linux/drivers/input/touchscreen/mms114.c
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   1/*
   2 * Copyright (C) 2012 Samsung Electronics Co.Ltd
   3 * Author: Joonyoung Shim <jy0922.shim@samsung.com>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License version 2 as
   7 * published by the Free Software Foundation.
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/delay.h>
  12#include <linux/of.h>
  13#include <linux/i2c.h>
  14#include <linux/i2c/mms114.h>
  15#include <linux/input/mt.h>
  16#include <linux/interrupt.h>
  17#include <linux/regulator/consumer.h>
  18#include <linux/slab.h>
  19
  20/* Write only registers */
  21#define MMS114_MODE_CONTROL             0x01
  22#define MMS114_OPERATION_MODE_MASK      0xE
  23#define MMS114_ACTIVE                   (1 << 1)
  24
  25#define MMS114_XY_RESOLUTION_H          0x02
  26#define MMS114_X_RESOLUTION             0x03
  27#define MMS114_Y_RESOLUTION             0x04
  28#define MMS114_CONTACT_THRESHOLD        0x05
  29#define MMS114_MOVING_THRESHOLD         0x06
  30
  31/* Read only registers */
  32#define MMS114_PACKET_SIZE              0x0F
  33#define MMS114_INFOMATION               0x10
  34#define MMS114_TSP_REV                  0xF0
  35
  36/* Minimum delay time is 50us between stop and start signal of i2c */
  37#define MMS114_I2C_DELAY                50
  38
  39/* 200ms needs after power on */
  40#define MMS114_POWERON_DELAY            200
  41
  42/* Touchscreen absolute values */
  43#define MMS114_MAX_AREA                 0xff
  44
  45#define MMS114_MAX_TOUCH                10
  46#define MMS114_PACKET_NUM               8
  47
  48/* Touch type */
  49#define MMS114_TYPE_NONE                0
  50#define MMS114_TYPE_TOUCHSCREEN         1
  51#define MMS114_TYPE_TOUCHKEY            2
  52
  53struct mms114_data {
  54        struct i2c_client       *client;
  55        struct input_dev        *input_dev;
  56        struct regulator        *core_reg;
  57        struct regulator        *io_reg;
  58        const struct mms114_platform_data       *pdata;
  59
  60        /* Use cache data for mode control register(write only) */
  61        u8                      cache_mode_control;
  62};
  63
  64struct mms114_touch {
  65        u8 id:4, reserved_bit4:1, type:2, pressed:1;
  66        u8 x_hi:4, y_hi:4;
  67        u8 x_lo;
  68        u8 y_lo;
  69        u8 width;
  70        u8 strength;
  71        u8 reserved[2];
  72} __packed;
  73
  74static int __mms114_read_reg(struct mms114_data *data, unsigned int reg,
  75                             unsigned int len, u8 *val)
  76{
  77        struct i2c_client *client = data->client;
  78        struct i2c_msg xfer[2];
  79        u8 buf = reg & 0xff;
  80        int error;
  81
  82        if (reg <= MMS114_MODE_CONTROL && reg + len > MMS114_MODE_CONTROL)
  83                BUG();
  84
  85        /* Write register: use repeated start */
  86        xfer[0].addr = client->addr;
  87        xfer[0].flags = I2C_M_TEN | I2C_M_NOSTART;
  88        xfer[0].len = 1;
  89        xfer[0].buf = &buf;
  90
  91        /* Read data */
  92        xfer[1].addr = client->addr;
  93        xfer[1].flags = I2C_M_RD;
  94        xfer[1].len = len;
  95        xfer[1].buf = val;
  96
  97        error = i2c_transfer(client->adapter, xfer, 2);
  98        if (error != 2) {
  99                dev_err(&client->dev,
 100                        "%s: i2c transfer failed (%d)\n", __func__, error);
 101                return error < 0 ? error : -EIO;
 102        }
 103        udelay(MMS114_I2C_DELAY);
 104
 105        return 0;
 106}
 107
 108static int mms114_read_reg(struct mms114_data *data, unsigned int reg)
 109{
 110        u8 val;
 111        int error;
 112
 113        if (reg == MMS114_MODE_CONTROL)
 114                return data->cache_mode_control;
 115
 116        error = __mms114_read_reg(data, reg, 1, &val);
 117        return error < 0 ? error : val;
 118}
 119
 120static int mms114_write_reg(struct mms114_data *data, unsigned int reg,
 121                            unsigned int val)
 122{
 123        struct i2c_client *client = data->client;
 124        u8 buf[2];
 125        int error;
 126
 127        buf[0] = reg & 0xff;
 128        buf[1] = val & 0xff;
 129
 130        error = i2c_master_send(client, buf, 2);
 131        if (error != 2) {
 132                dev_err(&client->dev,
 133                        "%s: i2c send failed (%d)\n", __func__, error);
 134                return error < 0 ? error : -EIO;
 135        }
 136        udelay(MMS114_I2C_DELAY);
 137
 138        if (reg == MMS114_MODE_CONTROL)
 139                data->cache_mode_control = val;
 140
 141        return 0;
 142}
 143
 144static void mms114_process_mt(struct mms114_data *data, struct mms114_touch *touch)
 145{
 146        const struct mms114_platform_data *pdata = data->pdata;
 147        struct i2c_client *client = data->client;
 148        struct input_dev *input_dev = data->input_dev;
 149        unsigned int id;
 150        unsigned int x;
 151        unsigned int y;
 152
 153        if (touch->id > MMS114_MAX_TOUCH) {
 154                dev_err(&client->dev, "Wrong touch id (%d)\n", touch->id);
 155                return;
 156        }
 157
 158        if (touch->type != MMS114_TYPE_TOUCHSCREEN) {
 159                dev_err(&client->dev, "Wrong touch type (%d)\n", touch->type);
 160                return;
 161        }
 162
 163        id = touch->id - 1;
 164        x = touch->x_lo | touch->x_hi << 8;
 165        y = touch->y_lo | touch->y_hi << 8;
 166        if (x > pdata->x_size || y > pdata->y_size) {
 167                dev_dbg(&client->dev,
 168                        "Wrong touch coordinates (%d, %d)\n", x, y);
 169                return;
 170        }
 171
 172        if (pdata->x_invert)
 173                x = pdata->x_size - x;
 174        if (pdata->y_invert)
 175                y = pdata->y_size - y;
 176
 177        dev_dbg(&client->dev,
 178                "id: %d, type: %d, pressed: %d, x: %d, y: %d, width: %d, strength: %d\n",
 179                id, touch->type, touch->pressed,
 180                x, y, touch->width, touch->strength);
 181
 182        input_mt_slot(input_dev, id);
 183        input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, touch->pressed);
 184
 185        if (touch->pressed) {
 186                input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, touch->width);
 187                input_report_abs(input_dev, ABS_MT_POSITION_X, x);
 188                input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
 189                input_report_abs(input_dev, ABS_MT_PRESSURE, touch->strength);
 190        }
 191}
 192
 193static irqreturn_t mms114_interrupt(int irq, void *dev_id)
 194{
 195        struct mms114_data *data = dev_id;
 196        struct input_dev *input_dev = data->input_dev;
 197        struct mms114_touch touch[MMS114_MAX_TOUCH];
 198        int packet_size;
 199        int touch_size;
 200        int index;
 201        int error;
 202
 203        mutex_lock(&input_dev->mutex);
 204        if (!input_dev->users) {
 205                mutex_unlock(&input_dev->mutex);
 206                goto out;
 207        }
 208        mutex_unlock(&input_dev->mutex);
 209
 210        packet_size = mms114_read_reg(data, MMS114_PACKET_SIZE);
 211        if (packet_size <= 0)
 212                goto out;
 213
 214        touch_size = packet_size / MMS114_PACKET_NUM;
 215
 216        error = __mms114_read_reg(data, MMS114_INFOMATION, packet_size,
 217                        (u8 *)touch);
 218        if (error < 0)
 219                goto out;
 220
 221        for (index = 0; index < touch_size; index++)
 222                mms114_process_mt(data, touch + index);
 223
 224        input_mt_report_pointer_emulation(data->input_dev, true);
 225        input_sync(data->input_dev);
 226
 227out:
 228        return IRQ_HANDLED;
 229}
 230
 231static int mms114_set_active(struct mms114_data *data, bool active)
 232{
 233        int val;
 234
 235        val = mms114_read_reg(data, MMS114_MODE_CONTROL);
 236        if (val < 0)
 237                return val;
 238
 239        val &= ~MMS114_OPERATION_MODE_MASK;
 240
 241        /* If active is false, sleep mode */
 242        if (active)
 243                val |= MMS114_ACTIVE;
 244
 245        return mms114_write_reg(data, MMS114_MODE_CONTROL, val);
 246}
 247
 248static int mms114_get_version(struct mms114_data *data)
 249{
 250        struct device *dev = &data->client->dev;
 251        u8 buf[6];
 252        int error;
 253
 254        error = __mms114_read_reg(data, MMS114_TSP_REV, 6, buf);
 255        if (error < 0)
 256                return error;
 257
 258        dev_info(dev, "TSP Rev: 0x%x, HW Rev: 0x%x, Firmware Ver: 0x%x\n",
 259                 buf[0], buf[1], buf[3]);
 260
 261        return 0;
 262}
 263
 264static int mms114_setup_regs(struct mms114_data *data)
 265{
 266        const struct mms114_platform_data *pdata = data->pdata;
 267        int val;
 268        int error;
 269
 270        error = mms114_get_version(data);
 271        if (error < 0)
 272                return error;
 273
 274        error = mms114_set_active(data, true);
 275        if (error < 0)
 276                return error;
 277
 278        val = (pdata->x_size >> 8) & 0xf;
 279        val |= ((pdata->y_size >> 8) & 0xf) << 4;
 280        error = mms114_write_reg(data, MMS114_XY_RESOLUTION_H, val);
 281        if (error < 0)
 282                return error;
 283
 284        val = pdata->x_size & 0xff;
 285        error = mms114_write_reg(data, MMS114_X_RESOLUTION, val);
 286        if (error < 0)
 287                return error;
 288
 289        val = pdata->y_size & 0xff;
 290        error = mms114_write_reg(data, MMS114_Y_RESOLUTION, val);
 291        if (error < 0)
 292                return error;
 293
 294        if (pdata->contact_threshold) {
 295                error = mms114_write_reg(data, MMS114_CONTACT_THRESHOLD,
 296                                pdata->contact_threshold);
 297                if (error < 0)
 298                        return error;
 299        }
 300
 301        if (pdata->moving_threshold) {
 302                error = mms114_write_reg(data, MMS114_MOVING_THRESHOLD,
 303                                pdata->moving_threshold);
 304                if (error < 0)
 305                        return error;
 306        }
 307
 308        return 0;
 309}
 310
 311static int mms114_start(struct mms114_data *data)
 312{
 313        struct i2c_client *client = data->client;
 314        int error;
 315
 316        error = regulator_enable(data->core_reg);
 317        if (error) {
 318                dev_err(&client->dev, "Failed to enable avdd: %d\n", error);
 319                return error;
 320        }
 321
 322        error = regulator_enable(data->io_reg);
 323        if (error) {
 324                dev_err(&client->dev, "Failed to enable vdd: %d\n", error);
 325                regulator_disable(data->core_reg);
 326                return error;
 327        }
 328
 329        mdelay(MMS114_POWERON_DELAY);
 330
 331        error = mms114_setup_regs(data);
 332        if (error < 0) {
 333                regulator_disable(data->io_reg);
 334                regulator_disable(data->core_reg);
 335                return error;
 336        }
 337
 338        if (data->pdata->cfg_pin)
 339                data->pdata->cfg_pin(true);
 340
 341        enable_irq(client->irq);
 342
 343        return 0;
 344}
 345
 346static void mms114_stop(struct mms114_data *data)
 347{
 348        struct i2c_client *client = data->client;
 349        int error;
 350
 351        disable_irq(client->irq);
 352
 353        if (data->pdata->cfg_pin)
 354                data->pdata->cfg_pin(false);
 355
 356        error = regulator_disable(data->io_reg);
 357        if (error)
 358                dev_warn(&client->dev, "Failed to disable vdd: %d\n", error);
 359
 360        error = regulator_disable(data->core_reg);
 361        if (error)
 362                dev_warn(&client->dev, "Failed to disable avdd: %d\n", error);
 363}
 364
 365static int mms114_input_open(struct input_dev *dev)
 366{
 367        struct mms114_data *data = input_get_drvdata(dev);
 368
 369        return mms114_start(data);
 370}
 371
 372static void mms114_input_close(struct input_dev *dev)
 373{
 374        struct mms114_data *data = input_get_drvdata(dev);
 375
 376        mms114_stop(data);
 377}
 378
 379#ifdef CONFIG_OF
 380static struct mms114_platform_data *mms114_parse_dt(struct device *dev)
 381{
 382        struct mms114_platform_data *pdata;
 383        struct device_node *np = dev->of_node;
 384
 385        if (!np)
 386                return NULL;
 387
 388        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 389        if (!pdata) {
 390                dev_err(dev, "failed to allocate platform data\n");
 391                return NULL;
 392        }
 393
 394        if (of_property_read_u32(np, "x-size", &pdata->x_size)) {
 395                dev_err(dev, "failed to get x-size property\n");
 396                return NULL;
 397        };
 398
 399        if (of_property_read_u32(np, "y-size", &pdata->y_size)) {
 400                dev_err(dev, "failed to get y-size property\n");
 401                return NULL;
 402        };
 403
 404        of_property_read_u32(np, "contact-threshold",
 405                                &pdata->contact_threshold);
 406        of_property_read_u32(np, "moving-threshold",
 407                                &pdata->moving_threshold);
 408
 409        if (of_find_property(np, "x-invert", NULL))
 410                pdata->x_invert = true;
 411        if (of_find_property(np, "y-invert", NULL))
 412                pdata->y_invert = true;
 413
 414        return pdata;
 415}
 416#else
 417static inline struct mms114_platform_data *mms114_parse_dt(struct device *dev)
 418{
 419        return NULL;
 420}
 421#endif
 422
 423static int mms114_probe(struct i2c_client *client,
 424                                  const struct i2c_device_id *id)
 425{
 426        const struct mms114_platform_data *pdata;
 427        struct mms114_data *data;
 428        struct input_dev *input_dev;
 429        int error;
 430
 431        pdata = dev_get_platdata(&client->dev);
 432        if (!pdata)
 433                pdata = mms114_parse_dt(&client->dev);
 434
 435        if (!pdata) {
 436                dev_err(&client->dev, "Need platform data\n");
 437                return -EINVAL;
 438        }
 439
 440        if (!i2c_check_functionality(client->adapter,
 441                                I2C_FUNC_PROTOCOL_MANGLING)) {
 442                dev_err(&client->dev,
 443                        "Need i2c bus that supports protocol mangling\n");
 444                return -ENODEV;
 445        }
 446
 447        data = devm_kzalloc(&client->dev, sizeof(struct mms114_data),
 448                            GFP_KERNEL);
 449        input_dev = devm_input_allocate_device(&client->dev);
 450        if (!data || !input_dev) {
 451                dev_err(&client->dev, "Failed to allocate memory\n");
 452                return -ENOMEM;
 453        }
 454
 455        data->client = client;
 456        data->input_dev = input_dev;
 457        data->pdata = pdata;
 458
 459        input_dev->name = "MELFAS MMS114 Touchscreen";
 460        input_dev->id.bustype = BUS_I2C;
 461        input_dev->dev.parent = &client->dev;
 462        input_dev->open = mms114_input_open;
 463        input_dev->close = mms114_input_close;
 464
 465        __set_bit(EV_ABS, input_dev->evbit);
 466        __set_bit(EV_KEY, input_dev->evbit);
 467        __set_bit(BTN_TOUCH, input_dev->keybit);
 468        input_set_abs_params(input_dev, ABS_X, 0, data->pdata->x_size, 0, 0);
 469        input_set_abs_params(input_dev, ABS_Y, 0, data->pdata->y_size, 0, 0);
 470
 471        /* For multi touch */
 472        input_mt_init_slots(input_dev, MMS114_MAX_TOUCH, 0);
 473        input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
 474                             0, MMS114_MAX_AREA, 0, 0);
 475        input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 476                             0, data->pdata->x_size, 0, 0);
 477        input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
 478                             0, data->pdata->y_size, 0, 0);
 479        input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 255, 0, 0);
 480
 481        input_set_drvdata(input_dev, data);
 482        i2c_set_clientdata(client, data);
 483
 484        data->core_reg = devm_regulator_get(&client->dev, "avdd");
 485        if (IS_ERR(data->core_reg)) {
 486                error = PTR_ERR(data->core_reg);
 487                dev_err(&client->dev,
 488                        "Unable to get the Core regulator (%d)\n", error);
 489                return error;
 490        }
 491
 492        data->io_reg = devm_regulator_get(&client->dev, "vdd");
 493        if (IS_ERR(data->io_reg)) {
 494                error = PTR_ERR(data->io_reg);
 495                dev_err(&client->dev,
 496                        "Unable to get the IO regulator (%d)\n", error);
 497                return error;
 498        }
 499
 500        error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 501                        mms114_interrupt, IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 502                        dev_name(&client->dev), data);
 503        if (error) {
 504                dev_err(&client->dev, "Failed to register interrupt\n");
 505                return error;
 506        }
 507        disable_irq(client->irq);
 508
 509        error = input_register_device(data->input_dev);
 510        if (error) {
 511                dev_err(&client->dev, "Failed to register input device\n");
 512                return error;
 513        }
 514
 515        return 0;
 516}
 517
 518static int __maybe_unused mms114_suspend(struct device *dev)
 519{
 520        struct i2c_client *client = to_i2c_client(dev);
 521        struct mms114_data *data = i2c_get_clientdata(client);
 522        struct input_dev *input_dev = data->input_dev;
 523        int id;
 524
 525        /* Release all touch */
 526        for (id = 0; id < MMS114_MAX_TOUCH; id++) {
 527                input_mt_slot(input_dev, id);
 528                input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, false);
 529        }
 530
 531        input_mt_report_pointer_emulation(input_dev, true);
 532        input_sync(input_dev);
 533
 534        mutex_lock(&input_dev->mutex);
 535        if (input_dev->users)
 536                mms114_stop(data);
 537        mutex_unlock(&input_dev->mutex);
 538
 539        return 0;
 540}
 541
 542static int __maybe_unused mms114_resume(struct device *dev)
 543{
 544        struct i2c_client *client = to_i2c_client(dev);
 545        struct mms114_data *data = i2c_get_clientdata(client);
 546        struct input_dev *input_dev = data->input_dev;
 547        int error;
 548
 549        mutex_lock(&input_dev->mutex);
 550        if (input_dev->users) {
 551                error = mms114_start(data);
 552                if (error < 0) {
 553                        mutex_unlock(&input_dev->mutex);
 554                        return error;
 555                }
 556        }
 557        mutex_unlock(&input_dev->mutex);
 558
 559        return 0;
 560}
 561
 562static SIMPLE_DEV_PM_OPS(mms114_pm_ops, mms114_suspend, mms114_resume);
 563
 564static const struct i2c_device_id mms114_id[] = {
 565        { "mms114", 0 },
 566        { }
 567};
 568MODULE_DEVICE_TABLE(i2c, mms114_id);
 569
 570#ifdef CONFIG_OF
 571static const struct of_device_id mms114_dt_match[] = {
 572        { .compatible = "melfas,mms114" },
 573        { }
 574};
 575#endif
 576
 577static struct i2c_driver mms114_driver = {
 578        .driver = {
 579                .name   = "mms114",
 580                .owner  = THIS_MODULE,
 581                .pm     = &mms114_pm_ops,
 582                .of_match_table = of_match_ptr(mms114_dt_match),
 583        },
 584        .probe          = mms114_probe,
 585        .id_table       = mms114_id,
 586};
 587
 588module_i2c_driver(mms114_driver);
 589
 590/* Module information */
 591MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
 592MODULE_DESCRIPTION("MELFAS mms114 Touchscreen driver");
 593MODULE_LICENSE("GPL");
 594