1 /*
2  *  GPIO driven matrix keyboard driver
3  *
4  *  Copyright (c) 2008 Marek Vasut <marek.vasut@gmail.com>
5  *
6  *  Based on corgikbd.c
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License version 2 as
10  *  published by the Free Software Foundation.
11  *
12  */
13 
14 #include <linux/types.h>
15 #include <linux/delay.h>
16 #include <linux/platform_device.h>
17 #include <linux/init.h>
18 #include <linux/input.h>
19 #include <linux/irq.h>
20 #include <linux/interrupt.h>
21 #include <linux/jiffies.h>
22 #include <linux/module.h>
23 #include <linux/gpio.h>
24 #include <linux/input/matrix_keypad.h>
25 #include <linux/slab.h>
26 
27 struct matrix_keypad {
28 	const struct matrix_keypad_platform_data *pdata;
29 	struct input_dev *input_dev;
30 	unsigned short *keycodes;
31 	unsigned int row_shift;
32 
33 	DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
34 
35 	uint32_t last_key_state[MATRIX_MAX_COLS];
36 	struct delayed_work work;
37 	spinlock_t lock;
38 	bool scan_pending;
39 	bool stopped;
40 	bool gpio_all_disabled;
41 };
42 
43 /*
44  * NOTE: normally the GPIO has to be put into HiZ when de-activated to cause
45  * minmal side effect when scanning other columns, here it is configured to
46  * be input, and it should work on most platforms.
47  */
48 static void __activate_col(const struct matrix_keypad_platform_data *pdata,
49 			   int col, bool on)
50 {
51 	bool level_on = !pdata->active_low;
52 
53 	if (on) {
54 		gpio_direction_output(pdata->col_gpios[col], level_on);
55 	} else {
56 		gpio_set_value_cansleep(pdata->col_gpios[col], !level_on);
57 		gpio_direction_input(pdata->col_gpios[col]);
58 	}
59 }
60 
61 static void activate_col(const struct matrix_keypad_platform_data *pdata,
62 			 int col, bool on)
63 {
64 	__activate_col(pdata, col, on);
65 
66 	if (on && pdata->col_scan_delay_us)
67 		udelay(pdata->col_scan_delay_us);
68 }
69 
70 static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
71 			      bool on)
72 {
73 	int col;
74 
75 	for (col = 0; col < pdata->num_col_gpios; col++)
76 		__activate_col(pdata, col, on);
77 }
78 
79 static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
80 			 int row)
81 {
82 	return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
83 			!pdata->active_low : pdata->active_low;
84 }
85 
86 static void enable_row_irqs(struct matrix_keypad *keypad)
87 {
88 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
89 	int i;
90 
91 	if (pdata->clustered_irq > 0)
92 		enable_irq(pdata->clustered_irq);
93 	else {
94 		for (i = 0; i < pdata->num_row_gpios; i++)
95 			enable_irq(gpio_to_irq(pdata->row_gpios[i]));
96 	}
97 }
98 
99 static void disable_row_irqs(struct matrix_keypad *keypad)
100 {
101 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
102 	int i;
103 
104 	if (pdata->clustered_irq > 0)
105 		disable_irq_nosync(pdata->clustered_irq);
106 	else {
107 		for (i = 0; i < pdata->num_row_gpios; i++)
108 			disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
109 	}
110 }
111 
112 /*
113  * This gets the keys from keyboard and reports it to input subsystem
114  */
115 static void matrix_keypad_scan(struct work_struct *work)
116 {
117 	struct matrix_keypad *keypad =
118 		container_of(work, struct matrix_keypad, work.work);
119 	struct input_dev *input_dev = keypad->input_dev;
120 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
121 	uint32_t new_state[MATRIX_MAX_COLS];
122 	int row, col, code;
123 
124 	/* de-activate all columns for scanning */
125 	activate_all_cols(pdata, false);
126 
127 	memset(new_state, 0, sizeof(new_state));
128 
129 	/* assert each column and read the row status out */
130 	for (col = 0; col < pdata->num_col_gpios; col++) {
131 
132 		activate_col(pdata, col, true);
133 
134 		for (row = 0; row < pdata->num_row_gpios; row++)
135 			new_state[col] |=
136 				row_asserted(pdata, row) ? (1 << row) : 0;
137 
138 		activate_col(pdata, col, false);
139 	}
140 
141 	for (col = 0; col < pdata->num_col_gpios; col++) {
142 		uint32_t bits_changed;
143 
144 		bits_changed = keypad->last_key_state[col] ^ new_state[col];
145 		if (bits_changed == 0)
146 			continue;
147 
148 		for (row = 0; row < pdata->num_row_gpios; row++) {
149 			if ((bits_changed & (1 << row)) == 0)
150 				continue;
151 
152 			code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
153 			input_event(input_dev, EV_MSC, MSC_SCAN, code);
154 			input_report_key(input_dev,
155 					 keypad->keycodes[code],
156 					 new_state[col] & (1 << row));
157 		}
158 	}
159 	input_sync(input_dev);
160 
161 	memcpy(keypad->last_key_state, new_state, sizeof(new_state));
162 
163 	activate_all_cols(pdata, true);
164 
165 	/* Enable IRQs again */
166 	spin_lock_irq(&keypad->lock);
167 	keypad->scan_pending = false;
168 	enable_row_irqs(keypad);
169 	spin_unlock_irq(&keypad->lock);
170 }
171 
172 static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
173 {
174 	struct matrix_keypad *keypad = id;
175 	unsigned long flags;
176 
177 	spin_lock_irqsave(&keypad->lock, flags);
178 
179 	/*
180 	 * See if another IRQ beaten us to it and scheduled the
181 	 * scan already. In that case we should not try to
182 	 * disable IRQs again.
183 	 */
184 	if (unlikely(keypad->scan_pending || keypad->stopped))
185 		goto out;
186 
187 	disable_row_irqs(keypad);
188 	keypad->scan_pending = true;
189 	schedule_delayed_work(&keypad->work,
190 		msecs_to_jiffies(keypad->pdata->debounce_ms));
191 
192 out:
193 	spin_unlock_irqrestore(&keypad->lock, flags);
194 	return IRQ_HANDLED;
195 }
196 
197 static int matrix_keypad_start(struct input_dev *dev)
198 {
199 	struct matrix_keypad *keypad = input_get_drvdata(dev);
200 
201 	keypad->stopped = false;
202 	mb();
203 
204 	/*
205 	 * Schedule an immediate key scan to capture current key state;
206 	 * columns will be activated and IRQs be enabled after the scan.
207 	 */
208 	schedule_delayed_work(&keypad->work, 0);
209 
210 	return 0;
211 }
212 
213 static void matrix_keypad_stop(struct input_dev *dev)
214 {
215 	struct matrix_keypad *keypad = input_get_drvdata(dev);
216 
217 	keypad->stopped = true;
218 	mb();
219 	flush_work(&keypad->work.work);
220 	/*
221 	 * matrix_keypad_scan() will leave IRQs enabled;
222 	 * we should disable them now.
223 	 */
224 	disable_row_irqs(keypad);
225 }
226 
227 #ifdef CONFIG_PM
228 static void matrix_keypad_enable_wakeup(struct matrix_keypad *keypad)
229 {
230 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
231 	unsigned int gpio;
232 	int i;
233 
234 	if (pdata->clustered_irq > 0) {
235 		if (enable_irq_wake(pdata->clustered_irq) == 0)
236 			keypad->gpio_all_disabled = true;
237 	} else {
238 
239 		for (i = 0; i < pdata->num_row_gpios; i++) {
240 			if (!test_bit(i, keypad->disabled_gpios)) {
241 				gpio = pdata->row_gpios[i];
242 
243 				if (enable_irq_wake(gpio_to_irq(gpio)) == 0)
244 					__set_bit(i, keypad->disabled_gpios);
245 			}
246 		}
247 	}
248 }
249 
250 static void matrix_keypad_disable_wakeup(struct matrix_keypad *keypad)
251 {
252 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
253 	unsigned int gpio;
254 	int i;
255 
256 	if (pdata->clustered_irq > 0) {
257 		if (keypad->gpio_all_disabled) {
258 			disable_irq_wake(pdata->clustered_irq);
259 			keypad->gpio_all_disabled = false;
260 		}
261 	} else {
262 		for (i = 0; i < pdata->num_row_gpios; i++) {
263 			if (test_and_clear_bit(i, keypad->disabled_gpios)) {
264 				gpio = pdata->row_gpios[i];
265 				disable_irq_wake(gpio_to_irq(gpio));
266 			}
267 		}
268 	}
269 }
270 
271 static int matrix_keypad_suspend(struct device *dev)
272 {
273 	struct platform_device *pdev = to_platform_device(dev);
274 	struct matrix_keypad *keypad = platform_get_drvdata(pdev);
275 
276 	matrix_keypad_stop(keypad->input_dev);
277 
278 	if (device_may_wakeup(&pdev->dev))
279 		matrix_keypad_enable_wakeup(keypad);
280 
281 	return 0;
282 }
283 
284 static int matrix_keypad_resume(struct device *dev)
285 {
286 	struct platform_device *pdev = to_platform_device(dev);
287 	struct matrix_keypad *keypad = platform_get_drvdata(pdev);
288 
289 	if (device_may_wakeup(&pdev->dev))
290 		matrix_keypad_disable_wakeup(keypad);
291 
292 	matrix_keypad_start(keypad->input_dev);
293 
294 	return 0;
295 }
296 
297 static const SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
298 				matrix_keypad_suspend, matrix_keypad_resume);
299 #endif
300 
301 static int __devinit init_matrix_gpio(struct platform_device *pdev,
302 					struct matrix_keypad *keypad)
303 {
304 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
305 	int i, err = -EINVAL;
306 
307 	/* initialized strobe lines as outputs, activated */
308 	for (i = 0; i < pdata->num_col_gpios; i++) {
309 		err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col");
310 		if (err) {
311 			dev_err(&pdev->dev,
312 				"failed to request GPIO%d for COL%d\n",
313 				pdata->col_gpios[i], i);
314 			goto err_free_cols;
315 		}
316 
317 		gpio_direction_output(pdata->col_gpios[i], !pdata->active_low);
318 	}
319 
320 	for (i = 0; i < pdata->num_row_gpios; i++) {
321 		err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row");
322 		if (err) {
323 			dev_err(&pdev->dev,
324 				"failed to request GPIO%d for ROW%d\n",
325 				pdata->row_gpios[i], i);
326 			goto err_free_rows;
327 		}
328 
329 		gpio_direction_input(pdata->row_gpios[i]);
330 	}
331 
332 	if (pdata->clustered_irq > 0) {
333 		err = request_irq(pdata->clustered_irq,
334 				matrix_keypad_interrupt,
335 				pdata->clustered_irq_flags,
336 				"matrix-keypad", keypad);
337 		if (err) {
338 			dev_err(&pdev->dev,
339 				"Unable to acquire clustered interrupt\n");
340 			goto err_free_rows;
341 		}
342 	} else {
343 		for (i = 0; i < pdata->num_row_gpios; i++) {
344 			err = request_irq(gpio_to_irq(pdata->row_gpios[i]),
345 					matrix_keypad_interrupt,
346 					IRQF_DISABLED |
347 					IRQF_TRIGGER_RISING |
348 					IRQF_TRIGGER_FALLING,
349 					"matrix-keypad", keypad);
350 			if (err) {
351 				dev_err(&pdev->dev,
352 					"Unable to acquire interrupt "
353 					"for GPIO line %i\n",
354 					pdata->row_gpios[i]);
355 				goto err_free_irqs;
356 			}
357 		}
358 	}
359 
360 	/* initialized as disabled - enabled by input->open */
361 	disable_row_irqs(keypad);
362 	return 0;
363 
364 err_free_irqs:
365 	while (--i >= 0)
366 		free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
367 	i = pdata->num_row_gpios;
368 err_free_rows:
369 	while (--i >= 0)
370 		gpio_free(pdata->row_gpios[i]);
371 	i = pdata->num_col_gpios;
372 err_free_cols:
373 	while (--i >= 0)
374 		gpio_free(pdata->col_gpios[i]);
375 
376 	return err;
377 }
378 
379 static int __devinit matrix_keypad_probe(struct platform_device *pdev)
380 {
381 	const struct matrix_keypad_platform_data *pdata;
382 	const struct matrix_keymap_data *keymap_data;
383 	struct matrix_keypad *keypad;
384 	struct input_dev *input_dev;
385 	unsigned short *keycodes;
386 	unsigned int row_shift;
387 	int err;
388 
389 	pdata = pdev->dev.platform_data;
390 	if (!pdata) {
391 		dev_err(&pdev->dev, "no platform data defined\n");
392 		return -EINVAL;
393 	}
394 
395 	keymap_data = pdata->keymap_data;
396 	if (!keymap_data) {
397 		dev_err(&pdev->dev, "no keymap data defined\n");
398 		return -EINVAL;
399 	}
400 
401 	row_shift = get_count_order(pdata->num_col_gpios);
402 
403 	keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
404 	keycodes = kzalloc((pdata->num_row_gpios << row_shift) *
405 				sizeof(*keycodes),
406 			   GFP_KERNEL);
407 	input_dev = input_allocate_device();
408 	if (!keypad || !keycodes || !input_dev) {
409 		err = -ENOMEM;
410 		goto err_free_mem;
411 	}
412 
413 	keypad->input_dev = input_dev;
414 	keypad->pdata = pdata;
415 	keypad->keycodes = keycodes;
416 	keypad->row_shift = row_shift;
417 	keypad->stopped = true;
418 	INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
419 	spin_lock_init(&keypad->lock);
420 
421 	input_dev->name		= pdev->name;
422 	input_dev->id.bustype	= BUS_HOST;
423 	input_dev->dev.parent	= &pdev->dev;
424 	input_dev->evbit[0]	= BIT_MASK(EV_KEY);
425 	if (!pdata->no_autorepeat)
426 		input_dev->evbit[0] |= BIT_MASK(EV_REP);
427 	input_dev->open		= matrix_keypad_start;
428 	input_dev->close	= matrix_keypad_stop;
429 
430 	input_dev->keycode	= keycodes;
431 	input_dev->keycodesize	= sizeof(*keycodes);
432 	input_dev->keycodemax	= pdata->num_row_gpios << row_shift;
433 
434 	matrix_keypad_build_keymap(keymap_data, row_shift,
435 				   input_dev->keycode, input_dev->keybit);
436 
437 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
438 	input_set_drvdata(input_dev, keypad);
439 
440 	err = init_matrix_gpio(pdev, keypad);
441 	if (err)
442 		goto err_free_mem;
443 
444 	err = input_register_device(keypad->input_dev);
445 	if (err)
446 		goto err_free_mem;
447 
448 	device_init_wakeup(&pdev->dev, pdata->wakeup);
449 	platform_set_drvdata(pdev, keypad);
450 
451 	return 0;
452 
453 err_free_mem:
454 	input_free_device(input_dev);
455 	kfree(keycodes);
456 	kfree(keypad);
457 	return err;
458 }
459 
460 static int __devexit matrix_keypad_remove(struct platform_device *pdev)
461 {
462 	struct matrix_keypad *keypad = platform_get_drvdata(pdev);
463 	const struct matrix_keypad_platform_data *pdata = keypad->pdata;
464 	int i;
465 
466 	device_init_wakeup(&pdev->dev, 0);
467 
468 	if (pdata->clustered_irq > 0) {
469 		free_irq(pdata->clustered_irq, keypad);
470 	} else {
471 		for (i = 0; i < pdata->num_row_gpios; i++)
472 			free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
473 	}
474 
475 	for (i = 0; i < pdata->num_row_gpios; i++)
476 		gpio_free(pdata->row_gpios[i]);
477 
478 	for (i = 0; i < pdata->num_col_gpios; i++)
479 		gpio_free(pdata->col_gpios[i]);
480 
481 	input_unregister_device(keypad->input_dev);
482 	platform_set_drvdata(pdev, NULL);
483 	kfree(keypad->keycodes);
484 	kfree(keypad);
485 
486 	return 0;
487 }
488 
489 static struct platform_driver matrix_keypad_driver = {
490 	.probe		= matrix_keypad_probe,
491 	.remove		= __devexit_p(matrix_keypad_remove),
492 	.driver		= {
493 		.name	= "matrix-keypad",
494 		.owner	= THIS_MODULE,
495 #ifdef CONFIG_PM
496 		.pm	= &matrix_keypad_pm_ops,
497 #endif
498 	},
499 };
500 
501 static int __init matrix_keypad_init(void)
502 {
503 	return platform_driver_register(&matrix_keypad_driver);
504 }
505 
506 static void __exit matrix_keypad_exit(void)
507 {
508 	platform_driver_unregister(&matrix_keypad_driver);
509 }
510 
511 module_init(matrix_keypad_init);
512 module_exit(matrix_keypad_exit);
513 
514 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
515 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
516 MODULE_LICENSE("GPL v2");
517 MODULE_ALIAS("platform:matrix-keypad");
518