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  * You should have received a copy of the GNU General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  18  */
  19
  20 #include <linux/delay.h>
  21 #include <linux/module.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/slab.h>
  24 #include <linux/i2c.h>
  25 #include <linux/input.h>
  26 #include <linux/input/mt.h>
  27 #include <linux/input/pixcir_ts.h>
  28 #include <linux/gpio.h>
  29 #include <linux/of.h>
  30 #include <linux/of_gpio.h>
  31 #include <linux/of_device.h>
  32
  33 #define PIXCIR_MAX_SLOTS       5 /* Max fingers supported by driver */
  34
  35 struct pixcir_i2c_ts_data {
  36         struct i2c_client *client;
  37         struct input_dev *input;
  38         const struct pixcir_ts_platform_data *pdata;
  39         bool running;
  40         int max_fingers;        /* Max fingers supported in this instance */
  41 };
  42
  43 struct pixcir_touch {
  44         int x;
  45         int y;
  46         int id;
  47 };
  48
  49 struct pixcir_report_data {
  50         int num_touches;
  51         struct pixcir_touch touches[PIXCIR_MAX_SLOTS];
  52 };
  53
  54 static void pixcir_ts_parse(struct pixcir_i2c_ts_data *tsdata,
  55                             struct pixcir_report_data *report)
  56 {
  57         u8 rdbuf[2 + PIXCIR_MAX_SLOTS * 5];
  58         u8 wrbuf[1] = { 0 };
  59         u8 *bufptr;
  60         u8 touch;
  61         int ret, i;
  62         int readsize;
  63         const struct pixcir_i2c_chip_data *chip = &tsdata->pdata->chip;
  64
  65         memset(report, 0, sizeof(struct pixcir_report_data));
  66
  67         i = chip->has_hw_ids ? 1 : 0;
  68         readsize = 2 + tsdata->max_fingers * (4 + i);
  69         if (readsize > sizeof(rdbuf))
  70                 readsize = sizeof(rdbuf);
  71
  72         ret = i2c_master_send(tsdata->client, wrbuf, sizeof(wrbuf));
  73         if (ret != sizeof(wrbuf)) {
  74                 dev_err(&tsdata->client->dev,
  75                         "%s: i2c_master_send failed(), ret=%d\n",
  76                         __func__, ret);
  77                 return;
  78         }
  79
  80         ret = i2c_master_recv(tsdata->client, rdbuf, readsize);
  81         if (ret != readsize) {
  82                 dev_err(&tsdata->client->dev,
  83                         "%s: i2c_master_recv failed(), ret=%d\n",
  84                         __func__, ret);
  85                 return;
  86         }
  87
  88         touch = rdbuf[0] & 0x7;
  89         if (touch > tsdata->max_fingers)
  90                 touch = tsdata->max_fingers;
  91
  92         report->num_touches = touch;
  93         bufptr = &rdbuf[2];
  94
  95         for (i = 0; i < touch; i++) {
  96                 report->touches[i].x = (bufptr[1] << 8) | bufptr[0];
  97                 report->touches[i].y = (bufptr[3] << 8) | bufptr[2];
  98
  99                 if (chip->has_hw_ids) {
 100                         report->touches[i].id = bufptr[4];
 101                         bufptr = bufptr + 5;
 102                 } else {
 103                         bufptr = bufptr + 4;
 104                 }
 105         }
 106 }
 107
 108 static void pixcir_ts_report(struct pixcir_i2c_ts_data *ts,
 109                              struct pixcir_report_data *report)
 110 {
 111         struct input_mt_pos pos[PIXCIR_MAX_SLOTS];
 112         int slots[PIXCIR_MAX_SLOTS];
 113         struct pixcir_touch *touch;
 114         int n, i, slot;
 115         struct device *dev = &ts->client->dev;
 116         const struct pixcir_i2c_chip_data *chip = &ts->pdata->chip;
 117
 118         n = report->num_touches;
 119         if (n > PIXCIR_MAX_SLOTS)
 120                 n = PIXCIR_MAX_SLOTS;
 121
 122         if (!chip->has_hw_ids) {
 123                 for (i = 0; i < n; i++) {
 124                         touch = &report->touches[i];
 125                         pos[i].x = touch->x;
 126                         pos[i].y = touch->y;
 127                 }
 128
 129                 input_mt_assign_slots(ts->input, slots, pos, n, 0);
 130         }
 131
 132         for (i = 0; i < n; i++) {
 133                 touch = &report->touches[i];
 134
 135                 if (chip->has_hw_ids) {
 136                         slot = input_mt_get_slot_by_key(ts->input, touch->id);
 137                         if (slot < 0) {
 138                                 dev_dbg(dev, "no free slot for id 0x%x\n",
 139                                         touch->id);
 140                                 continue;
 141                         }
 142                 } else {
 143                         slot = slots[i];
 144                 }
 145
 146                 input_mt_slot(ts->input, slot);
 147                 input_mt_report_slot_state(ts->input,
 148                                            MT_TOOL_FINGER, true);
 149
 150                 input_event(ts->input, EV_ABS, ABS_MT_POSITION_X, touch->x);
 151                 input_event(ts->input, EV_ABS, ABS_MT_POSITION_Y, touch->y);
 152
 153                 dev_dbg(dev, "%d: slot %d, x %d, y %d\n",
 154                         i, slot, touch->x, touch->y);
 155         }
 156
 157         input_mt_sync_frame(ts->input);
 158         input_sync(ts->input);
 159 }
 160
 161 static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
 162 {
 163         struct pixcir_i2c_ts_data *tsdata = dev_id;
 164         const struct pixcir_ts_platform_data *pdata = tsdata->pdata;
 165         struct pixcir_report_data report;
 166
 167         while (tsdata->running) {
 168                 /* parse packet */
 169                 pixcir_ts_parse(tsdata, &report);
 170
 171                 /* report it */
 172                 pixcir_ts_report(tsdata, &report);
 173
 174                 if (gpio_get_value(pdata->gpio_attb)) {
 175                         if (report.num_touches) {
 176                                 /*
 177                                  * Last report with no finger up?
 178                                  * Do it now then.
 179                                  */
 180                                 input_mt_sync_frame(tsdata->input);
 181                                 input_sync(tsdata->input);
 182                         }
 183                         break;
 184                 }
 185
 186                 msleep(20);
 187         }
 188
 189         return IRQ_HANDLED;
 190 }
 191
 192 static int pixcir_set_power_mode(struct pixcir_i2c_ts_data *ts,
 193                                  enum pixcir_power_mode mode)
 194 {
 195         struct device *dev = &ts->client->dev;
 196         int ret;
 197
 198         ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_POWER_MODE);
 199         if (ret < 0) {
 200                 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
 201                         __func__, PIXCIR_REG_POWER_MODE, ret);
 202                 return ret;
 203         }
 204
 205         ret &= ~PIXCIR_POWER_MODE_MASK;
 206         ret |= mode;
 207
 208         /* Always AUTO_IDLE */
 209         ret |= PIXCIR_POWER_ALLOW_IDLE;
 210
 211         ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_POWER_MODE, ret);
 212         if (ret < 0) {
 213                 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
 214                         __func__, PIXCIR_REG_POWER_MODE, ret);
 215                 return ret;
 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         /* LEVEL_TOUCH interrupt with active low polarity */
 293         error = pixcir_set_int_mode(ts, PIXCIR_INT_LEVEL_TOUCH, 0);
 294         if (error) {
 295                 dev_err(dev, "Failed to set interrupt mode: %d\n", error);
 296                 return error;
 297         }
 298
 299         ts->running = true;
 300         mb();   /* Update status before IRQ can fire */
 301
 302         /* enable interrupt generation */
 303         error = pixcir_int_enable(ts, true);
 304         if (error) {
 305                 dev_err(dev, "Failed to enable interrupt generation: %d\n",
 306                         error);
 307                 return error;
 308         }
 309
 310         return 0;
 311 }
 312
 313 static int pixcir_stop(struct pixcir_i2c_ts_data *ts)
 314 {
 315         int error;
 316
 317         /* Disable interrupt generation */
 318         error = pixcir_int_enable(ts, false);
 319         if (error) {
 320                 dev_err(&ts->client->dev,
 321                         "Failed to disable interrupt generation: %d\n",
 322                         error);
 323                 return error;
 324         }
 325
 326         /* Exit ISR if running, no more report parsing */
 327         ts->running = false;
 328         mb();   /* update status before we synchronize irq */
 329
 330         /* Wait till running ISR is complete */
 331         synchronize_irq(ts->client->irq);
 332
 333         return 0;
 334 }
 335
 336 static int pixcir_input_open(struct input_dev *dev)
 337 {
 338         struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
 339
 340         return pixcir_start(ts);
 341 }
 342
 343 static void pixcir_input_close(struct input_dev *dev)
 344 {
 345         struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
 346
 347         pixcir_stop(ts);
 348 }
 349
 350 static int __maybe_unused pixcir_i2c_ts_suspend(struct device *dev)
 351 {
 352         struct i2c_client *client = to_i2c_client(dev);
 353         struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
 354         struct input_dev *input = ts->input;
 355         int ret = 0;
 356
 357         mutex_lock(&input->mutex);
 358
 359         if (device_may_wakeup(&client->dev)) {
 360                 if (!input->users) {
 361                         ret = pixcir_start(ts);
 362                         if (ret) {
 363                                 dev_err(dev, "Failed to start\n");
 364                                 goto unlock;
 365                         }
 366                 }
 367
 368                 enable_irq_wake(client->irq);
 369         } else if (input->users) {
 370                 ret = pixcir_stop(ts);
 371         }
 372
 373 unlock:
 374         mutex_unlock(&input->mutex);
 375
 376         return ret;
 377 }
 378
 379 static int __maybe_unused pixcir_i2c_ts_resume(struct device *dev)
 380 {
 381         struct i2c_client *client = to_i2c_client(dev);
 382         struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
 383         struct input_dev *input = ts->input;
 384         int ret = 0;
 385
 386         mutex_lock(&input->mutex);
 387
 388         if (device_may_wakeup(&client->dev)) {
 389                 disable_irq_wake(client->irq);
 390
 391                 if (!input->users) {
 392                         ret = pixcir_stop(ts);
 393                         if (ret) {
 394                                 dev_err(dev, "Failed to stop\n");
 395                                 goto unlock;
 396                         }
 397                 }
 398         } else if (input->users) {
 399                 ret = pixcir_start(ts);
 400         }
 401
 402 unlock:
 403         mutex_unlock(&input->mutex);
 404
 405         return ret;
 406 }
 407
 408 static SIMPLE_DEV_PM_OPS(pixcir_dev_pm_ops,
 409                          pixcir_i2c_ts_suspend, pixcir_i2c_ts_resume);
 410
 411 #ifdef CONFIG_OF
 412 static const struct of_device_id pixcir_of_match[];
 413
 414 static struct pixcir_ts_platform_data *pixcir_parse_dt(struct device *dev)
 415 {
 416         struct pixcir_ts_platform_data *pdata;
 417         struct device_node *np = dev->of_node;
 418         const struct of_device_id *match;
 419
 420         match = of_match_device(of_match_ptr(pixcir_of_match), dev);
 421         if (!match)
 422                 return ERR_PTR(-EINVAL);
 423
 424         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 425         if (!pdata)
 426                 return ERR_PTR(-ENOMEM);
 427
 428         pdata->chip = *(const struct pixcir_i2c_chip_data *)match->data;
 429
 430         pdata->gpio_attb = of_get_named_gpio(np, "attb-gpio", 0);
 431         /* gpio_attb validity is checked in probe */
 432
 433         if (of_property_read_u32(np, "touchscreen-size-x", &pdata->x_max)) {
 434                 dev_err(dev, "Failed to get touchscreen-size-x property\n");
 435                 return ERR_PTR(-EINVAL);
 436         }
 437         pdata->x_max -= 1;
 438
 439         if (of_property_read_u32(np, "touchscreen-size-y", &pdata->y_max)) {
 440                 dev_err(dev, "Failed to get touchscreen-size-y property\n");
 441                 return ERR_PTR(-EINVAL);
 442         }
 443         pdata->y_max -= 1;
 444
 445         dev_dbg(dev, "%s: x %d, y %d, gpio %d\n", __func__,
 446                 pdata->x_max + 1, pdata->y_max + 1, pdata->gpio_attb);
 447
 448         return pdata;
 449 }
 450 #else
 451 static struct pixcir_ts_platform_data *pixcir_parse_dt(struct device *dev)
 452 {
 453         return ERR_PTR(-EINVAL);
 454 }
 455 #endif
 456
 457 static int pixcir_i2c_ts_probe(struct i2c_client *client,
 458                                          const struct i2c_device_id *id)
 459 {
 460         const struct pixcir_ts_platform_data *pdata =
 461                         dev_get_platdata(&client->dev);
 462         struct device *dev = &client->dev;
 463         struct device_node *np = dev->of_node;
 464         struct pixcir_i2c_ts_data *tsdata;
 465         struct input_dev *input;
 466         int error;
 467
 468         if (np && !pdata) {
 469                 pdata = pixcir_parse_dt(dev);
 470                 if (IS_ERR(pdata))
 471                         return PTR_ERR(pdata);
 472         }
 473
 474         if (!pdata) {
 475                 dev_err(&client->dev, "platform data not defined\n");
 476                 return -EINVAL;
 477         }
 478
 479         if (!gpio_is_valid(pdata->gpio_attb)) {
 480                 dev_err(dev, "Invalid gpio_attb in pdata\n");
 481                 return -EINVAL;
 482         }
 483
 484         if (!pdata->chip.max_fingers) {
 485                 dev_err(dev, "Invalid max_fingers in pdata\n");
 486                 return -EINVAL;
 487         }
 488
 489         tsdata = devm_kzalloc(dev, sizeof(*tsdata), GFP_KERNEL);
 490         if (!tsdata)
 491                 return -ENOMEM;
 492
 493         input = devm_input_allocate_device(dev);
 494         if (!input) {
 495                 dev_err(dev, "Failed to allocate input device\n");
 496                 return -ENOMEM;
 497         }
 498
 499         tsdata->client = client;
 500         tsdata->input = input;
 501         tsdata->pdata = pdata;
 502
 503         input->name = client->name;
 504         input->id.bustype = BUS_I2C;
 505         input->open = pixcir_input_open;
 506         input->close = pixcir_input_close;
 507         input->dev.parent = &client->dev;
 508
 509         __set_bit(EV_KEY, input->evbit);
 510         __set_bit(EV_ABS, input->evbit);
 511         __set_bit(BTN_TOUCH, input->keybit);
 512         input_set_abs_params(input, ABS_X, 0, pdata->x_max, 0, 0);
 513         input_set_abs_params(input, ABS_Y, 0, pdata->y_max, 0, 0);
 514         input_set_abs_params(input, ABS_MT_POSITION_X, 0, pdata->x_max, 0, 0);
 515         input_set_abs_params(input, ABS_MT_POSITION_Y, 0, pdata->y_max, 0, 0);
 516
 517         tsdata->max_fingers = tsdata->pdata->chip.max_fingers;
 518         if (tsdata->max_fingers > PIXCIR_MAX_SLOTS) {
 519                 tsdata->max_fingers = PIXCIR_MAX_SLOTS;
 520                 dev_info(dev, "Limiting maximum fingers to %d\n",
 521                          tsdata->max_fingers);
 522         }
 523
 524         error = input_mt_init_slots(input, tsdata->max_fingers,
 525                                     INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 526         if (error) {
 527                 dev_err(dev, "Error initializing Multi-Touch slots\n");
 528                 return error;
 529         }
 530
 531         input_set_drvdata(input, tsdata);
 532
 533         error = devm_gpio_request_one(dev, pdata->gpio_attb,
 534                                       GPIOF_DIR_IN, "pixcir_i2c_attb");
 535         if (error) {
 536                 dev_err(dev, "Failed to request ATTB gpio\n");
 537                 return error;
 538         }
 539
 540         error = devm_request_threaded_irq(dev, client->irq, NULL, pixcir_ts_isr,
 541                                           IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 542                                           client->name, tsdata);
 543         if (error) {
 544                 dev_err(dev, "failed to request irq %d\n", client->irq);
 545                 return error;
 546         }
 547
 548         /* Always be in IDLE mode to save power, device supports auto wake */
 549         error = pixcir_set_power_mode(tsdata, PIXCIR_POWER_IDLE);
 550         if (error) {
 551                 dev_err(dev, "Failed to set IDLE mode\n");
 552                 return error;
 553         }
 554
 555         /* Stop device till opened */
 556         error = pixcir_stop(tsdata);
 557         if (error)
 558                 return error;
 559
 560         error = input_register_device(input);
 561         if (error)
 562                 return error;
 563
 564         i2c_set_clientdata(client, tsdata);
 565         device_init_wakeup(&client->dev, 1);
 566
 567         return 0;
 568 }
 569
 570 static int pixcir_i2c_ts_remove(struct i2c_client *client)
 571 {
 572         device_init_wakeup(&client->dev, 0);
 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                 .owner  = THIS_MODULE,
 606                 .name   = "pixcir_ts",
 607                 .pm     = &pixcir_dev_pm_ops,
 608                 .of_match_table = of_match_ptr(pixcir_of_match),
 609         },
 610         .probe          = pixcir_i2c_ts_probe,
 611         .remove         = pixcir_i2c_ts_remove,
 612         .id_table       = pixcir_i2c_ts_id,
 613 };
 614
 615 module_i2c_driver(pixcir_i2c_ts_driver);
 616
 617 MODULE_AUTHOR("Jianchun Bian <jcbian@pixcir.com.cn>, Dequan Meng <dqmeng@pixcir.com.cn>");
 618 MODULE_DESCRIPTION("Pixcir I2C Touchscreen Driver");
 619 MODULE_LICENSE("GPL");