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
  27 struct matrix_keypad {
  28         const struct matrix_keypad_platform_data *pdata;
  29         struct input_dev *input_dev;
  30         unsigned short *keycodes;
  31         unsigned int row_shift;
  32
  33         DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
  34
  35         uint32_t last_key_state[MATRIX_MAX_COLS];
  36         struct delayed_work work;
  37         spinlock_t lock;
  38         bool scan_pending;
  39         bool stopped;
  40         bool gpio_all_disabled;
  41 };
  42
  43 /*
  44  * NOTE: normally the GPIO has to be put into HiZ when de-activated to cause
  45  * minmal side effect when scanning other columns, here it is configured to
  46  * be input, and it should work on most platforms.
  47  */
  48 static void __activate_col(const struct matrix_keypad_platform_data *pdata,
  49                            int col, bool on)
  50 {
  51         bool level_on = !pdata->active_low;
  52
  53         if (on) {
  54                 gpio_direction_output(pdata->col_gpios[col], level_on);
  55         } else {
  56                 gpio_set_value_cansleep(pdata->col_gpios[col], !level_on);
  57                 gpio_direction_input(pdata->col_gpios[col]);
  58         }
  59 }
  60
  61 static void activate_col(const struct matrix_keypad_platform_data *pdata,
  62                          int col, bool on)
  63 {
  64         __activate_col(pdata, col, on);
  65
  66         if (on && pdata->col_scan_delay_us)
  67                 udelay(pdata->col_scan_delay_us);
  68 }
  69
  70 static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
  71                               bool on)
  72 {
  73         int col;
  74
  75         for (col = 0; col < pdata->num_col_gpios; col++)
  76                 __activate_col(pdata, col, on);
  77 }
  78
  79 static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
  80                          int row)
  81 {
  82         return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
  83                         !pdata->active_low : pdata->active_low;
  84 }
  85
  86 static void enable_row_irqs(struct matrix_keypad *keypad)
  87 {
  88         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
  89         int i;
  90
  91         if (pdata->clustered_irq > 0)
  92                 enable_irq(pdata->clustered_irq);
  93         else {
  94                 for (i = 0; i < pdata->num_row_gpios; i++)
  95                         enable_irq(gpio_to_irq(pdata->row_gpios[i]));
  96         }
  97 }
  98
  99 static void disable_row_irqs(struct matrix_keypad *keypad)
 100 {
 101         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 102         int i;
 103
 104         if (pdata->clustered_irq > 0)
 105                 disable_irq_nosync(pdata->clustered_irq);
 106         else {
 107                 for (i = 0; i < pdata->num_row_gpios; i++)
 108                         disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
 109         }
 110 }
 111
 112 /*
 113  * This gets the keys from keyboard and reports it to input subsystem
 114  */
 115 static void matrix_keypad_scan(struct work_struct *work)
 116 {
 117         struct matrix_keypad *keypad =
 118                 container_of(work, struct matrix_keypad, work.work);
 119         struct input_dev *input_dev = keypad->input_dev;
 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                                          keypad->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         keypad->stopped = true;
 218         mb();
 219         flush_work(&keypad->work.work);
 220         /*
 221          * matrix_keypad_scan() will leave IRQs enabled;
 222          * we should disable them now.
 223          */
 224         disable_row_irqs(keypad);
 225 }
 226
 227 #ifdef CONFIG_PM
 228 static void matrix_keypad_enable_wakeup(struct matrix_keypad *keypad)
 229 {
 230         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 231         unsigned int gpio;
 232         int i;
 233
 234         if (pdata->clustered_irq > 0) {
 235                 if (enable_irq_wake(pdata->clustered_irq) == 0)
 236                         keypad->gpio_all_disabled = true;
 237         } else {
 238
 239                 for (i = 0; i < pdata->num_row_gpios; i++) {
 240                         if (!test_bit(i, keypad->disabled_gpios)) {
 241                                 gpio = pdata->row_gpios[i];
 242
 243                                 if (enable_irq_wake(gpio_to_irq(gpio)) == 0)
 244                                         __set_bit(i, keypad->disabled_gpios);
 245                         }
 246                 }
 247         }
 248 }
 249
 250 static void matrix_keypad_disable_wakeup(struct matrix_keypad *keypad)
 251 {
 252         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 253         unsigned int gpio;
 254         int i;
 255
 256         if (pdata->clustered_irq > 0) {
 257                 if (keypad->gpio_all_disabled) {
 258                         disable_irq_wake(pdata->clustered_irq);
 259                         keypad->gpio_all_disabled = false;
 260                 }
 261         } else {
 262                 for (i = 0; i < pdata->num_row_gpios; i++) {
 263                         if (test_and_clear_bit(i, keypad->disabled_gpios)) {
 264                                 gpio = pdata->row_gpios[i];
 265                                 disable_irq_wake(gpio_to_irq(gpio));
 266                         }
 267                 }
 268         }
 269 }
 270
 271 static int matrix_keypad_suspend(struct device *dev)
 272 {
 273         struct platform_device *pdev = to_platform_device(dev);
 274         struct matrix_keypad *keypad = platform_get_drvdata(pdev);
 275
 276         matrix_keypad_stop(keypad->input_dev);
 277
 278         if (device_may_wakeup(&pdev->dev))
 279                 matrix_keypad_enable_wakeup(keypad);
 280
 281         return 0;
 282 }
 283
 284 static int matrix_keypad_resume(struct device *dev)
 285 {
 286         struct platform_device *pdev = to_platform_device(dev);
 287         struct matrix_keypad *keypad = platform_get_drvdata(pdev);
 288
 289         if (device_may_wakeup(&pdev->dev))
 290                 matrix_keypad_disable_wakeup(keypad);
 291
 292         matrix_keypad_start(keypad->input_dev);
 293
 294         return 0;
 295 }
 296
 297 static const SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
 298                                 matrix_keypad_suspend, matrix_keypad_resume);
 299 #endif
 300
 301 static int __devinit init_matrix_gpio(struct platform_device *pdev,
 302                                         struct matrix_keypad *keypad)
 303 {
 304         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 305         int i, err = -EINVAL;
 306
 307         /* initialized strobe lines as outputs, activated */
 308         for (i = 0; i < pdata->num_col_gpios; i++) {
 309                 err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col");
 310                 if (err) {
 311                         dev_err(&pdev->dev,
 312                                 "failed to request GPIO%d for COL%d\n",
 313                                 pdata->col_gpios[i], i);
 314                         goto err_free_cols;
 315                 }
 316
 317                 gpio_direction_output(pdata->col_gpios[i], !pdata->active_low);
 318         }
 319
 320         for (i = 0; i < pdata->num_row_gpios; i++) {
 321                 err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row");
 322                 if (err) {
 323                         dev_err(&pdev->dev,
 324                                 "failed to request GPIO%d for ROW%d\n",
 325                                 pdata->row_gpios[i], i);
 326                         goto err_free_rows;
 327                 }
 328
 329                 gpio_direction_input(pdata->row_gpios[i]);
 330         }
 331
 332         if (pdata->clustered_irq > 0) {
 333                 err = request_irq(pdata->clustered_irq,
 334                                 matrix_keypad_interrupt,
 335                                 pdata->clustered_irq_flags,
 336                                 "matrix-keypad", keypad);
 337                 if (err) {
 338                         dev_err(&pdev->dev,
 339                                 "Unable to acquire clustered interrupt\n");
 340                         goto err_free_rows;
 341                 }
 342         } else {
 343                 for (i = 0; i < pdata->num_row_gpios; i++) {
 344                         err = request_irq(gpio_to_irq(pdata->row_gpios[i]),
 345                                         matrix_keypad_interrupt,
 346                                         IRQF_DISABLED |
 347                                         IRQF_TRIGGER_RISING |
 348                                         IRQF_TRIGGER_FALLING,
 349                                         "matrix-keypad", keypad);
 350                         if (err) {
 351                                 dev_err(&pdev->dev,
 352                                         "Unable to acquire interrupt "
 353                                         "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 int __devinit matrix_keypad_probe(struct platform_device *pdev)
 380 {
 381         const struct matrix_keypad_platform_data *pdata;
 382         const struct matrix_keymap_data *keymap_data;
 383         struct matrix_keypad *keypad;
 384         struct input_dev *input_dev;
 385         unsigned short *keycodes;
 386         unsigned int row_shift;
 387         int err;
 388
 389         pdata = pdev->dev.platform_data;
 390         if (!pdata) {
 391                 dev_err(&pdev->dev, "no platform data defined\n");
 392                 return -EINVAL;
 393         }
 394
 395         keymap_data = pdata->keymap_data;
 396         if (!keymap_data) {
 397                 dev_err(&pdev->dev, "no keymap data defined\n");
 398                 return -EINVAL;
 399         }
 400
 401         row_shift = get_count_order(pdata->num_col_gpios);
 402
 403         keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
 404         keycodes = kzalloc((pdata->num_row_gpios << row_shift) *
 405                                 sizeof(*keycodes),
 406                            GFP_KERNEL);
 407         input_dev = input_allocate_device();
 408         if (!keypad || !keycodes || !input_dev) {
 409                 err = -ENOMEM;
 410                 goto err_free_mem;
 411         }
 412
 413         keypad->input_dev = input_dev;
 414         keypad->pdata = pdata;
 415         keypad->keycodes = keycodes;
 416         keypad->row_shift = row_shift;
 417         keypad->stopped = true;
 418         INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
 419         spin_lock_init(&keypad->lock);
 420
 421         input_dev->name         = pdev->name;
 422         input_dev->id.bustype   = BUS_HOST;
 423         input_dev->dev.parent   = &pdev->dev;
 424         input_dev->evbit[0]     = BIT_MASK(EV_KEY);
 425         if (!pdata->no_autorepeat)
 426                 input_dev->evbit[0] |= BIT_MASK(EV_REP);
 427         input_dev->open         = matrix_keypad_start;
 428         input_dev->close        = matrix_keypad_stop;
 429
 430         input_dev->keycode      = keycodes;
 431         input_dev->keycodesize  = sizeof(*keycodes);
 432         input_dev->keycodemax   = pdata->num_row_gpios << row_shift;
 433
 434         matrix_keypad_build_keymap(keymap_data, row_shift,
 435                                    input_dev->keycode, input_dev->keybit);
 436
 437         input_set_capability(input_dev, EV_MSC, MSC_SCAN);
 438         input_set_drvdata(input_dev, keypad);
 439
 440         err = init_matrix_gpio(pdev, keypad);
 441         if (err)
 442                 goto err_free_mem;
 443
 444         err = input_register_device(keypad->input_dev);
 445         if (err)
 446                 goto err_free_mem;
 447
 448         device_init_wakeup(&pdev->dev, pdata->wakeup);
 449         platform_set_drvdata(pdev, keypad);
 450
 451         return 0;
 452
 453 err_free_mem:
 454         input_free_device(input_dev);
 455         kfree(keycodes);
 456         kfree(keypad);
 457         return err;
 458 }
 459
 460 static int __devexit matrix_keypad_remove(struct platform_device *pdev)
 461 {
 462         struct matrix_keypad *keypad = platform_get_drvdata(pdev);
 463         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 464         int i;
 465
 466         device_init_wakeup(&pdev->dev, 0);
 467
 468         if (pdata->clustered_irq > 0) {
 469                 free_irq(pdata->clustered_irq, keypad);
 470         } else {
 471                 for (i = 0; i < pdata->num_row_gpios; i++)
 472                         free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
 473         }
 474
 475         for (i = 0; i < pdata->num_row_gpios; i++)
 476                 gpio_free(pdata->row_gpios[i]);
 477
 478         for (i = 0; i < pdata->num_col_gpios; i++)
 479                 gpio_free(pdata->col_gpios[i]);
 480
 481         input_unregister_device(keypad->input_dev);
 482         platform_set_drvdata(pdev, NULL);
 483         kfree(keypad->keycodes);
 484         kfree(keypad);
 485
 486         return 0;
 487 }
 488
 489 static struct platform_driver matrix_keypad_driver = {
 490         .probe          = matrix_keypad_probe,
 491         .remove         = __devexit_p(matrix_keypad_remove),
 492         .driver         = {
 493                 .name   = "matrix-keypad",
 494                 .owner  = THIS_MODULE,
 495 #ifdef CONFIG_PM
 496                 .pm     = &matrix_keypad_pm_ops,
 497 #endif
 498         },
 499 };
 500
 501 static int __init matrix_keypad_init(void)
 502 {
 503         return platform_driver_register(&matrix_keypad_driver);
 504 }
 505
 506 static void __exit matrix_keypad_exit(void)
 507 {
 508         platform_driver_unregister(&matrix_keypad_driver);
 509 }
 510
 511 module_init(matrix_keypad_init);
 512 module_exit(matrix_keypad_exit);
 513
 514 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 515 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
 516 MODULE_LICENSE("GPL v2");
 517 MODULE_ALIAS("platform:matrix-keypad");