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