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Linux/drivers/input/keyboard/matrix_keypad.c

  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/input.h>
 18 #include <linux/irq.h>
 19 #include <linux/interrupt.h>
 20 #include <linux/jiffies.h>
 21 #include <linux/module.h>
 22 #include <linux/gpio.h>
 23 #include <linux/input/matrix_keypad.h>
 24 #include <linux/slab.h>
 25 #include <linux/of.h>
 26 #include <linux/of_gpio.h>
 27 #include <linux/of_platform.h>
 28 
 29 struct matrix_keypad {
 30         const struct matrix_keypad_platform_data *pdata;
 31         struct input_dev *input_dev;
 32         unsigned int row_shift;
 33 
 34         DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
 35 
 36         uint32_t last_key_state[MATRIX_MAX_COLS];
 37         struct delayed_work work;
 38         spinlock_t lock;
 39         bool scan_pending;
 40         bool stopped;
 41         bool gpio_all_disabled;
 42 };
 43 
 44 /*
 45  * NOTE: normally the GPIO has to be put into HiZ when de-activated to cause
 46  * minmal side effect when scanning other columns, here it is configured to
 47  * be input, and it should work on most platforms.
 48  */
 49 static void __activate_col(const struct matrix_keypad_platform_data *pdata,
 50                            int col, bool on)
 51 {
 52         bool level_on = !pdata->active_low;
 53 
 54         if (on) {
 55                 gpio_direction_output(pdata->col_gpios[col], level_on);
 56         } else {
 57                 gpio_set_value_cansleep(pdata->col_gpios[col], !level_on);
 58                 gpio_direction_input(pdata->col_gpios[col]);
 59         }
 60 }
 61 
 62 static void activate_col(const struct matrix_keypad_platform_data *pdata,
 63                          int col, bool on)
 64 {
 65         __activate_col(pdata, col, on);
 66 
 67         if (on && pdata->col_scan_delay_us)
 68                 udelay(pdata->col_scan_delay_us);
 69 }
 70 
 71 static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
 72                               bool on)
 73 {
 74         int col;
 75 
 76         for (col = 0; col < pdata->num_col_gpios; col++)
 77                 __activate_col(pdata, col, on);
 78 }
 79 
 80 static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
 81                          int row)
 82 {
 83         return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
 84                         !pdata->active_low : pdata->active_low;
 85 }
 86 
 87 static void enable_row_irqs(struct matrix_keypad *keypad)
 88 {
 89         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
 90         int i;
 91 
 92         if (pdata->clustered_irq > 0)
 93                 enable_irq(pdata->clustered_irq);
 94         else {
 95                 for (i = 0; i < pdata->num_row_gpios; i++)
 96                         enable_irq(gpio_to_irq(pdata->row_gpios[i]));
 97         }
 98 }
 99 
100 static void disable_row_irqs(struct matrix_keypad *keypad)
101 {
102         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
103         int i;
104 
105         if (pdata->clustered_irq > 0)
106                 disable_irq_nosync(pdata->clustered_irq);
107         else {
108                 for (i = 0; i < pdata->num_row_gpios; i++)
109                         disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
110         }
111 }
112 
113 /*
114  * This gets the keys from keyboard and reports it to input subsystem
115  */
116 static void matrix_keypad_scan(struct work_struct *work)
117 {
118         struct matrix_keypad *keypad =
119                 container_of(work, struct matrix_keypad, work.work);
120         struct input_dev *input_dev = keypad->input_dev;
121         const unsigned short *keycodes = input_dev->keycode;
122         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
123         uint32_t new_state[MATRIX_MAX_COLS];
124         int row, col, code;
125 
126         /* de-activate all columns for scanning */
127         activate_all_cols(pdata, false);
128 
129         memset(new_state, 0, sizeof(new_state));
130 
131         /* assert each column and read the row status out */
132         for (col = 0; col < pdata->num_col_gpios; col++) {
133 
134                 activate_col(pdata, col, true);
135 
136                 for (row = 0; row < pdata->num_row_gpios; row++)
137                         new_state[col] |=
138                                 row_asserted(pdata, row) ? (1 << row) : 0;
139 
140                 activate_col(pdata, col, false);
141         }
142 
143         for (col = 0; col < pdata->num_col_gpios; col++) {
144                 uint32_t bits_changed;
145 
146                 bits_changed = keypad->last_key_state[col] ^ new_state[col];
147                 if (bits_changed == 0)
148                         continue;
149 
150                 for (row = 0; row < pdata->num_row_gpios; row++) {
151                         if ((bits_changed & (1 << row)) == 0)
152                                 continue;
153 
154                         code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
155                         input_event(input_dev, EV_MSC, MSC_SCAN, code);
156                         input_report_key(input_dev,
157                                          keycodes[code],
158                                          new_state[col] & (1 << row));
159                 }
160         }
161         input_sync(input_dev);
162 
163         memcpy(keypad->last_key_state, new_state, sizeof(new_state));
164 
165         activate_all_cols(pdata, true);
166 
167         /* Enable IRQs again */
168         spin_lock_irq(&keypad->lock);
169         keypad->scan_pending = false;
170         enable_row_irqs(keypad);
171         spin_unlock_irq(&keypad->lock);
172 }
173 
174 static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
175 {
176         struct matrix_keypad *keypad = id;
177         unsigned long flags;
178 
179         spin_lock_irqsave(&keypad->lock, flags);
180 
181         /*
182          * See if another IRQ beaten us to it and scheduled the
183          * scan already. In that case we should not try to
184          * disable IRQs again.
185          */
186         if (unlikely(keypad->scan_pending || keypad->stopped))
187                 goto out;
188 
189         disable_row_irqs(keypad);
190         keypad->scan_pending = true;
191         schedule_delayed_work(&keypad->work,
192                 msecs_to_jiffies(keypad->pdata->debounce_ms));
193 
194 out:
195         spin_unlock_irqrestore(&keypad->lock, flags);
196         return IRQ_HANDLED;
197 }
198 
199 static int matrix_keypad_start(struct input_dev *dev)
200 {
201         struct matrix_keypad *keypad = input_get_drvdata(dev);
202 
203         keypad->stopped = false;
204         mb();
205 
206         /*
207          * Schedule an immediate key scan to capture current key state;
208          * columns will be activated and IRQs be enabled after the scan.
209          */
210         schedule_delayed_work(&keypad->work, 0);
211 
212         return 0;
213 }
214 
215 static void matrix_keypad_stop(struct input_dev *dev)
216 {
217         struct matrix_keypad *keypad = input_get_drvdata(dev);
218 
219         keypad->stopped = true;
220         mb();
221         flush_work(&keypad->work.work);
222         /*
223          * matrix_keypad_scan() will leave IRQs enabled;
224          * we should disable them now.
225          */
226         disable_row_irqs(keypad);
227 }
228 
229 #ifdef CONFIG_PM_SLEEP
230 static void matrix_keypad_enable_wakeup(struct matrix_keypad *keypad)
231 {
232         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
233         unsigned int gpio;
234         int i;
235 
236         if (pdata->clustered_irq > 0) {
237                 if (enable_irq_wake(pdata->clustered_irq) == 0)
238                         keypad->gpio_all_disabled = true;
239         } else {
240 
241                 for (i = 0; i < pdata->num_row_gpios; i++) {
242                         if (!test_bit(i, keypad->disabled_gpios)) {
243                                 gpio = pdata->row_gpios[i];
244 
245                                 if (enable_irq_wake(gpio_to_irq(gpio)) == 0)
246                                         __set_bit(i, keypad->disabled_gpios);
247                         }
248                 }
249         }
250 }
251 
252 static void matrix_keypad_disable_wakeup(struct matrix_keypad *keypad)
253 {
254         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
255         unsigned int gpio;
256         int i;
257 
258         if (pdata->clustered_irq > 0) {
259                 if (keypad->gpio_all_disabled) {
260                         disable_irq_wake(pdata->clustered_irq);
261                         keypad->gpio_all_disabled = false;
262                 }
263         } else {
264                 for (i = 0; i < pdata->num_row_gpios; i++) {
265                         if (test_and_clear_bit(i, keypad->disabled_gpios)) {
266                                 gpio = pdata->row_gpios[i];
267                                 disable_irq_wake(gpio_to_irq(gpio));
268                         }
269                 }
270         }
271 }
272 
273 static int matrix_keypad_suspend(struct device *dev)
274 {
275         struct platform_device *pdev = to_platform_device(dev);
276         struct matrix_keypad *keypad = platform_get_drvdata(pdev);
277 
278         matrix_keypad_stop(keypad->input_dev);
279 
280         if (device_may_wakeup(&pdev->dev))
281                 matrix_keypad_enable_wakeup(keypad);
282 
283         return 0;
284 }
285 
286 static int matrix_keypad_resume(struct device *dev)
287 {
288         struct platform_device *pdev = to_platform_device(dev);
289         struct matrix_keypad *keypad = platform_get_drvdata(pdev);
290 
291         if (device_may_wakeup(&pdev->dev))
292                 matrix_keypad_disable_wakeup(keypad);
293 
294         matrix_keypad_start(keypad->input_dev);
295 
296         return 0;
297 }
298 #endif
299 
300 static SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
301                          matrix_keypad_suspend, matrix_keypad_resume);
302 
303 static int matrix_keypad_init_gpio(struct platform_device *pdev,
304                                    struct matrix_keypad *keypad)
305 {
306         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
307         int i, err;
308 
309         /* initialized strobe lines as outputs, activated */
310         for (i = 0; i < pdata->num_col_gpios; i++) {
311                 err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col");
312                 if (err) {
313                         dev_err(&pdev->dev,
314                                 "failed to request GPIO%d for COL%d\n",
315                                 pdata->col_gpios[i], i);
316                         goto err_free_cols;
317                 }
318 
319                 gpio_direction_output(pdata->col_gpios[i], !pdata->active_low);
320         }
321 
322         for (i = 0; i < pdata->num_row_gpios; i++) {
323                 err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row");
324                 if (err) {
325                         dev_err(&pdev->dev,
326                                 "failed to request GPIO%d for ROW%d\n",
327                                 pdata->row_gpios[i], i);
328                         goto err_free_rows;
329                 }
330 
331                 gpio_direction_input(pdata->row_gpios[i]);
332         }
333 
334         if (pdata->clustered_irq > 0) {
335                 err = request_irq(pdata->clustered_irq,
336                                 matrix_keypad_interrupt,
337                                 pdata->clustered_irq_flags,
338                                 "matrix-keypad", keypad);
339                 if (err) {
340                         dev_err(&pdev->dev,
341                                 "Unable to acquire clustered interrupt\n");
342                         goto err_free_rows;
343                 }
344         } else {
345                 for (i = 0; i < pdata->num_row_gpios; i++) {
346                         err = request_irq(gpio_to_irq(pdata->row_gpios[i]),
347                                         matrix_keypad_interrupt,
348                                         IRQF_TRIGGER_RISING |
349                                         IRQF_TRIGGER_FALLING,
350                                         "matrix-keypad", keypad);
351                         if (err) {
352                                 dev_err(&pdev->dev,
353                                         "Unable to acquire interrupt 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 void matrix_keypad_free_gpio(struct matrix_keypad *keypad)
380 {
381         const struct matrix_keypad_platform_data *pdata = keypad->pdata;
382         int i;
383 
384         if (pdata->clustered_irq > 0) {
385                 free_irq(pdata->clustered_irq, keypad);
386         } else {
387                 for (i = 0; i < pdata->num_row_gpios; i++)
388                         free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
389         }
390 
391         for (i = 0; i < pdata->num_row_gpios; i++)
392                 gpio_free(pdata->row_gpios[i]);
393 
394         for (i = 0; i < pdata->num_col_gpios; i++)
395                 gpio_free(pdata->col_gpios[i]);
396 }
397 
398 #ifdef CONFIG_OF
399 static struct matrix_keypad_platform_data *
400 matrix_keypad_parse_dt(struct device *dev)
401 {
402         struct matrix_keypad_platform_data *pdata;
403         struct device_node *np = dev->of_node;
404         unsigned int *gpios;
405         int i, nrow, ncol;
406 
407         if (!np) {
408                 dev_err(dev, "device lacks DT data\n");
409                 return ERR_PTR(-ENODEV);
410         }
411 
412         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
413         if (!pdata) {
414                 dev_err(dev, "could not allocate memory for platform data\n");
415                 return ERR_PTR(-ENOMEM);
416         }
417 
418         pdata->num_row_gpios = nrow = of_gpio_named_count(np, "row-gpios");
419         pdata->num_col_gpios = ncol = of_gpio_named_count(np, "col-gpios");
420         if (nrow <= 0 || ncol <= 0) {
421                 dev_err(dev, "number of keypad rows/columns not specified\n");
422                 return ERR_PTR(-EINVAL);
423         }
424 
425         if (of_get_property(np, "linux,no-autorepeat", NULL))
426                 pdata->no_autorepeat = true;
427         if (of_get_property(np, "linux,wakeup", NULL))
428                 pdata->wakeup = true;
429         if (of_get_property(np, "gpio-activelow", NULL))
430                 pdata->active_low = true;
431 
432         of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms);
433         of_property_read_u32(np, "col-scan-delay-us",
434                                                 &pdata->col_scan_delay_us);
435 
436         gpios = devm_kzalloc(dev,
437                              sizeof(unsigned int) *
438                                 (pdata->num_row_gpios + pdata->num_col_gpios),
439                              GFP_KERNEL);
440         if (!gpios) {
441                 dev_err(dev, "could not allocate memory for gpios\n");
442                 return ERR_PTR(-ENOMEM);
443         }
444 
445         for (i = 0; i < pdata->num_row_gpios; i++)
446                 gpios[i] = of_get_named_gpio(np, "row-gpios", i);
447 
448         for (i = 0; i < pdata->num_col_gpios; i++)
449                 gpios[pdata->num_row_gpios + i] =
450                         of_get_named_gpio(np, "col-gpios", i);
451 
452         pdata->row_gpios = gpios;
453         pdata->col_gpios = &gpios[pdata->num_row_gpios];
454 
455         return pdata;
456 }
457 #else
458 static inline struct matrix_keypad_platform_data *
459 matrix_keypad_parse_dt(struct device *dev)
460 {
461         dev_err(dev, "no platform data defined\n");
462 
463         return ERR_PTR(-EINVAL);
464 }
465 #endif
466 
467 static int matrix_keypad_probe(struct platform_device *pdev)
468 {
469         const struct matrix_keypad_platform_data *pdata;
470         struct matrix_keypad *keypad;
471         struct input_dev *input_dev;
472         int err;
473 
474         pdata = dev_get_platdata(&pdev->dev);
475         if (!pdata) {
476                 pdata = matrix_keypad_parse_dt(&pdev->dev);
477                 if (IS_ERR(pdata)) {
478                         dev_err(&pdev->dev, "no platform data defined\n");
479                         return PTR_ERR(pdata);
480                 }
481         } else if (!pdata->keymap_data) {
482                 dev_err(&pdev->dev, "no keymap data defined\n");
483                 return -EINVAL;
484         }
485 
486         keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
487         input_dev = input_allocate_device();
488         if (!keypad || !input_dev) {
489                 err = -ENOMEM;
490                 goto err_free_mem;
491         }
492 
493         keypad->input_dev = input_dev;
494         keypad->pdata = pdata;
495         keypad->row_shift = get_count_order(pdata->num_col_gpios);
496         keypad->stopped = true;
497         INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
498         spin_lock_init(&keypad->lock);
499 
500         input_dev->name         = pdev->name;
501         input_dev->id.bustype   = BUS_HOST;
502         input_dev->dev.parent   = &pdev->dev;
503         input_dev->open         = matrix_keypad_start;
504         input_dev->close        = matrix_keypad_stop;
505 
506         err = matrix_keypad_build_keymap(pdata->keymap_data, NULL,
507                                          pdata->num_row_gpios,
508                                          pdata->num_col_gpios,
509                                          NULL, input_dev);
510         if (err) {
511                 dev_err(&pdev->dev, "failed to build keymap\n");
512                 goto err_free_mem;
513         }
514 
515         if (!pdata->no_autorepeat)
516                 __set_bit(EV_REP, input_dev->evbit);
517         input_set_capability(input_dev, EV_MSC, MSC_SCAN);
518         input_set_drvdata(input_dev, keypad);
519 
520         err = matrix_keypad_init_gpio(pdev, keypad);
521         if (err)
522                 goto err_free_mem;
523 
524         err = input_register_device(keypad->input_dev);
525         if (err)
526                 goto err_free_gpio;
527 
528         device_init_wakeup(&pdev->dev, pdata->wakeup);
529         platform_set_drvdata(pdev, keypad);
530 
531         return 0;
532 
533 err_free_gpio:
534         matrix_keypad_free_gpio(keypad);
535 err_free_mem:
536         input_free_device(input_dev);
537         kfree(keypad);
538         return err;
539 }
540 
541 static int matrix_keypad_remove(struct platform_device *pdev)
542 {
543         struct matrix_keypad *keypad = platform_get_drvdata(pdev);
544 
545         device_init_wakeup(&pdev->dev, 0);
546 
547         matrix_keypad_free_gpio(keypad);
548         input_unregister_device(keypad->input_dev);
549         kfree(keypad);
550 
551         return 0;
552 }
553 
554 #ifdef CONFIG_OF
555 static const struct of_device_id matrix_keypad_dt_match[] = {
556         { .compatible = "gpio-matrix-keypad" },
557         { }
558 };
559 MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
560 #endif
561 
562 static struct platform_driver matrix_keypad_driver = {
563         .probe          = matrix_keypad_probe,
564         .remove         = matrix_keypad_remove,
565         .driver         = {
566                 .name   = "matrix-keypad",
567                 .owner  = THIS_MODULE,
568                 .pm     = &matrix_keypad_pm_ops,
569                 .of_match_table = of_match_ptr(matrix_keypad_dt_match),
570         },
571 };
572 module_platform_driver(matrix_keypad_driver);
573 
574 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
575 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
576 MODULE_LICENSE("GPL v2");
577 MODULE_ALIAS("platform:matrix-keypad");
578 

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