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Linux/drivers/input/keyboard/gpio_keys.c

  1 /*
  2  * Driver for keys on GPIO lines capable of generating interrupts.
  3  *
  4  * Copyright 2005 Phil Blundell
  5  * Copyright 2010, 2011 David Jander <david@protonic.nl>
  6  *
  7  * This program is free software; you can redistribute it and/or modify
  8  * it under the terms of the GNU General Public License version 2 as
  9  * published by the Free Software Foundation.
 10  */
 11 
 12 #include <linux/module.h>
 13 
 14 #include <linux/init.h>
 15 #include <linux/fs.h>
 16 #include <linux/interrupt.h>
 17 #include <linux/irq.h>
 18 #include <linux/sched.h>
 19 #include <linux/pm.h>
 20 #include <linux/slab.h>
 21 #include <linux/sysctl.h>
 22 #include <linux/proc_fs.h>
 23 #include <linux/delay.h>
 24 #include <linux/platform_device.h>
 25 #include <linux/input.h>
 26 #include <linux/gpio_keys.h>
 27 #include <linux/workqueue.h>
 28 #include <linux/gpio.h>
 29 #include <linux/gpio/consumer.h>
 30 #include <linux/of.h>
 31 #include <linux/of_irq.h>
 32 #include <linux/spinlock.h>
 33 
 34 struct gpio_button_data {
 35         const struct gpio_keys_button *button;
 36         struct input_dev *input;
 37         struct gpio_desc *gpiod;
 38 
 39         struct timer_list release_timer;
 40         unsigned int release_delay;     /* in msecs, for IRQ-only buttons */
 41 
 42         struct delayed_work work;
 43         unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
 44 
 45         unsigned int irq;
 46         spinlock_t lock;
 47         bool disabled;
 48         bool key_pressed;
 49 };
 50 
 51 struct gpio_keys_drvdata {
 52         const struct gpio_keys_platform_data *pdata;
 53         struct input_dev *input;
 54         struct mutex disable_lock;
 55         struct gpio_button_data data[0];
 56 };
 57 
 58 /*
 59  * SYSFS interface for enabling/disabling keys and switches:
 60  *
 61  * There are 4 attributes under /sys/devices/platform/gpio-keys/
 62  *      keys [ro]              - bitmap of keys (EV_KEY) which can be
 63  *                               disabled
 64  *      switches [ro]          - bitmap of switches (EV_SW) which can be
 65  *                               disabled
 66  *      disabled_keys [rw]     - bitmap of keys currently disabled
 67  *      disabled_switches [rw] - bitmap of switches currently disabled
 68  *
 69  * Userland can change these values and hence disable event generation
 70  * for each key (or switch). Disabling a key means its interrupt line
 71  * is disabled.
 72  *
 73  * For example, if we have following switches set up as gpio-keys:
 74  *      SW_DOCK = 5
 75  *      SW_CAMERA_LENS_COVER = 9
 76  *      SW_KEYPAD_SLIDE = 10
 77  *      SW_FRONT_PROXIMITY = 11
 78  * This is read from switches:
 79  *      11-9,5
 80  * Next we want to disable proximity (11) and dock (5), we write:
 81  *      11,5
 82  * to file disabled_switches. Now proximity and dock IRQs are disabled.
 83  * This can be verified by reading the file disabled_switches:
 84  *      11,5
 85  * If we now want to enable proximity (11) switch we write:
 86  *      5
 87  * to disabled_switches.
 88  *
 89  * We can disable only those keys which don't allow sharing the irq.
 90  */
 91 
 92 /**
 93  * get_n_events_by_type() - returns maximum number of events per @type
 94  * @type: type of button (%EV_KEY, %EV_SW)
 95  *
 96  * Return value of this function can be used to allocate bitmap
 97  * large enough to hold all bits for given type.
 98  */
 99 static int get_n_events_by_type(int type)
100 {
101         BUG_ON(type != EV_SW && type != EV_KEY);
102 
103         return (type == EV_KEY) ? KEY_CNT : SW_CNT;
104 }
105 
106 /**
107  * get_bm_events_by_type() - returns bitmap of supported events per @type
108  * @input: input device from which bitmap is retrieved
109  * @type: type of button (%EV_KEY, %EV_SW)
110  *
111  * Return value of this function can be used to allocate bitmap
112  * large enough to hold all bits for given type.
113  */
114 static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
115                                                   int type)
116 {
117         BUG_ON(type != EV_SW && type != EV_KEY);
118 
119         return (type == EV_KEY) ? dev->keybit : dev->swbit;
120 }
121 
122 /**
123  * gpio_keys_disable_button() - disables given GPIO button
124  * @bdata: button data for button to be disabled
125  *
126  * Disables button pointed by @bdata. This is done by masking
127  * IRQ line. After this function is called, button won't generate
128  * input events anymore. Note that one can only disable buttons
129  * that don't share IRQs.
130  *
131  * Make sure that @bdata->disable_lock is locked when entering
132  * this function to avoid races when concurrent threads are
133  * disabling buttons at the same time.
134  */
135 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
136 {
137         if (!bdata->disabled) {
138                 /*
139                  * Disable IRQ and associated timer/work structure.
140                  */
141                 disable_irq(bdata->irq);
142 
143                 if (bdata->gpiod)
144                         cancel_delayed_work_sync(&bdata->work);
145                 else
146                         del_timer_sync(&bdata->release_timer);
147 
148                 bdata->disabled = true;
149         }
150 }
151 
152 /**
153  * gpio_keys_enable_button() - enables given GPIO button
154  * @bdata: button data for button to be disabled
155  *
156  * Enables given button pointed by @bdata.
157  *
158  * Make sure that @bdata->disable_lock is locked when entering
159  * this function to avoid races with concurrent threads trying
160  * to enable the same button at the same time.
161  */
162 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
163 {
164         if (bdata->disabled) {
165                 enable_irq(bdata->irq);
166                 bdata->disabled = false;
167         }
168 }
169 
170 /**
171  * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
172  * @ddata: pointer to drvdata
173  * @buf: buffer where stringified bitmap is written
174  * @type: button type (%EV_KEY, %EV_SW)
175  * @only_disabled: does caller want only those buttons that are
176  *                 currently disabled or all buttons that can be
177  *                 disabled
178  *
179  * This function writes buttons that can be disabled to @buf. If
180  * @only_disabled is true, then @buf contains only those buttons
181  * that are currently disabled. Returns 0 on success or negative
182  * errno on failure.
183  */
184 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
185                                           char *buf, unsigned int type,
186                                           bool only_disabled)
187 {
188         int n_events = get_n_events_by_type(type);
189         unsigned long *bits;
190         ssize_t ret;
191         int i;
192 
193         bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
194         if (!bits)
195                 return -ENOMEM;
196 
197         for (i = 0; i < ddata->pdata->nbuttons; i++) {
198                 struct gpio_button_data *bdata = &ddata->data[i];
199 
200                 if (bdata->button->type != type)
201                         continue;
202 
203                 if (only_disabled && !bdata->disabled)
204                         continue;
205 
206                 __set_bit(bdata->button->code, bits);
207         }
208 
209         ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
210         buf[ret++] = '\n';
211         buf[ret] = '\0';
212 
213         kfree(bits);
214 
215         return ret;
216 }
217 
218 /**
219  * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
220  * @ddata: pointer to drvdata
221  * @buf: buffer from userspace that contains stringified bitmap
222  * @type: button type (%EV_KEY, %EV_SW)
223  *
224  * This function parses stringified bitmap from @buf and disables/enables
225  * GPIO buttons accordingly. Returns 0 on success and negative error
226  * on failure.
227  */
228 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
229                                            const char *buf, unsigned int type)
230 {
231         int n_events = get_n_events_by_type(type);
232         const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
233         unsigned long *bits;
234         ssize_t error;
235         int i;
236 
237         bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
238         if (!bits)
239                 return -ENOMEM;
240 
241         error = bitmap_parselist(buf, bits, n_events);
242         if (error)
243                 goto out;
244 
245         /* First validate */
246         if (!bitmap_subset(bits, bitmap, n_events)) {
247                 error = -EINVAL;
248                 goto out;
249         }
250 
251         for (i = 0; i < ddata->pdata->nbuttons; i++) {
252                 struct gpio_button_data *bdata = &ddata->data[i];
253 
254                 if (bdata->button->type != type)
255                         continue;
256 
257                 if (test_bit(bdata->button->code, bits) &&
258                     !bdata->button->can_disable) {
259                         error = -EINVAL;
260                         goto out;
261                 }
262         }
263 
264         mutex_lock(&ddata->disable_lock);
265 
266         for (i = 0; i < ddata->pdata->nbuttons; i++) {
267                 struct gpio_button_data *bdata = &ddata->data[i];
268 
269                 if (bdata->button->type != type)
270                         continue;
271 
272                 if (test_bit(bdata->button->code, bits))
273                         gpio_keys_disable_button(bdata);
274                 else
275                         gpio_keys_enable_button(bdata);
276         }
277 
278         mutex_unlock(&ddata->disable_lock);
279 
280 out:
281         kfree(bits);
282         return error;
283 }
284 
285 #define ATTR_SHOW_FN(name, type, only_disabled)                         \
286 static ssize_t gpio_keys_show_##name(struct device *dev,                \
287                                      struct device_attribute *attr,     \
288                                      char *buf)                         \
289 {                                                                       \
290         struct platform_device *pdev = to_platform_device(dev);         \
291         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
292                                                                         \
293         return gpio_keys_attr_show_helper(ddata, buf,                   \
294                                           type, only_disabled);         \
295 }
296 
297 ATTR_SHOW_FN(keys, EV_KEY, false);
298 ATTR_SHOW_FN(switches, EV_SW, false);
299 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
300 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
301 
302 /*
303  * ATTRIBUTES:
304  *
305  * /sys/devices/platform/gpio-keys/keys [ro]
306  * /sys/devices/platform/gpio-keys/switches [ro]
307  */
308 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
309 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
310 
311 #define ATTR_STORE_FN(name, type)                                       \
312 static ssize_t gpio_keys_store_##name(struct device *dev,               \
313                                       struct device_attribute *attr,    \
314                                       const char *buf,                  \
315                                       size_t count)                     \
316 {                                                                       \
317         struct platform_device *pdev = to_platform_device(dev);         \
318         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
319         ssize_t error;                                                  \
320                                                                         \
321         error = gpio_keys_attr_store_helper(ddata, buf, type);          \
322         if (error)                                                      \
323                 return error;                                           \
324                                                                         \
325         return count;                                                   \
326 }
327 
328 ATTR_STORE_FN(disabled_keys, EV_KEY);
329 ATTR_STORE_FN(disabled_switches, EV_SW);
330 
331 /*
332  * ATTRIBUTES:
333  *
334  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
335  * /sys/devices/platform/gpio-keys/disables_switches [rw]
336  */
337 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
338                    gpio_keys_show_disabled_keys,
339                    gpio_keys_store_disabled_keys);
340 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
341                    gpio_keys_show_disabled_switches,
342                    gpio_keys_store_disabled_switches);
343 
344 static struct attribute *gpio_keys_attrs[] = {
345         &dev_attr_keys.attr,
346         &dev_attr_switches.attr,
347         &dev_attr_disabled_keys.attr,
348         &dev_attr_disabled_switches.attr,
349         NULL,
350 };
351 
352 static struct attribute_group gpio_keys_attr_group = {
353         .attrs = gpio_keys_attrs,
354 };
355 
356 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
357 {
358         const struct gpio_keys_button *button = bdata->button;
359         struct input_dev *input = bdata->input;
360         unsigned int type = button->type ?: EV_KEY;
361         int state;
362 
363         state = gpiod_get_value_cansleep(bdata->gpiod);
364         if (state < 0) {
365                 dev_err(input->dev.parent,
366                         "failed to get gpio state: %d\n", state);
367                 return;
368         }
369 
370         if (type == EV_ABS) {
371                 if (state)
372                         input_event(input, type, button->code, button->value);
373         } else {
374                 input_event(input, type, button->code, state);
375         }
376         input_sync(input);
377 }
378 
379 static void gpio_keys_gpio_work_func(struct work_struct *work)
380 {
381         struct gpio_button_data *bdata =
382                 container_of(work, struct gpio_button_data, work.work);
383 
384         gpio_keys_gpio_report_event(bdata);
385 
386         if (bdata->button->wakeup)
387                 pm_relax(bdata->input->dev.parent);
388 }
389 
390 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
391 {
392         struct gpio_button_data *bdata = dev_id;
393 
394         BUG_ON(irq != bdata->irq);
395 
396         if (bdata->button->wakeup)
397                 pm_stay_awake(bdata->input->dev.parent);
398 
399         mod_delayed_work(system_wq,
400                          &bdata->work,
401                          msecs_to_jiffies(bdata->software_debounce));
402 
403         return IRQ_HANDLED;
404 }
405 
406 static void gpio_keys_irq_timer(unsigned long _data)
407 {
408         struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
409         struct input_dev *input = bdata->input;
410         unsigned long flags;
411 
412         spin_lock_irqsave(&bdata->lock, flags);
413         if (bdata->key_pressed) {
414                 input_event(input, EV_KEY, bdata->button->code, 0);
415                 input_sync(input);
416                 bdata->key_pressed = false;
417         }
418         spin_unlock_irqrestore(&bdata->lock, flags);
419 }
420 
421 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
422 {
423         struct gpio_button_data *bdata = dev_id;
424         const struct gpio_keys_button *button = bdata->button;
425         struct input_dev *input = bdata->input;
426         unsigned long flags;
427 
428         BUG_ON(irq != bdata->irq);
429 
430         spin_lock_irqsave(&bdata->lock, flags);
431 
432         if (!bdata->key_pressed) {
433                 if (bdata->button->wakeup)
434                         pm_wakeup_event(bdata->input->dev.parent, 0);
435 
436                 input_event(input, EV_KEY, button->code, 1);
437                 input_sync(input);
438 
439                 if (!bdata->release_delay) {
440                         input_event(input, EV_KEY, button->code, 0);
441                         input_sync(input);
442                         goto out;
443                 }
444 
445                 bdata->key_pressed = true;
446         }
447 
448         if (bdata->release_delay)
449                 mod_timer(&bdata->release_timer,
450                         jiffies + msecs_to_jiffies(bdata->release_delay));
451 out:
452         spin_unlock_irqrestore(&bdata->lock, flags);
453         return IRQ_HANDLED;
454 }
455 
456 static void gpio_keys_quiesce_key(void *data)
457 {
458         struct gpio_button_data *bdata = data;
459 
460         if (bdata->gpiod)
461                 cancel_delayed_work_sync(&bdata->work);
462         else
463                 del_timer_sync(&bdata->release_timer);
464 }
465 
466 static int gpio_keys_setup_key(struct platform_device *pdev,
467                                 struct input_dev *input,
468                                 struct gpio_button_data *bdata,
469                                 const struct gpio_keys_button *button,
470                                 struct fwnode_handle *child)
471 {
472         const char *desc = button->desc ? button->desc : "gpio_keys";
473         struct device *dev = &pdev->dev;
474         irq_handler_t isr;
475         unsigned long irqflags;
476         int irq;
477         int error;
478 
479         bdata->input = input;
480         bdata->button = button;
481         spin_lock_init(&bdata->lock);
482 
483         if (child) {
484                 bdata->gpiod = devm_get_gpiod_from_child(dev, NULL, child);
485                 if (IS_ERR(bdata->gpiod)) {
486                         error = PTR_ERR(bdata->gpiod);
487                         if (error == -ENOENT) {
488                                 /*
489                                  * GPIO is optional, we may be dealing with
490                                  * purely interrupt-driven setup.
491                                  */
492                                 bdata->gpiod = NULL;
493                         } else {
494                                 if (error != -EPROBE_DEFER)
495                                         dev_err(dev, "failed to get gpio: %d\n",
496                                                 error);
497                                 return error;
498                         }
499                 } else {
500                         error = gpiod_direction_input(bdata->gpiod);
501                         if (error) {
502                                 dev_err(dev, "Failed to configure GPIO %d as input: %d\n",
503                                         desc_to_gpio(bdata->gpiod), error);
504                                 return error;
505                         }
506                 }
507         } else if (gpio_is_valid(button->gpio)) {
508                 /*
509                  * Legacy GPIO number, so request the GPIO here and
510                  * convert it to descriptor.
511                  */
512                 unsigned flags = GPIOF_IN;
513 
514                 if (button->active_low)
515                         flags |= GPIOF_ACTIVE_LOW;
516 
517                 error = devm_gpio_request_one(&pdev->dev, button->gpio, flags,
518                                               desc);
519                 if (error < 0) {
520                         dev_err(dev, "Failed to request GPIO %d, error %d\n",
521                                 button->gpio, error);
522                         return error;
523                 }
524 
525                 bdata->gpiod = gpio_to_desc(button->gpio);
526                 if (!bdata->gpiod)
527                         return -EINVAL;
528         }
529 
530         if (bdata->gpiod) {
531                 if (button->debounce_interval) {
532                         error = gpiod_set_debounce(bdata->gpiod,
533                                         button->debounce_interval * 1000);
534                         /* use timer if gpiolib doesn't provide debounce */
535                         if (error < 0)
536                                 bdata->software_debounce =
537                                                 button->debounce_interval;
538                 }
539 
540                 if (button->irq) {
541                         bdata->irq = button->irq;
542                 } else {
543                         irq = gpiod_to_irq(bdata->gpiod);
544                         if (irq < 0) {
545                                 error = irq;
546                                 dev_err(dev,
547                                         "Unable to get irq number for GPIO %d, error %d\n",
548                                         button->gpio, error);
549                                 return error;
550                         }
551                         bdata->irq = irq;
552                 }
553 
554                 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
555 
556                 isr = gpio_keys_gpio_isr;
557                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
558 
559         } else {
560                 if (!button->irq) {
561                         dev_err(dev, "Found button without gpio or irq\n");
562                         return -EINVAL;
563                 }
564 
565                 bdata->irq = button->irq;
566 
567                 if (button->type && button->type != EV_KEY) {
568                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
569                         return -EINVAL;
570                 }
571 
572                 bdata->release_delay = button->debounce_interval;
573                 setup_timer(&bdata->release_timer,
574                             gpio_keys_irq_timer, (unsigned long)bdata);
575 
576                 isr = gpio_keys_irq_isr;
577                 irqflags = 0;
578         }
579 
580         input_set_capability(input, button->type ?: EV_KEY, button->code);
581 
582         /*
583          * Install custom action to cancel release timer and
584          * workqueue item.
585          */
586         error = devm_add_action(&pdev->dev, gpio_keys_quiesce_key, bdata);
587         if (error) {
588                 dev_err(&pdev->dev,
589                         "failed to register quiesce action, error: %d\n",
590                         error);
591                 return error;
592         }
593 
594         /*
595          * If platform has specified that the button can be disabled,
596          * we don't want it to share the interrupt line.
597          */
598         if (!button->can_disable)
599                 irqflags |= IRQF_SHARED;
600 
601         error = devm_request_any_context_irq(&pdev->dev, bdata->irq,
602                                              isr, irqflags, desc, bdata);
603         if (error < 0) {
604                 dev_err(dev, "Unable to claim irq %d; error %d\n",
605                         bdata->irq, error);
606                 return error;
607         }
608 
609         return 0;
610 }
611 
612 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
613 {
614         struct input_dev *input = ddata->input;
615         int i;
616 
617         for (i = 0; i < ddata->pdata->nbuttons; i++) {
618                 struct gpio_button_data *bdata = &ddata->data[i];
619                 if (bdata->gpiod)
620                         gpio_keys_gpio_report_event(bdata);
621         }
622         input_sync(input);
623 }
624 
625 static int gpio_keys_open(struct input_dev *input)
626 {
627         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
628         const struct gpio_keys_platform_data *pdata = ddata->pdata;
629         int error;
630 
631         if (pdata->enable) {
632                 error = pdata->enable(input->dev.parent);
633                 if (error)
634                         return error;
635         }
636 
637         /* Report current state of buttons that are connected to GPIOs */
638         gpio_keys_report_state(ddata);
639 
640         return 0;
641 }
642 
643 static void gpio_keys_close(struct input_dev *input)
644 {
645         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
646         const struct gpio_keys_platform_data *pdata = ddata->pdata;
647 
648         if (pdata->disable)
649                 pdata->disable(input->dev.parent);
650 }
651 
652 /*
653  * Handlers for alternative sources of platform_data
654  */
655 
656 /*
657  * Translate properties into platform_data
658  */
659 static struct gpio_keys_platform_data *
660 gpio_keys_get_devtree_pdata(struct device *dev)
661 {
662         struct gpio_keys_platform_data *pdata;
663         struct gpio_keys_button *button;
664         struct fwnode_handle *child;
665         int nbuttons;
666 
667         nbuttons = device_get_child_node_count(dev);
668         if (nbuttons == 0)
669                 return ERR_PTR(-ENODEV);
670 
671         pdata = devm_kzalloc(dev,
672                              sizeof(*pdata) + nbuttons * sizeof(*button),
673                              GFP_KERNEL);
674         if (!pdata)
675                 return ERR_PTR(-ENOMEM);
676 
677         button = (struct gpio_keys_button *)(pdata + 1);
678 
679         pdata->buttons = button;
680         pdata->nbuttons = nbuttons;
681 
682         pdata->rep = device_property_read_bool(dev, "autorepeat");
683 
684         device_property_read_string(dev, "label", &pdata->name);
685 
686         device_for_each_child_node(dev, child) {
687                 if (is_of_node(child))
688                         button->irq =
689                                 irq_of_parse_and_map(to_of_node(child), 0);
690 
691                 if (fwnode_property_read_u32(child, "linux,code",
692                                              &button->code)) {
693                         dev_err(dev, "Button without keycode\n");
694                         fwnode_handle_put(child);
695                         return ERR_PTR(-EINVAL);
696                 }
697 
698                 fwnode_property_read_string(child, "label", &button->desc);
699 
700                 if (fwnode_property_read_u32(child, "linux,input-type",
701                                              &button->type))
702                         button->type = EV_KEY;
703 
704                 button->wakeup =
705                         fwnode_property_read_bool(child, "wakeup-source") ||
706                         /* legacy name */
707                         fwnode_property_read_bool(child, "gpio-key,wakeup");
708 
709                 button->can_disable =
710                         fwnode_property_read_bool(child, "linux,can-disable");
711 
712                 if (fwnode_property_read_u32(child, "debounce-interval",
713                                          &button->debounce_interval))
714                         button->debounce_interval = 5;
715 
716                 button++;
717         }
718 
719         return pdata;
720 }
721 
722 static const struct of_device_id gpio_keys_of_match[] = {
723         { .compatible = "gpio-keys", },
724         { },
725 };
726 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
727 
728 static int gpio_keys_probe(struct platform_device *pdev)
729 {
730         struct device *dev = &pdev->dev;
731         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
732         struct fwnode_handle *child = NULL;
733         struct gpio_keys_drvdata *ddata;
734         struct input_dev *input;
735         size_t size;
736         int i, error;
737         int wakeup = 0;
738 
739         if (!pdata) {
740                 pdata = gpio_keys_get_devtree_pdata(dev);
741                 if (IS_ERR(pdata))
742                         return PTR_ERR(pdata);
743         }
744 
745         size = sizeof(struct gpio_keys_drvdata) +
746                         pdata->nbuttons * sizeof(struct gpio_button_data);
747         ddata = devm_kzalloc(dev, size, GFP_KERNEL);
748         if (!ddata) {
749                 dev_err(dev, "failed to allocate state\n");
750                 return -ENOMEM;
751         }
752 
753         input = devm_input_allocate_device(dev);
754         if (!input) {
755                 dev_err(dev, "failed to allocate input device\n");
756                 return -ENOMEM;
757         }
758 
759         ddata->pdata = pdata;
760         ddata->input = input;
761         mutex_init(&ddata->disable_lock);
762 
763         platform_set_drvdata(pdev, ddata);
764         input_set_drvdata(input, ddata);
765 
766         input->name = pdata->name ? : pdev->name;
767         input->phys = "gpio-keys/input0";
768         input->dev.parent = &pdev->dev;
769         input->open = gpio_keys_open;
770         input->close = gpio_keys_close;
771 
772         input->id.bustype = BUS_HOST;
773         input->id.vendor = 0x0001;
774         input->id.product = 0x0001;
775         input->id.version = 0x0100;
776 
777         /* Enable auto repeat feature of Linux input subsystem */
778         if (pdata->rep)
779                 __set_bit(EV_REP, input->evbit);
780 
781         for (i = 0; i < pdata->nbuttons; i++) {
782                 const struct gpio_keys_button *button = &pdata->buttons[i];
783                 struct gpio_button_data *bdata = &ddata->data[i];
784 
785                 if (!dev_get_platdata(dev)) {
786                         child = device_get_next_child_node(&pdev->dev, child);
787                         if (!child) {
788                                 dev_err(&pdev->dev,
789                                         "missing child device node for entry %d\n",
790                                         i);
791                                 return -EINVAL;
792                         }
793                 }
794 
795                 error = gpio_keys_setup_key(pdev, input, bdata, button, child);
796                 if (error) {
797                         fwnode_handle_put(child);
798                         return error;
799                 }
800 
801                 if (button->wakeup)
802                         wakeup = 1;
803         }
804 
805         fwnode_handle_put(child);
806 
807         error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
808         if (error) {
809                 dev_err(dev, "Unable to export keys/switches, error: %d\n",
810                         error);
811                 return error;
812         }
813 
814         error = input_register_device(input);
815         if (error) {
816                 dev_err(dev, "Unable to register input device, error: %d\n",
817                         error);
818                 goto err_remove_group;
819         }
820 
821         device_init_wakeup(&pdev->dev, wakeup);
822 
823         return 0;
824 
825 err_remove_group:
826         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
827         return error;
828 }
829 
830 static int gpio_keys_remove(struct platform_device *pdev)
831 {
832         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
833 
834         device_init_wakeup(&pdev->dev, 0);
835 
836         return 0;
837 }
838 
839 static int __maybe_unused gpio_keys_suspend(struct device *dev)
840 {
841         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
842         struct input_dev *input = ddata->input;
843         int i;
844 
845         if (device_may_wakeup(dev)) {
846                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
847                         struct gpio_button_data *bdata = &ddata->data[i];
848                         if (bdata->button->wakeup)
849                                 enable_irq_wake(bdata->irq);
850                 }
851         } else {
852                 mutex_lock(&input->mutex);
853                 if (input->users)
854                         gpio_keys_close(input);
855                 mutex_unlock(&input->mutex);
856         }
857 
858         return 0;
859 }
860 
861 static int __maybe_unused gpio_keys_resume(struct device *dev)
862 {
863         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
864         struct input_dev *input = ddata->input;
865         int error = 0;
866         int i;
867 
868         if (device_may_wakeup(dev)) {
869                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
870                         struct gpio_button_data *bdata = &ddata->data[i];
871                         if (bdata->button->wakeup)
872                                 disable_irq_wake(bdata->irq);
873                 }
874         } else {
875                 mutex_lock(&input->mutex);
876                 if (input->users)
877                         error = gpio_keys_open(input);
878                 mutex_unlock(&input->mutex);
879         }
880 
881         if (error)
882                 return error;
883 
884         gpio_keys_report_state(ddata);
885         return 0;
886 }
887 
888 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
889 
890 static struct platform_driver gpio_keys_device_driver = {
891         .probe          = gpio_keys_probe,
892         .remove         = gpio_keys_remove,
893         .driver         = {
894                 .name   = "gpio-keys",
895                 .pm     = &gpio_keys_pm_ops,
896                 .of_match_table = gpio_keys_of_match,
897         }
898 };
899 
900 static int __init gpio_keys_init(void)
901 {
902         return platform_driver_register(&gpio_keys_device_driver);
903 }
904 
905 static void __exit gpio_keys_exit(void)
906 {
907         platform_driver_unregister(&gpio_keys_device_driver);
908 }
909 
910 late_initcall(gpio_keys_init);
911 module_exit(gpio_keys_exit);
912 
913 MODULE_LICENSE("GPL");
914 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
915 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
916 MODULE_ALIAS("platform:gpio-keys");
917 

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