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 <linux/delay.h>
   9 #include <linux/module.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/slab.h>
  12 #include <linux/i2c.h>
  13 #include <linux/input.h>
  14 #include <linux/input/mt.h>
  15 #include <linux/input/touchscreen.h>
  16 #include <linux/gpio.h>
  17 #include <linux/gpio/consumer.h>
  18 #include <linux/of_device.h>
  19 #include <linux/platform_data/pixcir_i2c_ts.h>
  20 #include <asm/unaligned.h>
  21
  22 #define PIXCIR_MAX_SLOTS       5 /* Max fingers supported by driver */
  23
  24 struct pixcir_i2c_ts_data {
  25         struct i2c_client *client;
  26         struct input_dev *input;
  27         struct gpio_desc *gpio_attb;
  28         struct gpio_desc *gpio_reset;
  29         struct gpio_desc *gpio_enable;
  30         struct gpio_desc *gpio_wake;
  31         const struct pixcir_i2c_chip_data *chip;
  32         struct touchscreen_properties prop;
  33         int max_fingers;        /* Max fingers supported in this instance */
  34         bool running;
  35 };
  36
  37 struct pixcir_report_data {
  38         int num_touches;
  39         struct input_mt_pos pos[PIXCIR_MAX_SLOTS];
  40         int ids[PIXCIR_MAX_SLOTS];
  41 };
  42
  43 static void pixcir_ts_parse(struct pixcir_i2c_ts_data *tsdata,
  44                             struct pixcir_report_data *report)
  45 {
  46         u8 rdbuf[2 + PIXCIR_MAX_SLOTS * 5];
  47         u8 wrbuf[1] = { 0 };
  48         u8 *bufptr;
  49         u8 touch;
  50         int ret, i;
  51         int readsize;
  52         const struct pixcir_i2c_chip_data *chip = tsdata->chip;
  53
  54         memset(report, 0, sizeof(struct pixcir_report_data));
  55
  56         i = chip->has_hw_ids ? 1 : 0;
  57         readsize = 2 + tsdata->max_fingers * (4 + i);
  58         if (readsize > sizeof(rdbuf))
  59                 readsize = sizeof(rdbuf);
  60
  61         ret = i2c_master_send(tsdata->client, wrbuf, sizeof(wrbuf));
  62         if (ret != sizeof(wrbuf)) {
  63                 dev_err(&tsdata->client->dev,
  64                         "%s: i2c_master_send failed(), ret=%d\n",
  65                         __func__, ret);
  66                 return;
  67         }
  68
  69         ret = i2c_master_recv(tsdata->client, rdbuf, readsize);
  70         if (ret != readsize) {
  71                 dev_err(&tsdata->client->dev,
  72                         "%s: i2c_master_recv failed(), ret=%d\n",
  73                         __func__, ret);
  74                 return;
  75         }
  76
  77         touch = rdbuf[0] & 0x7;
  78         if (touch > tsdata->max_fingers)
  79                 touch = tsdata->max_fingers;
  80
  81         report->num_touches = touch;
  82         bufptr = &rdbuf[2];
  83
  84         for (i = 0; i < touch; i++) {
  85                 touchscreen_set_mt_pos(&report->pos[i], &tsdata->prop,
  86                                        get_unaligned_le16(bufptr),
  87                                        get_unaligned_le16(bufptr + 2));
  88                 if (chip->has_hw_ids) {
  89                         report->ids[i] = bufptr[4];
  90                         bufptr = bufptr + 5;
  91                 } else {
  92                         bufptr = bufptr + 4;
  93                 }
  94         }
  95 }
  96
  97 static void pixcir_ts_report(struct pixcir_i2c_ts_data *ts,
  98                              struct pixcir_report_data *report)
  99 {
 100         int slots[PIXCIR_MAX_SLOTS];
 101         int n, i, slot;
 102         struct device *dev = &ts->client->dev;
 103         const struct pixcir_i2c_chip_data *chip = ts->chip;
 104
 105         n = report->num_touches;
 106         if (n > PIXCIR_MAX_SLOTS)
 107                 n = PIXCIR_MAX_SLOTS;
 108
 109         if (!ts->chip->has_hw_ids)
 110                 input_mt_assign_slots(ts->input, slots, report->pos, n, 0);
 111
 112         for (i = 0; i < n; i++) {
 113                 if (chip->has_hw_ids) {
 114                         slot = input_mt_get_slot_by_key(ts->input,
 115                                                         report->ids[i]);
 116                         if (slot < 0) {
 117                                 dev_dbg(dev, "no free slot for id 0x%x\n",
 118                                         report->ids[i]);
 119                                 continue;
 120                         }
 121                 } else {
 122                         slot = slots[i];
 123                 }
 124
 125                 input_mt_slot(ts->input, slot);
 126                 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
 127
 128                 input_report_abs(ts->input, ABS_MT_POSITION_X,
 129                                  report->pos[i].x);
 130                 input_report_abs(ts->input, ABS_MT_POSITION_Y,
 131                                  report->pos[i].y);
 132
 133                 dev_dbg(dev, "%d: slot %d, x %d, y %d\n",
 134                         i, slot, report->pos[i].x, report->pos[i].y);
 135         }
 136
 137         input_mt_sync_frame(ts->input);
 138         input_sync(ts->input);
 139 }
 140
 141 static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
 142 {
 143         struct pixcir_i2c_ts_data *tsdata = dev_id;
 144         struct pixcir_report_data report;
 145
 146         while (tsdata->running) {
 147                 /* parse packet */
 148                 pixcir_ts_parse(tsdata, &report);
 149
 150                 /* report it */
 151                 pixcir_ts_report(tsdata, &report);
 152
 153                 if (gpiod_get_value_cansleep(tsdata->gpio_attb)) {
 154                         if (report.num_touches) {
 155                                 /*
 156                                  * Last report with no finger up?
 157                                  * Do it now then.
 158                                  */
 159                                 input_mt_sync_frame(tsdata->input);
 160                                 input_sync(tsdata->input);
 161                         }
 162                         break;
 163                 }
 164
 165                 msleep(20);
 166         }
 167
 168         return IRQ_HANDLED;
 169 }
 170
 171 static void pixcir_reset(struct pixcir_i2c_ts_data *tsdata)
 172 {
 173         if (!IS_ERR_OR_NULL(tsdata->gpio_reset)) {
 174                 gpiod_set_value_cansleep(tsdata->gpio_reset, 1);
 175                 ndelay(100);    /* datasheet section 1.2.3 says 80ns min. */
 176                 gpiod_set_value_cansleep(tsdata->gpio_reset, 0);
 177                 /* wait for controller ready. 100ms guess. */
 178                 msleep(100);
 179         }
 180 }
 181
 182 static int pixcir_set_power_mode(struct pixcir_i2c_ts_data *ts,
 183                                  enum pixcir_power_mode mode)
 184 {
 185         struct device *dev = &ts->client->dev;
 186         int ret;
 187
 188         if (mode == PIXCIR_POWER_ACTIVE || mode == PIXCIR_POWER_IDLE) {
 189                 if (ts->gpio_wake)
 190                         gpiod_set_value_cansleep(ts->gpio_wake, 1);
 191         }
 192
 193         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_POWER_MODE);
 194         if (ret < 0) {
 195                 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
 196                         __func__, PIXCIR_REG_POWER_MODE, ret);
 197                 return ret;
 198         }
 199
 200         ret &= ~PIXCIR_POWER_MODE_MASK;
 201         ret |= mode;
 202
 203         /* Always AUTO_IDLE */
 204         ret |= PIXCIR_POWER_ALLOW_IDLE;
 205
 206         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_POWER_MODE, ret);
 207         if (ret < 0) {
 208                 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
 209                         __func__, PIXCIR_REG_POWER_MODE, ret);
 210                 return ret;
 211         }
 212
 213         if (mode == PIXCIR_POWER_HALT) {
 214                 if (ts->gpio_wake)
 215                         gpiod_set_value_cansleep(ts->gpio_wake, 0);
 216         }
 217
 218         return 0;
 219 }
 220
 221 /*
 222  * Set the interrupt mode for the device i.e. ATTB line behaviour
 223  *
 224  * @polarity : 1 for active high, 0 for active low.
 225  */
 226 static int pixcir_set_int_mode(struct pixcir_i2c_ts_data *ts,
 227                                enum pixcir_int_mode mode, bool polarity)
 228 {
 229         struct device *dev = &ts->client->dev;
 230         int ret;
 231
 232         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
 233         if (ret < 0) {
 234                 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
 235                         __func__, PIXCIR_REG_INT_MODE, ret);
 236                 return ret;
 237         }
 238
 239         ret &= ~PIXCIR_INT_MODE_MASK;
 240         ret |= mode;
 241
 242         if (polarity)
 243                 ret |= PIXCIR_INT_POL_HIGH;
 244         else
 245                 ret &= ~PIXCIR_INT_POL_HIGH;
 246
 247         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
 248         if (ret < 0) {
 249                 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
 250                         __func__, PIXCIR_REG_INT_MODE, ret);
 251                 return ret;
 252         }
 253
 254         return 0;
 255 }
 256
 257 /*
 258  * Enable/disable interrupt generation
 259  */
 260 static int pixcir_int_enable(struct pixcir_i2c_ts_data *ts, bool enable)
 261 {
 262         struct device *dev = &ts->client->dev;
 263         int ret;
 264
 265         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
 266         if (ret < 0) {
 267                 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
 268                         __func__, PIXCIR_REG_INT_MODE, ret);
 269                 return ret;
 270         }
 271
 272         if (enable)
 273                 ret |= PIXCIR_INT_ENABLE;
 274         else
 275                 ret &= ~PIXCIR_INT_ENABLE;
 276
 277         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
 278         if (ret < 0) {
 279                 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
 280                         __func__, PIXCIR_REG_INT_MODE, ret);
 281                 return ret;
 282         }
 283
 284         return 0;
 285 }
 286
 287 static int pixcir_start(struct pixcir_i2c_ts_data *ts)
 288 {
 289         struct device *dev = &ts->client->dev;
 290         int error;
 291
 292         if (ts->gpio_enable) {
 293                 gpiod_set_value_cansleep(ts->gpio_enable, 1);
 294                 msleep(100);
 295         }
 296
 297         /* LEVEL_TOUCH interrupt with active low polarity */
 298         error = pixcir_set_int_mode(ts, PIXCIR_INT_LEVEL_TOUCH, 0);
 299         if (error) {
 300                 dev_err(dev, "Failed to set interrupt mode: %d\n", error);
 301                 return error;
 302         }
 303
 304         ts->running = true;
 305         mb();   /* Update status before IRQ can fire */
 306
 307         /* enable interrupt generation */
 308         error = pixcir_int_enable(ts, true);
 309         if (error) {
 310                 dev_err(dev, "Failed to enable interrupt generation: %d\n",
 311                         error);
 312                 return error;
 313         }
 314
 315         return 0;
 316 }
 317
 318 static int pixcir_stop(struct pixcir_i2c_ts_data *ts)
 319 {
 320         int error;
 321
 322         /* Disable interrupt generation */
 323         error = pixcir_int_enable(ts, false);
 324         if (error) {
 325                 dev_err(&ts->client->dev,
 326                         "Failed to disable interrupt generation: %d\n",
 327                         error);
 328                 return error;
 329         }
 330
 331         /* Exit ISR if running, no more report parsing */
 332         ts->running = false;
 333         mb();   /* update status before we synchronize irq */
 334
 335         /* Wait till running ISR is complete */
 336         synchronize_irq(ts->client->irq);
 337
 338         if (ts->gpio_enable)
 339                 gpiod_set_value_cansleep(ts->gpio_enable, 0);
 340
 341         return 0;
 342 }
 343
 344 static int pixcir_input_open(struct input_dev *dev)
 345 {
 346         struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
 347
 348         return pixcir_start(ts);
 349 }
 350
 351 static void pixcir_input_close(struct input_dev *dev)
 352 {
 353         struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
 354
 355         pixcir_stop(ts);
 356 }
 357
 358 static int __maybe_unused pixcir_i2c_ts_suspend(struct device *dev)
 359 {
 360         struct i2c_client *client = to_i2c_client(dev);
 361         struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
 362         struct input_dev *input = ts->input;
 363         int ret = 0;
 364
 365         mutex_lock(&input->mutex);
 366
 367         if (device_may_wakeup(&client->dev)) {
 368                 if (!input->users) {
 369                         ret = pixcir_start(ts);
 370                         if (ret) {
 371                                 dev_err(dev, "Failed to start\n");
 372                                 goto unlock;
 373                         }
 374                 }
 375         } else if (input->users) {
 376                 ret = pixcir_stop(ts);
 377         }
 378
 379 unlock:
 380         mutex_unlock(&input->mutex);
 381
 382         return ret;
 383 }
 384
 385 static int __maybe_unused pixcir_i2c_ts_resume(struct device *dev)
 386 {
 387         struct i2c_client *client = to_i2c_client(dev);
 388         struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
 389         struct input_dev *input = ts->input;
 390         int ret = 0;
 391
 392         mutex_lock(&input->mutex);
 393
 394         if (device_may_wakeup(&client->dev)) {
 395                 if (!input->users) {
 396                         ret = pixcir_stop(ts);
 397                         if (ret) {
 398                                 dev_err(dev, "Failed to stop\n");
 399                                 goto unlock;
 400                         }
 401                 }
 402         } else if (input->users) {
 403                 ret = pixcir_start(ts);
 404         }
 405
 406 unlock:
 407         mutex_unlock(&input->mutex);
 408
 409         return ret;
 410 }
 411
 412 static SIMPLE_DEV_PM_OPS(pixcir_dev_pm_ops,
 413                          pixcir_i2c_ts_suspend, pixcir_i2c_ts_resume);
 414
 415 #ifdef CONFIG_OF
 416 static const struct of_device_id pixcir_of_match[];
 417
 418 static int pixcir_parse_dt(struct device *dev,
 419                            struct pixcir_i2c_ts_data *tsdata)
 420 {
 421         tsdata->chip = of_device_get_match_data(dev);
 422         if (!tsdata->chip)
 423                 return -EINVAL;
 424
 425         return 0;
 426 }
 427 #else
 428 static int pixcir_parse_dt(struct device *dev,
 429                            struct pixcir_i2c_ts_data *tsdata)
 430 {
 431         return -EINVAL;
 432 }
 433 #endif
 434
 435 static int pixcir_i2c_ts_probe(struct i2c_client *client,
 436                                const struct i2c_device_id *id)
 437 {
 438         const struct pixcir_ts_platform_data *pdata =
 439                         dev_get_platdata(&client->dev);
 440         struct device *dev = &client->dev;
 441         struct pixcir_i2c_ts_data *tsdata;
 442         struct input_dev *input;
 443         int error;
 444
 445         tsdata = devm_kzalloc(dev, sizeof(*tsdata), GFP_KERNEL);
 446         if (!tsdata)
 447                 return -ENOMEM;
 448
 449         if (pdata) {
 450                 tsdata->chip = &pdata->chip;
 451         } else if (dev->of_node) {
 452                 error = pixcir_parse_dt(dev, tsdata);
 453                 if (error)
 454                         return error;
 455         } else {
 456                 dev_err(dev, "platform data not defined\n");
 457                 return -EINVAL;
 458         }
 459
 460         if (!tsdata->chip->max_fingers) {
 461                 dev_err(dev, "Invalid max_fingers in chip data\n");
 462                 return -EINVAL;
 463         }
 464
 465         input = devm_input_allocate_device(dev);
 466         if (!input) {
 467                 dev_err(dev, "Failed to allocate input device\n");
 468                 return -ENOMEM;
 469         }
 470
 471         tsdata->client = client;
 472         tsdata->input = input;
 473
 474         input->name = client->name;
 475         input->id.bustype = BUS_I2C;
 476         input->open = pixcir_input_open;
 477         input->close = pixcir_input_close;
 478         input->dev.parent = dev;
 479
 480         if (pdata) {
 481                 input_set_abs_params(input, ABS_MT_POSITION_X, 0, pdata->x_max, 0, 0);
 482                 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, pdata->y_max, 0, 0);
 483         } else {
 484                 input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
 485                 input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
 486                 touchscreen_parse_properties(input, true, &tsdata->prop);
 487                 if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
 488                     !input_abs_get_max(input, ABS_MT_POSITION_Y)) {
 489                         dev_err(dev, "Touchscreen size is not specified\n");
 490                         return -EINVAL;
 491                 }
 492         }
 493
 494         tsdata->max_fingers = tsdata->chip->max_fingers;
 495         if (tsdata->max_fingers > PIXCIR_MAX_SLOTS) {
 496                 tsdata->max_fingers = PIXCIR_MAX_SLOTS;
 497                 dev_info(dev, "Limiting maximum fingers to %d\n",
 498                          tsdata->max_fingers);
 499         }
 500
 501         error = input_mt_init_slots(input, tsdata->max_fingers,
 502                                     INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 503         if (error) {
 504                 dev_err(dev, "Error initializing Multi-Touch slots\n");
 505                 return error;
 506         }
 507
 508         input_set_drvdata(input, tsdata);
 509
 510         tsdata->gpio_attb = devm_gpiod_get(dev, "attb", GPIOD_IN);
 511         if (IS_ERR(tsdata->gpio_attb)) {
 512                 error = PTR_ERR(tsdata->gpio_attb);
 513                 dev_err(dev, "Failed to request ATTB gpio: %d\n", error);
 514                 return error;
 515         }
 516
 517         tsdata->gpio_reset = devm_gpiod_get_optional(dev, "reset",
 518                                                      GPIOD_OUT_LOW);
 519         if (IS_ERR(tsdata->gpio_reset)) {
 520                 error = PTR_ERR(tsdata->gpio_reset);
 521                 dev_err(dev, "Failed to request RESET gpio: %d\n", error);
 522                 return error;
 523         }
 524
 525         tsdata->gpio_wake = devm_gpiod_get_optional(dev, "wake",
 526                                                     GPIOD_OUT_HIGH);
 527         if (IS_ERR(tsdata->gpio_wake)) {
 528                 error = PTR_ERR(tsdata->gpio_wake);
 529                 if (error != -EPROBE_DEFER)
 530                         dev_err(dev, "Failed to get wake gpio: %d\n", error);
 531                 return error;
 532         }
 533
 534         tsdata->gpio_enable = devm_gpiod_get_optional(dev, "enable",
 535                                                       GPIOD_OUT_HIGH);
 536         if (IS_ERR(tsdata->gpio_enable)) {
 537                 error = PTR_ERR(tsdata->gpio_enable);
 538                 if (error != -EPROBE_DEFER)
 539                         dev_err(dev, "Failed to get enable gpio: %d\n", error);
 540                 return error;
 541         }
 542
 543         if (tsdata->gpio_enable)
 544                 msleep(100);
 545
 546         error = devm_request_threaded_irq(dev, client->irq, NULL, pixcir_ts_isr,
 547                                           IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 548                                           client->name, tsdata);
 549         if (error) {
 550                 dev_err(dev, "failed to request irq %d\n", client->irq);
 551                 return error;
 552         }
 553
 554         pixcir_reset(tsdata);
 555
 556         /* Always be in IDLE mode to save power, device supports auto wake */
 557         error = pixcir_set_power_mode(tsdata, PIXCIR_POWER_IDLE);
 558         if (error) {
 559                 dev_err(dev, "Failed to set IDLE mode\n");
 560                 return error;
 561         }
 562
 563         /* Stop device till opened */
 564         error = pixcir_stop(tsdata);
 565         if (error)
 566                 return error;
 567
 568         error = input_register_device(input);
 569         if (error)
 570                 return error;
 571
 572         i2c_set_clientdata(client, tsdata);
 573
 574         return 0;
 575 }
 576
 577 static const struct i2c_device_id pixcir_i2c_ts_id[] = {
 578         { "pixcir_ts", 0 },
 579         { "pixcir_tangoc", 0 },
 580         { }
 581 };
 582 MODULE_DEVICE_TABLE(i2c, pixcir_i2c_ts_id);
 583
 584 #ifdef CONFIG_OF
 585 static const struct pixcir_i2c_chip_data pixcir_ts_data = {
 586         .max_fingers = 2,
 587         /* no hw id support */
 588 };
 589
 590 static const struct pixcir_i2c_chip_data pixcir_tangoc_data = {
 591         .max_fingers = 5,
 592         .has_hw_ids = true,
 593 };
 594
 595 static const struct of_device_id pixcir_of_match[] = {
 596         { .compatible = "pixcir,pixcir_ts", .data = &pixcir_ts_data },
 597         { .compatible = "pixcir,pixcir_tangoc", .data = &pixcir_tangoc_data },
 598         { }
 599 };
 600 MODULE_DEVICE_TABLE(of, pixcir_of_match);
 601 #endif
 602
 603 static struct i2c_driver pixcir_i2c_ts_driver = {
 604         .driver = {
 605                 .name   = "pixcir_ts",
 606                 .pm     = &pixcir_dev_pm_ops,
 607                 .of_match_table = of_match_ptr(pixcir_of_match),
 608         },
 609         .probe          = pixcir_i2c_ts_probe,
 610         .id_table       = pixcir_i2c_ts_id,
 611 };
 612
 613 module_i2c_driver(pixcir_i2c_ts_driver);
 614
 615 MODULE_AUTHOR("Jianchun Bian <jcbian@pixcir.com.cn>, Dequan Meng <dqmeng@pixcir.com.cn>");
 616 MODULE_DESCRIPTION("Pixcir I2C Touchscreen Driver");
 617 MODULE_LICENSE("GPL");