1 /* Copyright (c) 2009-2011, Code Aurora Forum. All rights reserved.
2  *
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License version 2 and
5  * only version 2 as published by the Free Software Foundation.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10  * GNU General Public License for more details.
11  */
12 
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/kernel.h>
16 #include <linux/interrupt.h>
17 #include <linux/slab.h>
18 #include <linux/input.h>
19 #include <linux/bitops.h>
20 #include <linux/delay.h>
21 #include <linux/mutex.h>
22 #include <linux/regmap.h>
23 #include <linux/of.h>
24 #include <linux/input/matrix_keypad.h>
25 
26 #define PM8XXX_MAX_ROWS		18
27 #define PM8XXX_MAX_COLS		8
28 #define PM8XXX_ROW_SHIFT	3
29 #define PM8XXX_MATRIX_MAX_SIZE	(PM8XXX_MAX_ROWS * PM8XXX_MAX_COLS)
30 
31 #define PM8XXX_MIN_ROWS		5
32 #define PM8XXX_MIN_COLS		5
33 
34 #define MAX_SCAN_DELAY		128
35 #define MIN_SCAN_DELAY		1
36 
37 /* in nanoseconds */
38 #define MAX_ROW_HOLD_DELAY	122000
39 #define MIN_ROW_HOLD_DELAY	30500
40 
41 #define MAX_DEBOUNCE_TIME	20
42 #define MIN_DEBOUNCE_TIME	5
43 
44 #define KEYP_CTRL			0x148
45 
46 #define KEYP_CTRL_EVNTS			BIT(0)
47 #define KEYP_CTRL_EVNTS_MASK		0x3
48 
49 #define KEYP_CTRL_SCAN_COLS_SHIFT	5
50 #define KEYP_CTRL_SCAN_COLS_MIN		5
51 #define KEYP_CTRL_SCAN_COLS_BITS	0x3
52 
53 #define KEYP_CTRL_SCAN_ROWS_SHIFT	2
54 #define KEYP_CTRL_SCAN_ROWS_MIN		5
55 #define KEYP_CTRL_SCAN_ROWS_BITS	0x7
56 
57 #define KEYP_CTRL_KEYP_EN		BIT(7)
58 
59 #define KEYP_SCAN			0x149
60 
61 #define KEYP_SCAN_READ_STATE		BIT(0)
62 #define KEYP_SCAN_DBOUNCE_SHIFT		1
63 #define KEYP_SCAN_PAUSE_SHIFT		3
64 #define KEYP_SCAN_ROW_HOLD_SHIFT	6
65 
66 #define KEYP_TEST			0x14A
67 
68 #define KEYP_TEST_CLEAR_RECENT_SCAN	BIT(6)
69 #define KEYP_TEST_CLEAR_OLD_SCAN	BIT(5)
70 #define KEYP_TEST_READ_RESET		BIT(4)
71 #define KEYP_TEST_DTEST_EN		BIT(3)
72 #define KEYP_TEST_ABORT_READ		BIT(0)
73 
74 #define KEYP_TEST_DBG_SELECT_SHIFT	1
75 
76 /* bits of these registers represent
77  * '0' for key press
78  * '1' for key release
79  */
80 #define KEYP_RECENT_DATA		0x14B
81 #define KEYP_OLD_DATA			0x14C
82 
83 #define KEYP_CLOCK_FREQ			32768
84 
85 /**
86  * struct pmic8xxx_kp - internal keypad data structure
87  * @num_cols - number of columns of keypad
88  * @num_rows - number of row of keypad
89  * @input - input device pointer for keypad
90  * @regmap - regmap handle
91  * @key_sense_irq - key press/release irq number
92  * @key_stuck_irq - key stuck notification irq number
93  * @keycodes - array to hold the key codes
94  * @dev - parent device pointer
95  * @keystate - present key press/release state
96  * @stuckstate - present state when key stuck irq
97  * @ctrl_reg - control register value
98  */
99 struct pmic8xxx_kp {
100 	unsigned int num_rows;
101 	unsigned int num_cols;
102 	struct input_dev *input;
103 	struct regmap *regmap;
104 	int key_sense_irq;
105 	int key_stuck_irq;
106 
107 	unsigned short keycodes[PM8XXX_MATRIX_MAX_SIZE];
108 
109 	struct device *dev;
110 	u16 keystate[PM8XXX_MAX_ROWS];
111 	u16 stuckstate[PM8XXX_MAX_ROWS];
112 
113 	u8 ctrl_reg;
114 };
115 
116 static u8 pmic8xxx_col_state(struct pmic8xxx_kp *kp, u8 col)
117 {
118 	/* all keys pressed on that particular row? */
119 	if (col == 0x00)
120 		return 1 << kp->num_cols;
121 	else
122 		return col & ((1 << kp->num_cols) - 1);
123 }
124 
125 /*
126  * Synchronous read protocol for RevB0 onwards:
127  *
128  * 1. Write '1' to ReadState bit in KEYP_SCAN register
129  * 2. Wait 2*32KHz clocks, so that HW can successfully enter read mode
130  *    synchronously
131  * 3. Read rows in old array first if events are more than one
132  * 4. Read rows in recent array
133  * 5. Wait 4*32KHz clocks
134  * 6. Write '0' to ReadState bit of KEYP_SCAN register so that hw can
135  *    synchronously exit read mode.
136  */
137 static int pmic8xxx_chk_sync_read(struct pmic8xxx_kp *kp)
138 {
139 	int rc;
140 	unsigned int scan_val;
141 
142 	rc = regmap_read(kp->regmap, KEYP_SCAN, &scan_val);
143 	if (rc < 0) {
144 		dev_err(kp->dev, "Error reading KEYP_SCAN reg, rc=%d\n", rc);
145 		return rc;
146 	}
147 
148 	scan_val |= 0x1;
149 
150 	rc = regmap_write(kp->regmap, KEYP_SCAN, scan_val);
151 	if (rc < 0) {
152 		dev_err(kp->dev, "Error writing KEYP_SCAN reg, rc=%d\n", rc);
153 		return rc;
154 	}
155 
156 	/* 2 * 32KHz clocks */
157 	udelay((2 * DIV_ROUND_UP(USEC_PER_SEC, KEYP_CLOCK_FREQ)) + 1);
158 
159 	return rc;
160 }
161 
162 static int pmic8xxx_kp_read_data(struct pmic8xxx_kp *kp, u16 *state,
163 					u16 data_reg, int read_rows)
164 {
165 	int rc, row;
166 	unsigned int val;
167 
168 	for (row = 0; row < read_rows; row++) {
169 		rc = regmap_read(kp->regmap, data_reg, &val);
170 		if (rc)
171 			return rc;
172 		dev_dbg(kp->dev, "%d = %d\n", row, val);
173 		state[row] = pmic8xxx_col_state(kp, val);
174 	}
175 
176 	return 0;
177 }
178 
179 static int pmic8xxx_kp_read_matrix(struct pmic8xxx_kp *kp, u16 *new_state,
180 					 u16 *old_state)
181 {
182 	int rc, read_rows;
183 	unsigned int scan_val;
184 
185 	if (kp->num_rows < PM8XXX_MIN_ROWS)
186 		read_rows = PM8XXX_MIN_ROWS;
187 	else
188 		read_rows = kp->num_rows;
189 
190 	pmic8xxx_chk_sync_read(kp);
191 
192 	if (old_state) {
193 		rc = pmic8xxx_kp_read_data(kp, old_state, KEYP_OLD_DATA,
194 						read_rows);
195 		if (rc < 0) {
196 			dev_err(kp->dev,
197 				"Error reading KEYP_OLD_DATA, rc=%d\n", rc);
198 			return rc;
199 		}
200 	}
201 
202 	rc = pmic8xxx_kp_read_data(kp, new_state, KEYP_RECENT_DATA,
203 					 read_rows);
204 	if (rc < 0) {
205 		dev_err(kp->dev,
206 			"Error reading KEYP_RECENT_DATA, rc=%d\n", rc);
207 		return rc;
208 	}
209 
210 	/* 4 * 32KHz clocks */
211 	udelay((4 * DIV_ROUND_UP(USEC_PER_SEC, KEYP_CLOCK_FREQ)) + 1);
212 
213 	rc = regmap_read(kp->regmap, KEYP_SCAN, &scan_val);
214 	if (rc < 0) {
215 		dev_err(kp->dev, "Error reading KEYP_SCAN reg, rc=%d\n", rc);
216 		return rc;
217 	}
218 
219 	scan_val &= 0xFE;
220 	rc = regmap_write(kp->regmap, KEYP_SCAN, scan_val);
221 	if (rc < 0)
222 		dev_err(kp->dev, "Error writing KEYP_SCAN reg, rc=%d\n", rc);
223 
224 	return rc;
225 }
226 
227 static void __pmic8xxx_kp_scan_matrix(struct pmic8xxx_kp *kp, u16 *new_state,
228 					 u16 *old_state)
229 {
230 	int row, col, code;
231 
232 	for (row = 0; row < kp->num_rows; row++) {
233 		int bits_changed = new_state[row] ^ old_state[row];
234 
235 		if (!bits_changed)
236 			continue;
237 
238 		for (col = 0; col < kp->num_cols; col++) {
239 			if (!(bits_changed & (1 << col)))
240 				continue;
241 
242 			dev_dbg(kp->dev, "key [%d:%d] %s\n", row, col,
243 					!(new_state[row] & (1 << col)) ?
244 					"pressed" : "released");
245 
246 			code = MATRIX_SCAN_CODE(row, col, PM8XXX_ROW_SHIFT);
247 
248 			input_event(kp->input, EV_MSC, MSC_SCAN, code);
249 			input_report_key(kp->input,
250 					kp->keycodes[code],
251 					!(new_state[row] & (1 << col)));
252 
253 			input_sync(kp->input);
254 		}
255 	}
256 }
257 
258 static bool pmic8xxx_detect_ghost_keys(struct pmic8xxx_kp *kp, u16 *new_state)
259 {
260 	int row, found_first = -1;
261 	u16 check, row_state;
262 
263 	check = 0;
264 	for (row = 0; row < kp->num_rows; row++) {
265 		row_state = (~new_state[row]) &
266 				 ((1 << kp->num_cols) - 1);
267 
268 		if (hweight16(row_state) > 1) {
269 			if (found_first == -1)
270 				found_first = row;
271 			if (check & row_state) {
272 				dev_dbg(kp->dev, "detected ghost key on row[%d]"
273 					 " and row[%d]\n", found_first, row);
274 				return true;
275 			}
276 		}
277 		check |= row_state;
278 	}
279 	return false;
280 }
281 
282 static int pmic8xxx_kp_scan_matrix(struct pmic8xxx_kp *kp, unsigned int events)
283 {
284 	u16 new_state[PM8XXX_MAX_ROWS];
285 	u16 old_state[PM8XXX_MAX_ROWS];
286 	int rc;
287 
288 	switch (events) {
289 	case 0x1:
290 		rc = pmic8xxx_kp_read_matrix(kp, new_state, NULL);
291 		if (rc < 0)
292 			return rc;
293 
294 		/* detecting ghost key is not an error */
295 		if (pmic8xxx_detect_ghost_keys(kp, new_state))
296 			return 0;
297 		__pmic8xxx_kp_scan_matrix(kp, new_state, kp->keystate);
298 		memcpy(kp->keystate, new_state, sizeof(new_state));
299 	break;
300 	case 0x3: /* two events - eventcounter is gray-coded */
301 		rc = pmic8xxx_kp_read_matrix(kp, new_state, old_state);
302 		if (rc < 0)
303 			return rc;
304 
305 		__pmic8xxx_kp_scan_matrix(kp, old_state, kp->keystate);
306 		__pmic8xxx_kp_scan_matrix(kp, new_state, old_state);
307 		memcpy(kp->keystate, new_state, sizeof(new_state));
308 	break;
309 	case 0x2:
310 		dev_dbg(kp->dev, "Some key events were lost\n");
311 		rc = pmic8xxx_kp_read_matrix(kp, new_state, old_state);
312 		if (rc < 0)
313 			return rc;
314 		__pmic8xxx_kp_scan_matrix(kp, old_state, kp->keystate);
315 		__pmic8xxx_kp_scan_matrix(kp, new_state, old_state);
316 		memcpy(kp->keystate, new_state, sizeof(new_state));
317 	break;
318 	default:
319 		rc = -EINVAL;
320 	}
321 	return rc;
322 }
323 
324 /*
325  * NOTE: We are reading recent and old data registers blindly
326  * whenever key-stuck interrupt happens, because events counter doesn't
327  * get updated when this interrupt happens due to key stuck doesn't get
328  * considered as key state change.
329  *
330  * We are not using old data register contents after they are being read
331  * because it might report the key which was pressed before the key being stuck
332  * as stuck key because it's pressed status is stored in the old data
333  * register.
334  */
335 static irqreturn_t pmic8xxx_kp_stuck_irq(int irq, void *data)
336 {
337 	u16 new_state[PM8XXX_MAX_ROWS];
338 	u16 old_state[PM8XXX_MAX_ROWS];
339 	int rc;
340 	struct pmic8xxx_kp *kp = data;
341 
342 	rc = pmic8xxx_kp_read_matrix(kp, new_state, old_state);
343 	if (rc < 0) {
344 		dev_err(kp->dev, "failed to read keypad matrix\n");
345 		return IRQ_HANDLED;
346 	}
347 
348 	__pmic8xxx_kp_scan_matrix(kp, new_state, kp->stuckstate);
349 
350 	return IRQ_HANDLED;
351 }
352 
353 static irqreturn_t pmic8xxx_kp_irq(int irq, void *data)
354 {
355 	struct pmic8xxx_kp *kp = data;
356 	unsigned int ctrl_val, events;
357 	int rc;
358 
359 	rc = regmap_read(kp->regmap, KEYP_CTRL, &ctrl_val);
360 	if (rc < 0) {
361 		dev_err(kp->dev, "failed to read keyp_ctrl register\n");
362 		return IRQ_HANDLED;
363 	}
364 
365 	events = ctrl_val & KEYP_CTRL_EVNTS_MASK;
366 
367 	rc = pmic8xxx_kp_scan_matrix(kp, events);
368 	if (rc < 0)
369 		dev_err(kp->dev, "failed to scan matrix\n");
370 
371 	return IRQ_HANDLED;
372 }
373 
374 static int pmic8xxx_kpd_init(struct pmic8xxx_kp *kp,
375 			     struct platform_device *pdev)
376 {
377 	const struct device_node *of_node = pdev->dev.of_node;
378 	unsigned int scan_delay_ms;
379 	unsigned int row_hold_ns;
380 	unsigned int debounce_ms;
381 	int bits, rc, cycles;
382 	u8 scan_val = 0, ctrl_val = 0;
383 	static const u8 row_bits[] = {
384 		0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 7, 7, 7,
385 	};
386 
387 	/* Find column bits */
388 	if (kp->num_cols < KEYP_CTRL_SCAN_COLS_MIN)
389 		bits = 0;
390 	else
391 		bits = kp->num_cols - KEYP_CTRL_SCAN_COLS_MIN;
392 	ctrl_val = (bits & KEYP_CTRL_SCAN_COLS_BITS) <<
393 		KEYP_CTRL_SCAN_COLS_SHIFT;
394 
395 	/* Find row bits */
396 	if (kp->num_rows < KEYP_CTRL_SCAN_ROWS_MIN)
397 		bits = 0;
398 	else
399 		bits = row_bits[kp->num_rows - KEYP_CTRL_SCAN_ROWS_MIN];
400 
401 	ctrl_val |= (bits << KEYP_CTRL_SCAN_ROWS_SHIFT);
402 
403 	rc = regmap_write(kp->regmap, KEYP_CTRL, ctrl_val);
404 	if (rc < 0) {
405 		dev_err(kp->dev, "Error writing KEYP_CTRL reg, rc=%d\n", rc);
406 		return rc;
407 	}
408 
409 	if (of_property_read_u32(of_node, "scan-delay", &scan_delay_ms))
410 		scan_delay_ms = MIN_SCAN_DELAY;
411 
412 	if (scan_delay_ms > MAX_SCAN_DELAY || scan_delay_ms < MIN_SCAN_DELAY ||
413 	    !is_power_of_2(scan_delay_ms)) {
414 		dev_err(&pdev->dev, "invalid keypad scan time supplied\n");
415 		return -EINVAL;
416 	}
417 
418 	if (of_property_read_u32(of_node, "row-hold", &row_hold_ns))
419 		row_hold_ns = MIN_ROW_HOLD_DELAY;
420 
421 	if (row_hold_ns > MAX_ROW_HOLD_DELAY ||
422 	    row_hold_ns < MIN_ROW_HOLD_DELAY ||
423 	    ((row_hold_ns % MIN_ROW_HOLD_DELAY) != 0)) {
424 		dev_err(&pdev->dev, "invalid keypad row hold time supplied\n");
425 		return -EINVAL;
426 	}
427 
428 	if (of_property_read_u32(of_node, "debounce", &debounce_ms))
429 		debounce_ms = MIN_DEBOUNCE_TIME;
430 
431 	if (((debounce_ms % 5) != 0) ||
432 	    debounce_ms > MAX_DEBOUNCE_TIME ||
433 	    debounce_ms < MIN_DEBOUNCE_TIME) {
434 		dev_err(&pdev->dev, "invalid debounce time supplied\n");
435 		return -EINVAL;
436 	}
437 
438 	bits = (debounce_ms / 5) - 1;
439 
440 	scan_val |= (bits << KEYP_SCAN_DBOUNCE_SHIFT);
441 
442 	bits = fls(scan_delay_ms) - 1;
443 	scan_val |= (bits << KEYP_SCAN_PAUSE_SHIFT);
444 
445 	/* Row hold time is a multiple of 32KHz cycles. */
446 	cycles = (row_hold_ns * KEYP_CLOCK_FREQ) / NSEC_PER_SEC;
447 
448 	scan_val |= (cycles << KEYP_SCAN_ROW_HOLD_SHIFT);
449 
450 	rc = regmap_write(kp->regmap, KEYP_SCAN, scan_val);
451 	if (rc)
452 		dev_err(kp->dev, "Error writing KEYP_SCAN reg, rc=%d\n", rc);
453 
454 	return rc;
455 
456 }
457 
458 static int pmic8xxx_kp_enable(struct pmic8xxx_kp *kp)
459 {
460 	int rc;
461 
462 	kp->ctrl_reg |= KEYP_CTRL_KEYP_EN;
463 
464 	rc = regmap_write(kp->regmap, KEYP_CTRL, kp->ctrl_reg);
465 	if (rc < 0)
466 		dev_err(kp->dev, "Error writing KEYP_CTRL reg, rc=%d\n", rc);
467 
468 	return rc;
469 }
470 
471 static int pmic8xxx_kp_disable(struct pmic8xxx_kp *kp)
472 {
473 	int rc;
474 
475 	kp->ctrl_reg &= ~KEYP_CTRL_KEYP_EN;
476 
477 	rc = regmap_write(kp->regmap, KEYP_CTRL, kp->ctrl_reg);
478 	if (rc < 0)
479 		return rc;
480 
481 	return rc;
482 }
483 
484 static int pmic8xxx_kp_open(struct input_dev *dev)
485 {
486 	struct pmic8xxx_kp *kp = input_get_drvdata(dev);
487 
488 	return pmic8xxx_kp_enable(kp);
489 }
490 
491 static void pmic8xxx_kp_close(struct input_dev *dev)
492 {
493 	struct pmic8xxx_kp *kp = input_get_drvdata(dev);
494 
495 	pmic8xxx_kp_disable(kp);
496 }
497 
498 /*
499  * keypad controller should be initialized in the following sequence
500  * only, otherwise it might get into FSM stuck state.
501  *
502  * - Initialize keypad control parameters, like no. of rows, columns,
503  *   timing values etc.,
504  * - configure rows and column gpios pull up/down.
505  * - set irq edge type.
506  * - enable the keypad controller.
507  */
508 static int pmic8xxx_kp_probe(struct platform_device *pdev)
509 {
510 	struct device_node *np = pdev->dev.of_node;
511 	unsigned int rows, cols;
512 	bool repeat;
513 	bool wakeup;
514 	struct pmic8xxx_kp *kp;
515 	int rc;
516 	unsigned int ctrl_val;
517 
518 	rc = matrix_keypad_parse_properties(&pdev->dev, &rows, &cols);
519 	if (rc)
520 		return rc;
521 
522 	if (cols > PM8XXX_MAX_COLS || rows > PM8XXX_MAX_ROWS ||
523 	    cols < PM8XXX_MIN_COLS) {
524 		dev_err(&pdev->dev, "invalid platform data\n");
525 		return -EINVAL;
526 	}
527 
528 	repeat = !of_property_read_bool(np, "linux,input-no-autorepeat");
529 
530 	wakeup = of_property_read_bool(np, "wakeup-source") ||
531 		 /* legacy name */
532 		 of_property_read_bool(np, "linux,keypad-wakeup");
533 
534 	kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
535 	if (!kp)
536 		return -ENOMEM;
537 
538 	kp->regmap = dev_get_regmap(pdev->dev.parent, NULL);
539 	if (!kp->regmap)
540 		return -ENODEV;
541 
542 	platform_set_drvdata(pdev, kp);
543 
544 	kp->num_rows	= rows;
545 	kp->num_cols	= cols;
546 	kp->dev		= &pdev->dev;
547 
548 	kp->input = devm_input_allocate_device(&pdev->dev);
549 	if (!kp->input) {
550 		dev_err(&pdev->dev, "unable to allocate input device\n");
551 		return -ENOMEM;
552 	}
553 
554 	kp->key_sense_irq = platform_get_irq(pdev, 0);
555 	if (kp->key_sense_irq < 0) {
556 		dev_err(&pdev->dev, "unable to get keypad sense irq\n");
557 		return kp->key_sense_irq;
558 	}
559 
560 	kp->key_stuck_irq = platform_get_irq(pdev, 1);
561 	if (kp->key_stuck_irq < 0) {
562 		dev_err(&pdev->dev, "unable to get keypad stuck irq\n");
563 		return kp->key_stuck_irq;
564 	}
565 
566 	kp->input->name = "PMIC8XXX keypad";
567 	kp->input->phys = "pmic8xxx_keypad/input0";
568 
569 	kp->input->id.bustype	= BUS_I2C;
570 	kp->input->id.version	= 0x0001;
571 	kp->input->id.product	= 0x0001;
572 	kp->input->id.vendor	= 0x0001;
573 
574 	kp->input->open		= pmic8xxx_kp_open;
575 	kp->input->close	= pmic8xxx_kp_close;
576 
577 	rc = matrix_keypad_build_keymap(NULL, NULL,
578 					PM8XXX_MAX_ROWS, PM8XXX_MAX_COLS,
579 					kp->keycodes, kp->input);
580 	if (rc) {
581 		dev_err(&pdev->dev, "failed to build keymap\n");
582 		return rc;
583 	}
584 
585 	if (repeat)
586 		__set_bit(EV_REP, kp->input->evbit);
587 	input_set_capability(kp->input, EV_MSC, MSC_SCAN);
588 
589 	input_set_drvdata(kp->input, kp);
590 
591 	/* initialize keypad state */
592 	memset(kp->keystate, 0xff, sizeof(kp->keystate));
593 	memset(kp->stuckstate, 0xff, sizeof(kp->stuckstate));
594 
595 	rc = pmic8xxx_kpd_init(kp, pdev);
596 	if (rc < 0) {
597 		dev_err(&pdev->dev, "unable to initialize keypad controller\n");
598 		return rc;
599 	}
600 
601 	rc = devm_request_any_context_irq(&pdev->dev, kp->key_sense_irq,
602 			pmic8xxx_kp_irq, IRQF_TRIGGER_RISING, "pmic-keypad",
603 			kp);
604 	if (rc < 0) {
605 		dev_err(&pdev->dev, "failed to request keypad sense irq\n");
606 		return rc;
607 	}
608 
609 	rc = devm_request_any_context_irq(&pdev->dev, kp->key_stuck_irq,
610 			pmic8xxx_kp_stuck_irq, IRQF_TRIGGER_RISING,
611 			"pmic-keypad-stuck", kp);
612 	if (rc < 0) {
613 		dev_err(&pdev->dev, "failed to request keypad stuck irq\n");
614 		return rc;
615 	}
616 
617 	rc = regmap_read(kp->regmap, KEYP_CTRL, &ctrl_val);
618 	if (rc < 0) {
619 		dev_err(&pdev->dev, "failed to read KEYP_CTRL register\n");
620 		return rc;
621 	}
622 
623 	kp->ctrl_reg = ctrl_val;
624 
625 	rc = input_register_device(kp->input);
626 	if (rc < 0) {
627 		dev_err(&pdev->dev, "unable to register keypad input device\n");
628 		return rc;
629 	}
630 
631 	device_init_wakeup(&pdev->dev, wakeup);
632 
633 	return 0;
634 }
635 
636 #ifdef CONFIG_PM_SLEEP
637 static int pmic8xxx_kp_suspend(struct device *dev)
638 {
639 	struct platform_device *pdev = to_platform_device(dev);
640 	struct pmic8xxx_kp *kp = platform_get_drvdata(pdev);
641 	struct input_dev *input_dev = kp->input;
642 
643 	if (device_may_wakeup(dev)) {
644 		enable_irq_wake(kp->key_sense_irq);
645 	} else {
646 		mutex_lock(&input_dev->mutex);
647 
648 		if (input_dev->users)
649 			pmic8xxx_kp_disable(kp);
650 
651 		mutex_unlock(&input_dev->mutex);
652 	}
653 
654 	return 0;
655 }
656 
657 static int pmic8xxx_kp_resume(struct device *dev)
658 {
659 	struct platform_device *pdev = to_platform_device(dev);
660 	struct pmic8xxx_kp *kp = platform_get_drvdata(pdev);
661 	struct input_dev *input_dev = kp->input;
662 
663 	if (device_may_wakeup(dev)) {
664 		disable_irq_wake(kp->key_sense_irq);
665 	} else {
666 		mutex_lock(&input_dev->mutex);
667 
668 		if (input_dev->users)
669 			pmic8xxx_kp_enable(kp);
670 
671 		mutex_unlock(&input_dev->mutex);
672 	}
673 
674 	return 0;
675 }
676 #endif
677 
678 static SIMPLE_DEV_PM_OPS(pm8xxx_kp_pm_ops,
679 			 pmic8xxx_kp_suspend, pmic8xxx_kp_resume);
680 
681 static const struct of_device_id pm8xxx_match_table[] = {
682 	{ .compatible = "qcom,pm8058-keypad" },
683 	{ .compatible = "qcom,pm8921-keypad" },
684 	{ }
685 };
686 MODULE_DEVICE_TABLE(of, pm8xxx_match_table);
687 
688 static struct platform_driver pmic8xxx_kp_driver = {
689 	.probe		= pmic8xxx_kp_probe,
690 	.driver		= {
691 		.name = "pm8xxx-keypad",
692 		.pm = &pm8xxx_kp_pm_ops,
693 		.of_match_table = pm8xxx_match_table,
694 	},
695 };
696 module_platform_driver(pmic8xxx_kp_driver);
697 
698 MODULE_LICENSE("GPL v2");
699 MODULE_DESCRIPTION("PMIC8XXX keypad driver");
700 MODULE_VERSION("1.0");
701 MODULE_ALIAS("platform:pmic8xxx_keypad");
702 MODULE_AUTHOR("Trilok Soni <tsoni@codeaurora.org>");
703