drivers/iio/proximity/sx_common.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright 2021 Google LLC.
   4  *
   5  * Common part of most Semtech SAR sensor.
   6  */
   7
   8 #include <linux/bitops.h>
   9 #include <linux/byteorder/generic.h>
  10 #include <linux/delay.h>
  11 #include <linux/device.h>
  12 #include <linux/err.h>
  13 #include <linux/export.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/irqreturn.h>
  16 #include <linux/i2c.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/regmap.h>
  20 #include <linux/regulator/consumer.h>
  21 #include <vdso/bits.h>
  22
  23 #include <linux/iio/buffer.h>
  24 #include <linux/iio/events.h>
  25 #include <linux/iio/iio.h>
  26 #include <linux/iio/trigger.h>
  27 #include <linux/iio/triggered_buffer.h>
  28 #include <linux/iio/trigger_consumer.h>
  29
  30 #include "sx_common.h"
  31
  32 /* All Semtech SAR sensors have IRQ bit in the same order. */
  33 #define   SX_COMMON_CONVDONE_IRQ                        BIT(0)
  34 #define   SX_COMMON_FAR_IRQ                             BIT(2)
  35 #define   SX_COMMON_CLOSE_IRQ                           BIT(3)
  36
  37 const struct iio_event_spec sx_common_events[3] = {
  38         {
  39                 .type = IIO_EV_TYPE_THRESH,
  40                 .dir = IIO_EV_DIR_RISING,
  41                 .mask_shared_by_all = BIT(IIO_EV_INFO_PERIOD),
  42         },
  43         {
  44                 .type = IIO_EV_TYPE_THRESH,
  45                 .dir = IIO_EV_DIR_FALLING,
  46                 .mask_shared_by_all = BIT(IIO_EV_INFO_PERIOD),
  47         },
  48         {
  49                 .type = IIO_EV_TYPE_THRESH,
  50                 .dir = IIO_EV_DIR_EITHER,
  51                 .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
  52                                  BIT(IIO_EV_INFO_HYSTERESIS) |
  53                                  BIT(IIO_EV_INFO_VALUE),
  54         },
  55 };
  56 EXPORT_SYMBOL_NS_GPL(sx_common_events, SEMTECH_PROX);
  57
  58 static irqreturn_t sx_common_irq_handler(int irq, void *private)
  59 {
  60         struct iio_dev *indio_dev = private;
  61         struct sx_common_data *data = iio_priv(indio_dev);
  62
  63         if (data->trigger_enabled)
  64                 iio_trigger_poll(data->trig);
  65
  66         /*
  67          * Even if no event is enabled, we need to wake the thread to clear the
  68          * interrupt state by reading SX_COMMON_REG_IRQ_SRC.
  69          * It is not possible to do that here because regmap_read takes a mutex.
  70          */
  71         return IRQ_WAKE_THREAD;
  72 }
  73
  74 static void sx_common_push_events(struct iio_dev *indio_dev)
  75 {
  76         int ret;
  77         unsigned int val, chan;
  78         struct sx_common_data *data = iio_priv(indio_dev);
  79         s64 timestamp = iio_get_time_ns(indio_dev);
  80         unsigned long prox_changed;
  81
  82         /* Read proximity state on all channels */
  83         ret = regmap_read(data->regmap, data->chip_info->reg_stat, &val);
  84         if (ret) {
  85                 dev_err(&data->client->dev, "i2c transfer error in irq\n");
  86                 return;
  87         }
  88
  89         val >>= data->chip_info->stat_offset;
  90
  91         /*
  92          * Only iterate over channels with changes on proximity status that have
  93          * events enabled.
  94          */
  95         prox_changed = (data->chan_prox_stat ^ val) & data->chan_event;
  96
  97         for_each_set_bit(chan, &prox_changed, data->chip_info->num_channels) {
  98                 int dir;
  99                 u64 ev;
 100
 101                 dir = (val & BIT(chan)) ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
 102                 ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan,
 103                                           IIO_EV_TYPE_THRESH, dir);
 104
 105                 iio_push_event(indio_dev, ev, timestamp);
 106         }
 107         data->chan_prox_stat = val;
 108 }
 109
 110 static int sx_common_enable_irq(struct sx_common_data *data, unsigned int irq)
 111 {
 112         if (!data->client->irq)
 113                 return 0;
 114         return regmap_update_bits(data->regmap, data->chip_info->reg_irq_msk,
 115                                   irq << data->chip_info->irq_msk_offset,
 116                                   irq << data->chip_info->irq_msk_offset);
 117 }
 118
 119 static int sx_common_disable_irq(struct sx_common_data *data, unsigned int irq)
 120 {
 121         if (!data->client->irq)
 122                 return 0;
 123         return regmap_update_bits(data->regmap, data->chip_info->reg_irq_msk,
 124                                   irq << data->chip_info->irq_msk_offset, 0);
 125 }
 126
 127 static int sx_common_update_chan_en(struct sx_common_data *data,
 128                                     unsigned long chan_read,
 129                                     unsigned long chan_event)
 130 {
 131         int ret;
 132         unsigned long channels = chan_read | chan_event;
 133
 134         if ((data->chan_read | data->chan_event) != channels) {
 135                 ret = regmap_update_bits(data->regmap,
 136                                          data->chip_info->reg_enable_chan,
 137                                          data->chip_info->mask_enable_chan,
 138                                          channels);
 139                 if (ret)
 140                         return ret;
 141         }
 142         data->chan_read = chan_read;
 143         data->chan_event = chan_event;
 144         return 0;
 145 }
 146
 147 static int sx_common_get_read_channel(struct sx_common_data *data, int channel)
 148 {
 149         return sx_common_update_chan_en(data, data->chan_read | BIT(channel),
 150                                      data->chan_event);
 151 }
 152
 153 static int sx_common_put_read_channel(struct sx_common_data *data, int channel)
 154 {
 155         return sx_common_update_chan_en(data, data->chan_read & ~BIT(channel),
 156                                      data->chan_event);
 157 }
 158
 159 static int sx_common_get_event_channel(struct sx_common_data *data, int channel)
 160 {
 161         return sx_common_update_chan_en(data, data->chan_read,
 162                                      data->chan_event | BIT(channel));
 163 }
 164
 165 static int sx_common_put_event_channel(struct sx_common_data *data, int channel)
 166 {
 167         return sx_common_update_chan_en(data, data->chan_read,
 168                                      data->chan_event & ~BIT(channel));
 169 }
 170
 171 /**
 172  * sx_common_read_proximity() - Read raw proximity value.
 173  * @data:       Internal data
 174  * @chan:       Channel to read
 175  * @val:        pointer to return read value.
 176  *
 177  * Request a conversion, wait for the sensor to be ready and
 178  * return the raw proximity value.
 179  */
 180 int sx_common_read_proximity(struct sx_common_data *data,
 181                              const struct iio_chan_spec *chan, int *val)
 182 {
 183         int ret;
 184         __be16 rawval;
 185
 186         mutex_lock(&data->mutex);
 187
 188         ret = sx_common_get_read_channel(data, chan->channel);
 189         if (ret)
 190                 goto out;
 191
 192         ret = sx_common_enable_irq(data, SX_COMMON_CONVDONE_IRQ);
 193         if (ret)
 194                 goto out_put_channel;
 195
 196         mutex_unlock(&data->mutex);
 197
 198         if (data->client->irq) {
 199                 ret = wait_for_completion_interruptible(&data->completion);
 200                 reinit_completion(&data->completion);
 201         } else {
 202                 ret = data->chip_info->ops.wait_for_sample(data);
 203         }
 204
 205         mutex_lock(&data->mutex);
 206
 207         if (ret)
 208                 goto out_disable_irq;
 209
 210         ret = data->chip_info->ops.read_prox_data(data, chan, &rawval);
 211         if (ret)
 212                 goto out_disable_irq;
 213
 214         *val = sign_extend32(be16_to_cpu(rawval), chan->scan_type.realbits - 1);
 215
 216         ret = sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ);
 217         if (ret)
 218                 goto out_put_channel;
 219
 220         ret = sx_common_put_read_channel(data, chan->channel);
 221         if (ret)
 222                 goto out;
 223
 224         mutex_unlock(&data->mutex);
 225
 226         return IIO_VAL_INT;
 227
 228 out_disable_irq:
 229         sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ);
 230 out_put_channel:
 231         sx_common_put_read_channel(data, chan->channel);
 232 out:
 233         mutex_unlock(&data->mutex);
 234
 235         return ret;
 236 }
 237 EXPORT_SYMBOL_NS_GPL(sx_common_read_proximity, SEMTECH_PROX);
 238
 239 /**
 240  * sx_common_read_event_config() - Configure event setting.
 241  * @indio_dev:  iio device object
 242  * @chan:       Channel to read
 243  * @type:       Type of event (unused)
 244  * @dir:        Direction of event (unused)
 245  *
 246  * return if the given channel is used for event gathering.
 247  */
 248 int sx_common_read_event_config(struct iio_dev *indio_dev,
 249                                 const struct iio_chan_spec *chan,
 250                                 enum iio_event_type type,
 251                                 enum iio_event_direction dir)
 252 {
 253         struct sx_common_data *data = iio_priv(indio_dev);
 254
 255         return !!(data->chan_event & BIT(chan->channel));
 256 }
 257 EXPORT_SYMBOL_NS_GPL(sx_common_read_event_config, SEMTECH_PROX);
 258
 259 /**
 260  * sx_common_write_event_config() - Configure event setting.
 261  * @indio_dev:  iio device object
 262  * @chan:       Channel to enable
 263  * @type:       Type of event (unused)
 264  * @dir:        Direction of event (unused)
 265  * @state:      State of the event.
 266  *
 267  * Enable/Disable event on a given channel.
 268  */
 269 int sx_common_write_event_config(struct iio_dev *indio_dev,
 270                                  const struct iio_chan_spec *chan,
 271                                  enum iio_event_type type,
 272                                  enum iio_event_direction dir, int state)
 273 {
 274         struct sx_common_data *data = iio_priv(indio_dev);
 275         unsigned int eventirq = SX_COMMON_FAR_IRQ | SX_COMMON_CLOSE_IRQ;
 276         int ret;
 277
 278         /* If the state hasn't changed, there's nothing to do. */
 279         if (!!(data->chan_event & BIT(chan->channel)) == state)
 280                 return 0;
 281
 282         mutex_lock(&data->mutex);
 283         if (state) {
 284                 ret = sx_common_get_event_channel(data, chan->channel);
 285                 if (ret)
 286                         goto out_unlock;
 287                 if (!(data->chan_event & ~BIT(chan->channel))) {
 288                         ret = sx_common_enable_irq(data, eventirq);
 289                         if (ret)
 290                                 sx_common_put_event_channel(data, chan->channel);
 291                 }
 292         } else {
 293                 ret = sx_common_put_event_channel(data, chan->channel);
 294                 if (ret)
 295                         goto out_unlock;
 296                 if (!data->chan_event) {
 297                         ret = sx_common_disable_irq(data, eventirq);
 298                         if (ret)
 299                                 sx_common_get_event_channel(data, chan->channel);
 300                 }
 301         }
 302
 303 out_unlock:
 304         mutex_unlock(&data->mutex);
 305         return ret;
 306 }
 307 EXPORT_SYMBOL_NS_GPL(sx_common_write_event_config, SEMTECH_PROX);
 308
 309 static int sx_common_set_trigger_state(struct iio_trigger *trig, bool state)
 310 {
 311         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 312         struct sx_common_data *data = iio_priv(indio_dev);
 313         int ret = 0;
 314
 315         mutex_lock(&data->mutex);
 316
 317         if (state)
 318                 ret = sx_common_enable_irq(data, SX_COMMON_CONVDONE_IRQ);
 319         else if (!data->chan_read)
 320                 ret = sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ);
 321         if (ret)
 322                 goto out;
 323
 324         data->trigger_enabled = state;
 325
 326 out:
 327         mutex_unlock(&data->mutex);
 328
 329         return ret;
 330 }
 331
 332 static const struct iio_trigger_ops sx_common_trigger_ops = {
 333         .set_trigger_state = sx_common_set_trigger_state,
 334 };
 335
 336 static irqreturn_t sx_common_irq_thread_handler(int irq, void *private)
 337 {
 338         struct iio_dev *indio_dev = private;
 339         struct sx_common_data *data = iio_priv(indio_dev);
 340         int ret;
 341         unsigned int val;
 342
 343         mutex_lock(&data->mutex);
 344
 345         ret = regmap_read(data->regmap, SX_COMMON_REG_IRQ_SRC, &val);
 346         if (ret) {
 347                 dev_err(&data->client->dev, "i2c transfer error in irq\n");
 348                 goto out;
 349         }
 350
 351         if (val & ((SX_COMMON_FAR_IRQ | SX_COMMON_CLOSE_IRQ) << data->chip_info->irq_msk_offset))
 352                 sx_common_push_events(indio_dev);
 353
 354         if (val & (SX_COMMON_CONVDONE_IRQ << data->chip_info->irq_msk_offset))
 355                 complete(&data->completion);
 356
 357 out:
 358         mutex_unlock(&data->mutex);
 359
 360         return IRQ_HANDLED;
 361 }
 362
 363 static irqreturn_t sx_common_trigger_handler(int irq, void *private)
 364 {
 365         struct iio_poll_func *pf = private;
 366         struct iio_dev *indio_dev = pf->indio_dev;
 367         struct sx_common_data *data = iio_priv(indio_dev);
 368         __be16 val;
 369         int bit, ret, i = 0;
 370
 371         mutex_lock(&data->mutex);
 372
 373         for_each_set_bit(bit, indio_dev->active_scan_mask,
 374                          indio_dev->masklength) {
 375                 ret = data->chip_info->ops.read_prox_data(data,
 376                                                      &indio_dev->channels[bit],
 377                                                      &val);
 378                 if (ret)
 379                         goto out;
 380
 381                 data->buffer.channels[i++] = val;
 382         }
 383
 384         iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer,
 385                                            pf->timestamp);
 386
 387 out:
 388         mutex_unlock(&data->mutex);
 389
 390         iio_trigger_notify_done(indio_dev->trig);
 391
 392         return IRQ_HANDLED;
 393 }
 394
 395 static int sx_common_buffer_preenable(struct iio_dev *indio_dev)
 396 {
 397         struct sx_common_data *data = iio_priv(indio_dev);
 398         unsigned long channels = 0;
 399         int bit, ret;
 400
 401         mutex_lock(&data->mutex);
 402         for_each_set_bit(bit, indio_dev->active_scan_mask,
 403                          indio_dev->masklength)
 404                 __set_bit(indio_dev->channels[bit].channel, &channels);
 405
 406         ret = sx_common_update_chan_en(data, channels, data->chan_event);
 407         mutex_unlock(&data->mutex);
 408         return ret;
 409 }
 410
 411 static int sx_common_buffer_postdisable(struct iio_dev *indio_dev)
 412 {
 413         struct sx_common_data *data = iio_priv(indio_dev);
 414         int ret;
 415
 416         mutex_lock(&data->mutex);
 417         ret = sx_common_update_chan_en(data, 0, data->chan_event);
 418         mutex_unlock(&data->mutex);
 419         return ret;
 420 }
 421
 422 static const struct iio_buffer_setup_ops sx_common_buffer_setup_ops = {
 423         .preenable = sx_common_buffer_preenable,
 424         .postdisable = sx_common_buffer_postdisable,
 425 };
 426
 427 static void sx_common_regulator_disable(void *_data)
 428 {
 429         struct sx_common_data *data = _data;
 430
 431         regulator_bulk_disable(ARRAY_SIZE(data->supplies), data->supplies);
 432 }
 433
 434 #define SX_COMMON_SOFT_RESET                            0xde
 435
 436 static int sx_common_init_device(struct device *dev, struct iio_dev *indio_dev)
 437 {
 438         struct sx_common_data *data = iio_priv(indio_dev);
 439         struct sx_common_reg_default tmp;
 440         const struct sx_common_reg_default *initval;
 441         int ret;
 442         unsigned int i, val;
 443
 444         ret = regmap_write(data->regmap, data->chip_info->reg_reset,
 445                            SX_COMMON_SOFT_RESET);
 446         if (ret)
 447                 return ret;
 448
 449         usleep_range(1000, 2000); /* power-up time is ~1ms. */
 450
 451         /* Clear reset interrupt state by reading SX_COMMON_REG_IRQ_SRC. */
 452         ret = regmap_read(data->regmap, SX_COMMON_REG_IRQ_SRC, &val);
 453         if (ret)
 454                 return ret;
 455
 456         /* Program defaults from constant or BIOS. */
 457         for (i = 0; i < data->chip_info->num_default_regs; i++) {
 458                 initval = data->chip_info->ops.get_default_reg(dev, i, &tmp);
 459                 ret = regmap_write(data->regmap, initval->reg, initval->def);
 460                 if (ret)
 461                         return ret;
 462         }
 463
 464         return data->chip_info->ops.init_compensation(indio_dev);
 465 }
 466
 467 /**
 468  * sx_common_probe() - Common setup for Semtech SAR sensor
 469  * @client:             I2C client object
 470  * @chip_info:          Semtech sensor chip information.
 471  * @regmap_config:      Sensor registers map configuration.
 472  */
 473 int sx_common_probe(struct i2c_client *client,
 474                     const struct sx_common_chip_info *chip_info,
 475                     const struct regmap_config *regmap_config)
 476 {
 477         struct device *dev = &client->dev;
 478         struct iio_dev *indio_dev;
 479         struct sx_common_data *data;
 480         int ret;
 481
 482         indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 483         if (!indio_dev)
 484                 return -ENOMEM;
 485
 486         data = iio_priv(indio_dev);
 487
 488         data->chip_info = chip_info;
 489         data->client = client;
 490         data->supplies[0].supply = "vdd";
 491         data->supplies[1].supply = "svdd";
 492         mutex_init(&data->mutex);
 493         init_completion(&data->completion);
 494
 495         data->regmap = devm_regmap_init_i2c(client, regmap_config);
 496         if (IS_ERR(data->regmap))
 497                 return dev_err_probe(dev, PTR_ERR(data->regmap),
 498                                      "Could init register map\n");
 499
 500         ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(data->supplies),
 501                                       data->supplies);
 502         if (ret)
 503                 return dev_err_probe(dev, ret, "Unable to get regulators\n");
 504
 505         ret = regulator_bulk_enable(ARRAY_SIZE(data->supplies), data->supplies);
 506         if (ret)
 507                 return dev_err_probe(dev, ret, "Unable to enable regulators\n");
 508
 509         /* Must wait for Tpor time after initial power up */
 510         usleep_range(1000, 1100);
 511
 512         ret = devm_add_action_or_reset(dev, sx_common_regulator_disable, data);
 513         if (ret)
 514                 return dev_err_probe(dev, ret,
 515                                      "Unable to register regulators deleter\n");
 516
 517         ret = data->chip_info->ops.check_whoami(dev, indio_dev);
 518         if (ret)
 519                 return dev_err_probe(dev, ret, "error reading WHOAMI\n");
 520
 521         indio_dev->modes = INDIO_DIRECT_MODE;
 522
 523         indio_dev->channels =  data->chip_info->iio_channels;
 524         indio_dev->num_channels = data->chip_info->num_iio_channels;
 525         indio_dev->info = &data->chip_info->iio_info;
 526
 527         i2c_set_clientdata(client, indio_dev);
 528
 529         ret = sx_common_init_device(dev, indio_dev);
 530         if (ret)
 531                 return dev_err_probe(dev, ret, "Unable to initialize sensor\n");
 532
 533         if (client->irq) {
 534                 ret = devm_request_threaded_irq(dev, client->irq,
 535                                                 sx_common_irq_handler,
 536                                                 sx_common_irq_thread_handler,
 537                                                 IRQF_ONESHOT,
 538                                                 "sx_event", indio_dev);
 539                 if (ret)
 540                         return dev_err_probe(dev, ret, "No IRQ\n");
 541
 542                 data->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
 543                                                     indio_dev->name,
 544                                                     iio_device_id(indio_dev));
 545                 if (!data->trig)
 546                         return -ENOMEM;
 547
 548                 data->trig->ops = &sx_common_trigger_ops;
 549                 iio_trigger_set_drvdata(data->trig, indio_dev);
 550
 551                 ret = devm_iio_trigger_register(dev, data->trig);
 552                 if (ret)
 553                         return ret;
 554         }
 555
 556         ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
 557                                               iio_pollfunc_store_time,
 558                                               sx_common_trigger_handler,
 559                                               &sx_common_buffer_setup_ops);
 560         if (ret)
 561                 return ret;
 562
 563         return devm_iio_device_register(dev, indio_dev);
 564 }
 565 EXPORT_SYMBOL_NS_GPL(sx_common_probe, SEMTECH_PROX);
 566
 567 MODULE_AUTHOR("Gwendal Grignou <[email protected]>");
 568 MODULE_DESCRIPTION("Common functions and structures for Semtech sensor");
 569 MODULE_LICENSE("GPL v2");