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