drivers/input/keyboard/matrix_keypad.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  GPIO driven matrix keyboard driver
   4  *
   5  *  Copyright (c) 2008 Marek Vasut <marek.vasut@gmail.com>
   6  *
   7  *  Based on corgikbd.c
   8  */
   9
  10 #include <linux/types.h>
  11 #include <linux/delay.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/input.h>
  14 #include <linux/irq.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/jiffies.h>
  17 #include <linux/module.h>
  18 #include <linux/gpio.h>
  19 #include <linux/input/matrix_keypad.h>
  20 #include <linux/slab.h>
  21 #include <linux/of.h>
  22 #include <linux/of_gpio.h>
  23 #include <linux/of_platform.h>
  24
  25 struct matrix_keypad {
  26         const struct matrix_keypad_platform_data *pdata;
  27         struct input_dev *input_dev;
  28         unsigned int row_shift;
  29
  30         DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
  31
  32         uint32_t last_key_state[MATRIX_MAX_COLS];
  33         struct delayed_work work;
  34         spinlock_t lock;
  35         bool scan_pending;
  36         bool stopped;
  37         bool gpio_all_disabled;
  38 };
  39
  40 /*
  41  * NOTE: If drive_inactive_cols is false, then the GPIO has to be put into
  42  * HiZ when de-activated to cause minmal side effect when scanning other
  43  * columns. In that case it is configured here to be input, otherwise it is
  44  * driven with the inactive value.
  45  */
  46 static void __activate_col(const struct matrix_keypad_platform_data *pdata,
  47                            int col, bool on)
  48 {
  49         bool level_on = !pdata->active_low;
  50
  51         if (on) {
  52                 gpio_direction_output(pdata->col_gpios[col], level_on);
  53         } else {
  54                 gpio_set_value_cansleep(pdata->col_gpios[col], !level_on);
  55                 if (!pdata->drive_inactive_cols)
  56                         gpio_direction_input(pdata->col_gpios[col]);
  57         }
  58 }
  59
  60 static void activate_col(const struct matrix_keypad_platform_data *pdata,
  61                          int col, bool on)
  62 {
  63         __activate_col(pdata, col, on);
  64
  65         if (on && pdata->col_scan_delay_us)
  66                 udelay(pdata->col_scan_delay_us);
  67 }
  68
  69 static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
  70                               bool on)
  71 {
  72         int col;
  73
  74         for (col = 0; col < pdata->num_col_gpios; col++)
  75                 __activate_col(pdata, col, on);
  76 }
  77
  78 static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
  79                          int row)
  80 {
  81         return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
  82                         !pdata->active_low : pdata->active_low;
  83 }
  84
  85 static void enable_row_irqs(struct matrix_keypad *keypad)
  86 {
  87         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
  88         int i;
  89
  90         if (pdata->clustered_irq > 0)
  91                 enable_irq(pdata->clustered_irq);
  92         else {
  93                 for (i = 0; i < pdata->num_row_gpios; i++)
  94                         enable_irq(gpio_to_irq(pdata->row_gpios[i]));
  95         }
  96 }
  97
  98 static void disable_row_irqs(struct matrix_keypad *keypad)
  99 {
 100         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 101         int i;
 102
 103         if (pdata->clustered_irq > 0)
 104                 disable_irq_nosync(pdata->clustered_irq);
 105         else {
 106                 for (i = 0; i < pdata->num_row_gpios; i++)
 107                         disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
 108         }
 109 }
 110
 111 /*
 112  * This gets the keys from keyboard and reports it to input subsystem
 113  */
 114 static void matrix_keypad_scan(struct work_struct *work)
 115 {
 116         struct matrix_keypad *keypad =
 117                 container_of(work, struct matrix_keypad, work.work);
 118         struct input_dev *input_dev = keypad->input_dev;
 119         const unsigned short *keycodes = input_dev->keycode;
 120         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 121         uint32_t new_state[MATRIX_MAX_COLS];
 122         int row, col, code;
 123
 124         /* de-activate all columns for scanning */
 125         activate_all_cols(pdata, false);
 126
 127         memset(new_state, 0, sizeof(new_state));
 128
 129         /* assert each column and read the row status out */
 130         for (col = 0; col < pdata->num_col_gpios; col++) {
 131
 132                 activate_col(pdata, col, true);
 133
 134                 for (row = 0; row < pdata->num_row_gpios; row++)
 135                         new_state[col] |=
 136                                 row_asserted(pdata, row) ? (1 << row) : 0;
 137
 138                 activate_col(pdata, col, false);
 139         }
 140
 141         for (col = 0; col < pdata->num_col_gpios; col++) {
 142                 uint32_t bits_changed;
 143
 144                 bits_changed = keypad->last_key_state[col] ^ new_state[col];
 145                 if (bits_changed == 0)
 146                         continue;
 147
 148                 for (row = 0; row < pdata->num_row_gpios; row++) {
 149                         if ((bits_changed & (1 << row)) == 0)
 150                                 continue;
 151
 152                         code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
 153                         input_event(input_dev, EV_MSC, MSC_SCAN, code);
 154                         input_report_key(input_dev,
 155                                          keycodes[code],
 156                                          new_state[col] & (1 << row));
 157                 }
 158         }
 159         input_sync(input_dev);
 160
 161         memcpy(keypad->last_key_state, new_state, sizeof(new_state));
 162
 163         activate_all_cols(pdata, true);
 164
 165         /* Enable IRQs again */
 166         spin_lock_irq(&keypad->lock);
 167         keypad->scan_pending = false;
 168         enable_row_irqs(keypad);
 169         spin_unlock_irq(&keypad->lock);
 170 }
 171
 172 static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
 173 {
 174         struct matrix_keypad *keypad = id;
 175         unsigned long flags;
 176
 177         spin_lock_irqsave(&keypad->lock, flags);
 178
 179         /*
 180          * See if another IRQ beaten us to it and scheduled the
 181          * scan already. In that case we should not try to
 182          * disable IRQs again.
 183          */
 184         if (unlikely(keypad->scan_pending || keypad->stopped))
 185                 goto out;
 186
 187         disable_row_irqs(keypad);
 188         keypad->scan_pending = true;
 189         schedule_delayed_work(&keypad->work,
 190                 msecs_to_jiffies(keypad->pdata->debounce_ms));
 191
 192 out:
 193         spin_unlock_irqrestore(&keypad->lock, flags);
 194         return IRQ_HANDLED;
 195 }
 196
 197 static int matrix_keypad_start(struct input_dev *dev)
 198 {
 199         struct matrix_keypad *keypad = input_get_drvdata(dev);
 200
 201         keypad->stopped = false;
 202         mb();
 203
 204         /*
 205          * Schedule an immediate key scan to capture current key state;
 206          * columns will be activated and IRQs be enabled after the scan.
 207          */
 208         schedule_delayed_work(&keypad->work, 0);
 209
 210         return 0;
 211 }
 212
 213 static void matrix_keypad_stop(struct input_dev *dev)
 214 {
 215         struct matrix_keypad *keypad = input_get_drvdata(dev);
 216
 217         spin_lock_irq(&keypad->lock);
 218         keypad->stopped = true;
 219         spin_unlock_irq(&keypad->lock);
 220
 221         flush_delayed_work(&keypad->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 ret, 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         pdata->drive_inactive_cols =
 436                 of_property_read_bool(np, "drive-inactive-cols");
 437
 438         of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms);
 439         of_property_read_u32(np, "col-scan-delay-us",
 440                                                 &pdata->col_scan_delay_us);
 441
 442         gpios = devm_kcalloc(dev,
 443                              pdata->num_row_gpios + pdata->num_col_gpios,
 444                              sizeof(unsigned int),
 445                              GFP_KERNEL);
 446         if (!gpios) {
 447                 dev_err(dev, "could not allocate memory for gpios\n");
 448                 return ERR_PTR(-ENOMEM);
 449         }
 450
 451         for (i = 0; i < nrow; i++) {
 452                 ret = of_get_named_gpio(np, "row-gpios", i);
 453                 if (ret < 0)
 454                         return ERR_PTR(ret);
 455                 gpios[i] = ret;
 456         }
 457
 458         for (i = 0; i < ncol; i++) {
 459                 ret = of_get_named_gpio(np, "col-gpios", i);
 460                 if (ret < 0)
 461                         return ERR_PTR(ret);
 462                 gpios[nrow + i] = ret;
 463         }
 464
 465         pdata->row_gpios = gpios;
 466         pdata->col_gpios = &gpios[pdata->num_row_gpios];
 467
 468         return pdata;
 469 }
 470 #else
 471 static inline struct matrix_keypad_platform_data *
 472 matrix_keypad_parse_dt(struct device *dev)
 473 {
 474         dev_err(dev, "no platform data defined\n");
 475
 476         return ERR_PTR(-EINVAL);
 477 }
 478 #endif
 479
 480 static int matrix_keypad_probe(struct platform_device *pdev)
 481 {
 482         const struct matrix_keypad_platform_data *pdata;
 483         struct matrix_keypad *keypad;
 484         struct input_dev *input_dev;
 485         int err;
 486
 487         pdata = dev_get_platdata(&pdev->dev);
 488         if (!pdata) {
 489                 pdata = matrix_keypad_parse_dt(&pdev->dev);
 490                 if (IS_ERR(pdata))
 491                         return PTR_ERR(pdata);
 492         } else if (!pdata->keymap_data) {
 493                 dev_err(&pdev->dev, "no keymap data defined\n");
 494                 return -EINVAL;
 495         }
 496
 497         keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
 498         input_dev = input_allocate_device();
 499         if (!keypad || !input_dev) {
 500                 err = -ENOMEM;
 501                 goto err_free_mem;
 502         }
 503
 504         keypad->input_dev = input_dev;
 505         keypad->pdata = pdata;
 506         keypad->row_shift = get_count_order(pdata->num_col_gpios);
 507         keypad->stopped = true;
 508         INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
 509         spin_lock_init(&keypad->lock);
 510
 511         input_dev->name         = pdev->name;
 512         input_dev->id.bustype   = BUS_HOST;
 513         input_dev->dev.parent   = &pdev->dev;
 514         input_dev->open         = matrix_keypad_start;
 515         input_dev->close        = matrix_keypad_stop;
 516
 517         err = matrix_keypad_build_keymap(pdata->keymap_data, NULL,
 518                                          pdata->num_row_gpios,
 519                                          pdata->num_col_gpios,
 520                                          NULL, input_dev);
 521         if (err) {
 522                 dev_err(&pdev->dev, "failed to build keymap\n");
 523                 goto err_free_mem;
 524         }
 525
 526         if (!pdata->no_autorepeat)
 527                 __set_bit(EV_REP, input_dev->evbit);
 528         input_set_capability(input_dev, EV_MSC, MSC_SCAN);
 529         input_set_drvdata(input_dev, keypad);
 530
 531         err = matrix_keypad_init_gpio(pdev, keypad);
 532         if (err)
 533                 goto err_free_mem;
 534
 535         err = input_register_device(keypad->input_dev);
 536         if (err)
 537                 goto err_free_gpio;
 538
 539         device_init_wakeup(&pdev->dev, pdata->wakeup);
 540         platform_set_drvdata(pdev, keypad);
 541
 542         return 0;
 543
 544 err_free_gpio:
 545         matrix_keypad_free_gpio(keypad);
 546 err_free_mem:
 547         input_free_device(input_dev);
 548         kfree(keypad);
 549         return err;
 550 }
 551
 552 static int matrix_keypad_remove(struct platform_device *pdev)
 553 {
 554         struct matrix_keypad *keypad = platform_get_drvdata(pdev);
 555
 556         matrix_keypad_free_gpio(keypad);
 557         input_unregister_device(keypad->input_dev);
 558         kfree(keypad);
 559
 560         return 0;
 561 }
 562
 563 #ifdef CONFIG_OF
 564 static const struct of_device_id matrix_keypad_dt_match[] = {
 565         { .compatible = "gpio-matrix-keypad" },
 566         { }
 567 };
 568 MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
 569 #endif
 570
 571 static struct platform_driver matrix_keypad_driver = {
 572         .probe          = matrix_keypad_probe,
 573         .remove         = matrix_keypad_remove,
 574         .driver         = {
 575                 .name   = "matrix-keypad",
 576                 .pm     = &matrix_keypad_pm_ops,
 577                 .of_match_table = of_match_ptr(matrix_keypad_dt_match),
 578         },
 579 };
 580 module_platform_driver(matrix_keypad_driver);
 581
 582 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 583 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
 584 MODULE_LICENSE("GPL v2");
 585 MODULE_ALIAS("platform:matrix-keypad");