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

SVN-Revision: 30659
This commit is contained in:
Felix Fietkau 2012-02-20 10:51:43 +00:00
parent 6bc9eafb97
commit 33bda4b64b
3 changed files with 495 additions and 0 deletions

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#
# 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))

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obj-m += gpio-button-hotplug.o

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/*
* 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);