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/acpi.h>
   9 #include <linux/bitops.h>
  10 #include <linux/byteorder/generic.h>
  11 #include <linux/delay.h>
  12 #include <linux/device.h>
  13 #include <linux/err.h>
  14 #include <linux/export.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irqreturn.h>
  17 #include <linux/i2c.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/regmap.h>
  21 #include <linux/regulator/consumer.h>
  22 #include <vdso/bits.h>
  23
  24 #include <linux/iio/buffer.h>
  25 #include <linux/iio/events.h>
  26 #include <linux/iio/iio.h>
  27 #include <linux/iio/trigger.h>
  28 #include <linux/iio/triggered_buffer.h>
  29 #include <linux/iio/trigger_consumer.h>
  30
  31 #include "sx_common.h"
  32
  33 /* All Semtech SAR sensors have IRQ bit in the same order. */
  34 #define   SX_COMMON_CONVDONE_IRQ                        BIT(0)
  35 #define   SX_COMMON_FAR_IRQ                             BIT(2)
  36 #define   SX_COMMON_CLOSE_IRQ                           BIT(3)
  37
  38 const struct iio_event_spec sx_common_events[3] = {
  39         {
  40                 .type = IIO_EV_TYPE_THRESH,
  41                 .dir = IIO_EV_DIR_RISING,
  42                 .mask_shared_by_all = BIT(IIO_EV_INFO_PERIOD),
  43         },
  44         {
  45                 .type = IIO_EV_TYPE_THRESH,
  46                 .dir = IIO_EV_DIR_FALLING,
  47                 .mask_shared_by_all = BIT(IIO_EV_INFO_PERIOD),
  48         },
  49         {
  50                 .type = IIO_EV_TYPE_THRESH,
  51                 .dir = IIO_EV_DIR_EITHER,
  52                 .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
  53                                  BIT(IIO_EV_INFO_HYSTERESIS) |
  54                                  BIT(IIO_EV_INFO_VALUE),
  55         },
  56 };
  57 EXPORT_SYMBOL_NS_GPL(sx_common_events, SEMTECH_PROX);
  58
  59 static irqreturn_t sx_common_irq_handler(int irq, void *private)
  60 {
  61         struct iio_dev *indio_dev = private;
  62         struct sx_common_data *data = iio_priv(indio_dev);
  63
  64         if (data->trigger_enabled)
  65                 iio_trigger_poll(data->trig);
  66
  67         /*
  68          * Even if no event is enabled, we need to wake the thread to clear the
  69          * interrupt state by reading SX_COMMON_REG_IRQ_SRC.
  70          * It is not possible to do that here because regmap_read takes a mutex.
  71          */
  72         return IRQ_WAKE_THREAD;
  73 }
  74
  75 static void sx_common_push_events(struct iio_dev *indio_dev)
  76 {
  77         int ret;
  78         unsigned int val, chan;
  79         struct sx_common_data *data = iio_priv(indio_dev);
  80         s64 timestamp = iio_get_time_ns(indio_dev);
  81         unsigned long prox_changed;
  82
  83         /* Read proximity state on all channels */
  84         ret = regmap_read(data->regmap, data->chip_info->reg_stat, &val);
  85         if (ret) {
  86                 dev_err(&data->client->dev, "i2c transfer error in irq\n");
  87                 return;
  88         }
  89
  90         val >>= data->chip_info->stat_offset;
  91
  92         /*
  93          * Only iterate over channels with changes on proximity status that have
  94          * events enabled.
  95          */
  96         prox_changed = (data->chan_prox_stat ^ val) & data->chan_event;
  97
  98         for_each_set_bit(chan, &prox_changed, data->chip_info->num_channels) {
  99                 int dir;
 100                 u64 ev;
 101
 102                 dir = (val & BIT(chan)) ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
 103                 ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan,
 104                                           IIO_EV_TYPE_THRESH, dir);
 105
 106                 iio_push_event(indio_dev, ev, timestamp);
 107         }
 108         data->chan_prox_stat = val;
 109 }
 110
 111 static int sx_common_enable_irq(struct sx_common_data *data, unsigned int irq)
 112 {
 113         if (!data->client->irq)
 114                 return 0;
 115         return regmap_update_bits(data->regmap, data->chip_info->reg_irq_msk,
 116                                   irq << data->chip_info->irq_msk_offset,
 117                                   irq << data->chip_info->irq_msk_offset);
 118 }
 119
 120 static int sx_common_disable_irq(struct sx_common_data *data, unsigned int irq)
 121 {
 122         if (!data->client->irq)
 123                 return 0;
 124         return regmap_update_bits(data->regmap, data->chip_info->reg_irq_msk,
 125                                   irq << data->chip_info->irq_msk_offset, 0);
 126 }
 127
 128 static int sx_common_update_chan_en(struct sx_common_data *data,
 129                                     unsigned long chan_read,
 130                                     unsigned long chan_event)
 131 {
 132         int ret;
 133         unsigned long channels = chan_read | chan_event;
 134
 135         if ((data->chan_read | data->chan_event) != channels) {
 136                 ret = regmap_update_bits(data->regmap,
 137                                          data->chip_info->reg_enable_chan,
 138                                          data->chip_info->mask_enable_chan,
 139                                          channels);
 140                 if (ret)
 141                         return ret;
 142         }
 143         data->chan_read = chan_read;
 144         data->chan_event = chan_event;
 145         return 0;
 146 }
 147
 148 static int sx_common_get_read_channel(struct sx_common_data *data, int channel)
 149 {
 150         return sx_common_update_chan_en(data, data->chan_read | BIT(channel),
 151                                      data->chan_event);
 152 }
 153
 154 static int sx_common_put_read_channel(struct sx_common_data *data, int channel)
 155 {
 156         return sx_common_update_chan_en(data, data->chan_read & ~BIT(channel),
 157                                      data->chan_event);
 158 }
 159
 160 static int sx_common_get_event_channel(struct sx_common_data *data, int channel)
 161 {
 162         return sx_common_update_chan_en(data, data->chan_read,
 163                                      data->chan_event | BIT(channel));
 164 }
 165
 166 static int sx_common_put_event_channel(struct sx_common_data *data, int channel)
 167 {
 168         return sx_common_update_chan_en(data, data->chan_read,
 169                                      data->chan_event & ~BIT(channel));
 170 }
 171
 172 /**
 173  * sx_common_read_proximity() - Read raw proximity value.
 174  * @data:       Internal data
 175  * @chan:       Channel to read
 176  * @val:        pointer to return read value.
 177  *
 178  * Request a conversion, wait for the sensor to be ready and
 179  * return the raw proximity value.
 180  */
 181 int sx_common_read_proximity(struct sx_common_data *data,
 182                              const struct iio_chan_spec *chan, int *val)
 183 {
 184         int ret;
 185         __be16 rawval;
 186
 187         mutex_lock(&data->mutex);
 188
 189         ret = sx_common_get_read_channel(data, chan->channel);
 190         if (ret)
 191                 goto out;
 192
 193         ret = sx_common_enable_irq(data, SX_COMMON_CONVDONE_IRQ);
 194         if (ret)
 195                 goto out_put_channel;
 196
 197         mutex_unlock(&data->mutex);
 198
 199         if (data->client->irq) {
 200                 ret = wait_for_completion_interruptible(&data->completion);
 201                 reinit_completion(&data->completion);
 202         } else {
 203                 ret = data->chip_info->ops.wait_for_sample(data);
 204         }
 205
 206         mutex_lock(&data->mutex);
 207
 208         if (ret)
 209                 goto out_disable_irq;
 210
 211         ret = data->chip_info->ops.read_prox_data(data, chan, &rawval);
 212         if (ret)
 213                 goto out_disable_irq;
 214
 215         *val = sign_extend32(be16_to_cpu(rawval), chan->scan_type.realbits - 1);
 216
 217         ret = sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ);
 218         if (ret)
 219                 goto out_put_channel;
 220
 221         ret = sx_common_put_read_channel(data, chan->channel);
 222         if (ret)
 223                 goto out;
 224
 225         mutex_unlock(&data->mutex);
 226
 227         return IIO_VAL_INT;
 228
 229 out_disable_irq:
 230         sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ);
 231 out_put_channel:
 232         sx_common_put_read_channel(data, chan->channel);
 233 out:
 234         mutex_unlock(&data->mutex);
 235
 236         return ret;
 237 }
 238 EXPORT_SYMBOL_NS_GPL(sx_common_read_proximity, SEMTECH_PROX);
 239
 240 /**
 241  * sx_common_read_event_config() - Configure event setting.
 242  * @indio_dev:  iio device object
 243  * @chan:       Channel to read
 244  * @type:       Type of event (unused)
 245  * @dir:        Direction of event (unused)
 246  *
 247  * return if the given channel is used for event gathering.
 248  */
 249 int sx_common_read_event_config(struct iio_dev *indio_dev,
 250                                 const struct iio_chan_spec *chan,
 251                                 enum iio_event_type type,
 252                                 enum iio_event_direction dir)
 253 {
 254         struct sx_common_data *data = iio_priv(indio_dev);
 255
 256         return !!(data->chan_event & BIT(chan->channel));
 257 }
 258 EXPORT_SYMBOL_NS_GPL(sx_common_read_event_config, SEMTECH_PROX);
 259
 260 /**
 261  * sx_common_write_event_config() - Configure event setting.
 262  * @indio_dev:  iio device object
 263  * @chan:       Channel to enable
 264  * @type:       Type of event (unused)
 265  * @dir:        Direction of event (unused)
 266  * @state:      State of the event.
 267  *
 268  * Enable/Disable event on a given channel.
 269  */
 270 int sx_common_write_event_config(struct iio_dev *indio_dev,
 271                                  const struct iio_chan_spec *chan,
 272                                  enum iio_event_type type,
 273                                  enum iio_event_direction dir, int state)
 274 {
 275         struct sx_common_data *data = iio_priv(indio_dev);
 276         unsigned int eventirq = SX_COMMON_FAR_IRQ | SX_COMMON_CLOSE_IRQ;
 277         int ret;
 278
 279         /* If the state hasn't changed, there's nothing to do. */
 280         if (!!(data->chan_event & BIT(chan->channel)) == state)
 281                 return 0;
 282
 283         mutex_lock(&data->mutex);
 284         if (state) {
 285                 ret = sx_common_get_event_channel(data, chan->channel);
 286                 if (ret)
 287                         goto out_unlock;
 288                 if (!(data->chan_event & ~BIT(chan->channel))) {
 289                         ret = sx_common_enable_irq(data, eventirq);
 290                         if (ret)
 291                                 sx_common_put_event_channel(data, chan->channel);
 292                 }
 293         } else {
 294                 ret = sx_common_put_event_channel(data, chan->channel);
 295                 if (ret)
 296                         goto out_unlock;
 297                 if (!data->chan_event) {
 298                         ret = sx_common_disable_irq(data, eventirq);
 299                         if (ret)
 300                                 sx_common_get_event_channel(data, chan->channel);
 301                 }
 302         }
 303
 304 out_unlock:
 305         mutex_unlock(&data->mutex);
 306         return ret;
 307 }
 308 EXPORT_SYMBOL_NS_GPL(sx_common_write_event_config, SEMTECH_PROX);
 309
 310 static int sx_common_set_trigger_state(struct iio_trigger *trig, bool state)
 311 {
 312         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 313         struct sx_common_data *data = iio_priv(indio_dev);
 314         int ret = 0;
 315
 316         mutex_lock(&data->mutex);
 317
 318         if (state)
 319                 ret = sx_common_enable_irq(data, SX_COMMON_CONVDONE_IRQ);
 320         else if (!data->chan_read)
 321                 ret = sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ);
 322         if (ret)
 323                 goto out;
 324
 325         data->trigger_enabled = state;
 326
 327 out:
 328         mutex_unlock(&data->mutex);
 329
 330         return ret;
 331 }
 332
 333 static const struct iio_trigger_ops sx_common_trigger_ops = {
 334         .set_trigger_state = sx_common_set_trigger_state,
 335 };
 336
 337 static irqreturn_t sx_common_irq_thread_handler(int irq, void *private)
 338 {
 339         struct iio_dev *indio_dev = private;
 340         struct sx_common_data *data = iio_priv(indio_dev);
 341         int ret;
 342         unsigned int val;
 343
 344         mutex_lock(&data->mutex);
 345
 346         ret = regmap_read(data->regmap, SX_COMMON_REG_IRQ_SRC, &val);
 347         if (ret) {
 348                 dev_err(&data->client->dev, "i2c transfer error in irq\n");
 349                 goto out;
 350         }
 351
 352         if (val & ((SX_COMMON_FAR_IRQ | SX_COMMON_CLOSE_IRQ) << data->chip_info->irq_msk_offset))
 353                 sx_common_push_events(indio_dev);
 354
 355         if (val & (SX_COMMON_CONVDONE_IRQ << data->chip_info->irq_msk_offset))
 356                 complete(&data->completion);
 357
 358 out:
 359         mutex_unlock(&data->mutex);
 360
 361         return IRQ_HANDLED;
 362 }
 363
 364 static irqreturn_t sx_common_trigger_handler(int irq, void *private)
 365 {
 366         struct iio_poll_func *pf = private;
 367         struct iio_dev *indio_dev = pf->indio_dev;
 368         struct sx_common_data *data = iio_priv(indio_dev);
 369         __be16 val;
 370         int bit, ret, i = 0;
 371
 372         mutex_lock(&data->mutex);
 373
 374         for_each_set_bit(bit, indio_dev->active_scan_mask,
 375                          indio_dev->masklength) {
 376                 ret = data->chip_info->ops.read_prox_data(data,
 377                                                      &indio_dev->channels[bit],
 378                                                      &val);
 379                 if (ret)
 380                         goto out;
 381
 382                 data->buffer.channels[i++] = val;
 383         }
 384
 385         iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer,
 386                                            pf->timestamp);
 387
 388 out:
 389         mutex_unlock(&data->mutex);
 390
 391         iio_trigger_notify_done(indio_dev->trig);
 392
 393         return IRQ_HANDLED;
 394 }
 395
 396 static int sx_common_buffer_preenable(struct iio_dev *indio_dev)
 397 {
 398         struct sx_common_data *data = iio_priv(indio_dev);
 399         unsigned long channels = 0;
 400         int bit, ret;
 401
 402         mutex_lock(&data->mutex);
 403         for_each_set_bit(bit, indio_dev->active_scan_mask,
 404                          indio_dev->masklength)
 405                 __set_bit(indio_dev->channels[bit].channel, &channels);
 406
 407         ret = sx_common_update_chan_en(data, channels, data->chan_event);
 408         mutex_unlock(&data->mutex);
 409         return ret;
 410 }
 411
 412 static int sx_common_buffer_postdisable(struct iio_dev *indio_dev)
 413 {
 414         struct sx_common_data *data = iio_priv(indio_dev);
 415         int ret;
 416
 417         mutex_lock(&data->mutex);
 418         ret = sx_common_update_chan_en(data, 0, data->chan_event);
 419         mutex_unlock(&data->mutex);
 420         return ret;
 421 }
 422
 423 static const struct iio_buffer_setup_ops sx_common_buffer_setup_ops = {
 424         .preenable = sx_common_buffer_preenable,
 425         .postdisable = sx_common_buffer_postdisable,
 426 };
 427
 428 static void sx_common_regulator_disable(void *_data)
 429 {
 430         struct sx_common_data *data = _data;
 431
 432         regulator_bulk_disable(ARRAY_SIZE(data->supplies), data->supplies);
 433 }
 434
 435 #define SX_COMMON_SOFT_RESET                            0xde
 436
 437 static int sx_common_init_device(struct iio_dev *indio_dev)
 438 {
 439         struct sx_common_data *data = iio_priv(indio_dev);
 440         struct sx_common_reg_default tmp;
 441         const struct sx_common_reg_default *initval;
 442         int ret;
 443         unsigned int i, val;
 444
 445         ret = regmap_write(data->regmap, data->chip_info->reg_reset,
 446                            SX_COMMON_SOFT_RESET);
 447         if (ret)
 448                 return ret;
 449
 450         usleep_range(1000, 2000); /* power-up time is ~1ms. */
 451
 452         /* Clear reset interrupt state by reading SX_COMMON_REG_IRQ_SRC. */
 453         ret = regmap_read(data->regmap, SX_COMMON_REG_IRQ_SRC, &val);
 454         if (ret)
 455                 return ret;
 456
 457         /* Program defaults from constant or BIOS. */
 458         for (i = 0; i < data->chip_info->num_default_regs; i++) {
 459                 initval = data->chip_info->ops.get_default_reg(&indio_dev->dev,
 460                                                                i, &tmp);
 461                 ret = regmap_write(data->regmap, initval->reg, initval->def);
 462                 if (ret)
 463                         return ret;
 464         }
 465
 466         return data->chip_info->ops.init_compensation(indio_dev);
 467 }
 468
 469 /**
 470  * sx_common_probe() - Common setup for Semtech SAR sensor
 471  * @client:             I2C client object
 472  * @chip_info:          Semtech sensor chip information.
 473  * @regmap_config:      Sensor registers map configuration.
 474  */
 475 int sx_common_probe(struct i2c_client *client,
 476                     const struct sx_common_chip_info *chip_info,
 477                     const struct regmap_config *regmap_config)
 478 {
 479         struct device *dev = &client->dev;
 480         struct iio_dev *indio_dev;
 481         struct sx_common_data *data;
 482         int ret;
 483
 484         indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 485         if (!indio_dev)
 486                 return -ENOMEM;
 487
 488         data = iio_priv(indio_dev);
 489
 490         data->chip_info = chip_info;
 491         data->client = client;
 492         data->supplies[0].supply = "vdd";
 493         data->supplies[1].supply = "svdd";
 494         mutex_init(&data->mutex);
 495         init_completion(&data->completion);
 496
 497         data->regmap = devm_regmap_init_i2c(client, regmap_config);
 498         if (IS_ERR(data->regmap))
 499                 return dev_err_probe(dev, PTR_ERR(data->regmap),
 500                                      "Could init register map\n");
 501
 502         ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(data->supplies),
 503                                       data->supplies);
 504         if (ret)
 505                 return dev_err_probe(dev, ret, "Unable to get regulators\n");
 506
 507         ret = regulator_bulk_enable(ARRAY_SIZE(data->supplies), data->supplies);
 508         if (ret)
 509                 return dev_err_probe(dev, ret, "Unable to enable regulators\n");
 510
 511         /* Must wait for Tpor time after initial power up */
 512         usleep_range(1000, 1100);
 513
 514         ret = devm_add_action_or_reset(dev, sx_common_regulator_disable, data);
 515         if (ret)
 516                 return dev_err_probe(dev, ret,
 517                                      "Unable to register regulators deleter\n");
 518
 519         ret = data->chip_info->ops.check_whoami(dev, indio_dev);
 520         if (ret)
 521                 return dev_err_probe(dev, ret, "error reading WHOAMI\n");
 522
 523         ACPI_COMPANION_SET(&indio_dev->dev, ACPI_COMPANION(dev));
 524         indio_dev->dev.of_node = client->dev.of_node;
 525         indio_dev->modes = INDIO_DIRECT_MODE;
 526
 527         indio_dev->channels =  data->chip_info->iio_channels;
 528         indio_dev->num_channels = data->chip_info->num_iio_channels;
 529         indio_dev->info = &data->chip_info->iio_info;
 530
 531         i2c_set_clientdata(client, indio_dev);
 532
 533         ret = sx_common_init_device(indio_dev);
 534         if (ret)
 535                 return dev_err_probe(dev, ret, "Unable to initialize sensor\n");
 536
 537         if (client->irq) {
 538                 ret = devm_request_threaded_irq(dev, client->irq,
 539                                                 sx_common_irq_handler,
 540                                                 sx_common_irq_thread_handler,
 541                                                 IRQF_ONESHOT,
 542                                                 "sx_event", indio_dev);
 543                 if (ret)
 544                         return dev_err_probe(dev, ret, "No IRQ\n");
 545
 546                 data->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
 547                                                     indio_dev->name,
 548                                                     iio_device_id(indio_dev));
 549                 if (!data->trig)
 550                         return -ENOMEM;
 551
 552                 data->trig->ops = &sx_common_trigger_ops;
 553                 iio_trigger_set_drvdata(data->trig, indio_dev);
 554
 555                 ret = devm_iio_trigger_register(dev, data->trig);
 556                 if (ret)
 557                         return ret;
 558         }
 559
 560         ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
 561                                               iio_pollfunc_store_time,
 562                                               sx_common_trigger_handler,
 563                                               &sx_common_buffer_setup_ops);
 564         if (ret)
 565                 return ret;
 566
 567         return devm_iio_device_register(dev, indio_dev);
 568 }
 569 EXPORT_SYMBOL_NS_GPL(sx_common_probe, SEMTECH_PROX);
 570
 571 MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
 572 MODULE_DESCRIPTION("Common functions and structures for Semtech sensor");
 573 MODULE_LICENSE("GPL v2");