/* * GPIO Button Hotplug driver * * Copyright (C) 2012 Felix Fietkau * Copyright (C) 2008-2010 Gabor Juhos * * Based on the diag.c - GPIO interface driver for Broadcom boards * Copyright (C) 2006 Mike Baker , * Copyright (C) 2006-2007 Felix Fietkau * Copyright (C) 2008 Andy Boyett * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define BH_SKB_SIZE 2048 #define DRV_NAME "gpio-keys" #define PFX DRV_NAME ": " struct bh_event { const char *name; unsigned int type; char *action; unsigned long seen; struct sk_buff *skb; struct work_struct work; }; struct bh_map { unsigned int code; const char *name; }; struct gpio_keys_button_data { struct delayed_work work; unsigned long seen; int map_entry; int last_state; int count; int threshold; int can_sleep; int irq; unsigned int software_debounce; struct gpio_desc *gpiod; const struct gpio_keys_button *b; }; extern u64 uevent_next_seqnum(void); #define BH_MAP(_code, _name) \ { \ .code = (_code), \ .name = (_name), \ } static struct bh_map button_map[] = { BH_MAP(BTN_0, "BTN_0"), BH_MAP(BTN_1, "BTN_1"), BH_MAP(BTN_2, "BTN_2"), BH_MAP(BTN_3, "BTN_3"), BH_MAP(BTN_4, "BTN_4"), BH_MAP(BTN_5, "BTN_5"), BH_MAP(BTN_6, "BTN_6"), BH_MAP(BTN_7, "BTN_7"), BH_MAP(BTN_8, "BTN_8"), BH_MAP(BTN_9, "BTN_9"), BH_MAP(KEY_BRIGHTNESS_ZERO, "brightness_zero"), BH_MAP(KEY_CONFIG, "config"), BH_MAP(KEY_COPY, "copy"), BH_MAP(KEY_EJECTCD, "eject"), BH_MAP(KEY_HELP, "help"), BH_MAP(KEY_LIGHTS_TOGGLE, "lights_toggle"), BH_MAP(KEY_PHONE, "phone"), BH_MAP(KEY_POWER, "power"), BH_MAP(KEY_POWER2, "reboot"), BH_MAP(KEY_RESTART, "reset"), BH_MAP(KEY_RFKILL, "rfkill"), BH_MAP(KEY_VIDEO, "video"), BH_MAP(KEY_WIMAX, "wwan"), BH_MAP(KEY_WLAN, "wlan"), BH_MAP(KEY_WPS_BUTTON, "wps"), }; /* -------------------------------------------------------------------------*/ static __printf(3, 4) int bh_event_add_var(struct bh_event *event, int argv, const char *format, ...) { static char buf[128]; char *s; va_list args; int len; if (argv) return 0; va_start(args, format); len = vsnprintf(buf, sizeof(buf), format, args); va_end(args); if (len >= sizeof(buf)) { WARN(1, "buffer size too small"); return -ENOMEM; } s = skb_put(event->skb, len + 1); strcpy(s, buf); pr_debug(PFX "added variable '%s'\n", s); return 0; } static int button_hotplug_fill_event(struct bh_event *event) { int ret; ret = bh_event_add_var(event, 0, "HOME=%s", "/"); if (ret) return ret; ret = bh_event_add_var(event, 0, "PATH=%s", "/sbin:/bin:/usr/sbin:/usr/bin"); if (ret) return ret; ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", "button"); if (ret) return ret; ret = bh_event_add_var(event, 0, "ACTION=%s", event->action); if (ret) return ret; ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name); if (ret) return ret; if (event->type == EV_SW) { ret = bh_event_add_var(event, 0, "TYPE=%s", "switch"); if (ret) return ret; } ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen); if (ret) return ret; ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum()); return ret; } static void button_hotplug_work(struct work_struct *work) { struct bh_event *event = container_of(work, struct bh_event, work); int ret = 0; event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL); if (!event->skb) goto out_free_event; ret = bh_event_add_var(event, 0, "%s@", event->action); if (ret) goto out_free_skb; ret = button_hotplug_fill_event(event); if (ret) goto out_free_skb; NETLINK_CB(event->skb).dst_group = 1; broadcast_uevent(event->skb, 0, 1, GFP_KERNEL); out_free_skb: if (ret) { pr_err(PFX "work error %d\n", ret); kfree_skb(event->skb); } out_free_event: kfree(event); } static int button_hotplug_create_event(const char *name, unsigned int type, unsigned long seen, int pressed) { struct bh_event *event; pr_debug(PFX "create event, name=%s, seen=%lu, pressed=%d\n", name, seen, pressed); event = kzalloc(sizeof(*event), GFP_KERNEL); if (!event) return -ENOMEM; event->name = name; event->type = type; event->seen = seen; event->action = pressed ? "pressed" : "released"; INIT_WORK(&event->work, (void *)(void *)button_hotplug_work); schedule_work(&event->work); return 0; } /* -------------------------------------------------------------------------*/ static int button_get_index(unsigned int code) { int i; for (i = 0; i < ARRAY_SIZE(button_map); i++) if (button_map[i].code == code) return i; return -1; } static int gpio_button_get_value(struct gpio_keys_button_data *bdata) { int val; if (bdata->can_sleep) val = !!gpio_get_value_cansleep(bdata->b->gpio); else val = !!gpio_get_value(bdata->b->gpio); return val ^ bdata->b->active_low; } static void gpio_keys_handle_button(struct gpio_keys_button_data *bdata) { unsigned int type = bdata->b->type ?: EV_KEY; int state = gpio_button_get_value(bdata); unsigned long seen = jiffies; pr_debug(PFX "event type=%u, code=%u, pressed=%d\n", type, bdata->b->code, state); /* is this the initialization state? */ if (bdata->last_state == -1) { /* * Don't advertise unpressed buttons on initialization. * Just save their state and continue otherwise this * can cause OpenWrt to enter failsafe. */ if (type == EV_KEY && state == 0) goto set_state; /* * But we are very interested in pressed buttons and * initial switch state. These will be reported to * userland. */ } else if (bdata->last_state == state) { /* reset asserted counter (only relevant for polled keys) */ bdata->count = 0; return; } if (bdata->count < bdata->threshold) { bdata->count++; return; } if (bdata->seen == 0) bdata->seen = seen; button_hotplug_create_event(button_map[bdata->map_entry].name, type, (seen - bdata->seen) / HZ, state); bdata->seen = seen; set_state: bdata->last_state = state; bdata->count = 0; } struct gpio_keys_button_dev { int polled; struct delayed_work work; struct device *dev; struct gpio_keys_platform_data *pdata; struct gpio_keys_button_data data[0]; }; static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev *bdev) { struct gpio_keys_platform_data *pdata = bdev->pdata; unsigned long delay = msecs_to_jiffies(pdata->poll_interval); if (delay >= HZ) delay = round_jiffies_relative(delay); schedule_delayed_work(&bdev->work, delay); } static void gpio_keys_polled_poll(struct work_struct *work) { struct gpio_keys_button_dev *bdev = container_of(work, struct gpio_keys_button_dev, work.work); int i; for (i = 0; i < bdev->pdata->nbuttons; i++) { struct gpio_keys_button_data *bdata = &bdev->data[i]; if (bdata->gpiod) gpio_keys_handle_button(bdata); } gpio_keys_polled_queue_work(bdev); } static void gpio_keys_polled_close(struct gpio_keys_button_dev *bdev) { struct gpio_keys_platform_data *pdata = bdev->pdata; cancel_delayed_work_sync(&bdev->work); if (pdata->disable) pdata->disable(bdev->dev); } static void gpio_keys_irq_work_func(struct work_struct *work) { struct gpio_keys_button_data *bdata = container_of(work, struct gpio_keys_button_data, work.work); gpio_keys_handle_button(bdata); } static irqreturn_t button_handle_irq(int irq, void *_bdata) { struct gpio_keys_button_data *bdata = (struct gpio_keys_button_data *) _bdata; mod_delayed_work(system_wq, &bdata->work, msecs_to_jiffies(bdata->software_debounce)); return IRQ_HANDLED; } #ifdef CONFIG_OF static struct gpio_keys_platform_data * gpio_keys_get_devtree_pdata(struct device *dev) { struct device_node *node, *pp; struct gpio_keys_platform_data *pdata; struct gpio_keys_button *button; int error; int nbuttons; int i = 0; node = dev->of_node; if (!node) return NULL; nbuttons = of_get_child_count(node); if (nbuttons == 0) return NULL; pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * (sizeof *button), GFP_KERNEL); if (!pdata) { error = -ENOMEM; goto err_out; } pdata->buttons = (struct gpio_keys_button *)(pdata + 1); pdata->nbuttons = nbuttons; pdata->rep = !!of_get_property(node, "autorepeat", NULL); of_property_read_u32(node, "poll-interval", &pdata->poll_interval); for_each_child_of_node(node, pp) { enum of_gpio_flags flags; if (!of_find_property(pp, "gpios", NULL)) { pdata->nbuttons--; dev_warn(dev, "Found button without gpios\n"); continue; } button = (struct gpio_keys_button *)(&pdata->buttons[i++]); button->irq = irq_of_parse_and_map(pp, 0); button->gpio = of_get_gpio_flags(pp, 0, &flags); if (button->gpio < 0) { error = button->gpio; if (error != -ENOENT) { if (error != -EPROBE_DEFER) dev_err(dev, "Failed to get gpio flags, error: %d\n", error); return ERR_PTR(error); } } else { button->active_low = !!(flags & OF_GPIO_ACTIVE_LOW); } if (of_property_read_u32(pp, "linux,code", &button->code)) { dev_err(dev, "Button without keycode: 0x%x\n", button->gpio); error = -EINVAL; goto err_out; } button->desc = of_get_property(pp, "label", NULL); if (of_property_read_u32(pp, "linux,input-type", &button->type)) button->type = EV_KEY; button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL); if (of_property_read_u32(pp, "debounce-interval", &button->debounce_interval)) button->debounce_interval = 5; } if (pdata->nbuttons == 0) { error = -EINVAL; goto err_out; } return pdata; err_out: return ERR_PTR(error); } static struct of_device_id gpio_keys_of_match[] = { { .compatible = "gpio-keys", }, { }, }; MODULE_DEVICE_TABLE(of, gpio_keys_of_match); static struct of_device_id gpio_keys_polled_of_match[] = { { .compatible = "gpio-keys-polled", }, { }, }; MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match); #else static inline struct gpio_keys_platform_data * gpio_keys_get_devtree_pdata(struct device *dev) { return NULL; } #endif static int gpio_keys_button_probe(struct platform_device *pdev, struct gpio_keys_button_dev **_bdev, int polled) { struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; struct device *dev = &pdev->dev; struct gpio_keys_button_dev *bdev; struct gpio_keys_button *buttons; int error; int i; if (!pdata) { pdata = gpio_keys_get_devtree_pdata(dev); if (IS_ERR(pdata)) return PTR_ERR(pdata); if (!pdata) { dev_err(dev, "missing platform data\n"); return -EINVAL; } } if (polled && !pdata->poll_interval) { dev_err(dev, "missing poll_interval value\n"); return -EINVAL; } buttons = devm_kzalloc(dev, pdata->nbuttons * sizeof(struct gpio_keys_button), GFP_KERNEL); if (!buttons) { dev_err(dev, "no memory for button data\n"); return -ENOMEM; } memcpy(buttons, pdata->buttons, pdata->nbuttons * sizeof(struct gpio_keys_button)); bdev = devm_kzalloc(dev, sizeof(struct gpio_keys_button_dev) + pdata->nbuttons * sizeof(struct gpio_keys_button_data), GFP_KERNEL); if (!bdev) { dev_err(dev, "no memory for private data\n"); return -ENOMEM; } bdev->polled = polled; for (i = 0; i < pdata->nbuttons; i++) { struct gpio_keys_button *button = &buttons[i]; struct gpio_keys_button_data *bdata = &bdev->data[i]; unsigned int gpio = button->gpio; if (button->wakeup) { dev_err(dev, DRV_NAME "does not support wakeup\n"); return -EINVAL; } bdata->map_entry = button_get_index(button->code); if (bdata->map_entry < 0) { dev_warn(dev, DRV_NAME "does not support key code:%u\n", button->code); continue; } if (!(button->type == 0 || button->type == EV_KEY || button->type == EV_SW)) { dev_warn(dev, DRV_NAME "only supports buttons or switches\n"); continue; } error = devm_gpio_request(dev, gpio, button->desc ? button->desc : DRV_NAME); if (error) { dev_err(dev, "unable to claim gpio %u, err=%d\n", gpio, error); return error; } bdata->gpiod = gpio_to_desc(gpio); if (!bdata->gpiod) return -EINVAL; error = gpio_direction_input(gpio); if (error) { dev_err(dev, "unable to set direction on gpio %u, err=%d\n", gpio, error); return error; } bdata->can_sleep = gpio_cansleep(gpio); bdata->last_state = -1; /* Unknown state on boot */ if (bdev->polled) { bdata->threshold = DIV_ROUND_UP(button->debounce_interval, pdata->poll_interval); } else { /* bdata->threshold = 0; already initialized */ if (button->debounce_interval) { error = gpiod_set_debounce(bdata->gpiod, button->debounce_interval * 1000); /* * use timer if gpiolib doesn't provide * debounce. */ if (error < 0) { bdata->software_debounce = button->debounce_interval; } } } bdata->b = &pdata->buttons[i]; } bdev->dev = &pdev->dev; bdev->pdata = pdata; platform_set_drvdata(pdev, bdev); *_bdev = bdev; return 0; } static int gpio_keys_probe(struct platform_device *pdev) { struct gpio_keys_platform_data *pdata; struct gpio_keys_button_dev *bdev; int ret, i; ret = gpio_keys_button_probe(pdev, &bdev, 0); if (ret) return ret; pdata = bdev->pdata; for (i = 0; i < pdata->nbuttons; i++) { const struct gpio_keys_button *button = &pdata->buttons[i]; struct gpio_keys_button_data *bdata = &bdev->data[i]; unsigned long irqflags = IRQF_ONESHOT; INIT_DELAYED_WORK(&bdata->work, gpio_keys_irq_work_func); if (!bdata->gpiod) continue; if (!button->irq) { bdata->irq = gpio_to_irq(button->gpio); if (bdata->irq < 0) { dev_err(&pdev->dev, "failed to get irq for gpio:%d\n", button->gpio); continue; } irqflags |= IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING; } else { bdata->irq = button->irq; } schedule_delayed_work(&bdata->work, msecs_to_jiffies(bdata->software_debounce)); ret = devm_request_threaded_irq(&pdev->dev, bdata->irq, NULL, button_handle_irq, irqflags, dev_name(&pdev->dev), bdata); if (ret < 0) { bdata->irq = 0; dev_err(&pdev->dev, "failed to request irq:%d for gpio:%d\n", bdata->irq, button->gpio); continue; } else { dev_dbg(&pdev->dev, "gpio:%d has irq:%d\n", button->gpio, bdata->irq); } } return 0; } static int gpio_keys_polled_probe(struct platform_device *pdev) { struct gpio_keys_platform_data *pdata; struct gpio_keys_button_dev *bdev; int ret; ret = gpio_keys_button_probe(pdev, &bdev, 1); if (ret) return ret; INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll); pdata = bdev->pdata; if (pdata->enable) pdata->enable(bdev->dev); gpio_keys_polled_queue_work(bdev); return ret; } static void gpio_keys_irq_close(struct gpio_keys_button_dev *bdev) { struct gpio_keys_platform_data *pdata = bdev->pdata; size_t i; for (i = 0; i < pdata->nbuttons; i++) { struct gpio_keys_button_data *bdata = &bdev->data[i]; disable_irq(bdata->irq); cancel_delayed_work_sync(&bdata->work); } } static int gpio_keys_remove(struct platform_device *pdev) { struct gpio_keys_button_dev *bdev = platform_get_drvdata(pdev); platform_set_drvdata(pdev, NULL); if (bdev->polled) gpio_keys_polled_close(bdev); else gpio_keys_irq_close(bdev); return 0; } static struct platform_driver gpio_keys_driver = { .probe = gpio_keys_probe, .remove = gpio_keys_remove, .driver = { .name = "gpio-keys", .owner = THIS_MODULE, .of_match_table = of_match_ptr(gpio_keys_of_match), }, }; static struct platform_driver gpio_keys_polled_driver = { .probe = gpio_keys_polled_probe, .remove = gpio_keys_remove, .driver = { .name = "gpio-keys-polled", .owner = THIS_MODULE, .of_match_table = of_match_ptr(gpio_keys_polled_of_match), }, }; static int __init gpio_button_init(void) { int ret; ret = platform_driver_register(&gpio_keys_driver); if (ret) return ret; ret = platform_driver_register(&gpio_keys_polled_driver); if (ret) platform_driver_unregister(&gpio_keys_driver); return ret; } static void __exit gpio_button_exit(void) { platform_driver_unregister(&gpio_keys_driver); platform_driver_unregister(&gpio_keys_polled_driver); } module_init(gpio_button_init); module_exit(gpio_button_exit); MODULE_AUTHOR("Gabor Juhos "); MODULE_AUTHOR("Felix Fietkau "); MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:" DRV_NAME);