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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/of.h>
 30 #include <linux/of_platform.h>
 31 #include <linux/of_gpio.h>
 32 #include <linux/of_irq.h>
 33 #include <linux/spinlock.h>
 34 
 35 struct gpio_button_data {
 36         const struct gpio_keys_button *button;
 37         struct input_dev *input;
 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 (gpio_is_valid(bdata->button->gpio))
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 = gpio_get_value_cansleep(button->gpio);
362 
363         if (state < 0) {
364                 dev_err(input->dev.parent, "failed to get gpio state\n");
365                 return;
366         }
367 
368         state = (state ? 1 : 0) ^ button->active_low;
369         if (type == EV_ABS) {
370                 if (state)
371                         input_event(input, type, button->code, button->value);
372         } else {
373                 input_event(input, type, button->code, !!state);
374         }
375         input_sync(input);
376 }
377 
378 static void gpio_keys_gpio_work_func(struct work_struct *work)
379 {
380         struct gpio_button_data *bdata =
381                 container_of(work, struct gpio_button_data, work.work);
382 
383         gpio_keys_gpio_report_event(bdata);
384 
385         if (bdata->button->wakeup)
386                 pm_relax(bdata->input->dev.parent);
387 }
388 
389 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
390 {
391         struct gpio_button_data *bdata = dev_id;
392 
393         BUG_ON(irq != bdata->irq);
394 
395         if (bdata->button->wakeup)
396                 pm_stay_awake(bdata->input->dev.parent);
397 
398         mod_delayed_work(system_wq,
399                          &bdata->work,
400                          msecs_to_jiffies(bdata->software_debounce));
401 
402         return IRQ_HANDLED;
403 }
404 
405 static void gpio_keys_irq_timer(unsigned long _data)
406 {
407         struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
408         struct input_dev *input = bdata->input;
409         unsigned long flags;
410 
411         spin_lock_irqsave(&bdata->lock, flags);
412         if (bdata->key_pressed) {
413                 input_event(input, EV_KEY, bdata->button->code, 0);
414                 input_sync(input);
415                 bdata->key_pressed = false;
416         }
417         spin_unlock_irqrestore(&bdata->lock, flags);
418 }
419 
420 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
421 {
422         struct gpio_button_data *bdata = dev_id;
423         const struct gpio_keys_button *button = bdata->button;
424         struct input_dev *input = bdata->input;
425         unsigned long flags;
426 
427         BUG_ON(irq != bdata->irq);
428 
429         spin_lock_irqsave(&bdata->lock, flags);
430 
431         if (!bdata->key_pressed) {
432                 if (bdata->button->wakeup)
433                         pm_wakeup_event(bdata->input->dev.parent, 0);
434 
435                 input_event(input, EV_KEY, button->code, 1);
436                 input_sync(input);
437 
438                 if (!bdata->release_delay) {
439                         input_event(input, EV_KEY, button->code, 0);
440                         input_sync(input);
441                         goto out;
442                 }
443 
444                 bdata->key_pressed = true;
445         }
446 
447         if (bdata->release_delay)
448                 mod_timer(&bdata->release_timer,
449                         jiffies + msecs_to_jiffies(bdata->release_delay));
450 out:
451         spin_unlock_irqrestore(&bdata->lock, flags);
452         return IRQ_HANDLED;
453 }
454 
455 static void gpio_keys_quiesce_key(void *data)
456 {
457         struct gpio_button_data *bdata = data;
458 
459         if (gpio_is_valid(bdata->button->gpio))
460                 cancel_delayed_work_sync(&bdata->work);
461         else
462                 del_timer_sync(&bdata->release_timer);
463 }
464 
465 static int gpio_keys_setup_key(struct platform_device *pdev,
466                                 struct input_dev *input,
467                                 struct gpio_button_data *bdata,
468                                 const struct gpio_keys_button *button)
469 {
470         const char *desc = button->desc ? button->desc : "gpio_keys";
471         struct device *dev = &pdev->dev;
472         irq_handler_t isr;
473         unsigned long irqflags;
474         int irq;
475         int error;
476 
477         bdata->input = input;
478         bdata->button = button;
479         spin_lock_init(&bdata->lock);
480 
481         if (gpio_is_valid(button->gpio)) {
482 
483                 error = devm_gpio_request_one(&pdev->dev, button->gpio,
484                                               GPIOF_IN, desc);
485                 if (error < 0) {
486                         dev_err(dev, "Failed to request GPIO %d, error %d\n",
487                                 button->gpio, error);
488                         return error;
489                 }
490 
491                 if (button->debounce_interval) {
492                         error = gpio_set_debounce(button->gpio,
493                                         button->debounce_interval * 1000);
494                         /* use timer if gpiolib doesn't provide debounce */
495                         if (error < 0)
496                                 bdata->software_debounce =
497                                                 button->debounce_interval;
498                 }
499 
500                 if (button->irq) {
501                         bdata->irq = button->irq;
502                 } else {
503                         irq = gpio_to_irq(button->gpio);
504                         if (irq < 0) {
505                                 error = irq;
506                                 dev_err(dev,
507                                         "Unable to get irq number for GPIO %d, error %d\n",
508                                         button->gpio, error);
509                                 return error;
510                         }
511                         bdata->irq = irq;
512                 }
513 
514                 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
515 
516                 isr = gpio_keys_gpio_isr;
517                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
518 
519         } else {
520                 if (!button->irq) {
521                         dev_err(dev, "No IRQ specified\n");
522                         return -EINVAL;
523                 }
524                 bdata->irq = button->irq;
525 
526                 if (button->type && button->type != EV_KEY) {
527                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
528                         return -EINVAL;
529                 }
530 
531                 bdata->release_delay = button->debounce_interval;
532                 setup_timer(&bdata->release_timer,
533                             gpio_keys_irq_timer, (unsigned long)bdata);
534 
535                 isr = gpio_keys_irq_isr;
536                 irqflags = 0;
537         }
538 
539         input_set_capability(input, button->type ?: EV_KEY, button->code);
540 
541         /*
542          * Install custom action to cancel release timer and
543          * workqueue item.
544          */
545         error = devm_add_action(&pdev->dev, gpio_keys_quiesce_key, bdata);
546         if (error) {
547                 dev_err(&pdev->dev,
548                         "failed to register quiesce action, error: %d\n",
549                         error);
550                 return error;
551         }
552 
553         /*
554          * If platform has specified that the button can be disabled,
555          * we don't want it to share the interrupt line.
556          */
557         if (!button->can_disable)
558                 irqflags |= IRQF_SHARED;
559 
560         error = devm_request_any_context_irq(&pdev->dev, bdata->irq,
561                                              isr, irqflags, desc, bdata);
562         if (error < 0) {
563                 dev_err(dev, "Unable to claim irq %d; error %d\n",
564                         bdata->irq, error);
565                 return error;
566         }
567 
568         return 0;
569 }
570 
571 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
572 {
573         struct input_dev *input = ddata->input;
574         int i;
575 
576         for (i = 0; i < ddata->pdata->nbuttons; i++) {
577                 struct gpio_button_data *bdata = &ddata->data[i];
578                 if (gpio_is_valid(bdata->button->gpio))
579                         gpio_keys_gpio_report_event(bdata);
580         }
581         input_sync(input);
582 }
583 
584 static int gpio_keys_open(struct input_dev *input)
585 {
586         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
587         const struct gpio_keys_platform_data *pdata = ddata->pdata;
588         int error;
589 
590         if (pdata->enable) {
591                 error = pdata->enable(input->dev.parent);
592                 if (error)
593                         return error;
594         }
595 
596         /* Report current state of buttons that are connected to GPIOs */
597         gpio_keys_report_state(ddata);
598 
599         return 0;
600 }
601 
602 static void gpio_keys_close(struct input_dev *input)
603 {
604         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
605         const struct gpio_keys_platform_data *pdata = ddata->pdata;
606 
607         if (pdata->disable)
608                 pdata->disable(input->dev.parent);
609 }
610 
611 /*
612  * Handlers for alternative sources of platform_data
613  */
614 
615 #ifdef CONFIG_OF
616 /*
617  * Translate OpenFirmware node properties into platform_data
618  */
619 static struct gpio_keys_platform_data *
620 gpio_keys_get_devtree_pdata(struct device *dev)
621 {
622         struct device_node *node, *pp;
623         struct gpio_keys_platform_data *pdata;
624         struct gpio_keys_button *button;
625         int error;
626         int nbuttons;
627         int i;
628 
629         node = dev->of_node;
630         if (!node)
631                 return ERR_PTR(-ENODEV);
632 
633         nbuttons = of_get_available_child_count(node);
634         if (nbuttons == 0)
635                 return ERR_PTR(-ENODEV);
636 
637         pdata = devm_kzalloc(dev,
638                              sizeof(*pdata) + nbuttons * sizeof(*button),
639                              GFP_KERNEL);
640         if (!pdata)
641                 return ERR_PTR(-ENOMEM);
642 
643         pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
644         pdata->nbuttons = nbuttons;
645 
646         pdata->rep = !!of_get_property(node, "autorepeat", NULL);
647 
648         of_property_read_string(node, "label", &pdata->name);
649 
650         i = 0;
651         for_each_available_child_of_node(node, pp) {
652                 enum of_gpio_flags flags;
653 
654                 button = &pdata->buttons[i++];
655 
656                 button->gpio = of_get_gpio_flags(pp, 0, &flags);
657                 if (button->gpio < 0) {
658                         error = button->gpio;
659                         if (error != -ENOENT) {
660                                 if (error != -EPROBE_DEFER)
661                                         dev_err(dev,
662                                                 "Failed to get gpio flags, error: %d\n",
663                                                 error);
664                                 return ERR_PTR(error);
665                         }
666                 } else {
667                         button->active_low = flags & OF_GPIO_ACTIVE_LOW;
668                 }
669 
670                 button->irq = irq_of_parse_and_map(pp, 0);
671 
672                 if (!gpio_is_valid(button->gpio) && !button->irq) {
673                         dev_err(dev, "Found button without gpios or irqs\n");
674                         return ERR_PTR(-EINVAL);
675                 }
676 
677                 if (of_property_read_u32(pp, "linux,code", &button->code)) {
678                         dev_err(dev, "Button without keycode: 0x%x\n",
679                                 button->gpio);
680                         return ERR_PTR(-EINVAL);
681                 }
682 
683                 button->desc = of_get_property(pp, "label", NULL);
684 
685                 if (of_property_read_u32(pp, "linux,input-type", &button->type))
686                         button->type = EV_KEY;
687 
688                 button->wakeup = of_property_read_bool(pp, "wakeup-source") ||
689                                  /* legacy name */
690                                  of_property_read_bool(pp, "gpio-key,wakeup");
691 
692                 button->can_disable = !!of_get_property(pp, "linux,can-disable", NULL);
693 
694                 if (of_property_read_u32(pp, "debounce-interval",
695                                          &button->debounce_interval))
696                         button->debounce_interval = 5;
697         }
698 
699         if (pdata->nbuttons == 0)
700                 return ERR_PTR(-EINVAL);
701 
702         return pdata;
703 }
704 
705 static const struct of_device_id gpio_keys_of_match[] = {
706         { .compatible = "gpio-keys", },
707         { },
708 };
709 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
710 
711 #else
712 
713 static inline struct gpio_keys_platform_data *
714 gpio_keys_get_devtree_pdata(struct device *dev)
715 {
716         return ERR_PTR(-ENODEV);
717 }
718 
719 #endif
720 
721 static int gpio_keys_probe(struct platform_device *pdev)
722 {
723         struct device *dev = &pdev->dev;
724         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
725         struct gpio_keys_drvdata *ddata;
726         struct input_dev *input;
727         size_t size;
728         int i, error;
729         int wakeup = 0;
730 
731         if (!pdata) {
732                 pdata = gpio_keys_get_devtree_pdata(dev);
733                 if (IS_ERR(pdata))
734                         return PTR_ERR(pdata);
735         }
736 
737         size = sizeof(struct gpio_keys_drvdata) +
738                         pdata->nbuttons * sizeof(struct gpio_button_data);
739         ddata = devm_kzalloc(dev, size, GFP_KERNEL);
740         if (!ddata) {
741                 dev_err(dev, "failed to allocate state\n");
742                 return -ENOMEM;
743         }
744 
745         input = devm_input_allocate_device(dev);
746         if (!input) {
747                 dev_err(dev, "failed to allocate input device\n");
748                 return -ENOMEM;
749         }
750 
751         ddata->pdata = pdata;
752         ddata->input = input;
753         mutex_init(&ddata->disable_lock);
754 
755         platform_set_drvdata(pdev, ddata);
756         input_set_drvdata(input, ddata);
757 
758         input->name = pdata->name ? : pdev->name;
759         input->phys = "gpio-keys/input0";
760         input->dev.parent = &pdev->dev;
761         input->open = gpio_keys_open;
762         input->close = gpio_keys_close;
763 
764         input->id.bustype = BUS_HOST;
765         input->id.vendor = 0x0001;
766         input->id.product = 0x0001;
767         input->id.version = 0x0100;
768 
769         /* Enable auto repeat feature of Linux input subsystem */
770         if (pdata->rep)
771                 __set_bit(EV_REP, input->evbit);
772 
773         for (i = 0; i < pdata->nbuttons; i++) {
774                 const struct gpio_keys_button *button = &pdata->buttons[i];
775                 struct gpio_button_data *bdata = &ddata->data[i];
776 
777                 error = gpio_keys_setup_key(pdev, input, bdata, button);
778                 if (error)
779                         return error;
780 
781                 if (button->wakeup)
782                         wakeup = 1;
783         }
784 
785         error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
786         if (error) {
787                 dev_err(dev, "Unable to export keys/switches, error: %d\n",
788                         error);
789                 return error;
790         }
791 
792         error = input_register_device(input);
793         if (error) {
794                 dev_err(dev, "Unable to register input device, error: %d\n",
795                         error);
796                 goto err_remove_group;
797         }
798 
799         device_init_wakeup(&pdev->dev, wakeup);
800 
801         return 0;
802 
803 err_remove_group:
804         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
805         return error;
806 }
807 
808 static int gpio_keys_remove(struct platform_device *pdev)
809 {
810         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
811 
812         device_init_wakeup(&pdev->dev, 0);
813 
814         return 0;
815 }
816 
817 #ifdef CONFIG_PM_SLEEP
818 static int gpio_keys_suspend(struct device *dev)
819 {
820         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
821         struct input_dev *input = ddata->input;
822         int i;
823 
824         if (device_may_wakeup(dev)) {
825                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
826                         struct gpio_button_data *bdata = &ddata->data[i];
827                         if (bdata->button->wakeup)
828                                 enable_irq_wake(bdata->irq);
829                 }
830         } else {
831                 mutex_lock(&input->mutex);
832                 if (input->users)
833                         gpio_keys_close(input);
834                 mutex_unlock(&input->mutex);
835         }
836 
837         return 0;
838 }
839 
840 static int gpio_keys_resume(struct device *dev)
841 {
842         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
843         struct input_dev *input = ddata->input;
844         int error = 0;
845         int i;
846 
847         if (device_may_wakeup(dev)) {
848                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
849                         struct gpio_button_data *bdata = &ddata->data[i];
850                         if (bdata->button->wakeup)
851                                 disable_irq_wake(bdata->irq);
852                 }
853         } else {
854                 mutex_lock(&input->mutex);
855                 if (input->users)
856                         error = gpio_keys_open(input);
857                 mutex_unlock(&input->mutex);
858         }
859 
860         if (error)
861                 return error;
862 
863         gpio_keys_report_state(ddata);
864         return 0;
865 }
866 #endif
867 
868 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
869 
870 static struct platform_driver gpio_keys_device_driver = {
871         .probe          = gpio_keys_probe,
872         .remove         = gpio_keys_remove,
873         .driver         = {
874                 .name   = "gpio-keys",
875                 .pm     = &gpio_keys_pm_ops,
876                 .of_match_table = of_match_ptr(gpio_keys_of_match),
877         }
878 };
879 
880 static int __init gpio_keys_init(void)
881 {
882         return platform_driver_register(&gpio_keys_device_driver);
883 }
884 
885 static void __exit gpio_keys_exit(void)
886 {
887         platform_driver_unregister(&gpio_keys_device_driver);
888 }
889 
890 late_initcall(gpio_keys_init);
891 module_exit(gpio_keys_exit);
892 
893 MODULE_LICENSE("GPL");
894 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
895 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
896 MODULE_ALIAS("platform:gpio-keys");
897 

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