drivers/input/keyboard/tegra-kbc.c

   1 /*
   2  * Keyboard class input driver for the NVIDIA Tegra SoC internal matrix
   3  * keyboard controller
   4  *
   5  * Copyright (c) 2009-2011, NVIDIA Corporation.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/input.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/delay.h>
  27 #include <linux/io.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/of.h>
  30 #include <linux/clk.h>
  31 #include <linux/slab.h>
  32 #include <linux/input/matrix_keypad.h>
  33 #include <linux/clk/tegra.h>
  34
  35 #define KBC_MAX_GPIO    24
  36 #define KBC_MAX_KPENT   8
  37
  38 #define KBC_MAX_ROW     16
  39 #define KBC_MAX_COL     8
  40 #define KBC_MAX_KEY     (KBC_MAX_ROW * KBC_MAX_COL)
  41
  42 #define KBC_MAX_DEBOUNCE_CNT    0x3ffu
  43
  44 /* KBC row scan time and delay for beginning the row scan. */
  45 #define KBC_ROW_SCAN_TIME       16
  46 #define KBC_ROW_SCAN_DLY        5
  47
  48 /* KBC uses a 32KHz clock so a cycle = 1/32Khz */
  49 #define KBC_CYCLE_MS    32
  50
  51 /* KBC Registers */
  52
  53 /* KBC Control Register */
  54 #define KBC_CONTROL_0   0x0
  55 #define KBC_FIFO_TH_CNT_SHIFT(cnt)      (cnt << 14)
  56 #define KBC_DEBOUNCE_CNT_SHIFT(cnt)     (cnt << 4)
  57 #define KBC_CONTROL_FIFO_CNT_INT_EN     (1 << 3)
  58 #define KBC_CONTROL_KEYPRESS_INT_EN     (1 << 1)
  59 #define KBC_CONTROL_KBC_EN              (1 << 0)
  60
  61 /* KBC Interrupt Register */
  62 #define KBC_INT_0       0x4
  63 #define KBC_INT_FIFO_CNT_INT_STATUS     (1 << 2)
  64 #define KBC_INT_KEYPRESS_INT_STATUS     (1 << 0)
  65
  66 #define KBC_ROW_CFG0_0  0x8
  67 #define KBC_COL_CFG0_0  0x18
  68 #define KBC_TO_CNT_0    0x24
  69 #define KBC_INIT_DLY_0  0x28
  70 #define KBC_RPT_DLY_0   0x2c
  71 #define KBC_KP_ENT0_0   0x30
  72 #define KBC_KP_ENT1_0   0x34
  73 #define KBC_ROW0_MASK_0 0x38
  74
  75 #define KBC_ROW_SHIFT   3
  76
  77 enum tegra_pin_type {
  78         PIN_CFG_IGNORE,
  79         PIN_CFG_COL,
  80         PIN_CFG_ROW,
  81 };
  82
  83 struct tegra_kbc_pin_cfg {
  84         enum tegra_pin_type type;
  85         unsigned char num;
  86 };
  87
  88 struct tegra_kbc {
  89         struct device *dev;
  90         unsigned int debounce_cnt;
  91         unsigned int repeat_cnt;
  92         struct tegra_kbc_pin_cfg pin_cfg[KBC_MAX_GPIO];
  93         const struct matrix_keymap_data *keymap_data;
  94         bool wakeup;
  95         void __iomem *mmio;
  96         struct input_dev *idev;
  97         int irq;
  98         spinlock_t lock;
  99         unsigned int repoll_dly;
 100         unsigned long cp_dly_jiffies;
 101         unsigned int cp_to_wkup_dly;
 102         bool use_fn_map;
 103         bool use_ghost_filter;
 104         bool keypress_caused_wake;
 105         unsigned short keycode[KBC_MAX_KEY * 2];
 106         unsigned short current_keys[KBC_MAX_KPENT];
 107         unsigned int num_pressed_keys;
 108         u32 wakeup_key;
 109         struct timer_list timer;
 110         struct clk *clk;
 111 };
 112
 113 static void tegra_kbc_report_released_keys(struct input_dev *input,
 114                                            unsigned short old_keycodes[],
 115                                            unsigned int old_num_keys,
 116                                            unsigned short new_keycodes[],
 117                                            unsigned int new_num_keys)
 118 {
 119         unsigned int i, j;
 120
 121         for (i = 0; i < old_num_keys; i++) {
 122                 for (j = 0; j < new_num_keys; j++)
 123                         if (old_keycodes[i] == new_keycodes[j])
 124                                 break;
 125
 126                 if (j == new_num_keys)
 127                         input_report_key(input, old_keycodes[i], 0);
 128         }
 129 }
 130
 131 static void tegra_kbc_report_pressed_keys(struct input_dev *input,
 132                                           unsigned char scancodes[],
 133                                           unsigned short keycodes[],
 134                                           unsigned int num_pressed_keys)
 135 {
 136         unsigned int i;
 137
 138         for (i = 0; i < num_pressed_keys; i++) {
 139                 input_event(input, EV_MSC, MSC_SCAN, scancodes[i]);
 140                 input_report_key(input, keycodes[i], 1);
 141         }
 142 }
 143
 144 static void tegra_kbc_report_keys(struct tegra_kbc *kbc)
 145 {
 146         unsigned char scancodes[KBC_MAX_KPENT];
 147         unsigned short keycodes[KBC_MAX_KPENT];
 148         u32 val = 0;
 149         unsigned int i;
 150         unsigned int num_down = 0;
 151         bool fn_keypress = false;
 152         bool key_in_same_row = false;
 153         bool key_in_same_col = false;
 154
 155         for (i = 0; i < KBC_MAX_KPENT; i++) {
 156                 if ((i % 4) == 0)
 157                         val = readl(kbc->mmio + KBC_KP_ENT0_0 + i);
 158
 159                 if (val & 0x80) {
 160                         unsigned int col = val & 0x07;
 161                         unsigned int row = (val >> 3) & 0x0f;
 162                         unsigned char scancode =
 163                                 MATRIX_SCAN_CODE(row, col, KBC_ROW_SHIFT);
 164
 165                         scancodes[num_down] = scancode;
 166                         keycodes[num_down] = kbc->keycode[scancode];
 167                         /* If driver uses Fn map, do not report the Fn key. */
 168                         if ((keycodes[num_down] == KEY_FN) && kbc->use_fn_map)
 169                                 fn_keypress = true;
 170                         else
 171                                 num_down++;
 172                 }
 173
 174                 val >>= 8;
 175         }
 176
 177         /*
 178          * Matrix keyboard designs are prone to keyboard ghosting.
 179          * Ghosting occurs if there are 3 keys such that -
 180          * any 2 of the 3 keys share a row, and any 2 of them share a column.
 181          * If so ignore the key presses for this iteration.
 182          */
 183         if (kbc->use_ghost_filter && num_down >= 3) {
 184                 for (i = 0; i < num_down; i++) {
 185                         unsigned int j;
 186                         u8 curr_col = scancodes[i] & 0x07;
 187                         u8 curr_row = scancodes[i] >> KBC_ROW_SHIFT;
 188
 189                         /*
 190                          * Find 2 keys such that one key is in the same row
 191                          * and the other is in the same column as the i-th key.
 192                          */
 193                         for (j = i + 1; j < num_down; j++) {
 194                                 u8 col = scancodes[j] & 0x07;
 195                                 u8 row = scancodes[j] >> KBC_ROW_SHIFT;
 196
 197                                 if (col == curr_col)
 198                                         key_in_same_col = true;
 199                                 if (row == curr_row)
 200                                         key_in_same_row = true;
 201                         }
 202                 }
 203         }
 204
 205         /*
 206          * If the platform uses Fn keymaps, translate keys on a Fn keypress.
 207          * Function keycodes are KBC_MAX_KEY apart from the plain keycodes.
 208          */
 209         if (fn_keypress) {
 210                 for (i = 0; i < num_down; i++) {
 211                         scancodes[i] += KBC_MAX_KEY;
 212                         keycodes[i] = kbc->keycode[scancodes[i]];
 213                 }
 214         }
 215
 216         /* Ignore the key presses for this iteration? */
 217         if (key_in_same_col && key_in_same_row)
 218                 return;
 219
 220         tegra_kbc_report_released_keys(kbc->idev,
 221                                        kbc->current_keys, kbc->num_pressed_keys,
 222                                        keycodes, num_down);
 223         tegra_kbc_report_pressed_keys(kbc->idev, scancodes, keycodes, num_down);
 224         input_sync(kbc->idev);
 225
 226         memcpy(kbc->current_keys, keycodes, sizeof(kbc->current_keys));
 227         kbc->num_pressed_keys = num_down;
 228 }
 229
 230 static void tegra_kbc_set_fifo_interrupt(struct tegra_kbc *kbc, bool enable)
 231 {
 232         u32 val;
 233
 234         val = readl(kbc->mmio + KBC_CONTROL_0);
 235         if (enable)
 236                 val |= KBC_CONTROL_FIFO_CNT_INT_EN;
 237         else
 238                 val &= ~KBC_CONTROL_FIFO_CNT_INT_EN;
 239         writel(val, kbc->mmio + KBC_CONTROL_0);
 240 }
 241
 242 static void tegra_kbc_keypress_timer(unsigned long data)
 243 {
 244         struct tegra_kbc *kbc = (struct tegra_kbc *)data;
 245         unsigned long flags;
 246         u32 val;
 247         unsigned int i;
 248
 249         spin_lock_irqsave(&kbc->lock, flags);
 250
 251         val = (readl(kbc->mmio + KBC_INT_0) >> 4) & 0xf;
 252         if (val) {
 253                 unsigned long dly;
 254
 255                 tegra_kbc_report_keys(kbc);
 256
 257                 /*
 258                  * If more than one keys are pressed we need not wait
 259                  * for the repoll delay.
 260                  */
 261                 dly = (val == 1) ? kbc->repoll_dly : 1;
 262                 mod_timer(&kbc->timer, jiffies + msecs_to_jiffies(dly));
 263         } else {
 264                 /* Release any pressed keys and exit the polling loop */
 265                 for (i = 0; i < kbc->num_pressed_keys; i++)
 266                         input_report_key(kbc->idev, kbc->current_keys[i], 0);
 267                 input_sync(kbc->idev);
 268
 269                 kbc->num_pressed_keys = 0;
 270
 271                 /* All keys are released so enable the keypress interrupt */
 272                 tegra_kbc_set_fifo_interrupt(kbc, true);
 273         }
 274
 275         spin_unlock_irqrestore(&kbc->lock, flags);
 276 }
 277
 278 static irqreturn_t tegra_kbc_isr(int irq, void *args)
 279 {
 280         struct tegra_kbc *kbc = args;
 281         unsigned long flags;
 282         u32 val;
 283
 284         spin_lock_irqsave(&kbc->lock, flags);
 285
 286         /*
 287          * Quickly bail out & reenable interrupts if the fifo threshold
 288          * count interrupt wasn't the interrupt source
 289          */
 290         val = readl(kbc->mmio + KBC_INT_0);
 291         writel(val, kbc->mmio + KBC_INT_0);
 292
 293         if (val & KBC_INT_FIFO_CNT_INT_STATUS) {
 294                 /*
 295                  * Until all keys are released, defer further processing to
 296                  * the polling loop in tegra_kbc_keypress_timer.
 297                  */
 298                 tegra_kbc_set_fifo_interrupt(kbc, false);
 299                 mod_timer(&kbc->timer, jiffies + kbc->cp_dly_jiffies);
 300         } else if (val & KBC_INT_KEYPRESS_INT_STATUS) {
 301                 /* We can be here only through system resume path */
 302                 kbc->keypress_caused_wake = true;
 303         }
 304
 305         spin_unlock_irqrestore(&kbc->lock, flags);
 306
 307         return IRQ_HANDLED;
 308 }
 309
 310 static void tegra_kbc_setup_wakekeys(struct tegra_kbc *kbc, bool filter)
 311 {
 312         int i;
 313         unsigned int rst_val;
 314
 315         /* Either mask all keys or none. */
 316         rst_val = (filter && !kbc->wakeup) ? ~0 : 0;
 317
 318         for (i = 0; i < KBC_MAX_ROW; i++)
 319                 writel(rst_val, kbc->mmio + KBC_ROW0_MASK_0 + i * 4);
 320 }
 321
 322 static void tegra_kbc_config_pins(struct tegra_kbc *kbc)
 323 {
 324         int i;
 325
 326         for (i = 0; i < KBC_MAX_GPIO; i++) {
 327                 u32 r_shft = 5 * (i % 6);
 328                 u32 c_shft = 4 * (i % 8);
 329                 u32 r_mask = 0x1f << r_shft;
 330                 u32 c_mask = 0x0f << c_shft;
 331                 u32 r_offs = (i / 6) * 4 + KBC_ROW_CFG0_0;
 332                 u32 c_offs = (i / 8) * 4 + KBC_COL_CFG0_0;
 333                 u32 row_cfg = readl(kbc->mmio + r_offs);
 334                 u32 col_cfg = readl(kbc->mmio + c_offs);
 335
 336                 row_cfg &= ~r_mask;
 337                 col_cfg &= ~c_mask;
 338
 339                 switch (kbc->pin_cfg[i].type) {
 340                 case PIN_CFG_ROW:
 341                         row_cfg |= ((kbc->pin_cfg[i].num << 1) | 1) << r_shft;
 342                         break;
 343
 344                 case PIN_CFG_COL:
 345                         col_cfg |= ((kbc->pin_cfg[i].num << 1) | 1) << c_shft;
 346                         break;
 347
 348                 case PIN_CFG_IGNORE:
 349                         break;
 350                 }
 351
 352                 writel(row_cfg, kbc->mmio + r_offs);
 353                 writel(col_cfg, kbc->mmio + c_offs);
 354         }
 355 }
 356
 357 static int tegra_kbc_start(struct tegra_kbc *kbc)
 358 {
 359         unsigned int debounce_cnt;
 360         u32 val = 0;
 361
 362         clk_prepare_enable(kbc->clk);
 363
 364         /* Reset the KBC controller to clear all previous status.*/
 365         tegra_periph_reset_assert(kbc->clk);
 366         udelay(100);
 367         tegra_periph_reset_deassert(kbc->clk);
 368         udelay(100);
 369
 370         tegra_kbc_config_pins(kbc);
 371         tegra_kbc_setup_wakekeys(kbc, false);
 372
 373         writel(kbc->repeat_cnt, kbc->mmio + KBC_RPT_DLY_0);
 374
 375         /* Keyboard debounce count is maximum of 12 bits. */
 376         debounce_cnt = min(kbc->debounce_cnt, KBC_MAX_DEBOUNCE_CNT);
 377         val = KBC_DEBOUNCE_CNT_SHIFT(debounce_cnt);
 378         val |= KBC_FIFO_TH_CNT_SHIFT(1); /* set fifo interrupt threshold to 1 */
 379         val |= KBC_CONTROL_FIFO_CNT_INT_EN;  /* interrupt on FIFO threshold */
 380         val |= KBC_CONTROL_KBC_EN;     /* enable */
 381         writel(val, kbc->mmio + KBC_CONTROL_0);
 382
 383         /*
 384          * Compute the delay(ns) from interrupt mode to continuous polling
 385          * mode so the timer routine is scheduled appropriately.
 386          */
 387         val = readl(kbc->mmio + KBC_INIT_DLY_0);
 388         kbc->cp_dly_jiffies = usecs_to_jiffies((val & 0xfffff) * 32);
 389
 390         kbc->num_pressed_keys = 0;
 391
 392         /*
 393          * Atomically clear out any remaining entries in the key FIFO
 394          * and enable keyboard interrupts.
 395          */
 396         while (1) {
 397                 val = readl(kbc->mmio + KBC_INT_0);
 398                 val >>= 4;
 399                 if (!val)
 400                         break;
 401
 402                 val = readl(kbc->mmio + KBC_KP_ENT0_0);
 403                 val = readl(kbc->mmio + KBC_KP_ENT1_0);
 404         }
 405         writel(0x7, kbc->mmio + KBC_INT_0);
 406
 407         enable_irq(kbc->irq);
 408
 409         return 0;
 410 }
 411
 412 static void tegra_kbc_stop(struct tegra_kbc *kbc)
 413 {
 414         unsigned long flags;
 415         u32 val;
 416
 417         spin_lock_irqsave(&kbc->lock, flags);
 418         val = readl(kbc->mmio + KBC_CONTROL_0);
 419         val &= ~1;
 420         writel(val, kbc->mmio + KBC_CONTROL_0);
 421         spin_unlock_irqrestore(&kbc->lock, flags);
 422
 423         disable_irq(kbc->irq);
 424         del_timer_sync(&kbc->timer);
 425
 426         clk_disable_unprepare(kbc->clk);
 427 }
 428
 429 static int tegra_kbc_open(struct input_dev *dev)
 430 {
 431         struct tegra_kbc *kbc = input_get_drvdata(dev);
 432
 433         return tegra_kbc_start(kbc);
 434 }
 435
 436 static void tegra_kbc_close(struct input_dev *dev)
 437 {
 438         struct tegra_kbc *kbc = input_get_drvdata(dev);
 439
 440         return tegra_kbc_stop(kbc);
 441 }
 442
 443 static bool tegra_kbc_check_pin_cfg(const struct tegra_kbc *kbc,
 444                                         unsigned int *num_rows)
 445 {
 446         int i;
 447
 448         *num_rows = 0;
 449
 450         for (i = 0; i < KBC_MAX_GPIO; i++) {
 451                 const struct tegra_kbc_pin_cfg *pin_cfg = &kbc->pin_cfg[i];
 452
 453                 switch (pin_cfg->type) {
 454                 case PIN_CFG_ROW:
 455                         if (pin_cfg->num >= KBC_MAX_ROW) {
 456                                 dev_err(kbc->dev,
 457                                         "pin_cfg[%d]: invalid row number %d\n",
 458                                         i, pin_cfg->num);
 459                                 return false;
 460                         }
 461                         (*num_rows)++;
 462                         break;
 463
 464                 case PIN_CFG_COL:
 465                         if (pin_cfg->num >= KBC_MAX_COL) {
 466                                 dev_err(kbc->dev,
 467                                         "pin_cfg[%d]: invalid column number %d\n",
 468                                         i, pin_cfg->num);
 469                                 return false;
 470                         }
 471                         break;
 472
 473                 case PIN_CFG_IGNORE:
 474                         break;
 475
 476                 default:
 477                         dev_err(kbc->dev,
 478                                 "pin_cfg[%d]: invalid entry type %d\n",
 479                                 pin_cfg->type, pin_cfg->num);
 480                         return false;
 481                 }
 482         }
 483
 484         return true;
 485 }
 486
 487 static int tegra_kbc_parse_dt(struct tegra_kbc *kbc)
 488 {
 489         struct device_node *np = kbc->dev->of_node;
 490         u32 prop;
 491         int i;
 492         u32 num_rows = 0;
 493         u32 num_cols = 0;
 494         u32 cols_cfg[KBC_MAX_GPIO];
 495         u32 rows_cfg[KBC_MAX_GPIO];
 496         int proplen;
 497         int ret;
 498
 499         if (!of_property_read_u32(np, "nvidia,debounce-delay-ms", &prop))
 500                 kbc->debounce_cnt = prop;
 501
 502         if (!of_property_read_u32(np, "nvidia,repeat-delay-ms", &prop))
 503                 kbc->repeat_cnt = prop;
 504
 505         if (of_find_property(np, "nvidia,needs-ghost-filter", NULL))
 506                 kbc->use_ghost_filter = true;
 507
 508         if (of_find_property(np, "nvidia,wakeup-source", NULL))
 509                 kbc->wakeup = true;
 510
 511         if (!of_get_property(np, "nvidia,kbc-row-pins", &proplen)) {
 512                 dev_err(kbc->dev, "property nvidia,kbc-row-pins not found\n");
 513                 return -ENOENT;
 514         }
 515         num_rows = proplen / sizeof(u32);
 516
 517         if (!of_get_property(np, "nvidia,kbc-col-pins", &proplen)) {
 518                 dev_err(kbc->dev, "property nvidia,kbc-col-pins not found\n");
 519                 return -ENOENT;
 520         }
 521         num_cols = proplen / sizeof(u32);
 522
 523         if (!of_get_property(np, "linux,keymap", &proplen)) {
 524                 dev_err(kbc->dev, "property linux,keymap not found\n");
 525                 return -ENOENT;
 526         }
 527
 528         if (!num_rows || !num_cols || ((num_rows + num_cols) > KBC_MAX_GPIO)) {
 529                 dev_err(kbc->dev,
 530                         "keypad rows/columns not porperly specified\n");
 531                 return -EINVAL;
 532         }
 533
 534         /* Set all pins as non-configured */
 535         for (i = 0; i < KBC_MAX_GPIO; i++)
 536                 kbc->pin_cfg[i].type = PIN_CFG_IGNORE;
 537
 538         ret = of_property_read_u32_array(np, "nvidia,kbc-row-pins",
 539                                 rows_cfg, num_rows);
 540         if (ret < 0) {
 541                 dev_err(kbc->dev, "Rows configurations are not proper\n");
 542                 return -EINVAL;
 543         }
 544
 545         ret = of_property_read_u32_array(np, "nvidia,kbc-col-pins",
 546                                 cols_cfg, num_cols);
 547         if (ret < 0) {
 548                 dev_err(kbc->dev, "Cols configurations are not proper\n");
 549                 return -EINVAL;
 550         }
 551
 552         for (i = 0; i < num_rows; i++) {
 553                 kbc->pin_cfg[rows_cfg[i]].type = PIN_CFG_ROW;
 554                 kbc->pin_cfg[rows_cfg[i]].num = i;
 555         }
 556
 557         for (i = 0; i < num_cols; i++) {
 558                 kbc->pin_cfg[cols_cfg[i]].type = PIN_CFG_COL;
 559                 kbc->pin_cfg[cols_cfg[i]].num = i;
 560         }
 561
 562         return 0;
 563 }
 564
 565 static int tegra_kbc_probe(struct platform_device *pdev)
 566 {
 567         struct tegra_kbc *kbc;
 568         struct resource *res;
 569         int err;
 570         int num_rows = 0;
 571         unsigned int debounce_cnt;
 572         unsigned int scan_time_rows;
 573         unsigned int keymap_rows = KBC_MAX_KEY;
 574
 575         kbc = devm_kzalloc(&pdev->dev, sizeof(*kbc), GFP_KERNEL);
 576         if (!kbc) {
 577                 dev_err(&pdev->dev, "failed to alloc memory for kbc\n");
 578                 return -ENOMEM;
 579         }
 580
 581         kbc->dev = &pdev->dev;
 582         spin_lock_init(&kbc->lock);
 583
 584         err = tegra_kbc_parse_dt(kbc);
 585         if (err)
 586                 return err;
 587
 588         if (!tegra_kbc_check_pin_cfg(kbc, &num_rows))
 589                 return -EINVAL;
 590
 591         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 592         if (!res) {
 593                 dev_err(&pdev->dev, "failed to get I/O memory\n");
 594                 return -ENXIO;
 595         }
 596
 597         kbc->irq = platform_get_irq(pdev, 0);
 598         if (kbc->irq < 0) {
 599                 dev_err(&pdev->dev, "failed to get keyboard IRQ\n");
 600                 return -ENXIO;
 601         }
 602
 603         kbc->idev = devm_input_allocate_device(&pdev->dev);
 604         if (!kbc->idev) {
 605                 dev_err(&pdev->dev, "failed to allocate input device\n");
 606                 return -ENOMEM;
 607         }
 608
 609         setup_timer(&kbc->timer, tegra_kbc_keypress_timer, (unsigned long)kbc);
 610
 611         kbc->mmio = devm_request_and_ioremap(&pdev->dev, res);
 612         if (!kbc->mmio) {
 613                 dev_err(&pdev->dev, "Cannot request memregion/iomap address\n");
 614                 return -EBUSY;
 615         }
 616
 617         kbc->clk = devm_clk_get(&pdev->dev, NULL);
 618         if (IS_ERR(kbc->clk)) {
 619                 dev_err(&pdev->dev, "failed to get keyboard clock\n");
 620                 return PTR_ERR(kbc->clk);
 621         }
 622
 623         /*
 624          * The time delay between two consecutive reads of the FIFO is
 625          * the sum of the repeat time and the time taken for scanning
 626          * the rows. There is an additional delay before the row scanning
 627          * starts. The repoll delay is computed in milliseconds.
 628          */
 629         debounce_cnt = min(kbc->debounce_cnt, KBC_MAX_DEBOUNCE_CNT);
 630         scan_time_rows = (KBC_ROW_SCAN_TIME + debounce_cnt) * num_rows;
 631         kbc->repoll_dly = KBC_ROW_SCAN_DLY + scan_time_rows + kbc->repeat_cnt;
 632         kbc->repoll_dly = DIV_ROUND_UP(kbc->repoll_dly, KBC_CYCLE_MS);
 633
 634         kbc->idev->name = pdev->name;
 635         kbc->idev->id.bustype = BUS_HOST;
 636         kbc->idev->dev.parent = &pdev->dev;
 637         kbc->idev->open = tegra_kbc_open;
 638         kbc->idev->close = tegra_kbc_close;
 639
 640         if (kbc->keymap_data && kbc->use_fn_map)
 641                 keymap_rows *= 2;
 642
 643         err = matrix_keypad_build_keymap(kbc->keymap_data, NULL,
 644                                          keymap_rows, KBC_MAX_COL,
 645                                          kbc->keycode, kbc->idev);
 646         if (err) {
 647                 dev_err(&pdev->dev, "failed to setup keymap\n");
 648                 return err;
 649         }
 650
 651         __set_bit(EV_REP, kbc->idev->evbit);
 652         input_set_capability(kbc->idev, EV_MSC, MSC_SCAN);
 653
 654         input_set_drvdata(kbc->idev, kbc);
 655
 656         err = devm_request_irq(&pdev->dev, kbc->irq, tegra_kbc_isr,
 657                           IRQF_NO_SUSPEND | IRQF_TRIGGER_HIGH, pdev->name, kbc);
 658         if (err) {
 659                 dev_err(&pdev->dev, "failed to request keyboard IRQ\n");
 660                 return err;
 661         }
 662
 663         disable_irq(kbc->irq);
 664
 665         err = input_register_device(kbc->idev);
 666         if (err) {
 667                 dev_err(&pdev->dev, "failed to register input device\n");
 668                 return err;
 669         }
 670
 671         platform_set_drvdata(pdev, kbc);
 672         device_init_wakeup(&pdev->dev, kbc->wakeup);
 673
 674         return 0;
 675 }
 676
 677 #ifdef CONFIG_PM_SLEEP
 678 static void tegra_kbc_set_keypress_interrupt(struct tegra_kbc *kbc, bool enable)
 679 {
 680         u32 val;
 681
 682         val = readl(kbc->mmio + KBC_CONTROL_0);
 683         if (enable)
 684                 val |= KBC_CONTROL_KEYPRESS_INT_EN;
 685         else
 686                 val &= ~KBC_CONTROL_KEYPRESS_INT_EN;
 687         writel(val, kbc->mmio + KBC_CONTROL_0);
 688 }
 689
 690 static int tegra_kbc_suspend(struct device *dev)
 691 {
 692         struct platform_device *pdev = to_platform_device(dev);
 693         struct tegra_kbc *kbc = platform_get_drvdata(pdev);
 694
 695         mutex_lock(&kbc->idev->mutex);
 696         if (device_may_wakeup(&pdev->dev)) {
 697                 disable_irq(kbc->irq);
 698                 del_timer_sync(&kbc->timer);
 699                 tegra_kbc_set_fifo_interrupt(kbc, false);
 700
 701                 /* Forcefully clear the interrupt status */
 702                 writel(0x7, kbc->mmio + KBC_INT_0);
 703                 /*
 704                  * Store the previous resident time of continuous polling mode.
 705                  * Force the keyboard into interrupt mode.
 706                  */
 707                 kbc->cp_to_wkup_dly = readl(kbc->mmio + KBC_TO_CNT_0);
 708                 writel(0, kbc->mmio + KBC_TO_CNT_0);
 709
 710                 tegra_kbc_setup_wakekeys(kbc, true);
 711                 msleep(30);
 712
 713                 kbc->keypress_caused_wake = false;
 714                 /* Enable keypress interrupt before going into suspend. */
 715                 tegra_kbc_set_keypress_interrupt(kbc, true);
 716                 enable_irq(kbc->irq);
 717                 enable_irq_wake(kbc->irq);
 718         } else {
 719                 if (kbc->idev->users)
 720                         tegra_kbc_stop(kbc);
 721         }
 722         mutex_unlock(&kbc->idev->mutex);
 723
 724         return 0;
 725 }
 726
 727 static int tegra_kbc_resume(struct device *dev)
 728 {
 729         struct platform_device *pdev = to_platform_device(dev);
 730         struct tegra_kbc *kbc = platform_get_drvdata(pdev);
 731         int err = 0;
 732
 733         mutex_lock(&kbc->idev->mutex);
 734         if (device_may_wakeup(&pdev->dev)) {
 735                 disable_irq_wake(kbc->irq);
 736                 tegra_kbc_setup_wakekeys(kbc, false);
 737                 /* We will use fifo interrupts for key detection. */
 738                 tegra_kbc_set_keypress_interrupt(kbc, false);
 739
 740                 /* Restore the resident time of continuous polling mode. */
 741                 writel(kbc->cp_to_wkup_dly, kbc->mmio + KBC_TO_CNT_0);
 742
 743                 tegra_kbc_set_fifo_interrupt(kbc, true);
 744
 745                 if (kbc->keypress_caused_wake && kbc->wakeup_key) {
 746                         /*
 747                          * We can't report events directly from the ISR
 748                          * because timekeeping is stopped when processing
 749                          * wakeup request and we get a nasty warning when
 750                          * we try to call do_gettimeofday() in evdev
 751                          * handler.
 752                          */
 753                         input_report_key(kbc->idev, kbc->wakeup_key, 1);
 754                         input_sync(kbc->idev);
 755                         input_report_key(kbc->idev, kbc->wakeup_key, 0);
 756                         input_sync(kbc->idev);
 757                 }
 758         } else {
 759                 if (kbc->idev->users)
 760                         err = tegra_kbc_start(kbc);
 761         }
 762         mutex_unlock(&kbc->idev->mutex);
 763
 764         return err;
 765 }
 766 #endif
 767
 768 static SIMPLE_DEV_PM_OPS(tegra_kbc_pm_ops, tegra_kbc_suspend, tegra_kbc_resume);
 769
 770 static const struct of_device_id tegra_kbc_of_match[] = {
 771         { .compatible = "nvidia,tegra20-kbc", },
 772         { },
 773 };
 774 MODULE_DEVICE_TABLE(of, tegra_kbc_of_match);
 775
 776 static struct platform_driver tegra_kbc_driver = {
 777         .probe          = tegra_kbc_probe,
 778         .driver = {
 779                 .name   = "tegra-kbc",
 780                 .owner  = THIS_MODULE,
 781                 .pm     = &tegra_kbc_pm_ops,
 782                 .of_match_table = tegra_kbc_of_match,
 783         },
 784 };
 785 module_platform_driver(tegra_kbc_driver);
 786
 787 MODULE_LICENSE("GPL");
 788 MODULE_AUTHOR("Rakesh Iyer <riyer@nvidia.com>");
 789 MODULE_DESCRIPTION("Tegra matrix keyboard controller driver");
 790 MODULE_ALIAS("platform:tegra-kbc");