linux/drivers/input/keyboard/matrix_keypad.c
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   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
  29struct 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 */
  50static 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
  64static 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
  73static 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
  82static 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
  89static 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
 102static 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 */
 118static 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
 176static 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
 196out:
 197        spin_unlock_irqrestore(&keypad->lock, flags);
 198        return IRQ_HANDLED;
 199}
 200
 201static 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
 217static 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
 232static 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
 254static 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
 275static 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
 288static 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
 302static SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
 303                         matrix_keypad_suspend, matrix_keypad_resume);
 304
 305static 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
 367err_free_irqs:
 368        while (--i >= 0)
 369                free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
 370        i = pdata->num_row_gpios;
 371err_free_rows:
 372        while (--i >= 0)
 373                gpio_free(pdata->row_gpios[i]);
 374        i = pdata->num_col_gpios;
 375err_free_cols:
 376        while (--i >= 0)
 377                gpio_free(pdata->col_gpios[i]);
 378
 379        return err;
 380}
 381
 382static 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
 402static struct matrix_keypad_platform_data *
 403matrix_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
 466static inline struct matrix_keypad_platform_data *
 467matrix_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
 475static 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
 541err_free_gpio:
 542        matrix_keypad_free_gpio(keypad);
 543err_free_mem:
 544        input_free_device(input_dev);
 545        kfree(keypad);
 546        return err;
 547}
 548
 549static 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
 561static const struct of_device_id matrix_keypad_dt_match[] = {
 562        { .compatible = "gpio-matrix-keypad" },
 563        { }
 564};
 565MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
 566#endif
 567
 568static 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};
 577module_platform_driver(matrix_keypad_driver);
 578
 579MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 580MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
 581MODULE_LICENSE("GPL v2");
 582MODULE_ALIAS("platform:matrix-keypad");
 583