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");
791