add gpio-button-hotplug, like button-hotplug + gpio-keys-polled, fully compatible, but without the nasty input-core dependency chain

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@30659 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/gpio-button-hotplug/Makefile

@@ -0,0 +1,44 @@
+#
+# Copyright (C) 2008-2012 OpenWrt.org
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/kernel.mk
+
+PKG_NAME:=gpio-button-hotplug
+PKG_RELEASE:=1
+
+include $(INCLUDE_DIR)/package.mk
+
+define KernelPackage/gpio-button-hotplug
+  SUBMENU:=Other modules
+  TITLE:=Simple GPIO Button Hotplug driver
+  FILES:=$(PKG_BUILD_DIR)/gpio-button-hotplug.ko
+  AUTOLOAD:=$(call AutoLoad,30,gpio-button-hotplug)
+  KCONFIG:=
+endef
+
+define KernelPackage/button-hotplug/description
+  Kernel module to generate GPIO button hotplug events
+endef
+
+MAKE_OPTS:= \
+	ARCH="$(LINUX_KARCH)" \
+	CROSS_COMPILE="$(TARGET_CROSS)" \
+	SUBDIRS="$(PKG_BUILD_DIR)"
+
+define Build/Prepare
+	mkdir -p $(PKG_BUILD_DIR)
+	$(CP) ./src/* $(PKG_BUILD_DIR)/
+endef
+
+define Build/Compile
+	$(MAKE) -C "$(LINUX_DIR)" \
+		$(MAKE_OPTS) \
+		modules
+endef
+
+$(eval $(call KernelPackage,gpio-button-hotplug))

package/gpio-button-hotplug/src/Makefile

@@ -0,0 +1 @@
+obj-m += gpio-button-hotplug.o

package/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);