator_disable(reg);
 337
 338         return ret;
 339 }
 340
 341 static int ad5504_remove(struct spi_device *spi)
 342 {
 343         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 344         struct ad5504_state *st = iio_priv(indio_dev);
 345
 346         iio_device_unregister(indio_dev);
 347
 348         if (!IS_ERR(st->reg))
 349                 regulator_disable(st->reg);
 350
 351         return 0;
 352 }
 353
 354 static const struct spi_device_id ad5504_id[] = {
 355         {"ad5504", ID_AD5504},
 356         {"ad5501", ID_AD5501},
 357         {}
 358 };
 359 MODULE_DEVICE_TABLE(spi, ad5504_id);
 360
 361 static struct spi_driver ad5504_driver = {
 362         .driver = {
 363                    .name = "ad5504",
 364                    },
 365         .probe = ad5504_probe,
 366         .remove = ad5504_remove,
 367         .id_table = ad5504_id,
 368 };
 369 module_spi_driver(ad5504_driver);
 370
 371 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 372 MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
 373 MODULE_LICENSE("GPL v2");