drivers/input/keyboard/matrix_keypad.c

   1 /*
   2  *  GPIO driven matrix keyboard driver
   3  *
   4  *  Copyright (c) 2008 Marek Vasut <marek.vasut@gmail.com>
   5  *
   6  *  Based on corgikbd.c
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License version 2 as
  10  *  published by the Free Software Foundation.
  11  *
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/delay.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/input.h>
  18 #include <linux/irq.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/jiffies.h>
  21 #include <linux/module.h>
  22 #include <linux/gpio.h>
  23 #include <linux/input/matrix_keypad.h>
  24 #include <linux/slab.h>
  25 #include <linux/of.h>
  26 #include <linux/of_gpio.h>
  27 #include <linux/of_platform.h>
  28
  29 struct matrix_keypad {
  30         const struct matrix_keypad_platform_data *pdata;
  31         struct input_dev *input_dev;
  32         unsigned int row_shift;
  33
  34         DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
  35
  36         uint32_t last_key_state[MATRIX_MAX_COLS];
  37         struct delayed_work work;
  38         spinlock_t lock;
  39         bool scan_pending;
  40         bool stopped;
  41         bool gpio_all_disabled;
  42 };
  43
  44 /*
  45  * NOTE: normally the GPIO has to be put into HiZ when de-activated to cause
  46  * minmal side effect when scanning other columns, here it is configured to
  47  * be input, and it should work on most platforms.
  48  */
  49 static void __activate_col(const struct matrix_keypad_platform_data *pdata,
  50                            int col, bool on)
  51 {
  52         bool level_on = !pdata->active_low;
  53
  54         if (on) {
  55                 gpio_direction_output(pdata->col_gpios[col], level_on);
  56         } else {
  57                 gpio_set_value_cansleep(pdata->col_gpios[col], !level_on);
  58                 gpio_direction_input(pdata->col_gpios[col]);
  59         }
  60 }
  61
  62 static void activate_col(const struct matrix_keypad_platform_data *pdata,
  63                          int col, bool on)
  64 {
  65         __activate_col(pdata, col, on);
  66
  67         if (on && pdata->col_scan_delay_us)
  68                 udelay(pdata->col_scan_delay_us);
  69 }
  70
  71 static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
  72                               bool on)
  73 {
  74         int col;
  75
  76         for (col = 0; col < pdata->num_col_gpios; col++)
  77                 __activate_col(pdata, col, on);
  78 }
  79
  80 static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
  81                          int row)
  82 {
  83         return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
  84                         !pdata->active_low : pdata->active_low;
  85 }
  86
  87 static void enable_row_irqs(struct matrix_keypad *keypad)
  88 {
  89         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
  90         int i;
  91
  92         if (pdata->clustered_irq > 0)
  93                 enable_irq(pdata->clustered_irq);
  94         else {
  95                 for (i = 0; i < pdata->num_row_gpios; i++)
  96                         enable_irq(gpio_to_irq(pdata->row_gpios[i]));
  97         }
  98 }
  99
 100 static void disable_row_irqs(struct matrix_keypad *keypad)
 101 {
 102         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 103         int i;
 104
 105         if (pdata->clustered_irq > 0)
 106                 disable_irq_nosync(pdata->clustered_irq);
 107         else {
 108                 for (i = 0; i < pdata->num_row_gpios; i++)
 109                         disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
 110         }
 111 }
 112
 113 /*
 114  * This gets the keys from keyboard and reports it to input subsystem
 115  */
 116 static void matrix_keypad_scan(struct work_struct *work)
 117 {
 118         struct matrix_keypad *keypad =
 119                 container_of(work, struct matrix_keypad, work.work);
 120         struct input_dev *input_dev = keypad->input_dev;
 121         const unsigned short *keycodes = input_dev->keycode;
 122         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 123         uint32_t new_state[MATRIX_MAX_COLS];
 124         int row, col, code;
 125
 126         /* de-activate all columns for scanning */
 127         activate_all_cols(pdata, false);
 128
 129         memset(new_state, 0, sizeof(new_state));
 130
 131         /* assert each column and read the row status out */
 132         for (col = 0; col < pdata->num_col_gpios; col++) {
 133
 134                 activate_col(pdata, col, true);
 135
 136                 for (row = 0; row < pdata->num_row_gpios; row++)
 137                         new_state[col] |=
 138                                 row_asserted(pdata, row) ? (1 << row) : 0;
 139
 140                 activate_col(pdata, col, false);
 141         }
 142
 143         for (col = 0; col < pdata->num_col_gpios; col++) {
 144                 uint32_t bits_changed;
 145
 146                 bits_changed = keypad->last_key_state[col] ^ new_state[col];
 147                 if (bits_changed == 0)
 148                         continue;
 149
 150                 for (row = 0; row < pdata->num_row_gpios; row++) {
 151                         if ((bits_changed & (1 << row)) == 0)
 152                                 continue;
 153
 154                         code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
 155                         input_event(input_dev, EV_MSC, MSC_SCAN, code);
 156                         input_report_key(input_dev,
 157                                          keycodes[code],
 158                                          new_state[col] & (1 << row));
 159                 }
 160         }
 161         input_sync(input_dev);
 162
 163         memcpy(keypad->last_key_state, new_state, sizeof(new_state));
 164
 165         activate_all_cols(pdata, true);
 166
 167         /* Enable IRQs again */
 168         spin_lock_irq(&keypad->lock);
 169         keypad->scan_pending = false;
 170         enable_row_irqs(keypad);
 171         spin_unlock_irq(&keypad->lock);
 172 }
 173
 174 static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
 175 {
 176         struct matrix_keypad *keypad = id;
 177         unsigned long flags;
 178
 179         spin_lock_irqsave(&keypad->lock, flags);
 180
 181         /*
 182          * See if another IRQ beaten us to it and scheduled the
 183          * scan already. In that case we should not try to
 184          * disable IRQs again.
 185          */
 186         if (unlikely(keypad->scan_pending || keypad->stopped))
 187                 goto out;
 188
 189         disable_row_irqs(keypad);
 190         keypad->scan_pending = true;
 191         schedule_delayed_work(&keypad->work,
 192                 msecs_to_jiffies(keypad->pdata->debounce_ms));
 193
 194 out:
 195         spin_unlock_irqrestore(&keypad->lock, flags);
 196         return IRQ_HANDLED;
 197 }
 198
 199 static int matrix_keypad_start(struct input_dev *dev)
 200 {
 201         struct matrix_keypad *keypad = input_get_drvdata(dev);
 202
 203         keypad->stopped = false;
 204         mb();
 205
 206         /*
 207          * Schedule an immediate key scan to capture current key state;
 208          * columns will be activated and IRQs be enabled after the scan.
 209          */
 210         schedule_delayed_work(&keypad->work, 0);
 211
 212         return 0;
 213 }
 214
 215 static void matrix_keypad_stop(struct input_dev *dev)
 216 {
 217         struct matrix_keypad *keypad = input_get_drvdata(dev);
 218
 219         keypad->stopped = true;
 220         mb();
 221         flush_work(&keypad->work.work);
 222         /*
 223          * matrix_keypad_scan() will leave IRQs enabled;
 224          * we should disable them now.
 225          */
 226         disable_row_irqs(keypad);
 227 }
 228
 229 #ifdef CONFIG_PM_SLEEP
 230 static void matrix_keypad_enable_wakeup(struct matrix_keypad *keypad)
 231 {
 232         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 233         unsigned int gpio;
 234         int i;
 235
 236         if (pdata->clustered_irq > 0) {
 237                 if (enable_irq_wake(pdata->clustered_irq) == 0)
 238                         keypad->gpio_all_disabled = true;
 239         } else {
 240
 241                 for (i = 0; i < pdata->num_row_gpios; i++) {
 242                         if (!test_bit(i, keypad->disabled_gpios)) {
 243                                 gpio = pdata->row_gpios[i];
 244
 245                                 if (enable_irq_wake(gpio_to_irq(gpio)) == 0)
 246                                         __set_bit(i, keypad->disabled_gpios);
 247                         }
 248                 }
 249         }
 250 }
 251
 252 static void matrix_keypad_disable_wakeup(struct matrix_keypad *keypad)
 253 {
 254         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 255         unsigned int gpio;
 256         int i;
 257
 258         if (pdata->clustered_irq > 0) {
 259                 if (keypad->gpio_all_disabled) {
 260                         disable_irq_wake(pdata->clustered_irq);
 261                         keypad->gpio_all_disabled = false;
 262                 }
 263         } else {
 264                 for (i = 0; i < pdata->num_row_gpios; i++) {
 265                         if (test_and_clear_bit(i, keypad->disabled_gpios)) {
 266                                 gpio = pdata->row_gpios[i];
 267                                 disable_irq_wake(gpio_to_irq(gpio));
 268                         }
 269                 }
 270         }
 271 }
 272
 273 static int matrix_keypad_suspend(struct device *dev)
 274 {
 275         struct platform_device *pdev = to_platform_device(dev);
 276         struct matrix_keypad *keypad = platform_get_drvdata(pdev);
 277
 278         matrix_keypad_stop(keypad->input_dev);
 279
 280         if (device_may_wakeup(&pdev->dev))
 281                 matrix_keypad_enable_wakeup(keypad);
 282
 283         return 0;
 284 }
 285
 286 static int matrix_keypad_resume(struct device *dev)
 287 {
 288         struct platform_device *pdev = to_platform_device(dev);
 289         struct matrix_keypad *keypad = platform_get_drvdata(pdev);
 290
 291         if (device_may_wakeup(&pdev->dev))
 292                 matrix_keypad_disable_wakeup(keypad);
 293
 294         matrix_keypad_start(keypad->input_dev);
 295
 296         return 0;
 297 }
 298 #endif
 299
 300 static SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
 301                          matrix_keypad_suspend, matrix_keypad_resume);
 302
 303 static int matrix_keypad_init_gpio(struct platform_device *pdev,
 304                                    struct matrix_keypad *keypad)
 305 {
 306         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 307         int i, err;
 308
 309         /* initialized strobe lines as outputs, activated */
 310         for (i = 0; i < pdata->num_col_gpios; i++) {
 311                 err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col");
 312                 if (err) {
 313                         dev_err(&pdev->dev,
 314                                 "failed to request GPIO%d for COL%d\n",
 315                                 pdata->col_gpios[i], i);
 316                         goto err_free_cols;
 317                 }
 318
 319                 gpio_direction_output(pdata->col_gpios[i], !pdata->active_low);
 320         }
 321
 322         for (i = 0; i < pdata->num_row_gpios; i++) {
 323                 err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row");
 324                 if (err) {
 325                         dev_err(&pdev->dev,
 326                                 "failed to request GPIO%d for ROW%d\n",
 327                                 pdata->row_gpios[i], i);
 328                         goto err_free_rows;
 329                 }
 330
 331                 gpio_direction_input(pdata->row_gpios[i]);
 332         }
 333
 334         if (pdata->clustered_irq > 0) {
 335                 err = request_any_context_irq(pdata->clustered_irq,
 336                                 matrix_keypad_interrupt,
 337                                 pdata->clustered_irq_flags,
 338                                 "matrix-keypad", keypad);
 339                 if (err < 0) {
 340                         dev_err(&pdev->dev,
 341                                 "Unable to acquire clustered interrupt\n");
 342                         goto err_free_rows;
 343                 }
 344         } else {
 345                 for (i = 0; i < pdata->num_row_gpios; i++) {
 346                         err = request_any_context_irq(
 347                                         gpio_to_irq(pdata->row_gpios[i]),
 348                                         matrix_keypad_interrupt,
 349                                         IRQF_TRIGGER_RISING |
 350                                         IRQF_TRIGGER_FALLING,
 351                                         "matrix-keypad", keypad);
 352                         if (err < 0) {
 353                                 dev_err(&pdev->dev,
 354                                         "Unable to acquire interrupt for GPIO line %i\n",
 355                                         pdata->row_gpios[i]);
 356                                 goto err_free_irqs;
 357                         }
 358                 }
 359         }
 360
 361         /* initialized as disabled - enabled by input->open */
 362         disable_row_irqs(keypad);
 363         return 0;
 364
 365 err_free_irqs:
 366         while (--i >= 0)
 367                 free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
 368         i = pdata->num_row_gpios;
 369 err_free_rows:
 370         while (--i >= 0)
 371                 gpio_free(pdata->row_gpios[i]);
 372         i = pdata->num_col_gpios;
 373 err_free_cols:
 374         while (--i >= 0)
 375                 gpio_free(pdata->col_gpios[i]);
 376
 377         return err;
 378 }
 379
 380 static void matrix_keypad_free_gpio(struct matrix_keypad *keypad)
 381 {
 382         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 383         int i;
 384
 385         if (pdata->clustered_irq > 0) {
 386                 free_irq(pdata->clustered_irq, keypad);
 387         } else {
 388                 for (i = 0; i < pdata->num_row_gpios; i++)
 389                         free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
 390         }
 391
 392         for (i = 0; i < pdata->num_row_gpios; i++)
 393                 gpio_free(pdata->row_gpios[i]);
 394
 395         for (i = 0; i < pdata->num_col_gpios; i++)
 396                 gpio_free(pdata->col_gpios[i]);
 397 }
 398
 399 #ifdef CONFIG_OF
 400 static struct matrix_keypad_platform_data *
 401 matrix_keypad_parse_dt(struct device *dev)
 402 {
 403         struct matrix_keypad_platform_data *pdata;
 404         struct device_node *np = dev->of_node;
 405         unsigned int *gpios;
 406         int i, nrow, ncol;
 407
 408         if (!np) {
 409                 dev_err(dev, "device lacks DT data\n");
 410                 return ERR_PTR(-ENODEV);
 411         }
 412
 413         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 414         if (!pdata) {
 415                 dev_err(dev, "could not allocate memory for platform data\n");
 416                 return ERR_PTR(-ENOMEM);
 417         }
 418
 419         pdata->num_row_gpios = nrow = of_gpio_named_count(np, "row-gpios");
 420         pdata->num_col_gpios = ncol = of_gpio_named_count(np, "col-gpios");
 421         if (nrow <= 0 || ncol <= 0) {
 422                 dev_err(dev, "number of keypad rows/columns not specified\n");
 423                 return ERR_PTR(-EINVAL);
 424         }
 425
 426         if (of_get_property(np, "linux,no-autorepeat", NULL))
 427                 pdata->no_autorepeat = true;
 428
 429         pdata->wakeup = of_property_read_bool(np, "wakeup-source") ||
 430                         of_property_read_bool(np, "linux,wakeup"); /* legacy */
 431
 432         if (of_get_property(np, "gpio-activelow", NULL))
 433                 pdata->active_low = true;
 434
 435         of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms);
 436         of_property_read_u32(np, "col-scan-delay-us",
 437                                                 &pdata->col_scan_delay_us);
 438
 439         gpios = devm_kzalloc(dev,
 440                              sizeof(unsigned int) *
 441                                 (pdata->num_row_gpios + pdata->num_col_gpios),
 442                              GFP_KERNEL);
 443         if (!gpios) {
 444                 dev_err(dev, "could not allocate memory for gpios\n");
 445                 return ERR_PTR(-ENOMEM);
 446         }
 447
 448         for (i = 0; i < pdata->num_row_gpios; i++)
 449                 gpios[i] = of_get_named_gpio(np, "row-gpios", i);
 450
 451         for (i = 0; i < pdata->num_col_gpios; i++)
 452                 gpios[pdata->num_row_gpios + i] =
 453                         of_get_named_gpio(np, "col-gpios", i);
 454
 455         pdata->row_gpios = gpios;
 456         pdata->col_gpios = &gpios[pdata->num_row_gpios];
 457
 458         return pdata;
 459 }
 460 #else
 461 static inline struct matrix_keypad_platform_data *
 462 matrix_keypad_parse_dt(struct device *dev)
 463 {
 464         dev_err(dev, "no platform data defined\n");
 465
 466         return ERR_PTR(-EINVAL);
 467 }
 468 #endif
 469
 470 static int matrix_keypad_probe(struct platform_device *pdev)
 471 {
 472         const struct matrix_keypad_platform_data *pdata;
 473         struct matrix_keypad *keypad;
 474         struct input_dev *input_dev;
 475         int err;
 476
 477         pdata = dev_get_platdata(&pdev->dev);
 478         if (!pdata) {
 479                 pdata = matrix_keypad_parse_dt(&pdev->dev);
 480                 if (IS_ERR(pdata)) {
 481                         dev_err(&pdev->dev, "no platform data defined\n");
 482                         return PTR_ERR(pdata);
 483                 }
 484         } else if (!pdata->keymap_data) {
 485                 dev_err(&pdev->dev, "no keymap data defined\n");
 486                 return -EINVAL;
 487         }
 488
 489         keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
 490         input_dev = input_allocate_device();
 491         if (!keypad || !input_dev) {
 492                 err = -ENOMEM;
 493                 goto err_free_mem;
 494         }
 495
 496         keypad->input_dev = input_dev;
 497         keypad->pdata = pdata;
 498         keypad->row_shift = get_count_order(pdata->num_col_gpios);
 499         keypad->stopped = true;
 500         INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
 501         spin_lock_init(&keypad->lock);
 502
 503         input_dev->name         = pdev->name;
 504         input_dev->id.bustype   = BUS_HOST;
 505         input_dev->dev.parent   = &pdev->dev;
 506         input_dev->open         = matrix_keypad_start;
 507         input_dev->close        = matrix_keypad_stop;
 508
 509         err = matrix_keypad_build_keymap(pdata->keymap_data, NULL,
 510                                          pdata->num_row_gpios,
 511                                          pdata->num_col_gpios,
 512                                          NULL, input_dev);
 513         if (err) {
 514                 dev_err(&pdev->dev, "failed to build keymap\n");
 515                 goto err_free_mem;
 516         }
 517
 518         if (!pdata->no_autorepeat)
 519                 __set_bit(EV_REP, input_dev->evbit);
 520         input_set_capability(input_dev, EV_MSC, MSC_SCAN);
 521         input_set_drvdata(input_dev, keypad);
 522
 523         err = matrix_keypad_init_gpio(pdev, keypad);
 524         if (err)
 525                 goto err_free_mem;
 526
 527         err = input_register_device(keypad->input_dev);
 528         if (err)
 529                 goto err_free_gpio;
 530
 531         device_init_wakeup(&pdev->dev, pdata->wakeup);
 532         platform_set_drvdata(pdev, keypad);
 533
 534         return 0;
 535
 536 err_free_gpio:
 537         matrix_keypad_free_gpio(keypad);
 538 err_free_mem:
 539         input_free_device(input_dev);
 540         kfree(keypad);
 541         return err;
 542 }
 543
 544 static int matrix_keypad_remove(struct platform_device *pdev)
 545 {
 546         struct matrix_keypad *keypad = platform_get_drvdata(pdev);
 547
 548         device_init_wakeup(&pdev->dev, 0);
 549
 550         matrix_keypad_free_gpio(keypad);
 551         input_unregister_device(keypad->input_dev);
 552         kfree(keypad);
 553
 554         return 0;
 555 }
 556
 557 #ifdef CONFIG_OF
 558 static const struct of_device_id matrix_keypad_dt_match[] = {
 559         { .compatible = "gpio-matrix-keypad" },
 560         { }
 561 };
 562 MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
 563 #endif
 564
 565 static struct platform_driver matrix_keypad_driver = {
 566         .probe          = matrix_keypad_probe,
 567         .remove         = matrix_keypad_remove,
 568         .driver         = {
 569                 .name   = "matrix-keypad",
 570                 .pm     = &matrix_keypad_pm_ops,
 571                 .of_match_table = of_match_ptr(matrix_keypad_dt_match),
 572         },
 573 };
 574 module_platform_driver(matrix_keypad_driver);
 575
 576 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 577 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
 578 MODULE_LICENSE("GPL v2");
 579 MODULE_ALIAS("platform:matrix-keypad");