linux/drivers/input/touchscreen/pixcir_i2c_ts.c
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   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
  32struct 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
  45struct pixcir_report_data {
  46        int num_touches;
  47        struct input_mt_pos pos[PIXCIR_MAX_SLOTS];
  48        int ids[PIXCIR_MAX_SLOTS];
  49};
  50
  51static 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
 105static 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
 149static 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
 179static 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
 190static 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 */
 234static 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 */
 268static 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
 295static 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
 326static 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
 352static 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
 359static 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
 366static 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
 387unlock:
 388        mutex_unlock(&input->mutex);
 389
 390        return ret;
 391}
 392
 393static 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
 414unlock:
 415        mutex_unlock(&input->mutex);
 416
 417        return ret;
 418}
 419
 420static SIMPLE_DEV_PM_OPS(pixcir_dev_pm_ops,
 421                         pixcir_i2c_ts_suspend, pixcir_i2c_ts_resume);
 422
 423#ifdef CONFIG_OF
 424static const struct of_device_id pixcir_of_match[];
 425
 426static 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
 436static int pixcir_parse_dt(struct device *dev,
 437                           struct pixcir_i2c_ts_data *tsdata)
 438{
 439        return -EINVAL;
 440}
 441#endif
 442
 443static 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
 585static const struct i2c_device_id pixcir_i2c_ts_id[] = {
 586        { "pixcir_ts", 0 },
 587        { "pixcir_tangoc", 0 },
 588        { }
 589};
 590MODULE_DEVICE_TABLE(i2c, pixcir_i2c_ts_id);
 591
 592#ifdef CONFIG_OF
 593static const struct pixcir_i2c_chip_data pixcir_ts_data = {
 594        .max_fingers = 2,
 595        /* no hw id support */
 596};
 597
 598static const struct pixcir_i2c_chip_data pixcir_tangoc_data = {
 599        .max_fingers = 5,
 600        .has_hw_ids = true,
 601};
 602
 603static 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};
 608MODULE_DEVICE_TABLE(of, pixcir_of_match);
 609#endif
 610
 611static 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
 621module_i2c_driver(pixcir_i2c_ts_driver);
 622
 623MODULE_AUTHOR("Jianchun Bian <jcbian@pixcir.com.cn>, Dequan Meng <dqmeng@pixcir.com.cn>");
 624MODULE_DESCRIPTION("Pixcir I2C Touchscreen Driver");
 625MODULE_LICENSE("GPL");
 626
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