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_irq(pdata->clustered_irq,
 336                                 matrix_keypad_interrupt,
 337                                 pdata->clustered_irq_flags,
 338                                 "matrix-keypad", keypad);
 339                 if (err) {
 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_irq(gpio_to_irq(pdata->row_gpios[i]),
 347                                         matrix_keypad_interrupt,
 348                                         IRQF_TRIGGER_RISING |
 349                                         IRQF_TRIGGER_FALLING,
 350                                         "matrix-keypad", keypad);
 351                         if (err) {
 352                                 dev_err(&pdev->dev,
 353                                         "Unable to acquire interrupt for GPIO line %i\n",
 354                                         pdata->row_gpios[i]);
 355                                 goto err_free_irqs;
 356                         }
 357                 }
 358         }
 359
 360         /* initialized as disabled - enabled by input->open */
 361         disable_row_irqs(keypad);
 362         return 0;
 363
 364 err_free_irqs:
 365         while (--i >= 0)
 366                 free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
 367         i = pdata->num_row_gpios;
 368 err_free_rows:
 369         while (--i >= 0)
 370                 gpio_free(pdata->row_gpios[i]);
 371         i = pdata->num_col_gpios;
 372 err_free_cols:
 373         while (--i >= 0)
 374                 gpio_free(pdata->col_gpios[i]);
 375
 376         return err;
 377 }
 378
 379 static void matrix_keypad_free_gpio(struct matrix_keypad *keypad)
 380 {
 381         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 382         int i;
 383
 384         if (pdata->clustered_irq > 0) {
 385                 free_irq(pdata->clustered_irq, keypad);
 386         } else {
 387                 for (i = 0; i < pdata->num_row_gpios; i++)
 388                         free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
 389         }
 390
 391         for (i = 0; i < pdata->num_row_gpios; i++)
 392                 gpio_free(pdata->row_gpios[i]);
 393
 394         for (i = 0; i < pdata->num_col_gpios; i++)
 395                 gpio_free(pdata->col_gpios[i]);
 396 }
 397
 398 #ifdef CONFIG_OF
 399 static struct matrix_keypad_platform_data *
 400 matrix_keypad_parse_dt(struct device *dev)
 401 {
 402         struct matrix_keypad_platform_data *pdata;
 403         struct device_node *np = dev->of_node;
 404         unsigned int *gpios;
 405         int i, nrow, ncol;
 406
 407         if (!np) {
 408                 dev_err(dev, "device lacks DT data\n");
 409                 return ERR_PTR(-ENODEV);
 410         }
 411
 412         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 413         if (!pdata) {
 414                 dev_err(dev, "could not allocate memory for platform data\n");
 415                 return ERR_PTR(-ENOMEM);
 416         }
 417
 418         pdata->num_row_gpios = nrow = of_gpio_named_count(np, "row-gpios");
 419         pdata->num_col_gpios = ncol = of_gpio_named_count(np, "col-gpios");
 420         if (nrow <= 0 || ncol <= 0) {
 421                 dev_err(dev, "number of keypad rows/columns not specified\n");
 422                 return ERR_PTR(-EINVAL);
 423         }
 424
 425         if (of_get_property(np, "linux,no-autorepeat", NULL))
 426                 pdata->no_autorepeat = true;
 427         if (of_get_property(np, "linux,wakeup", NULL))
 428                 pdata->wakeup = true;
 429         if (of_get_property(np, "gpio-activelow", NULL))
 430                 pdata->active_low = true;
 431
 432         of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms);
 433         of_property_read_u32(np, "col-scan-delay-us",
 434                                                 &pdata->col_scan_delay_us);
 435
 436         gpios = devm_kzalloc(dev,
 437                              sizeof(unsigned int) *
 438                                 (pdata->num_row_gpios + pdata->num_col_gpios),
 439                              GFP_KERNEL);
 440         if (!gpios) {
 441                 dev_err(dev, "could not allocate memory for gpios\n");
 442                 return ERR_PTR(-ENOMEM);
 443         }
 444
 445         for (i = 0; i < pdata->num_row_gpios; i++)
 446                 gpios[i] = of_get_named_gpio(np, "row-gpios", i);
 447
 448         for (i = 0; i < pdata->num_col_gpios; i++)
 449                 gpios[pdata->num_row_gpios + i] =
 450                         of_get_named_gpio(np, "col-gpios", i);
 451
 452         pdata->row_gpios = gpios;
 453         pdata->col_gpios = &gpios[pdata->num_row_gpios];
 454
 455         return pdata;
 456 }
 457 #else
 458 static inline struct matrix_keypad_platform_data *
 459 matrix_keypad_parse_dt(struct device *dev)
 460 {
 461         dev_err(dev, "no platform data defined\n");
 462
 463         return ERR_PTR(-EINVAL);
 464 }
 465 #endif
 466
 467 static int matrix_keypad_probe(struct platform_device *pdev)
 468 {
 469         const struct matrix_keypad_platform_data *pdata;
 470         struct matrix_keypad *keypad;
 471         struct input_dev *input_dev;
 472         int err;
 473
 474         pdata = dev_get_platdata(&pdev->dev);
 475         if (!pdata) {
 476                 pdata = matrix_keypad_parse_dt(&pdev->dev);
 477                 if (IS_ERR(pdata)) {
 478                         dev_err(&pdev->dev, "no platform data defined\n");
 479                         return PTR_ERR(pdata);
 480                 }
 481         } else if (!pdata->keymap_data) {
 482                 dev_err(&pdev->dev, "no keymap data defined\n");
 483                 return -EINVAL;
 484         }
 485
 486         keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
 487         input_dev = input_allocate_device();
 488         if (!keypad || !input_dev) {
 489                 err = -ENOMEM;
 490                 goto err_free_mem;
 491         }
 492
 493         keypad->input_dev = input_dev;
 494         keypad->pdata = pdata;
 495         keypad->row_shift = get_count_order(pdata->num_col_gpios);
 496         keypad->stopped = true;
 497         INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
 498         spin_lock_init(&keypad->lock);
 499
 500         input_dev->name         = pdev->name;
 501         input_dev->id.bustype   = BUS_HOST;
 502         input_dev->dev.parent   = &pdev->dev;
 503         input_dev->open         = matrix_keypad_start;
 504         input_dev->close        = matrix_keypad_stop;
 505
 506         err = matrix_keypad_build_keymap(pdata->keymap_data, NULL,
 507                                          pdata->num_row_gpios,
 508                                          pdata->num_col_gpios,
 509                                          NULL, input_dev);
 510         if (err) {
 511                 dev_err(&pdev->dev, "failed to build keymap\n");
 512                 goto err_free_mem;
 513         }
 514
 515         if (!pdata->no_autorepeat)
 516                 __set_bit(EV_REP, input_dev->evbit);
 517         input_set_capability(input_dev, EV_MSC, MSC_SCAN);
 518         input_set_drvdata(input_dev, keypad);
 519
 520         err = matrix_keypad_init_gpio(pdev, keypad);
 521         if (err)
 522                 goto err_free_mem;
 523
 524         err = input_register_device(keypad->input_dev);
 525         if (err)
 526                 goto err_free_gpio;
 527
 528         device_init_wakeup(&pdev->dev, pdata->wakeup);
 529         platform_set_drvdata(pdev, keypad);
 530
 531         return 0;
 532
 533 err_free_gpio:
 534         matrix_keypad_free_gpio(keypad);
 535 err_free_mem:
 536         input_free_device(input_dev);
 537         kfree(keypad);
 538         return err;
 539 }
 540
 541 static int matrix_keypad_remove(struct platform_device *pdev)
 542 {
 543         struct matrix_keypad *keypad = platform_get_drvdata(pdev);
 544
 545         device_init_wakeup(&pdev->dev, 0);
 546
 547         matrix_keypad_free_gpio(keypad);
 548         input_unregister_device(keypad->input_dev);
 549         kfree(keypad);
 550
 551         return 0;
 552 }
 553
 554 #ifdef CONFIG_OF
 555 static const struct of_device_id matrix_keypad_dt_match[] = {
 556         { .compatible = "gpio-matrix-keypad" },
 557         { }
 558 };
 559 MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
 560 #endif
 561
 562 static struct platform_driver matrix_keypad_driver = {
 563         .probe          = matrix_keypad_probe,
 564         .remove         = matrix_keypad_remove,
 565         .driver         = {
 566                 .name   = "matrix-keypad",
 567                 .owner  = THIS_MODULE,
 568                 .pm     = &matrix_keypad_pm_ops,
 569                 .of_match_table = of_match_ptr(matrix_keypad_dt_match),
 570         },
 571 };
 572 module_platform_driver(matrix_keypad_driver);
 573
 574 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 575 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
 576 MODULE_LICENSE("GPL v2");
 577 MODULE_ALIAS("platform:matrix-keypad");