drivers/iio/adc/ad7091r-base.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * AD7091RX Analog to Digital converter driver
   4  *
   5  * Copyright 2014-2019 Analog Devices Inc.
   6  */
   7
   8 #include <linux/bitops.h>
   9 #include <linux/bitfield.h>
  10 #include <linux/iio/events.h>
  11 #include <linux/iio/iio.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/module.h>
  14 #include <linux/regmap.h>
  15 #include <linux/regulator/consumer.h>
  16
  17 #include "ad7091r-base.h"
  18
  19 const struct iio_event_spec ad7091r_events[] = {
  20         {
  21                 .type = IIO_EV_TYPE_THRESH,
  22                 .dir = IIO_EV_DIR_RISING,
  23                 .mask_separate = BIT(IIO_EV_INFO_VALUE) |
  24                                  BIT(IIO_EV_INFO_ENABLE),
  25         },
  26         {
  27                 .type = IIO_EV_TYPE_THRESH,
  28                 .dir = IIO_EV_DIR_FALLING,
  29                 .mask_separate = BIT(IIO_EV_INFO_VALUE) |
  30                                  BIT(IIO_EV_INFO_ENABLE),
  31         },
  32         {
  33                 .type = IIO_EV_TYPE_THRESH,
  34                 .dir = IIO_EV_DIR_EITHER,
  35                 .mask_separate = BIT(IIO_EV_INFO_HYSTERESIS),
  36         },
  37 };
  38 EXPORT_SYMBOL_NS_GPL(ad7091r_events, "IIO_AD7091R");
  39
  40 static int ad7091r_set_channel(struct ad7091r_state *st, unsigned int channel)
  41 {
  42         unsigned int dummy;
  43         int ret;
  44
  45         /* AD7091R_REG_CHANNEL specified which channels to be converted */
  46         ret = regmap_write(st->map, AD7091R_REG_CHANNEL,
  47                         BIT(channel) | (BIT(channel) << 8));
  48         if (ret)
  49                 return ret;
  50
  51         /*
  52          * There is a latency of one conversion before the channel conversion
  53          * sequence is updated
  54          */
  55         return regmap_read(st->map, AD7091R_REG_RESULT, &dummy);
  56 }
  57
  58 static int ad7091r_read_one(struct iio_dev *iio_dev,
  59                 unsigned int channel, unsigned int *read_val)
  60 {
  61         struct ad7091r_state *st = iio_priv(iio_dev);
  62         unsigned int val;
  63         int ret;
  64
  65         ret = ad7091r_set_channel(st, channel);
  66         if (ret)
  67                 return ret;
  68
  69         ret = regmap_read(st->map, AD7091R_REG_RESULT, &val);
  70         if (ret)
  71                 return ret;
  72
  73         if (st->chip_info->reg_result_chan_id(val) != channel)
  74                 return -EIO;
  75
  76         *read_val = AD7091R_REG_RESULT_CONV_RESULT(val);
  77
  78         return 0;
  79 }
  80
  81 static int ad7091r_read_raw(struct iio_dev *iio_dev,
  82                            struct iio_chan_spec const *chan,
  83                            int *val, int *val2, long m)
  84 {
  85         struct ad7091r_state *st = iio_priv(iio_dev);
  86         unsigned int read_val;
  87         int ret;
  88
  89         guard(mutex)(&st->lock);
  90
  91         switch (m) {
  92         case IIO_CHAN_INFO_RAW:
  93                 if (st->mode != AD7091R_MODE_COMMAND)
  94                         return -EBUSY;
  95
  96                 ret = ad7091r_read_one(iio_dev, chan->channel, &read_val);
  97                 if (ret)
  98                         return ret;
  99
 100                 *val = read_val;
 101                 return IIO_VAL_INT;
 102
 103         case IIO_CHAN_INFO_SCALE:
 104                 if (st->vref) {
 105                         ret = regulator_get_voltage(st->vref);
 106                         if (ret < 0)
 107                                 return ret;
 108
 109                         *val = ret / 1000;
 110                 } else {
 111                         *val = st->chip_info->vref_mV;
 112                 }
 113
 114                 *val2 = chan->scan_type.realbits;
 115                 return IIO_VAL_FRACTIONAL_LOG2;
 116
 117         default:
 118                 return -EINVAL;
 119         }
 120 }
 121
 122 static int ad7091r_read_event_config(struct iio_dev *indio_dev,
 123                                      const struct iio_chan_spec *chan,
 124                                      enum iio_event_type type,
 125                                      enum iio_event_direction dir)
 126 {
 127         struct ad7091r_state *st = iio_priv(indio_dev);
 128         int val, ret;
 129
 130         switch (dir) {
 131         case IIO_EV_DIR_RISING:
 132                 ret = regmap_read(st->map,
 133                                   AD7091R_REG_CH_HIGH_LIMIT(chan->channel),
 134                                   &val);
 135                 if (ret)
 136                         return ret;
 137                 return val != AD7091R_HIGH_LIMIT;
 138         case IIO_EV_DIR_FALLING:
 139                 ret = regmap_read(st->map,
 140                                   AD7091R_REG_CH_LOW_LIMIT(chan->channel),
 141                                   &val);
 142                 if (ret)
 143                         return ret;
 144                 return val != AD7091R_LOW_LIMIT;
 145         default:
 146                 return -EINVAL;
 147         }
 148 }
 149
 150 static int ad7091r_write_event_config(struct iio_dev *indio_dev,
 151                                       const struct iio_chan_spec *chan,
 152                                       enum iio_event_type type,
 153                                       enum iio_event_direction dir,
 154                                       bool state)
 155 {
 156         struct ad7091r_state *st = iio_priv(indio_dev);
 157
 158         if (state) {
 159                 return regmap_set_bits(st->map, AD7091R_REG_CONF,
 160                                        AD7091R_REG_CONF_ALERT_EN);
 161         } else {
 162                 /*
 163                  * Set thresholds either to 0 or to 2^12 - 1 as appropriate to
 164                  * prevent alerts and thus disable event generation.
 165                  */
 166                 switch (dir) {
 167                 case IIO_EV_DIR_RISING:
 168                         return regmap_write(st->map,
 169                                             AD7091R_REG_CH_HIGH_LIMIT(chan->channel),
 170                                             AD7091R_HIGH_LIMIT);
 171                 case IIO_EV_DIR_FALLING:
 172                         return regmap_write(st->map,
 173                                             AD7091R_REG_CH_LOW_LIMIT(chan->channel),
 174                                             AD7091R_LOW_LIMIT);
 175                 default:
 176                         return -EINVAL;
 177                 }
 178         }
 179 }
 180
 181 static int ad7091r_read_event_value(struct iio_dev *indio_dev,
 182                                     const struct iio_chan_spec *chan,
 183                                     enum iio_event_type type,
 184                                     enum iio_event_direction dir,
 185                                     enum iio_event_info info, int *val, int *val2)
 186 {
 187         struct ad7091r_state *st = iio_priv(indio_dev);
 188         int ret;
 189
 190         switch (info) {
 191         case IIO_EV_INFO_VALUE:
 192                 switch (dir) {
 193                 case IIO_EV_DIR_RISING:
 194                         ret = regmap_read(st->map,
 195                                           AD7091R_REG_CH_HIGH_LIMIT(chan->channel),
 196                                           val);
 197                         if (ret)
 198                                 return ret;
 199                         return IIO_VAL_INT;
 200                 case IIO_EV_DIR_FALLING:
 201                         ret = regmap_read(st->map,
 202                                           AD7091R_REG_CH_LOW_LIMIT(chan->channel),
 203                                           val);
 204                         if (ret)
 205                                 return ret;
 206                         return IIO_VAL_INT;
 207                 default:
 208                         return -EINVAL;
 209                 }
 210         case IIO_EV_INFO_HYSTERESIS:
 211                 ret = regmap_read(st->map,
 212                                   AD7091R_REG_CH_HYSTERESIS(chan->channel),
 213                                   val);
 214                 if (ret)
 215                         return ret;
 216                 return IIO_VAL_INT;
 217         default:
 218                 return -EINVAL;
 219         }
 220 }
 221
 222 static int ad7091r_write_event_value(struct iio_dev *indio_dev,
 223                                      const struct iio_chan_spec *chan,
 224                                      enum iio_event_type type,
 225                                      enum iio_event_direction dir,
 226                                      enum iio_event_info info, int val, int val2)
 227 {
 228         struct ad7091r_state *st = iio_priv(indio_dev);
 229
 230         switch (info) {
 231         case IIO_EV_INFO_VALUE:
 232                 switch (dir) {
 233                 case IIO_EV_DIR_RISING:
 234                         return regmap_write(st->map,
 235                                             AD7091R_REG_CH_HIGH_LIMIT(chan->channel),
 236                                             val);
 237                 case IIO_EV_DIR_FALLING:
 238                         return regmap_write(st->map,
 239                                             AD7091R_REG_CH_LOW_LIMIT(chan->channel),
 240                                             val);
 241                 default:
 242                         return -EINVAL;
 243                 }
 244         case IIO_EV_INFO_HYSTERESIS:
 245                 return regmap_write(st->map,
 246                                     AD7091R_REG_CH_HYSTERESIS(chan->channel),
 247                                     val);
 248         default:
 249                 return -EINVAL;
 250         }
 251 }
 252
 253 static const struct iio_info ad7091r_info = {
 254         .read_raw = ad7091r_read_raw,
 255         .read_event_config = &ad7091r_read_event_config,
 256         .write_event_config = &ad7091r_write_event_config,
 257         .read_event_value = &ad7091r_read_event_value,
 258         .write_event_value = &ad7091r_write_event_value,
 259 };
 260
 261 static irqreturn_t ad7091r_event_handler(int irq, void *private)
 262 {
 263         struct iio_dev *iio_dev = private;
 264         struct ad7091r_state *st = iio_priv(iio_dev);
 265         unsigned int i, read_val;
 266         int ret;
 267         s64 timestamp = iio_get_time_ns(iio_dev);
 268
 269         ret = regmap_read(st->map, AD7091R_REG_ALERT, &read_val);
 270         if (ret)
 271                 return IRQ_HANDLED;
 272
 273         for (i = 0; i < st->chip_info->num_channels; i++) {
 274                 if (read_val & BIT(i * 2))
 275                         iio_push_event(iio_dev,
 276                                         IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i,
 277                                                 IIO_EV_TYPE_THRESH,
 278                                                 IIO_EV_DIR_RISING), timestamp);
 279                 if (read_val & BIT(i * 2 + 1))
 280                         iio_push_event(iio_dev,
 281                                         IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i,
 282                                                 IIO_EV_TYPE_THRESH,
 283                                                 IIO_EV_DIR_FALLING), timestamp);
 284         }
 285
 286         return IRQ_HANDLED;
 287 }
 288
 289 static void ad7091r_remove(void *data)
 290 {
 291         struct ad7091r_state *st = data;
 292
 293         regulator_disable(st->vref);
 294 }
 295
 296 int ad7091r_probe(struct device *dev, const struct ad7091r_init_info *init_info,
 297                   int irq)
 298 {
 299         struct iio_dev *iio_dev;
 300         struct ad7091r_state *st;
 301         int ret;
 302
 303         iio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 304         if (!iio_dev)
 305                 return -ENOMEM;
 306
 307         st = iio_priv(iio_dev);
 308         st->dev = dev;
 309         init_info->init_adc_regmap(st, init_info->regmap_config);
 310         if (IS_ERR(st->map))
 311                 return dev_err_probe(st->dev, PTR_ERR(st->map),
 312                                      "Error initializing regmap\n");
 313
 314         iio_dev->info = &ad7091r_info;
 315         iio_dev->modes = INDIO_DIRECT_MODE;
 316
 317         if (init_info->setup) {
 318                 ret = init_info->setup(st);
 319                 if (ret < 0)
 320                         return ret;
 321         }
 322
 323         if (irq) {
 324                 st->chip_info = init_info->info_irq;
 325                 ret = regmap_update_bits(st->map, AD7091R_REG_CONF,
 326                                          AD7091R_REG_CONF_ALERT_EN, BIT(4));
 327                 if (ret)
 328                         return ret;
 329
 330                 ret = devm_request_threaded_irq(dev, irq, NULL,
 331                                                 ad7091r_event_handler,
 332                                                 IRQF_TRIGGER_FALLING |
 333                                                 IRQF_ONESHOT,
 334                                                 st->chip_info->name, iio_dev);
 335                 if (ret)
 336                         return ret;
 337         } else {
 338                 st->chip_info = init_info->info_no_irq;
 339         }
 340
 341         iio_dev->name = st->chip_info->name;
 342         iio_dev->num_channels = st->chip_info->num_channels;
 343         iio_dev->channels = st->chip_info->channels;
 344
 345         st->vref = devm_regulator_get_optional(dev, "vref");
 346         if (IS_ERR(st->vref)) {
 347                 if (PTR_ERR(st->vref) == -EPROBE_DEFER)
 348                         return -EPROBE_DEFER;
 349
 350                 st->vref = NULL;
 351                 /* Enable internal vref */
 352                 ret = regmap_set_bits(st->map, AD7091R_REG_CONF,
 353                                       AD7091R_REG_CONF_INT_VREF);
 354                 if (ret)
 355                         return dev_err_probe(st->dev, ret,
 356                                              "Error on enable internal reference\n");
 357         } else {
 358                 ret = regulator_enable(st->vref);
 359                 if (ret)
 360                         return ret;
 361                 ret = devm_add_action_or_reset(dev, ad7091r_remove, st);
 362                 if (ret)
 363                         return ret;
 364         }
 365
 366         /* Use command mode by default to convert only desired channels*/
 367         ret = st->chip_info->set_mode(st, AD7091R_MODE_COMMAND);
 368         if (ret)
 369                 return ret;
 370
 371         return devm_iio_device_register(dev, iio_dev);
 372 }
 373 EXPORT_SYMBOL_NS_GPL(ad7091r_probe, "IIO_AD7091R");
 374
 375 bool ad7091r_writeable_reg(struct device *dev, unsigned int reg)
 376 {
 377         switch (reg) {
 378         case AD7091R_REG_RESULT:
 379         case AD7091R_REG_ALERT:
 380                 return false;
 381         default:
 382                 return true;
 383         }
 384 }
 385 EXPORT_SYMBOL_NS_GPL(ad7091r_writeable_reg, "IIO_AD7091R");
 386
 387 bool ad7091r_volatile_reg(struct device *dev, unsigned int reg)
 388 {
 389         switch (reg) {
 390         case AD7091R_REG_RESULT:
 391         case AD7091R_REG_ALERT:
 392                 return true;
 393         default:
 394                 return false;
 395         }
 396 }
 397 EXPORT_SYMBOL_NS_GPL(ad7091r_volatile_reg, "IIO_AD7091R");
 398
 399 MODULE_AUTHOR("Beniamin Bia <[email protected]>");
 400 MODULE_DESCRIPTION("Analog Devices AD7091Rx multi-channel converters");
 401 MODULE_LICENSE("GPL v2");