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