drivers/input/touchscreen/pixcir_i2c_ts.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for Pixcir I2C touchscreen controllers.
   4  *
   5  * Copyright (C) 2010-2011 Pixcir, Inc.
   6  */
   7
   8 #include <asm/unaligned.h>
   9 #include <linux/delay.h>
  10 #include <linux/gpio/consumer.h>
  11 #include <linux/i2c.h>
  12 #include <linux/input.h>
  13 #include <linux/input/mt.h>
  14 #include <linux/input/touchscreen.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/of_device.h>
  17 #include <linux/module.h>
  18 #include <linux/slab.h>
  19
  20 #define PIXCIR_MAX_SLOTS       5 /* Max fingers supported by driver */
  21
  22 /*
  23  * Register map
  24  */
  25 #define PIXCIR_REG_POWER_MODE   51
  26 #define PIXCIR_REG_INT_MODE     52
  27
  28 /*
  29  * Power modes:
  30  * active: max scan speed
  31  * idle: lower scan speed with automatic transition to active on touch
  32  * halt: datasheet says sleep but this is more like halt as the chip
  33  *       clocks are cut and it can only be brought out of this mode
  34  *       using the RESET pin.
  35  */
  36 enum pixcir_power_mode {
  37         PIXCIR_POWER_ACTIVE,
  38         PIXCIR_POWER_IDLE,
  39         PIXCIR_POWER_HALT,
  40 };
  41
  42 #define PIXCIR_POWER_MODE_MASK  0x03
  43 #define PIXCIR_POWER_ALLOW_IDLE (1UL << 2)
  44
  45 /*
  46  * Interrupt modes:
  47  * periodical: interrupt is asserted periodicaly
  48  * diff coordinates: interrupt is asserted when coordinates change
  49  * level on touch: interrupt level asserted during touch
  50  * pulse on touch: interrupt pulse asserted during touch
  51  *
  52  */
  53 enum pixcir_int_mode {
  54         PIXCIR_INT_PERIODICAL,
  55         PIXCIR_INT_DIFF_COORD,
  56         PIXCIR_INT_LEVEL_TOUCH,
  57         PIXCIR_INT_PULSE_TOUCH,
  58 };
  59
  60 #define PIXCIR_INT_MODE_MASK    0x03
  61 #define PIXCIR_INT_ENABLE       (1UL << 3)
  62 #define PIXCIR_INT_POL_HIGH     (1UL << 2)
  63
  64 /**
  65  * struct pixcir_i2c_chip_data - chip related data
  66  * @max_fingers:        Max number of fingers reported simultaneously by h/w
  67  * @has_hw_ids:         Hardware supports finger tracking IDs
  68  *
  69  */
  70 struct pixcir_i2c_chip_data {
  71         u8 max_fingers;
  72         bool has_hw_ids;
  73 };
  74
  75 struct pixcir_i2c_ts_data {
  76         struct i2c_client *client;
  77         struct input_dev *input;
  78         struct gpio_desc *gpio_attb;
  79         struct gpio_desc *gpio_reset;
  80         struct gpio_desc *gpio_enable;
  81         struct gpio_desc *gpio_wake;
  82         const struct pixcir_i2c_chip_data *chip;
  83         struct touchscreen_properties prop;
  84         bool running;
  85 };
  86
  87 struct pixcir_report_data {
  88         int num_touches;
  89         struct input_mt_pos pos[PIXCIR_MAX_SLOTS];
  90         int ids[PIXCIR_MAX_SLOTS];
  91 };
  92
  93 static void pixcir_ts_parse(struct pixcir_i2c_ts_data *tsdata,
  94                             struct pixcir_report_data *report)
  95 {
  96         u8 rdbuf[2 + PIXCIR_MAX_SLOTS * 5];
  97         u8 wrbuf[1] = { 0 };
  98         u8 *bufptr;
  99         u8 touch;
 100         int ret, i;
 101         int readsize;
 102         const struct pixcir_i2c_chip_data *chip = tsdata->chip;
 103
 104         memset(report, 0, sizeof(struct pixcir_report_data));
 105
 106         i = chip->has_hw_ids ? 1 : 0;
 107         readsize = 2 + tsdata->chip->max_fingers * (4 + i);
 108         if (readsize > sizeof(rdbuf))
 109                 readsize = sizeof(rdbuf);
 110
 111         ret = i2c_master_send(tsdata->client, wrbuf, sizeof(wrbuf));
 112         if (ret != sizeof(wrbuf)) {
 113                 dev_err(&tsdata->client->dev,
 114                         "%s: i2c_master_send failed(), ret=%d\n",
 115                         __func__, ret);
 116                 return;
 117         }
 118
 119         ret = i2c_master_recv(tsdata->client, rdbuf, readsize);
 120         if (ret != readsize) {
 121                 dev_err(&tsdata->client->dev,
 122                         "%s: i2c_master_recv failed(), ret=%d\n",
 123                         __func__, ret);
 124                 return;
 125         }
 126
 127         touch = rdbuf[0] & 0x7;
 128         if (touch > tsdata->chip->max_fingers)
 129                 touch = tsdata->chip->max_fingers;
 130
 131         report->num_touches = touch;
 132         bufptr = &rdbuf[2];
 133
 134         for (i = 0; i < touch; i++) {
 135                 touchscreen_set_mt_pos(&report->pos[i], &tsdata->prop,
 136                                        get_unaligned_le16(bufptr),
 137                                        get_unaligned_le16(bufptr + 2));
 138                 if (chip->has_hw_ids) {
 139                         report->ids[i] = bufptr[4];
 140                         bufptr = bufptr + 5;
 141                 } else {
 142                         bufptr = bufptr + 4;
 143                 }
 144         }
 145 }
 146
 147 static void pixcir_ts_report(struct pixcir_i2c_ts_data *ts,
 148                              struct pixcir_report_data *report)
 149 {
 150         int slots[PIXCIR_MAX_SLOTS];
 151         int n, i, slot;
 152         struct device *dev = &ts->client->dev;
 153         const struct pixcir_i2c_chip_data *chip = ts->chip;
 154
 155         n = report->num_touches;
 156         if (n > PIXCIR_MAX_SLOTS)
 157                 n = PIXCIR_MAX_SLOTS;
 158
 159         if (!ts->chip->has_hw_ids)
 160                 input_mt_assign_slots(ts->input, slots, report->pos, n, 0);
 161
 162         for (i = 0; i < n; i++) {
 163                 if (chip->has_hw_ids) {
 164                         slot = input_mt_get_slot_by_key(ts->input,
 165                                                         report->ids[i]);
 166                         if (slot < 0) {
 167                                 dev_dbg(dev, "no free slot for id 0x%x\n",
 168                                         report->ids[i]);
 169                                 continue;
 170                         }
 171                 } else {
 172                         slot = slots[i];
 173                 }
 174
 175                 input_mt_slot(ts->input, slot);
 176                 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
 177
 178                 input_report_abs(ts->input, ABS_MT_POSITION_X,
 179                                  report->pos[i].x);
 180                 input_report_abs(ts->input, ABS_MT_POSITION_Y,
 181                                  report->pos[i].y);
 182
 183                 dev_dbg(dev, "%d: slot %d, x %d, y %d\n",
 184                         i, slot, report->pos[i].x, report->pos[i].y);
 185         }
 186
 187         input_mt_sync_frame(ts->input);
 188         input_sync(ts->input);
 189 }
 190
 191 static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
 192 {
 193         struct pixcir_i2c_ts_data *tsdata = dev_id;
 194         struct pixcir_report_data report;
 195
 196         while (tsdata->running) {
 197                 /* parse packet */
 198                 pixcir_ts_parse(tsdata, &report);
 199
 200                 /* report it */
 201                 pixcir_ts_report(tsdata, &report);
 202
 203                 if (gpiod_get_value_cansleep(tsdata->gpio_attb)) {
 204                         if (report.num_touches) {
 205                                 /*
 206                                  * Last report with no finger up?
 207                                  * Do it now then.
 208                                  */
 209                                 input_mt_sync_frame(tsdata->input);
 210                                 input_sync(tsdata->input);
 211                         }
 212                         break;
 213                 }
 214
 215                 msleep(20);
 216         }
 217
 218         return IRQ_HANDLED;
 219 }
 220
 221 static void pixcir_reset(struct pixcir_i2c_ts_data *tsdata)
 222 {
 223         if (!IS_ERR_OR_NULL(tsdata->gpio_reset)) {
 224                 gpiod_set_value_cansleep(tsdata->gpio_reset, 1);
 225                 ndelay(100);    /* datasheet section 1.2.3 says 80ns min. */
 226                 gpiod_set_value_cansleep(tsdata->gpio_reset, 0);
 227                 /* wait for controller ready. 100ms guess. */
 228                 msleep(100);
 229         }
 230 }
 231
 232 static int pixcir_set_power_mode(struct pixcir_i2c_ts_data *ts,
 233                                  enum pixcir_power_mode mode)
 234 {
 235         struct device *dev = &ts->client->dev;
 236         int ret;
 237
 238         if (mode == PIXCIR_POWER_ACTIVE || mode == PIXCIR_POWER_IDLE) {
 239                 if (ts->gpio_wake)
 240                         gpiod_set_value_cansleep(ts->gpio_wake, 1);
 241         }
 242
 243         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_POWER_MODE);
 244         if (ret < 0) {
 245                 dev_err(dev, "%s: can't read reg %d : %d\n",
 246                         __func__, PIXCIR_REG_POWER_MODE, ret);
 247                 return ret;
 248         }
 249
 250         ret &= ~PIXCIR_POWER_MODE_MASK;
 251         ret |= mode;
 252
 253         /* Always AUTO_IDLE */
 254         ret |= PIXCIR_POWER_ALLOW_IDLE;
 255
 256         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_POWER_MODE, ret);
 257         if (ret < 0) {
 258                 dev_err(dev, "%s: can't write reg %d : %d\n",
 259                         __func__, PIXCIR_REG_POWER_MODE, ret);
 260                 return ret;
 261         }
 262
 263         if (mode == PIXCIR_POWER_HALT) {
 264                 if (ts->gpio_wake)
 265                         gpiod_set_value_cansleep(ts->gpio_wake, 0);
 266         }
 267
 268         return 0;
 269 }
 270
 271 /*
 272  * Set the interrupt mode for the device i.e. ATTB line behaviour
 273  *
 274  * @polarity : 1 for active high, 0 for active low.
 275  */
 276 static int pixcir_set_int_mode(struct pixcir_i2c_ts_data *ts,
 277                                enum pixcir_int_mode mode, bool polarity)
 278 {
 279         struct device *dev = &ts->client->dev;
 280         int ret;
 281
 282         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
 283         if (ret < 0) {
 284                 dev_err(dev, "%s: can't read reg %d : %d\n",
 285                         __func__, PIXCIR_REG_INT_MODE, ret);
 286                 return ret;
 287         }
 288
 289         ret &= ~PIXCIR_INT_MODE_MASK;
 290         ret |= mode;
 291
 292         if (polarity)
 293                 ret |= PIXCIR_INT_POL_HIGH;
 294         else
 295                 ret &= ~PIXCIR_INT_POL_HIGH;
 296
 297         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
 298         if (ret < 0) {
 299                 dev_err(dev, "%s: can't write reg %d : %d\n",
 300                         __func__, PIXCIR_REG_INT_MODE, ret);
 301                 return ret;
 302         }
 303
 304         return 0;
 305 }
 306
 307 /*
 308  * Enable/disable interrupt generation
 309  */
 310 static int pixcir_int_enable(struct pixcir_i2c_ts_data *ts, bool enable)
 311 {
 312         struct device *dev = &ts->client->dev;
 313         int ret;
 314
 315         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
 316         if (ret < 0) {
 317                 dev_err(dev, "%s: can't read reg %d : %d\n",
 318                         __func__, PIXCIR_REG_INT_MODE, ret);
 319                 return ret;
 320         }
 321
 322         if (enable)
 323                 ret |= PIXCIR_INT_ENABLE;
 324         else
 325                 ret &= ~PIXCIR_INT_ENABLE;
 326
 327         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
 328         if (ret < 0) {
 329                 dev_err(dev, "%s: can't write reg %d : %d\n",
 330                         __func__, PIXCIR_REG_INT_MODE, ret);
 331                 return ret;
 332         }
 333
 334         return 0;
 335 }
 336
 337 static int pixcir_start(struct pixcir_i2c_ts_data *ts)
 338 {
 339         struct device *dev = &ts->client->dev;
 340         int error;
 341
 342         if (ts->gpio_enable) {
 343                 gpiod_set_value_cansleep(ts->gpio_enable, 1);
 344                 msleep(100);
 345         }
 346
 347         /* LEVEL_TOUCH interrupt with active low polarity */
 348         error = pixcir_set_int_mode(ts, PIXCIR_INT_LEVEL_TOUCH, 0);
 349         if (error) {
 350                 dev_err(dev, "Failed to set interrupt mode: %d\n", error);
 351                 return error;
 352         }
 353
 354         ts->running = true;
 355         mb();   /* Update status before IRQ can fire */
 356
 357         /* enable interrupt generation */
 358         error = pixcir_int_enable(ts, true);
 359         if (error) {
 360                 dev_err(dev, "Failed to enable interrupt generation: %d\n",
 361                         error);
 362                 return error;
 363         }
 364
 365         return 0;
 366 }
 367
 368 static int pixcir_stop(struct pixcir_i2c_ts_data *ts)
 369 {
 370         int error;
 371
 372         /* Disable interrupt generation */
 373         error = pixcir_int_enable(ts, false);
 374         if (error) {
 375                 dev_err(&ts->client->dev,
 376                         "Failed to disable interrupt generation: %d\n",
 377                         error);
 378                 return error;
 379         }
 380
 381         /* Exit ISR if running, no more report parsing */
 382         ts->running = false;
 383         mb();   /* update status before we synchronize irq */
 384
 385         /* Wait till running ISR is complete */
 386         synchronize_irq(ts->client->irq);
 387
 388         if (ts->gpio_enable)
 389                 gpiod_set_value_cansleep(ts->gpio_enable, 0);
 390
 391         return 0;
 392 }
 393
 394 static int pixcir_input_open(struct input_dev *dev)
 395 {
 396         struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
 397
 398         return pixcir_start(ts);
 399 }
 400
 401 static void pixcir_input_close(struct input_dev *dev)
 402 {
 403         struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
 404
 405         pixcir_stop(ts);
 406 }
 407
 408 static int __maybe_unused pixcir_i2c_ts_suspend(struct device *dev)
 409 {
 410         struct i2c_client *client = to_i2c_client(dev);
 411         struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
 412         struct input_dev *input = ts->input;
 413         int ret = 0;
 414
 415         mutex_lock(&input->mutex);
 416
 417         if (device_may_wakeup(&client->dev)) {
 418                 if (!input_device_enabled(input)) {
 419                         ret = pixcir_start(ts);
 420                         if (ret) {
 421                                 dev_err(dev, "Failed to start\n");
 422                                 goto unlock;
 423                         }
 424                 }
 425         } else if (input_device_enabled(input)) {
 426                 ret = pixcir_stop(ts);
 427         }
 428
 429 unlock:
 430         mutex_unlock(&input->mutex);
 431
 432         return ret;
 433 }
 434
 435 static int __maybe_unused pixcir_i2c_ts_resume(struct device *dev)
 436 {
 437         struct i2c_client *client = to_i2c_client(dev);
 438         struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
 439         struct input_dev *input = ts->input;
 440         int ret = 0;
 441
 442         mutex_lock(&input->mutex);
 443
 444         if (device_may_wakeup(&client->dev)) {
 445                 if (!input_device_enabled(input)) {
 446                         ret = pixcir_stop(ts);
 447                         if (ret) {
 448                                 dev_err(dev, "Failed to stop\n");
 449                                 goto unlock;
 450                         }
 451                 }
 452         } else if (input_device_enabled(input)) {
 453                 ret = pixcir_start(ts);
 454         }
 455
 456 unlock:
 457         mutex_unlock(&input->mutex);
 458
 459         return ret;
 460 }
 461
 462 static SIMPLE_DEV_PM_OPS(pixcir_dev_pm_ops,
 463                          pixcir_i2c_ts_suspend, pixcir_i2c_ts_resume);
 464
 465 static int pixcir_i2c_ts_probe(struct i2c_client *client,
 466                                const struct i2c_device_id *id)
 467 {
 468         struct device *dev = &client->dev;
 469         struct pixcir_i2c_ts_data *tsdata;
 470         struct input_dev *input;
 471         int error;
 472
 473         tsdata = devm_kzalloc(dev, sizeof(*tsdata), GFP_KERNEL);
 474         if (!tsdata)
 475                 return -ENOMEM;
 476
 477         tsdata->chip = device_get_match_data(dev);
 478         if (!tsdata->chip && id)
 479                 tsdata->chip = (const void *)id->driver_data;
 480         if (!tsdata->chip) {
 481                 dev_err(dev, "can't locate chip data\n");
 482                 return -EINVAL;
 483         }
 484
 485         input = devm_input_allocate_device(dev);
 486         if (!input) {
 487                 dev_err(dev, "Failed to allocate input device\n");
 488                 return -ENOMEM;
 489         }
 490
 491         tsdata->client = client;
 492         tsdata->input = input;
 493
 494         input->name = client->name;
 495         input->id.bustype = BUS_I2C;
 496         input->open = pixcir_input_open;
 497         input->close = pixcir_input_close;
 498
 499         input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
 500         input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
 501         touchscreen_parse_properties(input, true, &tsdata->prop);
 502         if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
 503             !input_abs_get_max(input, ABS_MT_POSITION_Y)) {
 504                 dev_err(dev, "Touchscreen size is not specified\n");
 505                 return -EINVAL;
 506         }
 507
 508         error = input_mt_init_slots(input, tsdata->chip->max_fingers,
 509                                     INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 510         if (error) {
 511                 dev_err(dev, "Error initializing Multi-Touch slots\n");
 512                 return error;
 513         }
 514
 515         input_set_drvdata(input, tsdata);
 516
 517         tsdata->gpio_attb = devm_gpiod_get(dev, "attb", GPIOD_IN);
 518         if (IS_ERR(tsdata->gpio_attb)) {
 519                 error = PTR_ERR(tsdata->gpio_attb);
 520                 if (error != -EPROBE_DEFER)
 521                         dev_err(dev, "Failed to request ATTB gpio: %d\n",
 522                                 error);
 523                 return error;
 524         }
 525
 526         tsdata->gpio_reset = devm_gpiod_get_optional(dev, "reset",
 527                                                      GPIOD_OUT_LOW);
 528         if (IS_ERR(tsdata->gpio_reset)) {
 529                 error = PTR_ERR(tsdata->gpio_reset);
 530                 if (error != -EPROBE_DEFER)
 531                         dev_err(dev, "Failed to request RESET gpio: %d\n",
 532                                 error);
 533                 return error;
 534         }
 535
 536         tsdata->gpio_wake = devm_gpiod_get_optional(dev, "wake",
 537                                                     GPIOD_OUT_HIGH);
 538         if (IS_ERR(tsdata->gpio_wake)) {
 539                 error = PTR_ERR(tsdata->gpio_wake);
 540                 if (error != -EPROBE_DEFER)
 541                         dev_err(dev, "Failed to get wake gpio: %d\n", error);
 542                 return error;
 543         }
 544
 545         tsdata->gpio_enable = devm_gpiod_get_optional(dev, "enable",
 546                                                       GPIOD_OUT_HIGH);
 547         if (IS_ERR(tsdata->gpio_enable)) {
 548                 error = PTR_ERR(tsdata->gpio_enable);
 549                 if (error != -EPROBE_DEFER)
 550                         dev_err(dev, "Failed to get enable gpio: %d\n", error);
 551                 return error;
 552         }
 553
 554         if (tsdata->gpio_enable)
 555                 msleep(100);
 556
 557         error = devm_request_threaded_irq(dev, client->irq, NULL, pixcir_ts_isr,
 558                                           IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 559                                           client->name, tsdata);
 560         if (error) {
 561                 dev_err(dev, "failed to request irq %d\n", client->irq);
 562                 return error;
 563         }
 564
 565         pixcir_reset(tsdata);
 566
 567         /* Always be in IDLE mode to save power, device supports auto wake */
 568         error = pixcir_set_power_mode(tsdata, PIXCIR_POWER_IDLE);
 569         if (error) {
 570                 dev_err(dev, "Failed to set IDLE mode\n");
 571                 return error;
 572         }
 573
 574         /* Stop device till opened */
 575         error = pixcir_stop(tsdata);
 576         if (error)
 577                 return error;
 578
 579         error = input_register_device(input);
 580         if (error)
 581                 return error;
 582
 583         i2c_set_clientdata(client, tsdata);
 584
 585         return 0;
 586 }
 587
 588 static const struct pixcir_i2c_chip_data pixcir_ts_data = {
 589         .max_fingers = 2,
 590         /* no hw id support */
 591 };
 592
 593 static const struct pixcir_i2c_chip_data pixcir_tangoc_data = {
 594         .max_fingers = 5,
 595         .has_hw_ids = true,
 596 };
 597
 598 static const struct i2c_device_id pixcir_i2c_ts_id[] = {
 599         { "pixcir_ts", (unsigned long) &pixcir_ts_data },
 600         { "pixcir_tangoc", (unsigned long) &pixcir_tangoc_data },
 601         { }
 602 };
 603 MODULE_DEVICE_TABLE(i2c, pixcir_i2c_ts_id);
 604
 605 #ifdef CONFIG_OF
 606 static const struct of_device_id pixcir_of_match[] = {
 607         { .compatible = "pixcir,pixcir_ts", .data = &pixcir_ts_data },
 608         { .compatible = "pixcir,pixcir_tangoc", .data = &pixcir_tangoc_data },
 609         { }
 610 };
 611 MODULE_DEVICE_TABLE(of, pixcir_of_match);
 612 #endif
 613
 614 static struct i2c_driver pixcir_i2c_ts_driver = {
 615         .driver = {
 616                 .name   = "pixcir_ts",
 617                 .pm     = &pixcir_dev_pm_ops,
 618                 .of_match_table = of_match_ptr(pixcir_of_match),
 619         },
 620         .probe          = pixcir_i2c_ts_probe,
 621         .id_table       = pixcir_i2c_ts_id,
 622 };
 623
 624 module_i2c_driver(pixcir_i2c_ts_driver);
 625
 626 MODULE_AUTHOR("Jianchun Bian <jcbian@pixcir.com.cn>, Dequan Meng <dqmeng@pixcir.com.cn>");
 627 MODULE_DESCRIPTION("Pixcir I2C Touchscreen Driver");
 628 MODULE_LICENSE("GPL");