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/module.h>
23 #include <linux/input.h>
24 #include <linux/platform_device.h>
25 #include <linux/delay.h>
26 #include <linux/io.h>
27 #include <linux/interrupt.h>
28 #include <linux/clk.h>
29 #include <linux/slab.h>
30 #include <mach/clk.h>
31 #include <mach/kbc.h>
32 
33 #define KBC_MAX_DEBOUNCE_CNT	0x3ffu
34 
35 /* KBC row scan time and delay for beginning the row scan. */
36 #define KBC_ROW_SCAN_TIME	16
37 #define KBC_ROW_SCAN_DLY	5
38 
39 /* KBC uses a 32KHz clock so a cycle = 1/32Khz */
40 #define KBC_CYCLE_USEC	32
41 
42 /* KBC Registers */
43 
44 /* KBC Control Register */
45 #define KBC_CONTROL_0	0x0
46 #define KBC_FIFO_TH_CNT_SHIFT(cnt)	(cnt << 14)
47 #define KBC_DEBOUNCE_CNT_SHIFT(cnt)	(cnt << 4)
48 #define KBC_CONTROL_FIFO_CNT_INT_EN	(1 << 3)
49 #define KBC_CONTROL_KBC_EN		(1 << 0)
50 
51 /* KBC Interrupt Register */
52 #define KBC_INT_0	0x4
53 #define KBC_INT_FIFO_CNT_INT_STATUS	(1 << 2)
54 
55 #define KBC_ROW_CFG0_0	0x8
56 #define KBC_COL_CFG0_0	0x18
57 #define KBC_INIT_DLY_0	0x28
58 #define KBC_RPT_DLY_0	0x2c
59 #define KBC_KP_ENT0_0	0x30
60 #define KBC_KP_ENT1_0	0x34
61 #define KBC_ROW0_MASK_0	0x38
62 
63 #define KBC_ROW_SHIFT	3
64 
65 struct tegra_kbc {
66 	void __iomem *mmio;
67 	struct input_dev *idev;
68 	unsigned int irq;
69 	spinlock_t lock;
70 	unsigned int repoll_dly;
71 	unsigned long cp_dly_jiffies;
72 	bool use_fn_map;
73 	bool use_ghost_filter;
74 	const struct tegra_kbc_platform_data *pdata;
75 	unsigned short keycode[KBC_MAX_KEY * 2];
76 	unsigned short current_keys[KBC_MAX_KPENT];
77 	unsigned int num_pressed_keys;
78 	struct timer_list timer;
79 	struct clk *clk;
80 };
81 
82 static const u32 tegra_kbc_default_keymap[] = {
83 	KEY(0, 2, KEY_W),
84 	KEY(0, 3, KEY_S),
85 	KEY(0, 4, KEY_A),
86 	KEY(0, 5, KEY_Z),
87 	KEY(0, 7, KEY_FN),
88 
89 	KEY(1, 7, KEY_LEFTMETA),
90 
91 	KEY(2, 6, KEY_RIGHTALT),
92 	KEY(2, 7, KEY_LEFTALT),
93 
94 	KEY(3, 0, KEY_5),
95 	KEY(3, 1, KEY_4),
96 	KEY(3, 2, KEY_R),
97 	KEY(3, 3, KEY_E),
98 	KEY(3, 4, KEY_F),
99 	KEY(3, 5, KEY_D),
100 	KEY(3, 6, KEY_X),
101 
102 	KEY(4, 0, KEY_7),
103 	KEY(4, 1, KEY_6),
104 	KEY(4, 2, KEY_T),
105 	KEY(4, 3, KEY_H),
106 	KEY(4, 4, KEY_G),
107 	KEY(4, 5, KEY_V),
108 	KEY(4, 6, KEY_C),
109 	KEY(4, 7, KEY_SPACE),
110 
111 	KEY(5, 0, KEY_9),
112 	KEY(5, 1, KEY_8),
113 	KEY(5, 2, KEY_U),
114 	KEY(5, 3, KEY_Y),
115 	KEY(5, 4, KEY_J),
116 	KEY(5, 5, KEY_N),
117 	KEY(5, 6, KEY_B),
118 	KEY(5, 7, KEY_BACKSLASH),
119 
120 	KEY(6, 0, KEY_MINUS),
121 	KEY(6, 1, KEY_0),
122 	KEY(6, 2, KEY_O),
123 	KEY(6, 3, KEY_I),
124 	KEY(6, 4, KEY_L),
125 	KEY(6, 5, KEY_K),
126 	KEY(6, 6, KEY_COMMA),
127 	KEY(6, 7, KEY_M),
128 
129 	KEY(7, 1, KEY_EQUAL),
130 	KEY(7, 2, KEY_RIGHTBRACE),
131 	KEY(7, 3, KEY_ENTER),
132 	KEY(7, 7, KEY_MENU),
133 
134 	KEY(8, 4, KEY_RIGHTSHIFT),
135 	KEY(8, 5, KEY_LEFTSHIFT),
136 
137 	KEY(9, 5, KEY_RIGHTCTRL),
138 	KEY(9, 7, KEY_LEFTCTRL),
139 
140 	KEY(11, 0, KEY_LEFTBRACE),
141 	KEY(11, 1, KEY_P),
142 	KEY(11, 2, KEY_APOSTROPHE),
143 	KEY(11, 3, KEY_SEMICOLON),
144 	KEY(11, 4, KEY_SLASH),
145 	KEY(11, 5, KEY_DOT),
146 
147 	KEY(12, 0, KEY_F10),
148 	KEY(12, 1, KEY_F9),
149 	KEY(12, 2, KEY_BACKSPACE),
150 	KEY(12, 3, KEY_3),
151 	KEY(12, 4, KEY_2),
152 	KEY(12, 5, KEY_UP),
153 	KEY(12, 6, KEY_PRINT),
154 	KEY(12, 7, KEY_PAUSE),
155 
156 	KEY(13, 0, KEY_INSERT),
157 	KEY(13, 1, KEY_DELETE),
158 	KEY(13, 3, KEY_PAGEUP),
159 	KEY(13, 4, KEY_PAGEDOWN),
160 	KEY(13, 5, KEY_RIGHT),
161 	KEY(13, 6, KEY_DOWN),
162 	KEY(13, 7, KEY_LEFT),
163 
164 	KEY(14, 0, KEY_F11),
165 	KEY(14, 1, KEY_F12),
166 	KEY(14, 2, KEY_F8),
167 	KEY(14, 3, KEY_Q),
168 	KEY(14, 4, KEY_F4),
169 	KEY(14, 5, KEY_F3),
170 	KEY(14, 6, KEY_1),
171 	KEY(14, 7, KEY_F7),
172 
173 	KEY(15, 0, KEY_ESC),
174 	KEY(15, 1, KEY_GRAVE),
175 	KEY(15, 2, KEY_F5),
176 	KEY(15, 3, KEY_TAB),
177 	KEY(15, 4, KEY_F1),
178 	KEY(15, 5, KEY_F2),
179 	KEY(15, 6, KEY_CAPSLOCK),
180 	KEY(15, 7, KEY_F6),
181 
182 	/* Software Handled Function Keys */
183 	KEY(20, 0, KEY_KP7),
184 
185 	KEY(21, 0, KEY_KP9),
186 	KEY(21, 1, KEY_KP8),
187 	KEY(21, 2, KEY_KP4),
188 	KEY(21, 4, KEY_KP1),
189 
190 	KEY(22, 1, KEY_KPSLASH),
191 	KEY(22, 2, KEY_KP6),
192 	KEY(22, 3, KEY_KP5),
193 	KEY(22, 4, KEY_KP3),
194 	KEY(22, 5, KEY_KP2),
195 	KEY(22, 7, KEY_KP0),
196 
197 	KEY(27, 1, KEY_KPASTERISK),
198 	KEY(27, 3, KEY_KPMINUS),
199 	KEY(27, 4, KEY_KPPLUS),
200 	KEY(27, 5, KEY_KPDOT),
201 
202 	KEY(28, 5, KEY_VOLUMEUP),
203 
204 	KEY(29, 3, KEY_HOME),
205 	KEY(29, 4, KEY_END),
206 	KEY(29, 5, KEY_BRIGHTNESSDOWN),
207 	KEY(29, 6, KEY_VOLUMEDOWN),
208 	KEY(29, 7, KEY_BRIGHTNESSUP),
209 
210 	KEY(30, 0, KEY_NUMLOCK),
211 	KEY(30, 1, KEY_SCROLLLOCK),
212 	KEY(30, 2, KEY_MUTE),
213 
214 	KEY(31, 4, KEY_HELP),
215 };
216 
217 static const struct matrix_keymap_data tegra_kbc_default_keymap_data = {
218 	.keymap		= tegra_kbc_default_keymap,
219 	.keymap_size	= ARRAY_SIZE(tegra_kbc_default_keymap),
220 };
221 
222 static void tegra_kbc_report_released_keys(struct input_dev *input,
223 					   unsigned short old_keycodes[],
224 					   unsigned int old_num_keys,
225 					   unsigned short new_keycodes[],
226 					   unsigned int new_num_keys)
227 {
228 	unsigned int i, j;
229 
230 	for (i = 0; i < old_num_keys; i++) {
231 		for (j = 0; j < new_num_keys; j++)
232 			if (old_keycodes[i] == new_keycodes[j])
233 				break;
234 
235 		if (j == new_num_keys)
236 			input_report_key(input, old_keycodes[i], 0);
237 	}
238 }
239 
240 static void tegra_kbc_report_pressed_keys(struct input_dev *input,
241 					  unsigned char scancodes[],
242 					  unsigned short keycodes[],
243 					  unsigned int num_pressed_keys)
244 {
245 	unsigned int i;
246 
247 	for (i = 0; i < num_pressed_keys; i++) {
248 		input_event(input, EV_MSC, MSC_SCAN, scancodes[i]);
249 		input_report_key(input, keycodes[i], 1);
250 	}
251 }
252 
253 static void tegra_kbc_report_keys(struct tegra_kbc *kbc)
254 {
255 	unsigned char scancodes[KBC_MAX_KPENT];
256 	unsigned short keycodes[KBC_MAX_KPENT];
257 	u32 val = 0;
258 	unsigned int i;
259 	unsigned int num_down = 0;
260 	unsigned long flags;
261 	bool fn_keypress = false;
262 	bool key_in_same_row = false;
263 	bool key_in_same_col = false;
264 
265 	spin_lock_irqsave(&kbc->lock, flags);
266 	for (i = 0; i < KBC_MAX_KPENT; i++) {
267 		if ((i % 4) == 0)
268 			val = readl(kbc->mmio + KBC_KP_ENT0_0 + i);
269 
270 		if (val & 0x80) {
271 			unsigned int col = val & 0x07;
272 			unsigned int row = (val >> 3) & 0x0f;
273 			unsigned char scancode =
274 				MATRIX_SCAN_CODE(row, col, KBC_ROW_SHIFT);
275 
276 			scancodes[num_down] = scancode;
277 			keycodes[num_down] = kbc->keycode[scancode];
278 			/* If driver uses Fn map, do not report the Fn key. */
279 			if ((keycodes[num_down] == KEY_FN) && kbc->use_fn_map)
280 				fn_keypress = true;
281 			else
282 				num_down++;
283 		}
284 
285 		val >>= 8;
286 	}
287 
288 	/*
289 	 * Matrix keyboard designs are prone to keyboard ghosting.
290 	 * Ghosting occurs if there are 3 keys such that -
291 	 * any 2 of the 3 keys share a row, and any 2 of them share a column.
292 	 * If so ignore the key presses for this iteration.
293 	 */
294 	if ((kbc->use_ghost_filter) && (num_down >= 3)) {
295 		for (i = 0; i < num_down; i++) {
296 			unsigned int j;
297 			u8 curr_col = scancodes[i] & 0x07;
298 			u8 curr_row = scancodes[i] >> KBC_ROW_SHIFT;
299 
300 			/*
301 			 * Find 2 keys such that one key is in the same row
302 			 * and the other is in the same column as the i-th key.
303 			 */
304 			for (j = i + 1; j < num_down; j++) {
305 				u8 col = scancodes[j] & 0x07;
306 				u8 row = scancodes[j] >> KBC_ROW_SHIFT;
307 
308 				if (col == curr_col)
309 					key_in_same_col = true;
310 				if (row == curr_row)
311 					key_in_same_row = true;
312 			}
313 		}
314 	}
315 
316 	/*
317 	 * If the platform uses Fn keymaps, translate keys on a Fn keypress.
318 	 * Function keycodes are KBC_MAX_KEY apart from the plain keycodes.
319 	 */
320 	if (fn_keypress) {
321 		for (i = 0; i < num_down; i++) {
322 			scancodes[i] += KBC_MAX_KEY;
323 			keycodes[i] = kbc->keycode[scancodes[i]];
324 		}
325 	}
326 
327 	spin_unlock_irqrestore(&kbc->lock, flags);
328 
329 	/* Ignore the key presses for this iteration? */
330 	if (key_in_same_col && key_in_same_row)
331 		return;
332 
333 	tegra_kbc_report_released_keys(kbc->idev,
334 				       kbc->current_keys, kbc->num_pressed_keys,
335 				       keycodes, num_down);
336 	tegra_kbc_report_pressed_keys(kbc->idev, scancodes, keycodes, num_down);
337 	input_sync(kbc->idev);
338 
339 	memcpy(kbc->current_keys, keycodes, sizeof(kbc->current_keys));
340 	kbc->num_pressed_keys = num_down;
341 }
342 
343 static void tegra_kbc_keypress_timer(unsigned long data)
344 {
345 	struct tegra_kbc *kbc = (struct tegra_kbc *)data;
346 	unsigned long flags;
347 	u32 val;
348 	unsigned int i;
349 
350 	val = (readl(kbc->mmio + KBC_INT_0) >> 4) & 0xf;
351 	if (val) {
352 		unsigned long dly;
353 
354 		tegra_kbc_report_keys(kbc);
355 
356 		/*
357 		 * If more than one keys are pressed we need not wait
358 		 * for the repoll delay.
359 		 */
360 		dly = (val == 1) ? kbc->repoll_dly : 1;
361 		mod_timer(&kbc->timer, jiffies + msecs_to_jiffies(dly));
362 	} else {
363 		/* Release any pressed keys and exit the polling loop */
364 		for (i = 0; i < kbc->num_pressed_keys; i++)
365 			input_report_key(kbc->idev, kbc->current_keys[i], 0);
366 		input_sync(kbc->idev);
367 
368 		kbc->num_pressed_keys = 0;
369 
370 		/* All keys are released so enable the keypress interrupt */
371 		spin_lock_irqsave(&kbc->lock, flags);
372 		val = readl(kbc->mmio + KBC_CONTROL_0);
373 		val |= KBC_CONTROL_FIFO_CNT_INT_EN;
374 		writel(val, kbc->mmio + KBC_CONTROL_0);
375 		spin_unlock_irqrestore(&kbc->lock, flags);
376 	}
377 }
378 
379 static irqreturn_t tegra_kbc_isr(int irq, void *args)
380 {
381 	struct tegra_kbc *kbc = args;
382 	u32 val, ctl;
383 
384 	/*
385 	 * Until all keys are released, defer further processing to
386 	 * the polling loop in tegra_kbc_keypress_timer
387 	 */
388 	ctl = readl(kbc->mmio + KBC_CONTROL_0);
389 	ctl &= ~KBC_CONTROL_FIFO_CNT_INT_EN;
390 	writel(ctl, kbc->mmio + KBC_CONTROL_0);
391 
392 	/*
393 	 * Quickly bail out & reenable interrupts if the fifo threshold
394 	 * count interrupt wasn't the interrupt source
395 	 */
396 	val = readl(kbc->mmio + KBC_INT_0);
397 	writel(val, kbc->mmio + KBC_INT_0);
398 
399 	if (val & KBC_INT_FIFO_CNT_INT_STATUS) {
400 		/*
401 		 * Schedule timer to run when hardware is in continuous
402 		 * polling mode.
403 		 */
404 		mod_timer(&kbc->timer, jiffies + kbc->cp_dly_jiffies);
405 	} else {
406 		ctl |= KBC_CONTROL_FIFO_CNT_INT_EN;
407 		writel(ctl, kbc->mmio + KBC_CONTROL_0);
408 	}
409 
410 	return IRQ_HANDLED;
411 }
412 
413 static void tegra_kbc_setup_wakekeys(struct tegra_kbc *kbc, bool filter)
414 {
415 	const struct tegra_kbc_platform_data *pdata = kbc->pdata;
416 	int i;
417 	unsigned int rst_val;
418 
419 	/* Either mask all keys or none. */
420 	rst_val = (filter && !pdata->wakeup) ? ~0 : 0;
421 
422 	for (i = 0; i < KBC_MAX_ROW; i++)
423 		writel(rst_val, kbc->mmio + KBC_ROW0_MASK_0 + i * 4);
424 }
425 
426 static void tegra_kbc_config_pins(struct tegra_kbc *kbc)
427 {
428 	const struct tegra_kbc_platform_data *pdata = kbc->pdata;
429 	int i;
430 
431 	for (i = 0; i < KBC_MAX_GPIO; i++) {
432 		u32 r_shft = 5 * (i % 6);
433 		u32 c_shft = 4 * (i % 8);
434 		u32 r_mask = 0x1f << r_shft;
435 		u32 c_mask = 0x0f << c_shft;
436 		u32 r_offs = (i / 6) * 4 + KBC_ROW_CFG0_0;
437 		u32 c_offs = (i / 8) * 4 + KBC_COL_CFG0_0;
438 		u32 row_cfg = readl(kbc->mmio + r_offs);
439 		u32 col_cfg = readl(kbc->mmio + c_offs);
440 
441 		row_cfg &= ~r_mask;
442 		col_cfg &= ~c_mask;
443 
444 		if (pdata->pin_cfg[i].is_row)
445 			row_cfg |= ((pdata->pin_cfg[i].num << 1) | 1) << r_shft;
446 		else
447 			col_cfg |= ((pdata->pin_cfg[i].num << 1) | 1) << c_shft;
448 
449 		writel(row_cfg, kbc->mmio + r_offs);
450 		writel(col_cfg, kbc->mmio + c_offs);
451 	}
452 }
453 
454 static int tegra_kbc_start(struct tegra_kbc *kbc)
455 {
456 	const struct tegra_kbc_platform_data *pdata = kbc->pdata;
457 	unsigned long flags;
458 	unsigned int debounce_cnt;
459 	u32 val = 0;
460 
461 	clk_enable(kbc->clk);
462 
463 	/* Reset the KBC controller to clear all previous status.*/
464 	tegra_periph_reset_assert(kbc->clk);
465 	udelay(100);
466 	tegra_periph_reset_deassert(kbc->clk);
467 	udelay(100);
468 
469 	tegra_kbc_config_pins(kbc);
470 	tegra_kbc_setup_wakekeys(kbc, false);
471 
472 	writel(pdata->repeat_cnt, kbc->mmio + KBC_RPT_DLY_0);
473 
474 	/* Keyboard debounce count is maximum of 12 bits. */
475 	debounce_cnt = min(pdata->debounce_cnt, KBC_MAX_DEBOUNCE_CNT);
476 	val = KBC_DEBOUNCE_CNT_SHIFT(debounce_cnt);
477 	val |= KBC_FIFO_TH_CNT_SHIFT(1); /* set fifo interrupt threshold to 1 */
478 	val |= KBC_CONTROL_FIFO_CNT_INT_EN;  /* interrupt on FIFO threshold */
479 	val |= KBC_CONTROL_KBC_EN;     /* enable */
480 	writel(val, kbc->mmio + KBC_CONTROL_0);
481 
482 	/*
483 	 * Compute the delay(ns) from interrupt mode to continuous polling
484 	 * mode so the timer routine is scheduled appropriately.
485 	 */
486 	val = readl(kbc->mmio + KBC_INIT_DLY_0);
487 	kbc->cp_dly_jiffies = usecs_to_jiffies((val & 0xfffff) * 32);
488 
489 	kbc->num_pressed_keys = 0;
490 
491 	/*
492 	 * Atomically clear out any remaining entries in the key FIFO
493 	 * and enable keyboard interrupts.
494 	 */
495 	spin_lock_irqsave(&kbc->lock, flags);
496 	while (1) {
497 		val = readl(kbc->mmio + KBC_INT_0);
498 		val >>= 4;
499 		if (!val)
500 			break;
501 
502 		val = readl(kbc->mmio + KBC_KP_ENT0_0);
503 		val = readl(kbc->mmio + KBC_KP_ENT1_0);
504 	}
505 	writel(0x7, kbc->mmio + KBC_INT_0);
506 	spin_unlock_irqrestore(&kbc->lock, flags);
507 
508 	enable_irq(kbc->irq);
509 
510 	return 0;
511 }
512 
513 static void tegra_kbc_stop(struct tegra_kbc *kbc)
514 {
515 	unsigned long flags;
516 	u32 val;
517 
518 	spin_lock_irqsave(&kbc->lock, flags);
519 	val = readl(kbc->mmio + KBC_CONTROL_0);
520 	val &= ~1;
521 	writel(val, kbc->mmio + KBC_CONTROL_0);
522 	spin_unlock_irqrestore(&kbc->lock, flags);
523 
524 	disable_irq(kbc->irq);
525 	del_timer_sync(&kbc->timer);
526 
527 	clk_disable(kbc->clk);
528 }
529 
530 static int tegra_kbc_open(struct input_dev *dev)
531 {
532 	struct tegra_kbc *kbc = input_get_drvdata(dev);
533 
534 	return tegra_kbc_start(kbc);
535 }
536 
537 static void tegra_kbc_close(struct input_dev *dev)
538 {
539 	struct tegra_kbc *kbc = input_get_drvdata(dev);
540 
541 	return tegra_kbc_stop(kbc);
542 }
543 
544 static bool __devinit
545 tegra_kbc_check_pin_cfg(const struct tegra_kbc_platform_data *pdata,
546 			struct device *dev, unsigned int *num_rows)
547 {
548 	int i;
549 
550 	*num_rows = 0;
551 
552 	for (i = 0; i < KBC_MAX_GPIO; i++) {
553 		const struct tegra_kbc_pin_cfg *pin_cfg = &pdata->pin_cfg[i];
554 
555 		if (pin_cfg->is_row) {
556 			if (pin_cfg->num >= KBC_MAX_ROW) {
557 				dev_err(dev,
558 					"pin_cfg[%d]: invalid row number %d\n",
559 					i, pin_cfg->num);
560 				return false;
561 			}
562 			(*num_rows)++;
563 		} else {
564 			if (pin_cfg->num >= KBC_MAX_COL) {
565 				dev_err(dev,
566 					"pin_cfg[%d]: invalid column number %d\n",
567 					i, pin_cfg->num);
568 				return false;
569 			}
570 		}
571 	}
572 
573 	return true;
574 }
575 
576 static int __devinit tegra_kbc_probe(struct platform_device *pdev)
577 {
578 	const struct tegra_kbc_platform_data *pdata = pdev->dev.platform_data;
579 	const struct matrix_keymap_data *keymap_data;
580 	struct tegra_kbc *kbc;
581 	struct input_dev *input_dev;
582 	struct resource *res;
583 	int irq;
584 	int err;
585 	int num_rows = 0;
586 	unsigned int debounce_cnt;
587 	unsigned int scan_time_rows;
588 
589 	if (!pdata)
590 		return -EINVAL;
591 
592 	if (!tegra_kbc_check_pin_cfg(pdata, &pdev->dev, &num_rows))
593 		return -EINVAL;
594 
595 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
596 	if (!res) {
597 		dev_err(&pdev->dev, "failed to get I/O memory\n");
598 		return -ENXIO;
599 	}
600 
601 	irq = platform_get_irq(pdev, 0);
602 	if (irq < 0) {
603 		dev_err(&pdev->dev, "failed to get keyboard IRQ\n");
604 		return -ENXIO;
605 	}
606 
607 	kbc = kzalloc(sizeof(*kbc), GFP_KERNEL);
608 	input_dev = input_allocate_device();
609 	if (!kbc || !input_dev) {
610 		err = -ENOMEM;
611 		goto err_free_mem;
612 	}
613 
614 	kbc->pdata = pdata;
615 	kbc->idev = input_dev;
616 	kbc->irq = irq;
617 	spin_lock_init(&kbc->lock);
618 	setup_timer(&kbc->timer, tegra_kbc_keypress_timer, (unsigned long)kbc);
619 
620 	res = request_mem_region(res->start, resource_size(res), pdev->name);
621 	if (!res) {
622 		dev_err(&pdev->dev, "failed to request I/O memory\n");
623 		err = -EBUSY;
624 		goto err_free_mem;
625 	}
626 
627 	kbc->mmio = ioremap(res->start, resource_size(res));
628 	if (!kbc->mmio) {
629 		dev_err(&pdev->dev, "failed to remap I/O memory\n");
630 		err = -ENXIO;
631 		goto err_free_mem_region;
632 	}
633 
634 	kbc->clk = clk_get(&pdev->dev, NULL);
635 	if (IS_ERR(kbc->clk)) {
636 		dev_err(&pdev->dev, "failed to get keyboard clock\n");
637 		err = PTR_ERR(kbc->clk);
638 		goto err_iounmap;
639 	}
640 
641 	/*
642 	 * The time delay between two consecutive reads of the FIFO is
643 	 * the sum of the repeat time and the time taken for scanning
644 	 * the rows. There is an additional delay before the row scanning
645 	 * starts. The repoll delay is computed in milliseconds.
646 	 */
647 	debounce_cnt = min(pdata->debounce_cnt, KBC_MAX_DEBOUNCE_CNT);
648 	scan_time_rows = (KBC_ROW_SCAN_TIME + debounce_cnt) * num_rows;
649 	kbc->repoll_dly = KBC_ROW_SCAN_DLY + scan_time_rows + pdata->repeat_cnt;
650 	kbc->repoll_dly = ((kbc->repoll_dly * KBC_CYCLE_USEC) + 999) / 1000;
651 
652 	input_dev->name = pdev->name;
653 	input_dev->id.bustype = BUS_HOST;
654 	input_dev->dev.parent = &pdev->dev;
655 	input_dev->open = tegra_kbc_open;
656 	input_dev->close = tegra_kbc_close;
657 
658 	input_set_drvdata(input_dev, kbc);
659 
660 	input_dev->evbit[0] = BIT_MASK(EV_KEY);
661 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
662 
663 	input_dev->keycode = kbc->keycode;
664 	input_dev->keycodesize = sizeof(kbc->keycode[0]);
665 	input_dev->keycodemax = KBC_MAX_KEY;
666 	if (pdata->use_fn_map)
667 		input_dev->keycodemax *= 2;
668 
669 	kbc->use_fn_map = pdata->use_fn_map;
670 	kbc->use_ghost_filter = pdata->use_ghost_filter;
671 	keymap_data = pdata->keymap_data ?: &tegra_kbc_default_keymap_data;
672 	matrix_keypad_build_keymap(keymap_data, KBC_ROW_SHIFT,
673 				   input_dev->keycode, input_dev->keybit);
674 
675 	err = request_irq(kbc->irq, tegra_kbc_isr, IRQF_TRIGGER_HIGH,
676 			  pdev->name, kbc);
677 	if (err) {
678 		dev_err(&pdev->dev, "failed to request keyboard IRQ\n");
679 		goto err_put_clk;
680 	}
681 
682 	disable_irq(kbc->irq);
683 
684 	err = input_register_device(kbc->idev);
685 	if (err) {
686 		dev_err(&pdev->dev, "failed to register input device\n");
687 		goto err_free_irq;
688 	}
689 
690 	platform_set_drvdata(pdev, kbc);
691 	device_init_wakeup(&pdev->dev, pdata->wakeup);
692 
693 	return 0;
694 
695 err_free_irq:
696 	free_irq(kbc->irq, pdev);
697 err_put_clk:
698 	clk_put(kbc->clk);
699 err_iounmap:
700 	iounmap(kbc->mmio);
701 err_free_mem_region:
702 	release_mem_region(res->start, resource_size(res));
703 err_free_mem:
704 	input_free_device(kbc->idev);
705 	kfree(kbc);
706 
707 	return err;
708 }
709 
710 static int __devexit tegra_kbc_remove(struct platform_device *pdev)
711 {
712 	struct tegra_kbc *kbc = platform_get_drvdata(pdev);
713 	struct resource *res;
714 
715 	free_irq(kbc->irq, pdev);
716 	clk_put(kbc->clk);
717 
718 	input_unregister_device(kbc->idev);
719 	iounmap(kbc->mmio);
720 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
721 	release_mem_region(res->start, resource_size(res));
722 
723 	kfree(kbc);
724 
725 	platform_set_drvdata(pdev, NULL);
726 
727 	return 0;
728 }
729 
730 #ifdef CONFIG_PM_SLEEP
731 static int tegra_kbc_suspend(struct device *dev)
732 {
733 	struct platform_device *pdev = to_platform_device(dev);
734 	struct tegra_kbc *kbc = platform_get_drvdata(pdev);
735 
736 	if (device_may_wakeup(&pdev->dev)) {
737 		tegra_kbc_setup_wakekeys(kbc, true);
738 		enable_irq_wake(kbc->irq);
739 		/* Forcefully clear the interrupt status */
740 		writel(0x7, kbc->mmio + KBC_INT_0);
741 		msleep(30);
742 	} else {
743 		mutex_lock(&kbc->idev->mutex);
744 		if (kbc->idev->users)
745 			tegra_kbc_stop(kbc);
746 		mutex_unlock(&kbc->idev->mutex);
747 	}
748 
749 	return 0;
750 }
751 
752 static int tegra_kbc_resume(struct device *dev)
753 {
754 	struct platform_device *pdev = to_platform_device(dev);
755 	struct tegra_kbc *kbc = platform_get_drvdata(pdev);
756 	int err = 0;
757 
758 	if (device_may_wakeup(&pdev->dev)) {
759 		disable_irq_wake(kbc->irq);
760 		tegra_kbc_setup_wakekeys(kbc, false);
761 	} else {
762 		mutex_lock(&kbc->idev->mutex);
763 		if (kbc->idev->users)
764 			err = tegra_kbc_start(kbc);
765 		mutex_unlock(&kbc->idev->mutex);
766 	}
767 
768 	return err;
769 }
770 #endif
771 
772 static SIMPLE_DEV_PM_OPS(tegra_kbc_pm_ops, tegra_kbc_suspend, tegra_kbc_resume);
773 
774 static struct platform_driver tegra_kbc_driver = {
775 	.probe		= tegra_kbc_probe,
776 	.remove		= __devexit_p(tegra_kbc_remove),
777 	.driver	= {
778 		.name	= "tegra-kbc",
779 		.owner  = THIS_MODULE,
780 		.pm	= &tegra_kbc_pm_ops,
781 	},
782 };
783 
784 static void __exit tegra_kbc_exit(void)
785 {
786 	platform_driver_unregister(&tegra_kbc_driver);
787 }
788 module_exit(tegra_kbc_exit);
789 
790 static int __init tegra_kbc_init(void)
791 {
792 	return platform_driver_register(&tegra_kbc_driver);
793 }
794 module_init(tegra_kbc_init);
795 
796 MODULE_LICENSE("GPL");
797 MODULE_AUTHOR("Rakesh Iyer <riyer@nvidia.com>");
798 MODULE_DESCRIPTION("Tegra matrix keyboard controller driver");
799 MODULE_ALIAS("platform:tegra-kbc");
800