drivers/input/touchscreen/pixcir_i2c_ts.c

   1 /*
   2  * Driver for Pixcir I2C touchscreen controllers.
   3  *
   4  * Copyright (C) 2010-2011 Pixcir, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/delay.h>
  17 #include <linux/module.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/slab.h>
  20 #include <linux/i2c.h>
  21 #include <linux/input.h>
  22 #include <linux/input/mt.h>
  23 #include <linux/input/touchscreen.h>
  24 #include <linux/gpio.h>
  25 #include <linux/gpio/consumer.h>
  26 #include <linux/of_device.h>
  27 #include <linux/platform_data/pixcir_i2c_ts.h>
  28 #include <asm/unaligned.h>
  29
  30 #define PIXCIR_MAX_SLOTS       5 /* Max fingers supported by driver */
  31
  32 struct pixcir_i2c_ts_data {
  33         struct i2c_client *client;
  34         struct input_dev *input;
  35         struct gpio_desc *gpio_attb;
  36         struct gpio_desc *gpio_reset;
  37         struct gpio_desc *gpio_enable;
  38         struct gpio_desc *gpio_wake;
  39         const struct pixcir_i2c_chip_data *chip;
  40         struct touchscreen_properties prop;
  41         int max_fingers;        /* Max fingers supported in this instance */
  42         bool running;
  43 };
  44
  45 struct pixcir_report_data {
  46         int num_touches;
  47         struct input_mt_pos pos[PIXCIR_MAX_SLOTS];
  48         int ids[PIXCIR_MAX_SLOTS];
  49 };
  50
  51 static void pixcir_ts_parse(struct pixcir_i2c_ts_data *tsdata,
  52                             struct pixcir_report_data *report)
  53 {
  54         u8 rdbuf[2 + PIXCIR_MAX_SLOTS * 5];
  55         u8 wrbuf[1] = { 0 };
  56         u8 *bufptr;
  57         u8 touch;
  58         int ret, i;
  59         int readsize;
  60         const struct pixcir_i2c_chip_data *chip = tsdata->chip;
  61
  62         memset(report, 0, sizeof(struct pixcir_report_data));
  63
  64         i = chip->has_hw_ids ? 1 : 0;
  65         readsize = 2 + tsdata->max_fingers * (4 + i);
  66         if (readsize > sizeof(rdbuf))
  67                 readsize = sizeof(rdbuf);
  68
  69         ret = i2c_master_send(tsdata->client, wrbuf, sizeof(wrbuf));
  70         if (ret != sizeof(wrbuf)) {
  71                 dev_err(&tsdata->client->dev,
  72                         "%s: i2c_master_send failed(), ret=%d\n",
  73                         __func__, ret);
  74                 return;
  75         }
  76
  77         ret = i2c_master_recv(tsdata->client, rdbuf, readsize);
  78         if (ret != readsize) {
  79                 dev_err(&tsdata->client->dev,
  80                         "%s: i2c_master_recv failed(), ret=%d\n",
  81                         __func__, ret);
  82                 return;
  83         }
  84
  85         touch = rdbuf[0] & 0x7;
  86         if (touch > tsdata->max_fingers)
  87                 touch = tsdata->max_fingers;
  88
  89         report->num_touches = touch;
  90         bufptr = &rdbuf[2];
  91
  92         for (i = 0; i < touch; i++) {
  93                 touchscreen_set_mt_pos(&report->pos[i], &tsdata->prop,
  94                                        get_unaligned_le16(bufptr),
  95                                        get_unaligned_le16(bufptr + 2));
  96                 if (chip->has_hw_ids) {
  97                         report->ids[i] = bufptr[4];
  98                         bufptr = bufptr + 5;
  99                 } else {
 100                         bufptr = bufptr + 4;
 101                 }
 102         }
 103 }
 104
 105 static void pixcir_ts_report(struct pixcir_i2c_ts_data *ts,
 106                              struct pixcir_report_data *report)
 107 {
 108         int slots[PIXCIR_MAX_SLOTS];
 109         int n, i, slot;
 110         struct device *dev = &ts->client->dev;
 111         const struct pixcir_i2c_chip_data *chip = ts->chip;
 112
 113         n = report->num_touches;
 114         if (n > PIXCIR_MAX_SLOTS)
 115                 n = PIXCIR_MAX_SLOTS;
 116
 117         if (!ts->chip->has_hw_ids)
 118                 input_mt_assign_slots(ts->input, slots, report->pos, n, 0);
 119
 120         for (i = 0; i < n; i++) {
 121                 if (chip->has_hw_ids) {
 122                         slot = input_mt_get_slot_by_key(ts->input,
 123                                                         report->ids[i]);
 124                         if (slot < 0) {
 125                                 dev_dbg(dev, "no free slot for id 0x%x\n",
 126                                         report->ids[i]);
 127                                 continue;
 128                         }
 129                 } else {
 130                         slot = slots[i];
 131                 }
 132
 133                 input_mt_slot(ts->input, slot);
 134                 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
 135
 136                 input_report_abs(ts->input, ABS_MT_POSITION_X,
 137                                  report->pos[i].x);
 138                 input_report_abs(ts->input, ABS_MT_POSITION_Y,
 139                                  report->pos[i].y);
 140
 141                 dev_dbg(dev, "%d: slot %d, x %d, y %d\n",
 142                         i, slot, report->pos[i].x, report->pos[i].y);
 143         }
 144
 145         input_mt_sync_frame(ts->input);
 146         input_sync(ts->input);
 147 }
 148
 149 static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
 150 {
 151         struct pixcir_i2c_ts_data *tsdata = dev_id;
 152         struct pixcir_report_data report;
 153
 154         while (tsdata->running) {
 155                 /* parse packet */
 156                 pixcir_ts_parse(tsdata, &report);
 157
 158                 /* report it */
 159                 pixcir_ts_report(tsdata, &report);
 160
 161                 if (gpiod_get_value_cansleep(tsdata->gpio_attb)) {
 162                         if (report.num_touches) {
 163                                 /*
 164                                  * Last report with no finger up?
 165                                  * Do it now then.
 166                                  */
 167                                 input_mt_sync_frame(tsdata->input);
 168                                 input_sync(tsdata->input);
 169                         }
 170                         break;
 171                 }
 172
 173                 msleep(20);
 174         }
 175
 176         return IRQ_HANDLED;
 177 }
 178
 179 static void pixcir_reset(struct pixcir_i2c_ts_data *tsdata)
 180 {
 181         if (!IS_ERR_OR_NULL(tsdata->gpio_reset)) {
 182                 gpiod_set_value_cansleep(tsdata->gpio_reset, 1);
 183                 ndelay(100);    /* datasheet section 1.2.3 says 80ns min. */
 184                 gpiod_set_value_cansleep(tsdata->gpio_reset, 0);
 185                 /* wait for controller ready. 100ms guess. */
 186                 msleep(100);
 187         }
 188 }
 189
 190 static int pixcir_set_power_mode(struct pixcir_i2c_ts_data *ts,
 191                                  enum pixcir_power_mode mode)
 192 {
 193         struct device *dev = &ts->client->dev;
 194         int ret;
 195
 196         if (mode == PIXCIR_POWER_ACTIVE || mode == PIXCIR_POWER_IDLE) {
 197                 if (ts->gpio_wake)
 198                         gpiod_set_value_cansleep(ts->gpio_wake, 1);
 199         }
 200
 201         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_POWER_MODE);
 202         if (ret < 0) {
 203                 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
 204                         __func__, PIXCIR_REG_POWER_MODE, ret);
 205                 return ret;
 206         }
 207
 208         ret &= ~PIXCIR_POWER_MODE_MASK;
 209         ret |= mode;
 210
 211         /* Always AUTO_IDLE */
 212         ret |= PIXCIR_POWER_ALLOW_IDLE;
 213
 214         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_POWER_MODE, ret);
 215         if (ret < 0) {
 216                 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
 217                         __func__, PIXCIR_REG_POWER_MODE, ret);
 218                 return ret;
 219         }
 220
 221         if (mode == PIXCIR_POWER_HALT) {
 222                 if (ts->gpio_wake)
 223                         gpiod_set_value_cansleep(ts->gpio_wake, 0);
 224         }
 225
 226         return 0;
 227 }
 228
 229 /*
 230  * Set the interrupt mode for the device i.e. ATTB line behaviour
 231  *
 232  * @polarity : 1 for active high, 0 for active low.
 233  */
 234 static int pixcir_set_int_mode(struct pixcir_i2c_ts_data *ts,
 235                                enum pixcir_int_mode mode, bool polarity)
 236 {
 237         struct device *dev = &ts->client->dev;
 238         int ret;
 239
 240         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
 241         if (ret < 0) {
 242                 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
 243                         __func__, PIXCIR_REG_INT_MODE, ret);
 244                 return ret;
 245         }
 246
 247         ret &= ~PIXCIR_INT_MODE_MASK;
 248         ret |= mode;
 249
 250         if (polarity)
 251                 ret |= PIXCIR_INT_POL_HIGH;
 252         else
 253                 ret &= ~PIXCIR_INT_POL_HIGH;
 254
 255         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
 256         if (ret < 0) {
 257                 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
 258                         __func__, PIXCIR_REG_INT_MODE, ret);
 259                 return ret;
 260         }
 261
 262         return 0;
 263 }
 264
 265 /*
 266  * Enable/disable interrupt generation
 267  */
 268 static int pixcir_int_enable(struct pixcir_i2c_ts_data *ts, bool enable)
 269 {
 270         struct device *dev = &ts->client->dev;
 271         int ret;
 272
 273         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
 274         if (ret < 0) {
 275                 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
 276                         __func__, PIXCIR_REG_INT_MODE, ret);
 277                 return ret;
 278         }
 279
 280         if (enable)
 281                 ret |= PIXCIR_INT_ENABLE;
 282         else
 283                 ret &= ~PIXCIR_INT_ENABLE;
 284
 285         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
 286         if (ret < 0) {
 287                 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
 288                         __func__, PIXCIR_REG_INT_MODE, ret);
 289                 return ret;
 290         }
 291
 292         return 0;
 293 }
 294
 295 static int pixcir_start(struct pixcir_i2c_ts_data *ts)
 296 {
 297         struct device *dev = &ts->client->dev;
 298         int error;
 299
 300         if (ts->gpio_enable) {
 301                 gpiod_set_value_cansleep(ts->gpio_enable, 1);
 302                 msleep(100);
 303         }
 304
 305         /* LEVEL_TOUCH interrupt with active low polarity */
 306         error = pixcir_set_int_mode(ts, PIXCIR_INT_LEVEL_TOUCH, 0);
 307         if (error) {
 308                 dev_err(dev, "Failed to set interrupt mode: %d\n", error);
 309                 return error;
 310         }
 311
 312         ts->running = true;
 313         mb();   /* Update status before IRQ can fire */
 314
 315         /* enable interrupt generation */
 316         error = pixcir_int_enable(ts, true);
 317         if (error) {
 318                 dev_err(dev, "Failed to enable interrupt generation: %d\n",
 319                         error);
 320                 return error;
 321         }
 322
 323         return 0;
 324 }
 325
 326 static int pixcir_stop(struct pixcir_i2c_ts_data *ts)
 327 {
 328         int error;
 329
 330         /* Disable interrupt generation */
 331         error = pixcir_int_enable(ts, false);
 332         if (error) {
 333                 dev_err(&ts->client->dev,
 334                         "Failed to disable interrupt generation: %d\n",
 335                         error);
 336                 return error;
 337         }
 338
 339         /* Exit ISR if running, no more report parsing */
 340         ts->running = false;
 341         mb();   /* update status before we synchronize irq */
 342
 343         /* Wait till running ISR is complete */
 344         synchronize_irq(ts->client->irq);
 345
 346         if (ts->gpio_enable)
 347                 gpiod_set_value_cansleep(ts->gpio_enable, 0);
 348
 349         return 0;
 350 }
 351
 352 static int pixcir_input_open(struct input_dev *dev)
 353 {
 354         struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
 355
 356         return pixcir_start(ts);
 357 }
 358
 359 static void pixcir_input_close(struct input_dev *dev)
 360 {
 361         struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
 362
 363         pixcir_stop(ts);
 364 }
 365
 366 static int __maybe_unused pixcir_i2c_ts_suspend(struct device *dev)
 367 {
 368         struct i2c_client *client = to_i2c_client(dev);
 369         struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
 370         struct input_dev *input = ts->input;
 371         int ret = 0;
 372
 373         mutex_lock(&input->mutex);
 374
 375         if (device_may_wakeup(&client->dev)) {
 376                 if (!input->users) {
 377                         ret = pixcir_start(ts);
 378                         if (ret) {
 379                                 dev_err(dev, "Failed to start\n");
 380                                 goto unlock;
 381                         }
 382                 }
 383         } else if (input->users) {
 384                 ret = pixcir_stop(ts);
 385         }
 386
 387 unlock:
 388         mutex_unlock(&input->mutex);
 389
 390         return ret;
 391 }
 392
 393 static int __maybe_unused pixcir_i2c_ts_resume(struct device *dev)
 394 {
 395         struct i2c_client *client = to_i2c_client(dev);
 396         struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
 397         struct input_dev *input = ts->input;
 398         int ret = 0;
 399
 400         mutex_lock(&input->mutex);
 401
 402         if (device_may_wakeup(&client->dev)) {
 403                 if (!input->users) {
 404                         ret = pixcir_stop(ts);
 405                         if (ret) {
 406                                 dev_err(dev, "Failed to stop\n");
 407                                 goto unlock;
 408                         }
 409                 }
 410         } else if (input->users) {
 411                 ret = pixcir_start(ts);
 412         }
 413
 414 unlock:
 415         mutex_unlock(&input->mutex);
 416
 417         return ret;
 418 }
 419
 420 static SIMPLE_DEV_PM_OPS(pixcir_dev_pm_ops,
 421                          pixcir_i2c_ts_suspend, pixcir_i2c_ts_resume);
 422
 423 #ifdef CONFIG_OF
 424 static const struct of_device_id pixcir_of_match[];
 425
 426 static int pixcir_parse_dt(struct device *dev,
 427                            struct pixcir_i2c_ts_data *tsdata)
 428 {
 429         tsdata->chip = of_device_get_match_data(dev);
 430         if (!tsdata->chip)
 431                 return -EINVAL;
 432
 433         return 0;
 434 }
 435 #else
 436 static int pixcir_parse_dt(struct device *dev,
 437                            struct pixcir_i2c_ts_data *tsdata)
 438 {
 439         return -EINVAL;
 440 }
 441 #endif
 442
 443 static int pixcir_i2c_ts_probe(struct i2c_client *client,
 444                                const struct i2c_device_id *id)
 445 {
 446         const struct pixcir_ts_platform_data *pdata =
 447                         dev_get_platdata(&client->dev);
 448         struct device *dev = &client->dev;
 449         struct pixcir_i2c_ts_data *tsdata;
 450         struct input_dev *input;
 451         int error;
 452
 453         tsdata = devm_kzalloc(dev, sizeof(*tsdata), GFP_KERNEL);
 454         if (!tsdata)
 455                 return -ENOMEM;
 456
 457         if (pdata) {
 458                 tsdata->chip = &pdata->chip;
 459         } else if (dev->of_node) {
 460                 error = pixcir_parse_dt(dev, tsdata);
 461                 if (error)
 462                         return error;
 463         } else {
 464                 dev_err(&client->dev, "platform data not defined\n");
 465                 return -EINVAL;
 466         }
 467
 468         if (!tsdata->chip->max_fingers) {
 469                 dev_err(dev, "Invalid max_fingers in chip data\n");
 470                 return -EINVAL;
 471         }
 472
 473         input = devm_input_allocate_device(dev);
 474         if (!input) {
 475                 dev_err(dev, "Failed to allocate input device\n");
 476                 return -ENOMEM;
 477         }
 478
 479         tsdata->client = client;
 480         tsdata->input = input;
 481
 482         input->name = client->name;
 483         input->id.bustype = BUS_I2C;
 484         input->open = pixcir_input_open;
 485         input->close = pixcir_input_close;
 486         input->dev.parent = &client->dev;
 487
 488         if (pdata) {
 489                 input_set_abs_params(input, ABS_MT_POSITION_X, 0, pdata->x_max, 0, 0);
 490                 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, pdata->y_max, 0, 0);
 491         } else {
 492                 input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
 493                 input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
 494                 touchscreen_parse_properties(input, true, &tsdata->prop);
 495                 if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
 496                     !input_abs_get_max(input, ABS_MT_POSITION_Y)) {
 497                         dev_err(dev, "Touchscreen size is not specified\n");
 498                         return -EINVAL;
 499                 }
 500         }
 501
 502         tsdata->max_fingers = tsdata->chip->max_fingers;
 503         if (tsdata->max_fingers > PIXCIR_MAX_SLOTS) {
 504                 tsdata->max_fingers = PIXCIR_MAX_SLOTS;
 505                 dev_info(dev, "Limiting maximum fingers to %d\n",
 506                          tsdata->max_fingers);
 507         }
 508
 509         error = input_mt_init_slots(input, tsdata->max_fingers,
 510                                     INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 511         if (error) {
 512                 dev_err(dev, "Error initializing Multi-Touch slots\n");
 513                 return error;
 514         }
 515
 516         input_set_drvdata(input, tsdata);
 517
 518         tsdata->gpio_attb = devm_gpiod_get(dev, "attb", GPIOD_IN);
 519         if (IS_ERR(tsdata->gpio_attb)) {
 520                 error = PTR_ERR(tsdata->gpio_attb);
 521                 dev_err(dev, "Failed to request ATTB gpio: %d\n", error);
 522                 return error;
 523         }
 524
 525         tsdata->gpio_reset = devm_gpiod_get_optional(dev, "reset",
 526                                                      GPIOD_OUT_LOW);
 527         if (IS_ERR(tsdata->gpio_reset)) {
 528                 error = PTR_ERR(tsdata->gpio_reset);
 529                 dev_err(dev, "Failed to request RESET gpio: %d\n", error);
 530                 return error;
 531         }
 532
 533         tsdata->gpio_wake = devm_gpiod_get_optional(dev, "wake",
 534                                                     GPIOD_OUT_HIGH);
 535         if (IS_ERR(tsdata->gpio_wake)) {
 536                 error = PTR_ERR(tsdata->gpio_wake);
 537                 if (error != -EPROBE_DEFER)
 538                         dev_err(dev, "Failed to get wake gpio: %d\n", error);
 539                 return error;
 540         }
 541
 542         tsdata->gpio_enable = devm_gpiod_get_optional(dev, "enable",
 543                                                       GPIOD_OUT_HIGH);
 544         if (IS_ERR(tsdata->gpio_enable)) {
 545                 error = PTR_ERR(tsdata->gpio_enable);
 546                 if (error != -EPROBE_DEFER)
 547                         dev_err(dev, "Failed to get enable gpio: %d\n", error);
 548                 return error;
 549         }
 550
 551         if (tsdata->gpio_enable)
 552                 msleep(100);
 553
 554         error = devm_request_threaded_irq(dev, client->irq, NULL, pixcir_ts_isr,
 555                                           IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 556                                           client->name, tsdata);
 557         if (error) {
 558                 dev_err(dev, "failed to request irq %d\n", client->irq);
 559                 return error;
 560         }
 561
 562         pixcir_reset(tsdata);
 563
 564         /* Always be in IDLE mode to save power, device supports auto wake */
 565         error = pixcir_set_power_mode(tsdata, PIXCIR_POWER_IDLE);
 566         if (error) {
 567                 dev_err(dev, "Failed to set IDLE mode\n");
 568                 return error;
 569         }
 570
 571         /* Stop device till opened */
 572         error = pixcir_stop(tsdata);
 573         if (error)
 574                 return error;
 575
 576         error = input_register_device(input);
 577         if (error)
 578                 return error;
 579
 580         i2c_set_clientdata(client, tsdata);
 581
 582         return 0;
 583 }
 584
 585 static const struct i2c_device_id pixcir_i2c_ts_id[] = {
 586         { "pixcir_ts", 0 },
 587         { "pixcir_tangoc", 0 },
 588         { }
 589 };
 590 MODULE_DEVICE_TABLE(i2c, pixcir_i2c_ts_id);
 591
 592 #ifdef CONFIG_OF
 593 static const struct pixcir_i2c_chip_data pixcir_ts_data = {
 594         .max_fingers = 2,
 595         /* no hw id support */
 596 };
 597
 598 static const struct pixcir_i2c_chip_data pixcir_tangoc_data = {
 599         .max_fingers = 5,
 600         .has_hw_ids = true,
 601 };
 602
 603 static const struct of_device_id pixcir_of_match[] = {
 604         { .compatible = "pixcir,pixcir_ts", .data = &pixcir_ts_data },
 605         { .compatible = "pixcir,pixcir_tangoc", .data = &pixcir_tangoc_data },
 606         { }
 607 };
 608 MODULE_DEVICE_TABLE(of, pixcir_of_match);
 609 #endif
 610
 611 static struct i2c_driver pixcir_i2c_ts_driver = {
 612         .driver = {
 613                 .name   = "pixcir_ts",
 614                 .pm     = &pixcir_dev_pm_ops,
 615                 .of_match_table = of_match_ptr(pixcir_of_match),
 616         },
 617         .probe          = pixcir_i2c_ts_probe,
 618         .id_table       = pixcir_i2c_ts_id,
 619 };
 620
 621 module_i2c_driver(pixcir_i2c_ts_driver);
 622
 623 MODULE_AUTHOR("Jianchun Bian <jcbian@pixcir.com.cn>, Dequan Meng <dqmeng@pixcir.com.cn>");
 624 MODULE_DESCRIPTION("Pixcir I2C Touchscreen Driver");
 625 MODULE_LICENSE("GPL");