Add linux-next specific files for 20110831
[linux-2.6/next.git] / drivers / input / keyboard / gpio_keys.c
blob67df91af84244c40185ecb27c4bbdd2ae29f615b
1 /*
2 * Driver for keys on GPIO lines capable of generating interrupts.
4 * Copyright 2005 Phil Blundell
5 * Copyright 2010, 2011 David Jander <david@protonic.nl>
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.
12 #include <linux/module.h>
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_platform.h>
30 #include <linux/of_gpio.h>
32 struct gpio_button_data {
33 struct gpio_keys_button *button;
34 struct input_dev *input;
35 struct timer_list timer;
36 struct work_struct work;
37 int timer_debounce; /* in msecs */
38 bool disabled;
41 struct gpio_keys_drvdata {
42 struct input_dev *input;
43 struct mutex disable_lock;
44 unsigned int n_buttons;
45 int (*enable)(struct device *dev);
46 void (*disable)(struct device *dev);
47 struct gpio_button_data data[0];
51 * SYSFS interface for enabling/disabling keys and switches:
53 * There are 4 attributes under /sys/devices/platform/gpio-keys/
54 * keys [ro] - bitmap of keys (EV_KEY) which can be
55 * disabled
56 * switches [ro] - bitmap of switches (EV_SW) which can be
57 * disabled
58 * disabled_keys [rw] - bitmap of keys currently disabled
59 * disabled_switches [rw] - bitmap of switches currently disabled
61 * Userland can change these values and hence disable event generation
62 * for each key (or switch). Disabling a key means its interrupt line
63 * is disabled.
65 * For example, if we have following switches set up as gpio-keys:
66 * SW_DOCK = 5
67 * SW_CAMERA_LENS_COVER = 9
68 * SW_KEYPAD_SLIDE = 10
69 * SW_FRONT_PROXIMITY = 11
70 * This is read from switches:
71 * 11-9,5
72 * Next we want to disable proximity (11) and dock (5), we write:
73 * 11,5
74 * to file disabled_switches. Now proximity and dock IRQs are disabled.
75 * This can be verified by reading the file disabled_switches:
76 * 11,5
77 * If we now want to enable proximity (11) switch we write:
78 * 5
79 * to disabled_switches.
81 * We can disable only those keys which don't allow sharing the irq.
84 /**
85 * get_n_events_by_type() - returns maximum number of events per @type
86 * @type: type of button (%EV_KEY, %EV_SW)
88 * Return value of this function can be used to allocate bitmap
89 * large enough to hold all bits for given type.
91 static inline int get_n_events_by_type(int type)
93 BUG_ON(type != EV_SW && type != EV_KEY);
95 return (type == EV_KEY) ? KEY_CNT : SW_CNT;
98 /**
99 * gpio_keys_disable_button() - disables given GPIO button
100 * @bdata: button data for button to be disabled
102 * Disables button pointed by @bdata. This is done by masking
103 * IRQ line. After this function is called, button won't generate
104 * input events anymore. Note that one can only disable buttons
105 * that don't share IRQs.
107 * Make sure that @bdata->disable_lock is locked when entering
108 * this function to avoid races when concurrent threads are
109 * disabling buttons at the same time.
111 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
113 if (!bdata->disabled) {
115 * Disable IRQ and possible debouncing timer.
117 disable_irq(gpio_to_irq(bdata->button->gpio));
118 if (bdata->timer_debounce)
119 del_timer_sync(&bdata->timer);
121 bdata->disabled = true;
126 * gpio_keys_enable_button() - enables given GPIO button
127 * @bdata: button data for button to be disabled
129 * Enables given button pointed by @bdata.
131 * Make sure that @bdata->disable_lock is locked when entering
132 * this function to avoid races with concurrent threads trying
133 * to enable the same button at the same time.
135 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
137 if (bdata->disabled) {
138 enable_irq(gpio_to_irq(bdata->button->gpio));
139 bdata->disabled = false;
144 * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
145 * @ddata: pointer to drvdata
146 * @buf: buffer where stringified bitmap is written
147 * @type: button type (%EV_KEY, %EV_SW)
148 * @only_disabled: does caller want only those buttons that are
149 * currently disabled or all buttons that can be
150 * disabled
152 * This function writes buttons that can be disabled to @buf. If
153 * @only_disabled is true, then @buf contains only those buttons
154 * that are currently disabled. Returns 0 on success or negative
155 * errno on failure.
157 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
158 char *buf, unsigned int type,
159 bool only_disabled)
161 int n_events = get_n_events_by_type(type);
162 unsigned long *bits;
163 ssize_t ret;
164 int i;
166 bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
167 if (!bits)
168 return -ENOMEM;
170 for (i = 0; i < ddata->n_buttons; i++) {
171 struct gpio_button_data *bdata = &ddata->data[i];
173 if (bdata->button->type != type)
174 continue;
176 if (only_disabled && !bdata->disabled)
177 continue;
179 __set_bit(bdata->button->code, bits);
182 ret = bitmap_scnlistprintf(buf, PAGE_SIZE - 2, bits, n_events);
183 buf[ret++] = '\n';
184 buf[ret] = '\0';
186 kfree(bits);
188 return ret;
192 * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
193 * @ddata: pointer to drvdata
194 * @buf: buffer from userspace that contains stringified bitmap
195 * @type: button type (%EV_KEY, %EV_SW)
197 * This function parses stringified bitmap from @buf and disables/enables
198 * GPIO buttons accordinly. Returns 0 on success and negative error
199 * on failure.
201 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
202 const char *buf, unsigned int type)
204 int n_events = get_n_events_by_type(type);
205 unsigned long *bits;
206 ssize_t error;
207 int i;
209 bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
210 if (!bits)
211 return -ENOMEM;
213 error = bitmap_parselist(buf, bits, n_events);
214 if (error)
215 goto out;
217 /* First validate */
218 for (i = 0; i < ddata->n_buttons; i++) {
219 struct gpio_button_data *bdata = &ddata->data[i];
221 if (bdata->button->type != type)
222 continue;
224 if (test_bit(bdata->button->code, bits) &&
225 !bdata->button->can_disable) {
226 error = -EINVAL;
227 goto out;
231 mutex_lock(&ddata->disable_lock);
233 for (i = 0; i < ddata->n_buttons; i++) {
234 struct gpio_button_data *bdata = &ddata->data[i];
236 if (bdata->button->type != type)
237 continue;
239 if (test_bit(bdata->button->code, bits))
240 gpio_keys_disable_button(bdata);
241 else
242 gpio_keys_enable_button(bdata);
245 mutex_unlock(&ddata->disable_lock);
247 out:
248 kfree(bits);
249 return error;
252 #define ATTR_SHOW_FN(name, type, only_disabled) \
253 static ssize_t gpio_keys_show_##name(struct device *dev, \
254 struct device_attribute *attr, \
255 char *buf) \
257 struct platform_device *pdev = to_platform_device(dev); \
258 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
260 return gpio_keys_attr_show_helper(ddata, buf, \
261 type, only_disabled); \
264 ATTR_SHOW_FN(keys, EV_KEY, false);
265 ATTR_SHOW_FN(switches, EV_SW, false);
266 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
267 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
270 * ATTRIBUTES:
272 * /sys/devices/platform/gpio-keys/keys [ro]
273 * /sys/devices/platform/gpio-keys/switches [ro]
275 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
276 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
278 #define ATTR_STORE_FN(name, type) \
279 static ssize_t gpio_keys_store_##name(struct device *dev, \
280 struct device_attribute *attr, \
281 const char *buf, \
282 size_t count) \
284 struct platform_device *pdev = to_platform_device(dev); \
285 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
286 ssize_t error; \
288 error = gpio_keys_attr_store_helper(ddata, buf, type); \
289 if (error) \
290 return error; \
292 return count; \
295 ATTR_STORE_FN(disabled_keys, EV_KEY);
296 ATTR_STORE_FN(disabled_switches, EV_SW);
299 * ATTRIBUTES:
301 * /sys/devices/platform/gpio-keys/disabled_keys [rw]
302 * /sys/devices/platform/gpio-keys/disables_switches [rw]
304 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
305 gpio_keys_show_disabled_keys,
306 gpio_keys_store_disabled_keys);
307 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
308 gpio_keys_show_disabled_switches,
309 gpio_keys_store_disabled_switches);
311 static struct attribute *gpio_keys_attrs[] = {
312 &dev_attr_keys.attr,
313 &dev_attr_switches.attr,
314 &dev_attr_disabled_keys.attr,
315 &dev_attr_disabled_switches.attr,
316 NULL,
319 static struct attribute_group gpio_keys_attr_group = {
320 .attrs = gpio_keys_attrs,
323 static void gpio_keys_report_event(struct gpio_button_data *bdata)
325 struct gpio_keys_button *button = bdata->button;
326 struct input_dev *input = bdata->input;
327 unsigned int type = button->type ?: EV_KEY;
328 int state = (gpio_get_value_cansleep(button->gpio) ? 1 : 0) ^ button->active_low;
330 if (type == EV_ABS) {
331 if (state)
332 input_event(input, type, button->code, button->value);
333 } else {
334 input_event(input, type, button->code, !!state);
336 input_sync(input);
339 static void gpio_keys_work_func(struct work_struct *work)
341 struct gpio_button_data *bdata =
342 container_of(work, struct gpio_button_data, work);
344 gpio_keys_report_event(bdata);
347 static void gpio_keys_timer(unsigned long _data)
349 struct gpio_button_data *data = (struct gpio_button_data *)_data;
351 schedule_work(&data->work);
354 static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
356 struct gpio_button_data *bdata = dev_id;
357 struct gpio_keys_button *button = bdata->button;
359 BUG_ON(irq != gpio_to_irq(button->gpio));
361 if (bdata->timer_debounce)
362 mod_timer(&bdata->timer,
363 jiffies + msecs_to_jiffies(bdata->timer_debounce));
364 else
365 schedule_work(&bdata->work);
367 return IRQ_HANDLED;
370 static int __devinit gpio_keys_setup_key(struct platform_device *pdev,
371 struct gpio_button_data *bdata,
372 struct gpio_keys_button *button)
374 const char *desc = button->desc ? button->desc : "gpio_keys";
375 struct device *dev = &pdev->dev;
376 unsigned long irqflags;
377 int irq, error;
379 setup_timer(&bdata->timer, gpio_keys_timer, (unsigned long)bdata);
380 INIT_WORK(&bdata->work, gpio_keys_work_func);
382 error = gpio_request(button->gpio, desc);
383 if (error < 0) {
384 dev_err(dev, "failed to request GPIO %d, error %d\n",
385 button->gpio, error);
386 goto fail2;
389 error = gpio_direction_input(button->gpio);
390 if (error < 0) {
391 dev_err(dev, "failed to configure"
392 " direction for GPIO %d, error %d\n",
393 button->gpio, error);
394 goto fail3;
397 if (button->debounce_interval) {
398 error = gpio_set_debounce(button->gpio,
399 button->debounce_interval * 1000);
400 /* use timer if gpiolib doesn't provide debounce */
401 if (error < 0)
402 bdata->timer_debounce = button->debounce_interval;
405 irq = gpio_to_irq(button->gpio);
406 if (irq < 0) {
407 error = irq;
408 dev_err(dev, "Unable to get irq number for GPIO %d, error %d\n",
409 button->gpio, error);
410 goto fail3;
413 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
415 * If platform has specified that the button can be disabled,
416 * we don't want it to share the interrupt line.
418 if (!button->can_disable)
419 irqflags |= IRQF_SHARED;
421 error = request_threaded_irq(irq, NULL, gpio_keys_isr, irqflags, desc, bdata);
422 if (error < 0) {
423 dev_err(dev, "Unable to claim irq %d; error %d\n",
424 irq, error);
425 goto fail3;
428 return 0;
430 fail3:
431 gpio_free(button->gpio);
432 fail2:
433 return error;
436 static int gpio_keys_open(struct input_dev *input)
438 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
440 return ddata->enable ? ddata->enable(input->dev.parent) : 0;
443 static void gpio_keys_close(struct input_dev *input)
445 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
447 if (ddata->disable)
448 ddata->disable(input->dev.parent);
452 * Handlers for alternative sources of platform_data
454 #ifdef CONFIG_OF
456 * Translate OpenFirmware node properties into platform_data
458 static int gpio_keys_get_devtree_pdata(struct device *dev,
459 struct gpio_keys_platform_data *pdata)
461 struct device_node *node, *pp;
462 int i;
463 struct gpio_keys_button *buttons;
464 const u32 *reg;
465 int len;
467 node = dev->of_node;
468 if (node == NULL)
469 return -ENODEV;
471 memset(pdata, 0, sizeof *pdata);
473 pdata->rep = !!of_get_property(node, "autorepeat", &len);
475 /* First count the subnodes */
476 pdata->nbuttons = 0;
477 pp = NULL;
478 while ((pp = of_get_next_child(node, pp)))
479 pdata->nbuttons++;
481 if (pdata->nbuttons == 0)
482 return -ENODEV;
484 buttons = kzalloc(pdata->nbuttons * (sizeof *buttons), GFP_KERNEL);
485 if (!buttons)
486 return -ENOMEM;
488 pp = NULL;
489 i = 0;
490 while ((pp = of_get_next_child(node, pp))) {
491 enum of_gpio_flags flags;
493 if (!of_find_property(pp, "gpios", NULL)) {
494 pdata->nbuttons--;
495 dev_warn(dev, "Found button without gpios\n");
496 continue;
498 buttons[i].gpio = of_get_gpio_flags(pp, 0, &flags);
499 buttons[i].active_low = flags & OF_GPIO_ACTIVE_LOW;
501 reg = of_get_property(pp, "linux,code", &len);
502 if (!reg) {
503 dev_err(dev, "Button without keycode: 0x%x\n", buttons[i].gpio);
504 goto out_fail;
506 buttons[i].code = be32_to_cpup(reg);
508 buttons[i].desc = of_get_property(pp, "label", &len);
510 reg = of_get_property(pp, "linux,input-type", &len);
511 buttons[i].type = reg ? be32_to_cpup(reg) : EV_KEY;
513 buttons[i].wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
515 reg = of_get_property(pp, "debounce-interval", &len);
516 buttons[i].debounce_interval = reg ? be32_to_cpup(reg) : 5;
518 i++;
521 pdata->buttons = buttons;
523 return 0;
525 out_fail:
526 kfree(buttons);
527 return -ENODEV;
530 static struct of_device_id gpio_keys_of_match[] = {
531 { .compatible = "gpio-keys", },
532 { },
534 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
536 #else
538 static int gpio_keys_get_devtree_pdata(struct device *dev,
539 struct gpio_keys_platform_data *altp)
541 return -ENODEV;
544 #define gpio_keys_of_match NULL
546 #endif
548 static int __devinit gpio_keys_probe(struct platform_device *pdev)
550 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
551 struct gpio_keys_drvdata *ddata;
552 struct device *dev = &pdev->dev;
553 struct gpio_keys_platform_data alt_pdata;
554 struct input_dev *input;
555 int i, error;
556 int wakeup = 0;
558 if (!pdata) {
559 error = gpio_keys_get_devtree_pdata(dev, &alt_pdata);
560 if (error)
561 return error;
562 pdata = &alt_pdata;
565 ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
566 pdata->nbuttons * sizeof(struct gpio_button_data),
567 GFP_KERNEL);
568 input = input_allocate_device();
569 if (!ddata || !input) {
570 dev_err(dev, "failed to allocate state\n");
571 error = -ENOMEM;
572 goto fail1;
575 ddata->input = input;
576 ddata->n_buttons = pdata->nbuttons;
577 ddata->enable = pdata->enable;
578 ddata->disable = pdata->disable;
579 mutex_init(&ddata->disable_lock);
581 platform_set_drvdata(pdev, ddata);
582 input_set_drvdata(input, ddata);
584 input->name = pdata->name ? : pdev->name;
585 input->phys = "gpio-keys/input0";
586 input->dev.parent = &pdev->dev;
587 input->open = gpio_keys_open;
588 input->close = gpio_keys_close;
590 input->id.bustype = BUS_HOST;
591 input->id.vendor = 0x0001;
592 input->id.product = 0x0001;
593 input->id.version = 0x0100;
595 /* Enable auto repeat feature of Linux input subsystem */
596 if (pdata->rep)
597 __set_bit(EV_REP, input->evbit);
599 for (i = 0; i < pdata->nbuttons; i++) {
600 struct gpio_keys_button *button = &pdata->buttons[i];
601 struct gpio_button_data *bdata = &ddata->data[i];
602 unsigned int type = button->type ?: EV_KEY;
604 bdata->input = input;
605 bdata->button = button;
607 error = gpio_keys_setup_key(pdev, bdata, button);
608 if (error)
609 goto fail2;
611 if (button->wakeup)
612 wakeup = 1;
614 input_set_capability(input, type, button->code);
617 error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
618 if (error) {
619 dev_err(dev, "Unable to export keys/switches, error: %d\n",
620 error);
621 goto fail2;
624 error = input_register_device(input);
625 if (error) {
626 dev_err(dev, "Unable to register input device, error: %d\n",
627 error);
628 goto fail3;
631 /* get current state of buttons */
632 for (i = 0; i < pdata->nbuttons; i++)
633 gpio_keys_report_event(&ddata->data[i]);
634 input_sync(input);
636 device_init_wakeup(&pdev->dev, wakeup);
638 return 0;
640 fail3:
641 sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
642 fail2:
643 while (--i >= 0) {
644 free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
645 if (ddata->data[i].timer_debounce)
646 del_timer_sync(&ddata->data[i].timer);
647 cancel_work_sync(&ddata->data[i].work);
648 gpio_free(pdata->buttons[i].gpio);
651 platform_set_drvdata(pdev, NULL);
652 fail1:
653 input_free_device(input);
654 kfree(ddata);
655 /* If we have no platform_data, we allocated buttons dynamically. */
656 if (!pdev->dev.platform_data)
657 kfree(pdata->buttons);
659 return error;
662 static int __devexit gpio_keys_remove(struct platform_device *pdev)
664 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
665 struct input_dev *input = ddata->input;
666 int i;
668 sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
670 device_init_wakeup(&pdev->dev, 0);
672 for (i = 0; i < ddata->n_buttons; i++) {
673 int irq = gpio_to_irq(ddata->data[i].button->gpio);
674 free_irq(irq, &ddata->data[i]);
675 if (ddata->data[i].timer_debounce)
676 del_timer_sync(&ddata->data[i].timer);
677 cancel_work_sync(&ddata->data[i].work);
678 gpio_free(ddata->data[i].button->gpio);
681 input_unregister_device(input);
684 * If we had no platform_data, we allocated buttons dynamically, and
685 * must free them here. ddata->data[0].button is the pointer to the
686 * beginning of the allocated array.
688 if (!pdev->dev.platform_data)
689 kfree(ddata->data[0].button);
691 kfree(ddata);
693 return 0;
696 #ifdef CONFIG_PM_SLEEP
697 static int gpio_keys_suspend(struct device *dev)
699 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
700 int i;
702 if (device_may_wakeup(dev)) {
703 for (i = 0; i < ddata->n_buttons; i++) {
704 struct gpio_keys_button *button = ddata->data[i].button;
705 if (button->wakeup) {
706 int irq = gpio_to_irq(button->gpio);
707 enable_irq_wake(irq);
712 return 0;
715 static int gpio_keys_resume(struct device *dev)
717 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
718 int i;
720 for (i = 0; i < ddata->n_buttons; i++) {
722 struct gpio_keys_button *button = ddata->data[i].button;
723 if (button->wakeup && device_may_wakeup(dev)) {
724 int irq = gpio_to_irq(button->gpio);
725 disable_irq_wake(irq);
728 gpio_keys_report_event(&ddata->data[i]);
730 input_sync(ddata->input);
732 return 0;
734 #endif
736 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
738 static struct platform_driver gpio_keys_device_driver = {
739 .probe = gpio_keys_probe,
740 .remove = __devexit_p(gpio_keys_remove),
741 .driver = {
742 .name = "gpio-keys",
743 .owner = THIS_MODULE,
744 .pm = &gpio_keys_pm_ops,
745 .of_match_table = gpio_keys_of_match,
749 static int __init gpio_keys_init(void)
751 return platform_driver_register(&gpio_keys_device_driver);
754 static void __exit gpio_keys_exit(void)
756 platform_driver_unregister(&gpio_keys_device_driver);
759 late_initcall(gpio_keys_init);
760 module_exit(gpio_keys_exit);
762 MODULE_LICENSE("GPL");
763 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
764 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
765 MODULE_ALIAS("platform:gpio-keys");