diff options
Diffstat (limited to 'package/system/gpio-button-hotplug/src')
| -rw-r--r-- | package/system/gpio-button-hotplug/src/Makefile | 1 | ||||
| -rw-r--r-- | package/system/gpio-button-hotplug/src/gpio-button-hotplug.c | 450 |
2 files changed, 451 insertions, 0 deletions
diff --git a/package/system/gpio-button-hotplug/src/Makefile b/package/system/gpio-button-hotplug/src/Makefile new file mode 100644 index 000000000..e96886563 --- /dev/null +++ b/package/system/gpio-button-hotplug/src/Makefile @@ -0,0 +1 @@ +obj-m += gpio-button-hotplug.o diff --git a/package/system/gpio-button-hotplug/src/gpio-button-hotplug.c b/package/system/gpio-button-hotplug/src/gpio-button-hotplug.c new file mode 100644 index 000000000..d25e70fec --- /dev/null +++ b/package/system/gpio-button-hotplug/src/gpio-button-hotplug.c @@ -0,0 +1,450 @@ +/* + * GPIO Button Hotplug driver + * + * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org> + * Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org> + * + * Based on the diag.c - GPIO interface driver for Broadcom boards + * Copyright (C) 2006 Mike Baker <mbm@openwrt.org>, + * Copyright (C) 2006-2007 Felix Fietkau <nbd@openwrt.org> + * Copyright (C) 2008 Andy Boyett <agb@openwrt.org> + * + * 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 <linux/module.h> +#include <linux/version.h> +#include <linux/kmod.h> + +#include <linux/workqueue.h> +#include <linux/skbuff.h> +#include <linux/netlink.h> +#include <linux/kobject.h> +#include <linux/input.h> +#include <linux/platform_device.h> +#include <linux/gpio.h> +#include <linux/gpio_keys.h> + +#define DRV_NAME "gpio-keys-polled" + +#define BH_SKB_SIZE 2048 + +#define PFX DRV_NAME ": " + +#undef BH_DEBUG + +#ifdef BH_DEBUG +#define BH_DBG(fmt, args...) printk(KERN_DEBUG "%s: " fmt, DRV_NAME, ##args ) +#else +#define BH_DBG(fmt, args...) do {} while (0) +#endif + +#define BH_ERR(fmt, args...) printk(KERN_ERR "%s: " fmt, DRV_NAME, ##args ) + +struct bh_priv { + unsigned long seen; +}; + +struct bh_event { + const char *name; + 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; + struct bh_priv bh; + int last_state; + int count; + int threshold; + int can_sleep; +}; + +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_RESTART, "reset"), +#ifdef KEY_WPS_BUTTON + BH_MAP(KEY_WPS_BUTTON, "wps"), +#endif /* KEY_WPS_BUTTON */ +}; + +/* -------------------------------------------------------------------------*/ + +static 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)) { + BH_ERR("buffer size too small\n"); + WARN_ON(1); + return -ENOMEM; + } + + s = skb_put(event->skb, len + 1); + strcpy(s, buf); + + BH_DBG("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; + + 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) { + BH_ERR("work error %d\n", ret); + kfree_skb(event->skb); + } + out_free_event: + kfree(event); +} + +static int button_hotplug_create_event(const char *name, unsigned long seen, + int pressed) +{ + struct bh_event *event; + + BH_DBG("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->seen = seen; + event->action = pressed ? "pressed" : "released"; + + INIT_WORK(&event->work, (void *)(void *)button_hotplug_work); + schedule_work(&event->work); + + return 0; +} + +/* -------------------------------------------------------------------------*/ + +#ifdef CONFIG_HOTPLUG +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 void button_hotplug_event(struct gpio_keys_button_data *data, + unsigned int type, unsigned int code, int value) +{ + struct bh_priv *priv = &data->bh; + unsigned long seen = jiffies; + int btn; + + BH_DBG("event type=%u, code=%u, value=%d\n", type, code, value); + + if (type != EV_KEY) + return; + + btn = button_get_index(code); + if (btn < 0) + return; + + button_hotplug_create_event(button_map[btn].name, + (seen - priv->seen) / HZ, value); + priv->seen = seen; +} +#else +static void button_hotplug_event(struct gpio_keys_button_data *data, + unsigned int type, unsigned int code, int value) +{ +} +#endif /* CONFIG_HOTPLUG */ + +struct gpio_keys_polled_dev { + 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_check_state(struct gpio_keys_button *button, + struct gpio_keys_button_data *bdata) +{ + int state; + + if (bdata->can_sleep) + state = !!gpio_get_value_cansleep(button->gpio); + else + state = !!gpio_get_value(button->gpio); + + state = !!(state ^ button->active_low); + if (state != bdata->last_state) { + unsigned int type = button->type ?: EV_KEY; + + button_hotplug_event(bdata, type, button->code, state); + bdata->count = 0; + bdata->last_state = state; + } +} + +static void gpio_keys_polled_queue_work(struct gpio_keys_polled_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_polled_dev *bdev = + container_of(work, struct gpio_keys_polled_dev, work.work); + struct gpio_keys_platform_data *pdata = bdev->pdata; + int i; + + for (i = 0; i < bdev->pdata->nbuttons; i++) { + struct gpio_keys_button_data *bdata = &bdev->data[i]; + + if (bdata->count < bdata->threshold) + bdata->count++; + else + gpio_keys_polled_check_state(&pdata->buttons[i], bdata); + } + gpio_keys_polled_queue_work(bdev); +} + +static void __devinit gpio_keys_polled_open(struct gpio_keys_polled_dev *bdev) +{ + struct gpio_keys_platform_data *pdata = bdev->pdata; + int i; + + if (pdata->enable) + pdata->enable(bdev->dev); + + /* report initial state of the buttons */ + for (i = 0; i < pdata->nbuttons; i++) + gpio_keys_polled_check_state(&pdata->buttons[i], &bdev->data[i]); + + gpio_keys_polled_queue_work(bdev); +} + +static void __devexit gpio_keys_polled_close(struct gpio_keys_polled_dev *bdev) +{ + struct gpio_keys_platform_data *pdata = bdev->pdata; + + cancel_delayed_work_sync(&bdev->work); + + if (pdata->disable) + pdata->disable(bdev->dev); +} + +static int __devinit gpio_keys_polled_probe(struct platform_device *pdev) +{ + struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; + struct device *dev = &pdev->dev; + struct gpio_keys_polled_dev *bdev; + int error; + int i; + + if (!pdata || !pdata->poll_interval) + return -EINVAL; + + bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) + + pdata->nbuttons * sizeof(struct gpio_keys_button_data), + GFP_KERNEL); + if (!bdev) { + dev_err(dev, "no memory for private data\n"); + return -ENOMEM; + } + + for (i = 0; i < pdata->nbuttons; i++) { + struct gpio_keys_button *button = &pdata->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"); + error = -EINVAL; + goto err_free_gpio; + } + + error = gpio_request(gpio, + button->desc ? button->desc : DRV_NAME); + if (error) { + dev_err(dev, "unable to claim gpio %u, err=%d\n", + gpio, error); + goto err_free_gpio; + } + + error = gpio_direction_input(gpio); + if (error) { + dev_err(dev, + "unable to set direction on gpio %u, err=%d\n", + gpio, error); + goto err_free_gpio; + } + + bdata->can_sleep = gpio_cansleep(gpio); + bdata->last_state = 0; + bdata->threshold = DIV_ROUND_UP(button->debounce_interval, + pdata->poll_interval); + } + + bdev->dev = &pdev->dev; + bdev->pdata = pdata; + platform_set_drvdata(pdev, bdev); + + INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll); + + gpio_keys_polled_open(bdev); + + return 0; + +err_free_gpio: + while (--i >= 0) + gpio_free(pdata->buttons[i].gpio); + + kfree(bdev); + platform_set_drvdata(pdev, NULL); + + return error; +} + +static int __devexit gpio_keys_polled_remove(struct platform_device *pdev) +{ + struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev); + struct gpio_keys_platform_data *pdata = bdev->pdata; + int i = pdata->nbuttons; + + gpio_keys_polled_close(bdev); + + while (--i >= 0) + gpio_free(pdata->buttons[i].gpio); + + kfree(bdev); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_driver gpio_keys_polled_driver = { + .probe = gpio_keys_polled_probe, + .remove = __devexit_p(gpio_keys_polled_remove), + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, +}; + +static int __init gpio_keys_polled_init(void) +{ + return platform_driver_register(&gpio_keys_polled_driver); +} + +static void __exit gpio_keys_polled_exit(void) +{ + platform_driver_unregister(&gpio_keys_polled_driver); +} + +module_init(gpio_keys_polled_init); +module_exit(gpio_keys_polled_exit); + +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); +MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); +MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRV_NAME); |