xref: /linux/drivers/input/keyboard/pxa27x_keypad.c (revision c2e1ff39c106ab026e3feb29c038855b7ed00393)
1 /*
2  * linux/drivers/input/keyboard/pxa27x_keypad.c
3  *
4  * Driver for the pxa27x matrix keyboard controller.
5  *
6  * Created:	Feb 22, 2007
7  * Author:	Rodolfo Giometti <giometti@linux.it>
8  *
9  * Based on a previous implementations by Kevin O'Connor
10  * <kevin_at_koconnor.net> and Alex Osborne <bobofdoom@gmail.com> and
11  * on some suggestions by Nicolas Pitre <nico@fluxnic.net>.
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License version 2 as
15  * published by the Free Software Foundation.
16  */
17 
18 
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/interrupt.h>
23 #include <linux/input.h>
24 #include <linux/device.h>
25 #include <linux/platform_device.h>
26 #include <linux/clk.h>
27 #include <linux/err.h>
28 #include <linux/input/matrix_keypad.h>
29 #include <linux/slab.h>
30 
31 #include <asm/mach/arch.h>
32 #include <asm/mach/map.h>
33 
34 #include <mach/hardware.h>
35 #include <plat/pxa27x_keypad.h>
36 /*
37  * Keypad Controller registers
38  */
39 #define KPC             0x0000 /* Keypad Control register */
40 #define KPDK            0x0008 /* Keypad Direct Key register */
41 #define KPREC           0x0010 /* Keypad Rotary Encoder register */
42 #define KPMK            0x0018 /* Keypad Matrix Key register */
43 #define KPAS            0x0020 /* Keypad Automatic Scan register */
44 
45 /* Keypad Automatic Scan Multiple Key Presser register 0-3 */
46 #define KPASMKP0        0x0028
47 #define KPASMKP1        0x0030
48 #define KPASMKP2        0x0038
49 #define KPASMKP3        0x0040
50 #define KPKDI           0x0048
51 
52 /* bit definitions */
53 #define KPC_MKRN(n)	((((n) - 1) & 0x7) << 26) /* matrix key row number */
54 #define KPC_MKCN(n)	((((n) - 1) & 0x7) << 23) /* matrix key column number */
55 #define KPC_DKN(n)	((((n) - 1) & 0x7) << 6)  /* direct key number */
56 
57 #define KPC_AS          (0x1 << 30)  /* Automatic Scan bit */
58 #define KPC_ASACT       (0x1 << 29)  /* Automatic Scan on Activity */
59 #define KPC_MI          (0x1 << 22)  /* Matrix interrupt bit */
60 #define KPC_IMKP        (0x1 << 21)  /* Ignore Multiple Key Press */
61 
62 #define KPC_MS(n)	(0x1 << (13 + (n)))	/* Matrix scan line 'n' */
63 #define KPC_MS_ALL      (0xff << 13)
64 
65 #define KPC_ME          (0x1 << 12)  /* Matrix Keypad Enable */
66 #define KPC_MIE         (0x1 << 11)  /* Matrix Interrupt Enable */
67 #define KPC_DK_DEB_SEL	(0x1 <<  9)  /* Direct Keypad Debounce Select */
68 #define KPC_DI          (0x1 <<  5)  /* Direct key interrupt bit */
69 #define KPC_RE_ZERO_DEB (0x1 <<  4)  /* Rotary Encoder Zero Debounce */
70 #define KPC_REE1        (0x1 <<  3)  /* Rotary Encoder1 Enable */
71 #define KPC_REE0        (0x1 <<  2)  /* Rotary Encoder0 Enable */
72 #define KPC_DE          (0x1 <<  1)  /* Direct Keypad Enable */
73 #define KPC_DIE         (0x1 <<  0)  /* Direct Keypad interrupt Enable */
74 
75 #define KPDK_DKP        (0x1 << 31)
76 #define KPDK_DK(n)	((n) & 0xff)
77 
78 #define KPREC_OF1       (0x1 << 31)
79 #define kPREC_UF1       (0x1 << 30)
80 #define KPREC_OF0       (0x1 << 15)
81 #define KPREC_UF0       (0x1 << 14)
82 
83 #define KPREC_RECOUNT0(n)	((n) & 0xff)
84 #define KPREC_RECOUNT1(n)	(((n) >> 16) & 0xff)
85 
86 #define KPMK_MKP        (0x1 << 31)
87 #define KPAS_SO         (0x1 << 31)
88 #define KPASMKPx_SO     (0x1 << 31)
89 
90 #define KPAS_MUKP(n)	(((n) >> 26) & 0x1f)
91 #define KPAS_RP(n)	(((n) >> 4) & 0xf)
92 #define KPAS_CP(n)	((n) & 0xf)
93 
94 #define KPASMKP_MKC_MASK	(0xff)
95 
96 #define keypad_readl(off)	__raw_readl(keypad->mmio_base + (off))
97 #define keypad_writel(off, v)	__raw_writel((v), keypad->mmio_base + (off))
98 
99 #define MAX_MATRIX_KEY_NUM	(MAX_MATRIX_KEY_ROWS * MAX_MATRIX_KEY_COLS)
100 #define MAX_KEYPAD_KEYS		(MAX_MATRIX_KEY_NUM + MAX_DIRECT_KEY_NUM)
101 
102 struct pxa27x_keypad {
103 	struct pxa27x_keypad_platform_data *pdata;
104 
105 	struct clk *clk;
106 	struct input_dev *input_dev;
107 	void __iomem *mmio_base;
108 
109 	int irq;
110 
111 	unsigned short keycodes[MAX_KEYPAD_KEYS];
112 	int rotary_rel_code[2];
113 
114 	/* state row bits of each column scan */
115 	uint32_t matrix_key_state[MAX_MATRIX_KEY_COLS];
116 	uint32_t direct_key_state;
117 
118 	unsigned int direct_key_mask;
119 };
120 
121 static void pxa27x_keypad_build_keycode(struct pxa27x_keypad *keypad)
122 {
123 	struct pxa27x_keypad_platform_data *pdata = keypad->pdata;
124 	struct input_dev *input_dev = keypad->input_dev;
125 	unsigned short keycode;
126 	int i;
127 
128 	for (i = 0; i < pdata->matrix_key_map_size; i++) {
129 		unsigned int key = pdata->matrix_key_map[i];
130 		unsigned int row = KEY_ROW(key);
131 		unsigned int col = KEY_COL(key);
132 		unsigned int scancode = MATRIX_SCAN_CODE(row, col,
133 							 MATRIX_ROW_SHIFT);
134 
135 		keycode = KEY_VAL(key);
136 		keypad->keycodes[scancode] = keycode;
137 		__set_bit(keycode, input_dev->keybit);
138 	}
139 
140 	for (i = 0; i < pdata->direct_key_num; i++) {
141 		keycode = pdata->direct_key_map[i];
142 		keypad->keycodes[MAX_MATRIX_KEY_NUM + i] = keycode;
143 		__set_bit(keycode, input_dev->keybit);
144 	}
145 
146 	if (pdata->enable_rotary0) {
147 		if (pdata->rotary0_up_key && pdata->rotary0_down_key) {
148 			keycode = pdata->rotary0_up_key;
149 			keypad->keycodes[MAX_MATRIX_KEY_NUM + 0] = keycode;
150 			__set_bit(keycode, input_dev->keybit);
151 
152 			keycode = pdata->rotary0_down_key;
153 			keypad->keycodes[MAX_MATRIX_KEY_NUM + 1] = keycode;
154 			__set_bit(keycode, input_dev->keybit);
155 
156 			keypad->rotary_rel_code[0] = -1;
157 		} else {
158 			keypad->rotary_rel_code[0] = pdata->rotary0_rel_code;
159 			__set_bit(pdata->rotary0_rel_code, input_dev->relbit);
160 		}
161 	}
162 
163 	if (pdata->enable_rotary1) {
164 		if (pdata->rotary1_up_key && pdata->rotary1_down_key) {
165 			keycode = pdata->rotary1_up_key;
166 			keypad->keycodes[MAX_MATRIX_KEY_NUM + 2] = keycode;
167 			__set_bit(keycode, input_dev->keybit);
168 
169 			keycode = pdata->rotary1_down_key;
170 			keypad->keycodes[MAX_MATRIX_KEY_NUM + 3] = keycode;
171 			__set_bit(keycode, input_dev->keybit);
172 
173 			keypad->rotary_rel_code[1] = -1;
174 		} else {
175 			keypad->rotary_rel_code[1] = pdata->rotary1_rel_code;
176 			__set_bit(pdata->rotary1_rel_code, input_dev->relbit);
177 		}
178 	}
179 
180 	__clear_bit(KEY_RESERVED, input_dev->keybit);
181 }
182 
183 static void pxa27x_keypad_scan_matrix(struct pxa27x_keypad *keypad)
184 {
185 	struct pxa27x_keypad_platform_data *pdata = keypad->pdata;
186 	struct input_dev *input_dev = keypad->input_dev;
187 	int row, col, num_keys_pressed = 0;
188 	uint32_t new_state[MAX_MATRIX_KEY_COLS];
189 	uint32_t kpas = keypad_readl(KPAS);
190 
191 	num_keys_pressed = KPAS_MUKP(kpas);
192 
193 	memset(new_state, 0, sizeof(new_state));
194 
195 	if (num_keys_pressed == 0)
196 		goto scan;
197 
198 	if (num_keys_pressed == 1) {
199 		col = KPAS_CP(kpas);
200 		row = KPAS_RP(kpas);
201 
202 		/* if invalid row/col, treat as no key pressed */
203 		if (col >= pdata->matrix_key_cols ||
204 		    row >= pdata->matrix_key_rows)
205 			goto scan;
206 
207 		new_state[col] = (1 << row);
208 		goto scan;
209 	}
210 
211 	if (num_keys_pressed > 1) {
212 		uint32_t kpasmkp0 = keypad_readl(KPASMKP0);
213 		uint32_t kpasmkp1 = keypad_readl(KPASMKP1);
214 		uint32_t kpasmkp2 = keypad_readl(KPASMKP2);
215 		uint32_t kpasmkp3 = keypad_readl(KPASMKP3);
216 
217 		new_state[0] = kpasmkp0 & KPASMKP_MKC_MASK;
218 		new_state[1] = (kpasmkp0 >> 16) & KPASMKP_MKC_MASK;
219 		new_state[2] = kpasmkp1 & KPASMKP_MKC_MASK;
220 		new_state[3] = (kpasmkp1 >> 16) & KPASMKP_MKC_MASK;
221 		new_state[4] = kpasmkp2 & KPASMKP_MKC_MASK;
222 		new_state[5] = (kpasmkp2 >> 16) & KPASMKP_MKC_MASK;
223 		new_state[6] = kpasmkp3 & KPASMKP_MKC_MASK;
224 		new_state[7] = (kpasmkp3 >> 16) & KPASMKP_MKC_MASK;
225 	}
226 scan:
227 	for (col = 0; col < pdata->matrix_key_cols; col++) {
228 		uint32_t bits_changed;
229 		int code;
230 
231 		bits_changed = keypad->matrix_key_state[col] ^ new_state[col];
232 		if (bits_changed == 0)
233 			continue;
234 
235 		for (row = 0; row < pdata->matrix_key_rows; row++) {
236 			if ((bits_changed & (1 << row)) == 0)
237 				continue;
238 
239 			code = MATRIX_SCAN_CODE(row, col, MATRIX_ROW_SHIFT);
240 			input_event(input_dev, EV_MSC, MSC_SCAN, code);
241 			input_report_key(input_dev, keypad->keycodes[code],
242 					 new_state[col] & (1 << row));
243 		}
244 	}
245 	input_sync(input_dev);
246 	memcpy(keypad->matrix_key_state, new_state, sizeof(new_state));
247 }
248 
249 #define DEFAULT_KPREC	(0x007f007f)
250 
251 static inline int rotary_delta(uint32_t kprec)
252 {
253 	if (kprec & KPREC_OF0)
254 		return (kprec & 0xff) + 0x7f;
255 	else if (kprec & KPREC_UF0)
256 		return (kprec & 0xff) - 0x7f - 0xff;
257 	else
258 		return (kprec & 0xff) - 0x7f;
259 }
260 
261 static void report_rotary_event(struct pxa27x_keypad *keypad, int r, int delta)
262 {
263 	struct input_dev *dev = keypad->input_dev;
264 
265 	if (delta == 0)
266 		return;
267 
268 	if (keypad->rotary_rel_code[r] == -1) {
269 		int code = MAX_MATRIX_KEY_NUM + 2 * r + (delta > 0 ? 0 : 1);
270 		unsigned char keycode = keypad->keycodes[code];
271 
272 		/* simulate a press-n-release */
273 		input_event(dev, EV_MSC, MSC_SCAN, code);
274 		input_report_key(dev, keycode, 1);
275 		input_sync(dev);
276 		input_event(dev, EV_MSC, MSC_SCAN, code);
277 		input_report_key(dev, keycode, 0);
278 		input_sync(dev);
279 	} else {
280 		input_report_rel(dev, keypad->rotary_rel_code[r], delta);
281 		input_sync(dev);
282 	}
283 }
284 
285 static void pxa27x_keypad_scan_rotary(struct pxa27x_keypad *keypad)
286 {
287 	struct pxa27x_keypad_platform_data *pdata = keypad->pdata;
288 	uint32_t kprec;
289 
290 	/* read and reset to default count value */
291 	kprec = keypad_readl(KPREC);
292 	keypad_writel(KPREC, DEFAULT_KPREC);
293 
294 	if (pdata->enable_rotary0)
295 		report_rotary_event(keypad, 0, rotary_delta(kprec));
296 
297 	if (pdata->enable_rotary1)
298 		report_rotary_event(keypad, 1, rotary_delta(kprec >> 16));
299 }
300 
301 static void pxa27x_keypad_scan_direct(struct pxa27x_keypad *keypad)
302 {
303 	struct pxa27x_keypad_platform_data *pdata = keypad->pdata;
304 	struct input_dev *input_dev = keypad->input_dev;
305 	unsigned int new_state;
306 	uint32_t kpdk, bits_changed;
307 	int i;
308 
309 	kpdk = keypad_readl(KPDK);
310 
311 	if (pdata->enable_rotary0 || pdata->enable_rotary1)
312 		pxa27x_keypad_scan_rotary(keypad);
313 
314 	/*
315 	 * The KPDR_DK only output the key pin level, so it relates to board,
316 	 * and low level may be active.
317 	 */
318 	if (pdata->direct_key_low_active)
319 		new_state = ~KPDK_DK(kpdk) & keypad->direct_key_mask;
320 	else
321 		new_state = KPDK_DK(kpdk) & keypad->direct_key_mask;
322 
323 	bits_changed = keypad->direct_key_state ^ new_state;
324 
325 	if (bits_changed == 0)
326 		return;
327 
328 	for (i = 0; i < pdata->direct_key_num; i++) {
329 		if (bits_changed & (1 << i)) {
330 			int code = MAX_MATRIX_KEY_NUM + i;
331 
332 			input_event(input_dev, EV_MSC, MSC_SCAN, code);
333 			input_report_key(input_dev, keypad->keycodes[code],
334 					 new_state & (1 << i));
335 		}
336 	}
337 	input_sync(input_dev);
338 	keypad->direct_key_state = new_state;
339 }
340 
341 static void clear_wakeup_event(struct pxa27x_keypad *keypad)
342 {
343 	struct pxa27x_keypad_platform_data *pdata = keypad->pdata;
344 
345 	if (pdata->clear_wakeup_event)
346 		(pdata->clear_wakeup_event)();
347 }
348 
349 static irqreturn_t pxa27x_keypad_irq_handler(int irq, void *dev_id)
350 {
351 	struct pxa27x_keypad *keypad = dev_id;
352 	unsigned long kpc = keypad_readl(KPC);
353 
354 	clear_wakeup_event(keypad);
355 
356 	if (kpc & KPC_DI)
357 		pxa27x_keypad_scan_direct(keypad);
358 
359 	if (kpc & KPC_MI)
360 		pxa27x_keypad_scan_matrix(keypad);
361 
362 	return IRQ_HANDLED;
363 }
364 
365 static void pxa27x_keypad_config(struct pxa27x_keypad *keypad)
366 {
367 	struct pxa27x_keypad_platform_data *pdata = keypad->pdata;
368 	unsigned int mask = 0, direct_key_num = 0;
369 	unsigned long kpc = 0;
370 
371 	/* enable matrix keys with automatic scan */
372 	if (pdata->matrix_key_rows && pdata->matrix_key_cols) {
373 		kpc |= KPC_ASACT | KPC_MIE | KPC_ME | KPC_MS_ALL;
374 		kpc |= KPC_MKRN(pdata->matrix_key_rows) |
375 		       KPC_MKCN(pdata->matrix_key_cols);
376 	}
377 
378 	/* enable rotary key, debounce interval same as direct keys */
379 	if (pdata->enable_rotary0) {
380 		mask |= 0x03;
381 		direct_key_num = 2;
382 		kpc |= KPC_REE0;
383 	}
384 
385 	if (pdata->enable_rotary1) {
386 		mask |= 0x0c;
387 		direct_key_num = 4;
388 		kpc |= KPC_REE1;
389 	}
390 
391 	if (pdata->direct_key_num > direct_key_num)
392 		direct_key_num = pdata->direct_key_num;
393 
394 	/*
395 	 * Direct keys usage may not start from KP_DKIN0, check the platfrom
396 	 * mask data to config the specific.
397 	 */
398 	if (pdata->direct_key_mask)
399 		keypad->direct_key_mask = pdata->direct_key_mask;
400 	else
401 		keypad->direct_key_mask = ((1 << direct_key_num) - 1) & ~mask;
402 
403 	/* enable direct key */
404 	if (direct_key_num)
405 		kpc |= KPC_DE | KPC_DIE | KPC_DKN(direct_key_num);
406 
407 	keypad_writel(KPC, kpc | KPC_RE_ZERO_DEB);
408 	keypad_writel(KPREC, DEFAULT_KPREC);
409 	keypad_writel(KPKDI, pdata->debounce_interval);
410 }
411 
412 static int pxa27x_keypad_open(struct input_dev *dev)
413 {
414 	struct pxa27x_keypad *keypad = input_get_drvdata(dev);
415 
416 	/* Enable unit clock */
417 	clk_prepare_enable(keypad->clk);
418 	pxa27x_keypad_config(keypad);
419 
420 	return 0;
421 }
422 
423 static void pxa27x_keypad_close(struct input_dev *dev)
424 {
425 	struct pxa27x_keypad *keypad = input_get_drvdata(dev);
426 
427 	/* Disable clock unit */
428 	clk_disable_unprepare(keypad->clk);
429 }
430 
431 #ifdef CONFIG_PM
432 static int pxa27x_keypad_suspend(struct device *dev)
433 {
434 	struct platform_device *pdev = to_platform_device(dev);
435 	struct pxa27x_keypad *keypad = platform_get_drvdata(pdev);
436 
437 	/*
438 	 * If the keypad is used a wake up source, clock can not be disabled.
439 	 * Or it can not detect the key pressing.
440 	 */
441 	if (device_may_wakeup(&pdev->dev))
442 		enable_irq_wake(keypad->irq);
443 	else
444 		clk_disable_unprepare(keypad->clk);
445 
446 	return 0;
447 }
448 
449 static int pxa27x_keypad_resume(struct device *dev)
450 {
451 	struct platform_device *pdev = to_platform_device(dev);
452 	struct pxa27x_keypad *keypad = platform_get_drvdata(pdev);
453 	struct input_dev *input_dev = keypad->input_dev;
454 
455 	/*
456 	 * If the keypad is used as wake up source, the clock is not turned
457 	 * off. So do not need configure it again.
458 	 */
459 	if (device_may_wakeup(&pdev->dev)) {
460 		disable_irq_wake(keypad->irq);
461 	} else {
462 		mutex_lock(&input_dev->mutex);
463 
464 		if (input_dev->users) {
465 			/* Enable unit clock */
466 			clk_prepare_enable(keypad->clk);
467 			pxa27x_keypad_config(keypad);
468 		}
469 
470 		mutex_unlock(&input_dev->mutex);
471 	}
472 
473 	return 0;
474 }
475 
476 static const struct dev_pm_ops pxa27x_keypad_pm_ops = {
477 	.suspend	= pxa27x_keypad_suspend,
478 	.resume		= pxa27x_keypad_resume,
479 };
480 #endif
481 
482 static int __devinit pxa27x_keypad_probe(struct platform_device *pdev)
483 {
484 	struct pxa27x_keypad_platform_data *pdata = pdev->dev.platform_data;
485 	struct pxa27x_keypad *keypad;
486 	struct input_dev *input_dev;
487 	struct resource *res;
488 	int irq, error;
489 
490 	if (pdata == NULL) {
491 		dev_err(&pdev->dev, "no platform data defined\n");
492 		return -EINVAL;
493 	}
494 
495 	irq = platform_get_irq(pdev, 0);
496 	if (irq < 0) {
497 		dev_err(&pdev->dev, "failed to get keypad irq\n");
498 		return -ENXIO;
499 	}
500 
501 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
502 	if (res == NULL) {
503 		dev_err(&pdev->dev, "failed to get I/O memory\n");
504 		return -ENXIO;
505 	}
506 
507 	keypad = kzalloc(sizeof(struct pxa27x_keypad), GFP_KERNEL);
508 	input_dev = input_allocate_device();
509 	if (!keypad || !input_dev) {
510 		dev_err(&pdev->dev, "failed to allocate memory\n");
511 		error = -ENOMEM;
512 		goto failed_free;
513 	}
514 
515 	keypad->pdata = pdata;
516 	keypad->input_dev = input_dev;
517 	keypad->irq = irq;
518 
519 	res = request_mem_region(res->start, resource_size(res), pdev->name);
520 	if (res == NULL) {
521 		dev_err(&pdev->dev, "failed to request I/O memory\n");
522 		error = -EBUSY;
523 		goto failed_free;
524 	}
525 
526 	keypad->mmio_base = ioremap(res->start, resource_size(res));
527 	if (keypad->mmio_base == NULL) {
528 		dev_err(&pdev->dev, "failed to remap I/O memory\n");
529 		error = -ENXIO;
530 		goto failed_free_mem;
531 	}
532 
533 	keypad->clk = clk_get(&pdev->dev, NULL);
534 	if (IS_ERR(keypad->clk)) {
535 		dev_err(&pdev->dev, "failed to get keypad clock\n");
536 		error = PTR_ERR(keypad->clk);
537 		goto failed_free_io;
538 	}
539 
540 	input_dev->name = pdev->name;
541 	input_dev->id.bustype = BUS_HOST;
542 	input_dev->open = pxa27x_keypad_open;
543 	input_dev->close = pxa27x_keypad_close;
544 	input_dev->dev.parent = &pdev->dev;
545 
546 	input_dev->keycode = keypad->keycodes;
547 	input_dev->keycodesize = sizeof(keypad->keycodes[0]);
548 	input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
549 
550 	input_set_drvdata(input_dev, keypad);
551 
552 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
553 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
554 
555 	pxa27x_keypad_build_keycode(keypad);
556 
557 	if ((pdata->enable_rotary0 && keypad->rotary_rel_code[0] != -1) ||
558 	    (pdata->enable_rotary1 && keypad->rotary_rel_code[1] != -1)) {
559 		input_dev->evbit[0] |= BIT_MASK(EV_REL);
560 	}
561 
562 	error = request_irq(irq, pxa27x_keypad_irq_handler, 0,
563 			    pdev->name, keypad);
564 	if (error) {
565 		dev_err(&pdev->dev, "failed to request IRQ\n");
566 		goto failed_put_clk;
567 	}
568 
569 	/* Register the input device */
570 	error = input_register_device(input_dev);
571 	if (error) {
572 		dev_err(&pdev->dev, "failed to register input device\n");
573 		goto failed_free_irq;
574 	}
575 
576 	platform_set_drvdata(pdev, keypad);
577 	device_init_wakeup(&pdev->dev, 1);
578 
579 	return 0;
580 
581 failed_free_irq:
582 	free_irq(irq, pdev);
583 failed_put_clk:
584 	clk_put(keypad->clk);
585 failed_free_io:
586 	iounmap(keypad->mmio_base);
587 failed_free_mem:
588 	release_mem_region(res->start, resource_size(res));
589 failed_free:
590 	input_free_device(input_dev);
591 	kfree(keypad);
592 	return error;
593 }
594 
595 static int __devexit pxa27x_keypad_remove(struct platform_device *pdev)
596 {
597 	struct pxa27x_keypad *keypad = platform_get_drvdata(pdev);
598 	struct resource *res;
599 
600 	free_irq(keypad->irq, pdev);
601 	clk_put(keypad->clk);
602 
603 	input_unregister_device(keypad->input_dev);
604 	iounmap(keypad->mmio_base);
605 
606 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
607 	release_mem_region(res->start, resource_size(res));
608 
609 	platform_set_drvdata(pdev, NULL);
610 	kfree(keypad);
611 
612 	return 0;
613 }
614 
615 /* work with hotplug and coldplug */
616 MODULE_ALIAS("platform:pxa27x-keypad");
617 
618 static struct platform_driver pxa27x_keypad_driver = {
619 	.probe		= pxa27x_keypad_probe,
620 	.remove		= __devexit_p(pxa27x_keypad_remove),
621 	.driver		= {
622 		.name	= "pxa27x-keypad",
623 		.owner	= THIS_MODULE,
624 #ifdef CONFIG_PM
625 		.pm	= &pxa27x_keypad_pm_ops,
626 #endif
627 	},
628 };
629 module_platform_driver(pxa27x_keypad_driver);
630 
631 MODULE_DESCRIPTION("PXA27x Keypad Controller Driver");
632 MODULE_LICENSE("GPL");
633