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1/*
2 * Driver for the IMX keypad port.
3 * Copyright (C) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * <<Power management needs to be implemented>>.
10 */
11
12#include <linux/clk.h>
13#include <linux/delay.h>
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/input/matrix_keypad.h>
17#include <linux/interrupt.h>
18#include <linux/io.h>
19#include <linux/jiffies.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/of.h>
23#include <linux/platform_device.h>
24#include <linux/slab.h>
25#include <linux/timer.h>
26
27/*
28 * Keypad Controller registers (halfword)
29 */
30#define KPCR 0x00 /* Keypad Control Register */
31
32#define KPSR 0x02 /* Keypad Status Register */
33#define KBD_STAT_KPKD (0x1 << 0) /* Key Press Interrupt Status bit (w1c) */
34#define KBD_STAT_KPKR (0x1 << 1) /* Key Release Interrupt Status bit (w1c) */
35#define KBD_STAT_KDSC (0x1 << 2) /* Key Depress Synch Chain Status bit (w1c)*/
36#define KBD_STAT_KRSS (0x1 << 3) /* Key Release Synch Status bit (w1c)*/
37#define KBD_STAT_KDIE (0x1 << 8) /* Key Depress Interrupt Enable Status bit */
38#define KBD_STAT_KRIE (0x1 << 9) /* Key Release Interrupt Enable */
39#define KBD_STAT_KPPEN (0x1 << 10) /* Keypad Clock Enable */
40
41#define KDDR 0x04 /* Keypad Data Direction Register */
42#define KPDR 0x06 /* Keypad Data Register */
43
44#define MAX_MATRIX_KEY_ROWS 8
45#define MAX_MATRIX_KEY_COLS 8
46#define MATRIX_ROW_SHIFT 3
47
48#define MAX_MATRIX_KEY_NUM (MAX_MATRIX_KEY_ROWS * MAX_MATRIX_KEY_COLS)
49
50struct imx_keypad {
51
52 struct clk *clk;
53 struct input_dev *input_dev;
54 void __iomem *mmio_base;
55
56 int irq;
57 struct timer_list check_matrix_timer;
58
59 /*
60 * The matrix is stable only if no changes are detected after
61 * IMX_KEYPAD_SCANS_FOR_STABILITY scans
62 */
63#define IMX_KEYPAD_SCANS_FOR_STABILITY 3
64 int stable_count;
65
66 bool enabled;
67
68 /* Masks for enabled rows/cols */
69 unsigned short rows_en_mask;
70 unsigned short cols_en_mask;
71
72 unsigned short keycodes[MAX_MATRIX_KEY_NUM];
73
74 /*
75 * Matrix states:
76 * -stable: achieved after a complete debounce process.
77 * -unstable: used in the debouncing process.
78 */
79 unsigned short matrix_stable_state[MAX_MATRIX_KEY_COLS];
80 unsigned short matrix_unstable_state[MAX_MATRIX_KEY_COLS];
81};
82
83/* Scan the matrix and return the new state in *matrix_volatile_state. */
84static void imx_keypad_scan_matrix(struct imx_keypad *keypad,
85 unsigned short *matrix_volatile_state)
86{
87 int col;
88 unsigned short reg_val;
89
90 for (col = 0; col < MAX_MATRIX_KEY_COLS; col++) {
91 if ((keypad->cols_en_mask & (1 << col)) == 0)
92 continue;
93 /*
94 * Discharge keypad capacitance:
95 * 2. write 1s on column data.
96 * 3. configure columns as totem-pole to discharge capacitance.
97 * 4. configure columns as open-drain.
98 */
99 reg_val = readw(keypad->mmio_base + KPDR);
100 reg_val |= 0xff00;
101 writew(reg_val, keypad->mmio_base + KPDR);
102
103 reg_val = readw(keypad->mmio_base + KPCR);
104 reg_val &= ~((keypad->cols_en_mask & 0xff) << 8);
105 writew(reg_val, keypad->mmio_base + KPCR);
106
107 udelay(2);
108
109 reg_val = readw(keypad->mmio_base + KPCR);
110 reg_val |= (keypad->cols_en_mask & 0xff) << 8;
111 writew(reg_val, keypad->mmio_base + KPCR);
112
113 /*
114 * 5. Write a single column to 0, others to 1.
115 * 6. Sample row inputs and save data.
116 * 7. Repeat steps 2 - 6 for remaining columns.
117 */
118 reg_val = readw(keypad->mmio_base + KPDR);
119 reg_val &= ~(1 << (8 + col));
120 writew(reg_val, keypad->mmio_base + KPDR);
121
122 /*
123 * Delay added to avoid propagating the 0 from column to row
124 * when scanning.
125 */
126 udelay(5);
127
128 /*
129 * 1s in matrix_volatile_state[col] means key pressures
130 * throw data from non enabled rows.
131 */
132 reg_val = readw(keypad->mmio_base + KPDR);
133 matrix_volatile_state[col] = (~reg_val) & keypad->rows_en_mask;
134 }
135
136 /*
137 * Return in standby mode:
138 * 9. write 0s to columns
139 */
140 reg_val = readw(keypad->mmio_base + KPDR);
141 reg_val &= 0x00ff;
142 writew(reg_val, keypad->mmio_base + KPDR);
143}
144
145/*
146 * Compare the new matrix state (volatile) with the stable one stored in
147 * keypad->matrix_stable_state and fire events if changes are detected.
148 */
149static void imx_keypad_fire_events(struct imx_keypad *keypad,
150 unsigned short *matrix_volatile_state)
151{
152 struct input_dev *input_dev = keypad->input_dev;
153 int row, col;
154
155 for (col = 0; col < MAX_MATRIX_KEY_COLS; col++) {
156 unsigned short bits_changed;
157 int code;
158
159 if ((keypad->cols_en_mask & (1 << col)) == 0)
160 continue; /* Column is not enabled */
161
162 bits_changed = keypad->matrix_stable_state[col] ^
163 matrix_volatile_state[col];
164
165 if (bits_changed == 0)
166 continue; /* Column does not contain changes */
167
168 for (row = 0; row < MAX_MATRIX_KEY_ROWS; row++) {
169 if ((keypad->rows_en_mask & (1 << row)) == 0)
170 continue; /* Row is not enabled */
171 if ((bits_changed & (1 << row)) == 0)
172 continue; /* Row does not contain changes */
173
174 code = MATRIX_SCAN_CODE(row, col, MATRIX_ROW_SHIFT);
175 input_event(input_dev, EV_MSC, MSC_SCAN, code);
176 input_report_key(input_dev, keypad->keycodes[code],
177 matrix_volatile_state[col] & (1 << row));
178 dev_dbg(&input_dev->dev, "Event code: %d, val: %d",
179 keypad->keycodes[code],
180 matrix_volatile_state[col] & (1 << row));
181 }
182 }
183 input_sync(input_dev);
184}
185
186/*
187 * imx_keypad_check_for_events is the timer handler.
188 */
189static void imx_keypad_check_for_events(unsigned long data)
190{
191 struct imx_keypad *keypad = (struct imx_keypad *) data;
192 unsigned short matrix_volatile_state[MAX_MATRIX_KEY_COLS];
193 unsigned short reg_val;
194 bool state_changed, is_zero_matrix;
195 int i;
196
197 memset(matrix_volatile_state, 0, sizeof(matrix_volatile_state));
198
199 imx_keypad_scan_matrix(keypad, matrix_volatile_state);
200
201 state_changed = false;
202 for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
203 if ((keypad->cols_en_mask & (1 << i)) == 0)
204 continue;
205
206 if (keypad->matrix_unstable_state[i] ^ matrix_volatile_state[i]) {
207 state_changed = true;
208 break;
209 }
210 }
211
212 /*
213 * If the matrix state is changed from the previous scan
214 * (Re)Begin the debouncing process, saving the new state in
215 * keypad->matrix_unstable_state.
216 * else
217 * Increase the count of number of scans with a stable state.
218 */
219 if (state_changed) {
220 memcpy(keypad->matrix_unstable_state, matrix_volatile_state,
221 sizeof(matrix_volatile_state));
222 keypad->stable_count = 0;
223 } else
224 keypad->stable_count++;
225
226 /*
227 * If the matrix is not as stable as we want reschedule scan
228 * in the near future.
229 */
230 if (keypad->stable_count < IMX_KEYPAD_SCANS_FOR_STABILITY) {
231 mod_timer(&keypad->check_matrix_timer,
232 jiffies + msecs_to_jiffies(10));
233 return;
234 }
235
236 /*
237 * If the matrix state is stable, fire the events and save the new
238 * stable state. Note, if the matrix is kept stable for longer
239 * (keypad->stable_count > IMX_KEYPAD_SCANS_FOR_STABILITY) all
240 * events have already been generated.
241 */
242 if (keypad->stable_count == IMX_KEYPAD_SCANS_FOR_STABILITY) {
243 imx_keypad_fire_events(keypad, matrix_volatile_state);
244
245 memcpy(keypad->matrix_stable_state, matrix_volatile_state,
246 sizeof(matrix_volatile_state));
247 }
248
249 is_zero_matrix = true;
250 for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
251 if (matrix_volatile_state[i] != 0) {
252 is_zero_matrix = false;
253 break;
254 }
255 }
256
257
258 if (is_zero_matrix) {
259 /*
260 * All keys have been released. Enable only the KDI
261 * interrupt for future key presses (clear the KDI
262 * status bit and its sync chain before that).
263 */
264 reg_val = readw(keypad->mmio_base + KPSR);
265 reg_val |= KBD_STAT_KPKD | KBD_STAT_KDSC;
266 writew(reg_val, keypad->mmio_base + KPSR);
267
268 reg_val = readw(keypad->mmio_base + KPSR);
269 reg_val |= KBD_STAT_KDIE;
270 reg_val &= ~KBD_STAT_KRIE;
271 writew(reg_val, keypad->mmio_base + KPSR);
272 } else {
273 /*
274 * Some keys are still pressed. Schedule a rescan in
275 * attempt to detect multiple key presses and enable
276 * the KRI interrupt to react quickly to key release
277 * event.
278 */
279 mod_timer(&keypad->check_matrix_timer,
280 jiffies + msecs_to_jiffies(60));
281
282 reg_val = readw(keypad->mmio_base + KPSR);
283 reg_val |= KBD_STAT_KPKR | KBD_STAT_KRSS;
284 writew(reg_val, keypad->mmio_base + KPSR);
285
286 reg_val = readw(keypad->mmio_base + KPSR);
287 reg_val |= KBD_STAT_KRIE;
288 reg_val &= ~KBD_STAT_KDIE;
289 writew(reg_val, keypad->mmio_base + KPSR);
290 }
291}
292
293static irqreturn_t imx_keypad_irq_handler(int irq, void *dev_id)
294{
295 struct imx_keypad *keypad = dev_id;
296 unsigned short reg_val;
297
298 reg_val = readw(keypad->mmio_base + KPSR);
299
300 /* Disable both interrupt types */
301 reg_val &= ~(KBD_STAT_KRIE | KBD_STAT_KDIE);
302 /* Clear interrupts status bits */
303 reg_val |= KBD_STAT_KPKR | KBD_STAT_KPKD;
304 writew(reg_val, keypad->mmio_base + KPSR);
305
306 if (keypad->enabled) {
307 /* The matrix is supposed to be changed */
308 keypad->stable_count = 0;
309
310 /* Schedule the scanning procedure near in the future */
311 mod_timer(&keypad->check_matrix_timer,
312 jiffies + msecs_to_jiffies(2));
313 }
314
315 return IRQ_HANDLED;
316}
317
318static void imx_keypad_config(struct imx_keypad *keypad)
319{
320 unsigned short reg_val;
321
322 /*
323 * Include enabled rows in interrupt generation (KPCR[7:0])
324 * Configure keypad columns as open-drain (KPCR[15:8])
325 */
326 reg_val = readw(keypad->mmio_base + KPCR);
327 reg_val |= keypad->rows_en_mask & 0xff; /* rows */
328 reg_val |= (keypad->cols_en_mask & 0xff) << 8; /* cols */
329 writew(reg_val, keypad->mmio_base + KPCR);
330
331 /* Write 0's to KPDR[15:8] (Colums) */
332 reg_val = readw(keypad->mmio_base + KPDR);
333 reg_val &= 0x00ff;
334 writew(reg_val, keypad->mmio_base + KPDR);
335
336 /* Configure columns as output, rows as input (KDDR[15:0]) */
337 writew(0xff00, keypad->mmio_base + KDDR);
338
339 /*
340 * Clear Key Depress and Key Release status bit.
341 * Clear both synchronizer chain.
342 */
343 reg_val = readw(keypad->mmio_base + KPSR);
344 reg_val |= KBD_STAT_KPKR | KBD_STAT_KPKD |
345 KBD_STAT_KDSC | KBD_STAT_KRSS;
346 writew(reg_val, keypad->mmio_base + KPSR);
347
348 /* Enable KDI and disable KRI (avoid false release events). */
349 reg_val |= KBD_STAT_KDIE;
350 reg_val &= ~KBD_STAT_KRIE;
351 writew(reg_val, keypad->mmio_base + KPSR);
352}
353
354static void imx_keypad_inhibit(struct imx_keypad *keypad)
355{
356 unsigned short reg_val;
357
358 /* Inhibit KDI and KRI interrupts. */
359 reg_val = readw(keypad->mmio_base + KPSR);
360 reg_val &= ~(KBD_STAT_KRIE | KBD_STAT_KDIE);
361 reg_val |= KBD_STAT_KPKR | KBD_STAT_KPKD;
362 writew(reg_val, keypad->mmio_base + KPSR);
363
364 /* Colums as open drain and disable all rows */
365 reg_val = (keypad->cols_en_mask & 0xff) << 8;
366 writew(reg_val, keypad->mmio_base + KPCR);
367}
368
369static void imx_keypad_close(struct input_dev *dev)
370{
371 struct imx_keypad *keypad = input_get_drvdata(dev);
372
373 dev_dbg(&dev->dev, ">%s\n", __func__);
374
375 /* Mark keypad as being inactive */
376 keypad->enabled = false;
377 synchronize_irq(keypad->irq);
378 del_timer_sync(&keypad->check_matrix_timer);
379
380 imx_keypad_inhibit(keypad);
381
382 /* Disable clock unit */
383 clk_disable_unprepare(keypad->clk);
384}
385
386static int imx_keypad_open(struct input_dev *dev)
387{
388 struct imx_keypad *keypad = input_get_drvdata(dev);
389 int error;
390
391 dev_dbg(&dev->dev, ">%s\n", __func__);
392
393 /* Enable the kpp clock */
394 error = clk_prepare_enable(keypad->clk);
395 if (error)
396 return error;
397
398 /* We became active from now */
399 keypad->enabled = true;
400
401 imx_keypad_config(keypad);
402
403 /* Sanity control, not all the rows must be actived now. */
404 if ((readw(keypad->mmio_base + KPDR) & keypad->rows_en_mask) == 0) {
405 dev_err(&dev->dev,
406 "too many keys pressed, control pins initialisation\n");
407 goto open_err;
408 }
409
410 return 0;
411
412open_err:
413 imx_keypad_close(dev);
414 return -EIO;
415}
416
417#ifdef CONFIG_OF
418static struct of_device_id imx_keypad_of_match[] = {
419 { .compatible = "fsl,imx21-kpp", },
420 { /* sentinel */ }
421};
422MODULE_DEVICE_TABLE(of, imx_keypad_of_match);
423#endif
424
425static int imx_keypad_probe(struct platform_device *pdev)
426{
427 const struct matrix_keymap_data *keymap_data =
428 dev_get_platdata(&pdev->dev);
429 struct imx_keypad *keypad;
430 struct input_dev *input_dev;
431 struct resource *res;
432 int irq, error, i, row, col;
433
434 if (!keymap_data && !pdev->dev.of_node) {
435 dev_err(&pdev->dev, "no keymap defined\n");
436 return -EINVAL;
437 }
438
439 irq = platform_get_irq(pdev, 0);
440 if (irq < 0) {
441 dev_err(&pdev->dev, "no irq defined in platform data\n");
442 return irq;
443 }
444
445 input_dev = devm_input_allocate_device(&pdev->dev);
446 if (!input_dev) {
447 dev_err(&pdev->dev, "failed to allocate the input device\n");
448 return -ENOMEM;
449 }
450
451 keypad = devm_kzalloc(&pdev->dev, sizeof(struct imx_keypad),
452 GFP_KERNEL);
453 if (!keypad) {
454 dev_err(&pdev->dev, "not enough memory for driver data\n");
455 return -ENOMEM;
456 }
457
458 keypad->input_dev = input_dev;
459 keypad->irq = irq;
460 keypad->stable_count = 0;
461
462 setup_timer(&keypad->check_matrix_timer,
463 imx_keypad_check_for_events, (unsigned long) keypad);
464
465 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
466 keypad->mmio_base = devm_ioremap_resource(&pdev->dev, res);
467 if (IS_ERR(keypad->mmio_base))
468 return PTR_ERR(keypad->mmio_base);
469
470 keypad->clk = devm_clk_get(&pdev->dev, NULL);
471 if (IS_ERR(keypad->clk)) {
472 dev_err(&pdev->dev, "failed to get keypad clock\n");
473 return PTR_ERR(keypad->clk);
474 }
475
476 /* Init the Input device */
477 input_dev->name = pdev->name;
478 input_dev->id.bustype = BUS_HOST;
479 input_dev->dev.parent = &pdev->dev;
480 input_dev->open = imx_keypad_open;
481 input_dev->close = imx_keypad_close;
482
483 error = matrix_keypad_build_keymap(keymap_data, NULL,
484 MAX_MATRIX_KEY_ROWS,
485 MAX_MATRIX_KEY_COLS,
486 keypad->keycodes, input_dev);
487 if (error) {
488 dev_err(&pdev->dev, "failed to build keymap\n");
489 return error;
490 }
491
492 /* Search for rows and cols enabled */
493 for (row = 0; row < MAX_MATRIX_KEY_ROWS; row++) {
494 for (col = 0; col < MAX_MATRIX_KEY_COLS; col++) {
495 i = MATRIX_SCAN_CODE(row, col, MATRIX_ROW_SHIFT);
496 if (keypad->keycodes[i] != KEY_RESERVED) {
497 keypad->rows_en_mask |= 1 << row;
498 keypad->cols_en_mask |= 1 << col;
499 }
500 }
501 }
502 dev_dbg(&pdev->dev, "enabled rows mask: %x\n", keypad->rows_en_mask);
503 dev_dbg(&pdev->dev, "enabled cols mask: %x\n", keypad->cols_en_mask);
504
505 __set_bit(EV_REP, input_dev->evbit);
506 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
507 input_set_drvdata(input_dev, keypad);
508
509 /* Ensure that the keypad will stay dormant until opened */
510 clk_prepare_enable(keypad->clk);
511 imx_keypad_inhibit(keypad);
512 clk_disable_unprepare(keypad->clk);
513
514 error = devm_request_irq(&pdev->dev, irq, imx_keypad_irq_handler, 0,
515 pdev->name, keypad);
516 if (error) {
517 dev_err(&pdev->dev, "failed to request IRQ\n");
518 return error;
519 }
520
521 /* Register the input device */
522 error = input_register_device(input_dev);
523 if (error) {
524 dev_err(&pdev->dev, "failed to register input device\n");
525 return error;
526 }
527
528 platform_set_drvdata(pdev, keypad);
529 device_init_wakeup(&pdev->dev, 1);
530
531 return 0;
532}
533
534#ifdef CONFIG_PM_SLEEP
535static int imx_kbd_suspend(struct device *dev)
536{
537 struct platform_device *pdev = to_platform_device(dev);
538 struct imx_keypad *kbd = platform_get_drvdata(pdev);
539 struct input_dev *input_dev = kbd->input_dev;
540
541 /* imx kbd can wake up system even clock is disabled */
542 mutex_lock(&input_dev->mutex);
543
544 if (input_dev->users)
545 clk_disable_unprepare(kbd->clk);
546
547 mutex_unlock(&input_dev->mutex);
548
549 if (device_may_wakeup(&pdev->dev))
550 enable_irq_wake(kbd->irq);
551
552 return 0;
553}
554
555static int imx_kbd_resume(struct device *dev)
556{
557 struct platform_device *pdev = to_platform_device(dev);
558 struct imx_keypad *kbd = platform_get_drvdata(pdev);
559 struct input_dev *input_dev = kbd->input_dev;
560 int ret = 0;
561
562 if (device_may_wakeup(&pdev->dev))
563 disable_irq_wake(kbd->irq);
564
565 mutex_lock(&input_dev->mutex);
566
567 if (input_dev->users) {
568 ret = clk_prepare_enable(kbd->clk);
569 if (ret)
570 goto err_clk;
571 }
572
573err_clk:
574 mutex_unlock(&input_dev->mutex);
575
576 return ret;
577}
578#endif
579
580static SIMPLE_DEV_PM_OPS(imx_kbd_pm_ops, imx_kbd_suspend, imx_kbd_resume);
581
582static struct platform_driver imx_keypad_driver = {
583 .driver = {
584 .name = "imx-keypad",
585 .owner = THIS_MODULE,
586 .pm = &imx_kbd_pm_ops,
587 .of_match_table = of_match_ptr(imx_keypad_of_match),
588 },
589 .probe = imx_keypad_probe,
590};
591module_platform_driver(imx_keypad_driver);
592
593MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
594MODULE_DESCRIPTION("IMX Keypad Port Driver");
595MODULE_LICENSE("GPL v2");
596MODULE_ALIAS("platform:imx-keypad");
1/*
2 * Driver for the IMX keypad port.
3 * Copyright (C) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * <<Power management needs to be implemented>>.
10 */
11
12#include <linux/clk.h>
13#include <linux/delay.h>
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/init.h>
17#include <linux/input/matrix_keypad.h>
18#include <linux/interrupt.h>
19#include <linux/io.h>
20#include <linux/jiffies.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/platform_device.h>
24#include <linux/slab.h>
25#include <linux/timer.h>
26
27/*
28 * Keypad Controller registers (halfword)
29 */
30#define KPCR 0x00 /* Keypad Control Register */
31
32#define KPSR 0x02 /* Keypad Status Register */
33#define KBD_STAT_KPKD (0x1 << 0) /* Key Press Interrupt Status bit (w1c) */
34#define KBD_STAT_KPKR (0x1 << 1) /* Key Release Interrupt Status bit (w1c) */
35#define KBD_STAT_KDSC (0x1 << 2) /* Key Depress Synch Chain Status bit (w1c)*/
36#define KBD_STAT_KRSS (0x1 << 3) /* Key Release Synch Status bit (w1c)*/
37#define KBD_STAT_KDIE (0x1 << 8) /* Key Depress Interrupt Enable Status bit */
38#define KBD_STAT_KRIE (0x1 << 9) /* Key Release Interrupt Enable */
39#define KBD_STAT_KPPEN (0x1 << 10) /* Keypad Clock Enable */
40
41#define KDDR 0x04 /* Keypad Data Direction Register */
42#define KPDR 0x06 /* Keypad Data Register */
43
44#define MAX_MATRIX_KEY_ROWS 8
45#define MAX_MATRIX_KEY_COLS 8
46#define MATRIX_ROW_SHIFT 3
47
48#define MAX_MATRIX_KEY_NUM (MAX_MATRIX_KEY_ROWS * MAX_MATRIX_KEY_COLS)
49
50struct imx_keypad {
51
52 struct clk *clk;
53 struct input_dev *input_dev;
54 void __iomem *mmio_base;
55
56 int irq;
57 struct timer_list check_matrix_timer;
58
59 /*
60 * The matrix is stable only if no changes are detected after
61 * IMX_KEYPAD_SCANS_FOR_STABILITY scans
62 */
63#define IMX_KEYPAD_SCANS_FOR_STABILITY 3
64 int stable_count;
65
66 bool enabled;
67
68 /* Masks for enabled rows/cols */
69 unsigned short rows_en_mask;
70 unsigned short cols_en_mask;
71
72 unsigned short keycodes[MAX_MATRIX_KEY_NUM];
73
74 /*
75 * Matrix states:
76 * -stable: achieved after a complete debounce process.
77 * -unstable: used in the debouncing process.
78 */
79 unsigned short matrix_stable_state[MAX_MATRIX_KEY_COLS];
80 unsigned short matrix_unstable_state[MAX_MATRIX_KEY_COLS];
81};
82
83/* Scan the matrix and return the new state in *matrix_volatile_state. */
84static void imx_keypad_scan_matrix(struct imx_keypad *keypad,
85 unsigned short *matrix_volatile_state)
86{
87 int col;
88 unsigned short reg_val;
89
90 for (col = 0; col < MAX_MATRIX_KEY_COLS; col++) {
91 if ((keypad->cols_en_mask & (1 << col)) == 0)
92 continue;
93 /*
94 * Discharge keypad capacitance:
95 * 2. write 1s on column data.
96 * 3. configure columns as totem-pole to discharge capacitance.
97 * 4. configure columns as open-drain.
98 */
99 reg_val = readw(keypad->mmio_base + KPDR);
100 reg_val |= 0xff00;
101 writew(reg_val, keypad->mmio_base + KPDR);
102
103 reg_val = readw(keypad->mmio_base + KPCR);
104 reg_val &= ~((keypad->cols_en_mask & 0xff) << 8);
105 writew(reg_val, keypad->mmio_base + KPCR);
106
107 udelay(2);
108
109 reg_val = readw(keypad->mmio_base + KPCR);
110 reg_val |= (keypad->cols_en_mask & 0xff) << 8;
111 writew(reg_val, keypad->mmio_base + KPCR);
112
113 /*
114 * 5. Write a single column to 0, others to 1.
115 * 6. Sample row inputs and save data.
116 * 7. Repeat steps 2 - 6 for remaining columns.
117 */
118 reg_val = readw(keypad->mmio_base + KPDR);
119 reg_val &= ~(1 << (8 + col));
120 writew(reg_val, keypad->mmio_base + KPDR);
121
122 /*
123 * Delay added to avoid propagating the 0 from column to row
124 * when scanning.
125 */
126 udelay(5);
127
128 /*
129 * 1s in matrix_volatile_state[col] means key pressures
130 * throw data from non enabled rows.
131 */
132 reg_val = readw(keypad->mmio_base + KPDR);
133 matrix_volatile_state[col] = (~reg_val) & keypad->rows_en_mask;
134 }
135
136 /*
137 * Return in standby mode:
138 * 9. write 0s to columns
139 */
140 reg_val = readw(keypad->mmio_base + KPDR);
141 reg_val &= 0x00ff;
142 writew(reg_val, keypad->mmio_base + KPDR);
143}
144
145/*
146 * Compare the new matrix state (volatile) with the stable one stored in
147 * keypad->matrix_stable_state and fire events if changes are detected.
148 */
149static void imx_keypad_fire_events(struct imx_keypad *keypad,
150 unsigned short *matrix_volatile_state)
151{
152 struct input_dev *input_dev = keypad->input_dev;
153 int row, col;
154
155 for (col = 0; col < MAX_MATRIX_KEY_COLS; col++) {
156 unsigned short bits_changed;
157 int code;
158
159 if ((keypad->cols_en_mask & (1 << col)) == 0)
160 continue; /* Column is not enabled */
161
162 bits_changed = keypad->matrix_stable_state[col] ^
163 matrix_volatile_state[col];
164
165 if (bits_changed == 0)
166 continue; /* Column does not contain changes */
167
168 for (row = 0; row < MAX_MATRIX_KEY_ROWS; row++) {
169 if ((keypad->rows_en_mask & (1 << row)) == 0)
170 continue; /* Row is not enabled */
171 if ((bits_changed & (1 << row)) == 0)
172 continue; /* Row does not contain changes */
173
174 code = MATRIX_SCAN_CODE(row, col, MATRIX_ROW_SHIFT);
175 input_event(input_dev, EV_MSC, MSC_SCAN, code);
176 input_report_key(input_dev, keypad->keycodes[code],
177 matrix_volatile_state[col] & (1 << row));
178 dev_dbg(&input_dev->dev, "Event code: %d, val: %d",
179 keypad->keycodes[code],
180 matrix_volatile_state[col] & (1 << row));
181 }
182 }
183 input_sync(input_dev);
184}
185
186/*
187 * imx_keypad_check_for_events is the timer handler.
188 */
189static void imx_keypad_check_for_events(unsigned long data)
190{
191 struct imx_keypad *keypad = (struct imx_keypad *) data;
192 unsigned short matrix_volatile_state[MAX_MATRIX_KEY_COLS];
193 unsigned short reg_val;
194 bool state_changed, is_zero_matrix;
195 int i;
196
197 memset(matrix_volatile_state, 0, sizeof(matrix_volatile_state));
198
199 imx_keypad_scan_matrix(keypad, matrix_volatile_state);
200
201 state_changed = false;
202 for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
203 if ((keypad->cols_en_mask & (1 << i)) == 0)
204 continue;
205
206 if (keypad->matrix_unstable_state[i] ^ matrix_volatile_state[i]) {
207 state_changed = true;
208 break;
209 }
210 }
211
212 /*
213 * If the matrix state is changed from the previous scan
214 * (Re)Begin the debouncing process, saving the new state in
215 * keypad->matrix_unstable_state.
216 * else
217 * Increase the count of number of scans with a stable state.
218 */
219 if (state_changed) {
220 memcpy(keypad->matrix_unstable_state, matrix_volatile_state,
221 sizeof(matrix_volatile_state));
222 keypad->stable_count = 0;
223 } else
224 keypad->stable_count++;
225
226 /*
227 * If the matrix is not as stable as we want reschedule scan
228 * in the near future.
229 */
230 if (keypad->stable_count < IMX_KEYPAD_SCANS_FOR_STABILITY) {
231 mod_timer(&keypad->check_matrix_timer,
232 jiffies + msecs_to_jiffies(10));
233 return;
234 }
235
236 /*
237 * If the matrix state is stable, fire the events and save the new
238 * stable state. Note, if the matrix is kept stable for longer
239 * (keypad->stable_count > IMX_KEYPAD_SCANS_FOR_STABILITY) all
240 * events have already been generated.
241 */
242 if (keypad->stable_count == IMX_KEYPAD_SCANS_FOR_STABILITY) {
243 imx_keypad_fire_events(keypad, matrix_volatile_state);
244
245 memcpy(keypad->matrix_stable_state, matrix_volatile_state,
246 sizeof(matrix_volatile_state));
247 }
248
249 is_zero_matrix = true;
250 for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
251 if (matrix_volatile_state[i] != 0) {
252 is_zero_matrix = false;
253 break;
254 }
255 }
256
257
258 if (is_zero_matrix) {
259 /*
260 * All keys have been released. Enable only the KDI
261 * interrupt for future key presses (clear the KDI
262 * status bit and its sync chain before that).
263 */
264 reg_val = readw(keypad->mmio_base + KPSR);
265 reg_val |= KBD_STAT_KPKD | KBD_STAT_KDSC;
266 writew(reg_val, keypad->mmio_base + KPSR);
267
268 reg_val = readw(keypad->mmio_base + KPSR);
269 reg_val |= KBD_STAT_KDIE;
270 reg_val &= ~KBD_STAT_KRIE;
271 writew(reg_val, keypad->mmio_base + KPSR);
272 } else {
273 /*
274 * Some keys are still pressed. Schedule a rescan in
275 * attempt to detect multiple key presses and enable
276 * the KRI interrupt to react quickly to key release
277 * event.
278 */
279 mod_timer(&keypad->check_matrix_timer,
280 jiffies + msecs_to_jiffies(60));
281
282 reg_val = readw(keypad->mmio_base + KPSR);
283 reg_val |= KBD_STAT_KPKR | KBD_STAT_KRSS;
284 writew(reg_val, keypad->mmio_base + KPSR);
285
286 reg_val = readw(keypad->mmio_base + KPSR);
287 reg_val |= KBD_STAT_KRIE;
288 reg_val &= ~KBD_STAT_KDIE;
289 writew(reg_val, keypad->mmio_base + KPSR);
290 }
291}
292
293static irqreturn_t imx_keypad_irq_handler(int irq, void *dev_id)
294{
295 struct imx_keypad *keypad = dev_id;
296 unsigned short reg_val;
297
298 reg_val = readw(keypad->mmio_base + KPSR);
299
300 /* Disable both interrupt types */
301 reg_val &= ~(KBD_STAT_KRIE | KBD_STAT_KDIE);
302 /* Clear interrupts status bits */
303 reg_val |= KBD_STAT_KPKR | KBD_STAT_KPKD;
304 writew(reg_val, keypad->mmio_base + KPSR);
305
306 if (keypad->enabled) {
307 /* The matrix is supposed to be changed */
308 keypad->stable_count = 0;
309
310 /* Schedule the scanning procedure near in the future */
311 mod_timer(&keypad->check_matrix_timer,
312 jiffies + msecs_to_jiffies(2));
313 }
314
315 return IRQ_HANDLED;
316}
317
318static void imx_keypad_config(struct imx_keypad *keypad)
319{
320 unsigned short reg_val;
321
322 /*
323 * Include enabled rows in interrupt generation (KPCR[7:0])
324 * Configure keypad columns as open-drain (KPCR[15:8])
325 */
326 reg_val = readw(keypad->mmio_base + KPCR);
327 reg_val |= keypad->rows_en_mask & 0xff; /* rows */
328 reg_val |= (keypad->cols_en_mask & 0xff) << 8; /* cols */
329 writew(reg_val, keypad->mmio_base + KPCR);
330
331 /* Write 0's to KPDR[15:8] (Colums) */
332 reg_val = readw(keypad->mmio_base + KPDR);
333 reg_val &= 0x00ff;
334 writew(reg_val, keypad->mmio_base + KPDR);
335
336 /* Configure columns as output, rows as input (KDDR[15:0]) */
337 writew(0xff00, keypad->mmio_base + KDDR);
338
339 /*
340 * Clear Key Depress and Key Release status bit.
341 * Clear both synchronizer chain.
342 */
343 reg_val = readw(keypad->mmio_base + KPSR);
344 reg_val |= KBD_STAT_KPKR | KBD_STAT_KPKD |
345 KBD_STAT_KDSC | KBD_STAT_KRSS;
346 writew(reg_val, keypad->mmio_base + KPSR);
347
348 /* Enable KDI and disable KRI (avoid false release events). */
349 reg_val |= KBD_STAT_KDIE;
350 reg_val &= ~KBD_STAT_KRIE;
351 writew(reg_val, keypad->mmio_base + KPSR);
352}
353
354static void imx_keypad_inhibit(struct imx_keypad *keypad)
355{
356 unsigned short reg_val;
357
358 /* Inhibit KDI and KRI interrupts. */
359 reg_val = readw(keypad->mmio_base + KPSR);
360 reg_val &= ~(KBD_STAT_KRIE | KBD_STAT_KDIE);
361 writew(reg_val, keypad->mmio_base + KPSR);
362
363 /* Colums as open drain and disable all rows */
364 writew(0xff00, keypad->mmio_base + KPCR);
365}
366
367static void imx_keypad_close(struct input_dev *dev)
368{
369 struct imx_keypad *keypad = input_get_drvdata(dev);
370
371 dev_dbg(&dev->dev, ">%s\n", __func__);
372
373 /* Mark keypad as being inactive */
374 keypad->enabled = false;
375 synchronize_irq(keypad->irq);
376 del_timer_sync(&keypad->check_matrix_timer);
377
378 imx_keypad_inhibit(keypad);
379
380 /* Disable clock unit */
381 clk_disable(keypad->clk);
382}
383
384static int imx_keypad_open(struct input_dev *dev)
385{
386 struct imx_keypad *keypad = input_get_drvdata(dev);
387
388 dev_dbg(&dev->dev, ">%s\n", __func__);
389
390 /* We became active from now */
391 keypad->enabled = true;
392
393 /* Enable the kpp clock */
394 clk_enable(keypad->clk);
395 imx_keypad_config(keypad);
396
397 /* Sanity control, not all the rows must be actived now. */
398 if ((readw(keypad->mmio_base + KPDR) & keypad->rows_en_mask) == 0) {
399 dev_err(&dev->dev,
400 "too many keys pressed, control pins initialisation\n");
401 goto open_err;
402 }
403
404 return 0;
405
406open_err:
407 imx_keypad_close(dev);
408 return -EIO;
409}
410
411static int __devinit imx_keypad_probe(struct platform_device *pdev)
412{
413 const struct matrix_keymap_data *keymap_data = pdev->dev.platform_data;
414 struct imx_keypad *keypad;
415 struct input_dev *input_dev;
416 struct resource *res;
417 int irq, error, i;
418
419 if (keymap_data == NULL) {
420 dev_err(&pdev->dev, "no keymap defined\n");
421 return -EINVAL;
422 }
423
424 irq = platform_get_irq(pdev, 0);
425 if (irq < 0) {
426 dev_err(&pdev->dev, "no irq defined in platform data\n");
427 return -EINVAL;
428 }
429
430 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
431 if (res == NULL) {
432 dev_err(&pdev->dev, "no I/O memory defined in platform data\n");
433 return -EINVAL;
434 }
435
436 res = request_mem_region(res->start, resource_size(res), pdev->name);
437 if (res == NULL) {
438 dev_err(&pdev->dev, "failed to request I/O memory\n");
439 return -EBUSY;
440 }
441
442 input_dev = input_allocate_device();
443 if (!input_dev) {
444 dev_err(&pdev->dev, "failed to allocate the input device\n");
445 error = -ENOMEM;
446 goto failed_rel_mem;
447 }
448
449 keypad = kzalloc(sizeof(struct imx_keypad), GFP_KERNEL);
450 if (!keypad) {
451 dev_err(&pdev->dev, "not enough memory for driver data\n");
452 error = -ENOMEM;
453 goto failed_free_input;
454 }
455
456 keypad->input_dev = input_dev;
457 keypad->irq = irq;
458 keypad->stable_count = 0;
459
460 setup_timer(&keypad->check_matrix_timer,
461 imx_keypad_check_for_events, (unsigned long) keypad);
462
463 keypad->mmio_base = ioremap(res->start, resource_size(res));
464 if (keypad->mmio_base == NULL) {
465 dev_err(&pdev->dev, "failed to remap I/O memory\n");
466 error = -ENOMEM;
467 goto failed_free_priv;
468 }
469
470 keypad->clk = clk_get(&pdev->dev, "kpp");
471 if (IS_ERR(keypad->clk)) {
472 dev_err(&pdev->dev, "failed to get keypad clock\n");
473 error = PTR_ERR(keypad->clk);
474 goto failed_unmap;
475 }
476
477 /* Search for rows and cols enabled */
478 for (i = 0; i < keymap_data->keymap_size; i++) {
479 keypad->rows_en_mask |= 1 << KEY_ROW(keymap_data->keymap[i]);
480 keypad->cols_en_mask |= 1 << KEY_COL(keymap_data->keymap[i]);
481 }
482
483 if (keypad->rows_en_mask > ((1 << MAX_MATRIX_KEY_ROWS) - 1) ||
484 keypad->cols_en_mask > ((1 << MAX_MATRIX_KEY_COLS) - 1)) {
485 dev_err(&pdev->dev,
486 "invalid key data (too many rows or colums)\n");
487 error = -EINVAL;
488 goto failed_clock_put;
489 }
490 dev_dbg(&pdev->dev, "enabled rows mask: %x\n", keypad->rows_en_mask);
491 dev_dbg(&pdev->dev, "enabled cols mask: %x\n", keypad->cols_en_mask);
492
493 /* Init the Input device */
494 input_dev->name = pdev->name;
495 input_dev->id.bustype = BUS_HOST;
496 input_dev->dev.parent = &pdev->dev;
497 input_dev->open = imx_keypad_open;
498 input_dev->close = imx_keypad_close;
499
500 error = matrix_keypad_build_keymap(keymap_data, NULL,
501 MAX_MATRIX_KEY_ROWS,
502 MAX_MATRIX_KEY_COLS,
503 keypad->keycodes, input_dev);
504 if (error) {
505 dev_err(&pdev->dev, "failed to build keymap\n");
506 goto failed_clock_put;
507 }
508
509 __set_bit(EV_REP, input_dev->evbit);
510 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
511 input_set_drvdata(input_dev, keypad);
512
513 /* Ensure that the keypad will stay dormant until opened */
514 imx_keypad_inhibit(keypad);
515
516 error = request_irq(irq, imx_keypad_irq_handler, 0,
517 pdev->name, keypad);
518 if (error) {
519 dev_err(&pdev->dev, "failed to request IRQ\n");
520 goto failed_clock_put;
521 }
522
523 /* Register the input device */
524 error = input_register_device(input_dev);
525 if (error) {
526 dev_err(&pdev->dev, "failed to register input device\n");
527 goto failed_free_irq;
528 }
529
530 platform_set_drvdata(pdev, keypad);
531 device_init_wakeup(&pdev->dev, 1);
532
533 return 0;
534
535failed_free_irq:
536 free_irq(irq, pdev);
537failed_clock_put:
538 clk_put(keypad->clk);
539failed_unmap:
540 iounmap(keypad->mmio_base);
541failed_free_priv:
542 kfree(keypad);
543failed_free_input:
544 input_free_device(input_dev);
545failed_rel_mem:
546 release_mem_region(res->start, resource_size(res));
547 return error;
548}
549
550static int __devexit imx_keypad_remove(struct platform_device *pdev)
551{
552 struct imx_keypad *keypad = platform_get_drvdata(pdev);
553 struct resource *res;
554
555 dev_dbg(&pdev->dev, ">%s\n", __func__);
556
557 platform_set_drvdata(pdev, NULL);
558
559 input_unregister_device(keypad->input_dev);
560
561 free_irq(keypad->irq, keypad);
562 clk_put(keypad->clk);
563
564 iounmap(keypad->mmio_base);
565 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
566 release_mem_region(res->start, resource_size(res));
567
568 kfree(keypad);
569
570 return 0;
571}
572
573#ifdef CONFIG_PM_SLEEP
574static int imx_kbd_suspend(struct device *dev)
575{
576 struct platform_device *pdev = to_platform_device(dev);
577 struct imx_keypad *kbd = platform_get_drvdata(pdev);
578 struct input_dev *input_dev = kbd->input_dev;
579
580 /* imx kbd can wake up system even clock is disabled */
581 mutex_lock(&input_dev->mutex);
582
583 if (input_dev->users)
584 clk_disable(kbd->clk);
585
586 mutex_unlock(&input_dev->mutex);
587
588 if (device_may_wakeup(&pdev->dev))
589 enable_irq_wake(kbd->irq);
590
591 return 0;
592}
593
594static int imx_kbd_resume(struct device *dev)
595{
596 struct platform_device *pdev = to_platform_device(dev);
597 struct imx_keypad *kbd = platform_get_drvdata(pdev);
598 struct input_dev *input_dev = kbd->input_dev;
599
600 if (device_may_wakeup(&pdev->dev))
601 disable_irq_wake(kbd->irq);
602
603 mutex_lock(&input_dev->mutex);
604
605 if (input_dev->users)
606 clk_enable(kbd->clk);
607
608 mutex_unlock(&input_dev->mutex);
609
610 return 0;
611}
612#endif
613
614static SIMPLE_DEV_PM_OPS(imx_kbd_pm_ops, imx_kbd_suspend, imx_kbd_resume);
615
616static struct platform_driver imx_keypad_driver = {
617 .driver = {
618 .name = "imx-keypad",
619 .owner = THIS_MODULE,
620 .pm = &imx_kbd_pm_ops,
621 },
622 .probe = imx_keypad_probe,
623 .remove = __devexit_p(imx_keypad_remove),
624};
625module_platform_driver(imx_keypad_driver);
626
627MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
628MODULE_DESCRIPTION("IMX Keypad Port Driver");
629MODULE_LICENSE("GPL v2");
630MODULE_ALIAS("platform:imx-keypad");