OpenWrt – Rev 4
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/*
* GPIO Button Hotplug driver
*
* Copyright (C) 2012 Felix Fietkau <nbd@nbd.name>
* 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@nbd.name>
* 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/interrupt.h>
#include <linux/platform_device.h>
#include <linux/of_gpio.h>
#include <linux/gpio_keys.h>
#define DRV_NAME "gpio-keys"
#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;
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;
struct bh_priv bh;
int last_state;
int count;
int threshold;
int can_sleep;
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_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);
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;
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) {
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 int type,
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->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 void button_hotplug_event(struct gpio_keys_button_data *data,
unsigned int type, 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, data->b->code, value);
if ((type != EV_KEY) && (type != EV_SW))
return;
btn = button_get_index(data->b->code);
if (btn < 0)
return;
button_hotplug_create_event(button_map[btn].name, type,
(seen - priv->seen) / HZ, value);
priv->seen = seen;
}
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 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_polled_check_state(struct gpio_keys_button_data *bdata)
{
int state = gpio_button_get_value(bdata);
if (state != bdata->last_state) {
unsigned int type = bdata->b->type ?: EV_KEY;
if (bdata->count < bdata->threshold) {
bdata->count++;
return;
}
if ((bdata->last_state != -1) || (type == EV_SW))
button_hotplug_event(bdata, type, state);
bdata->last_state = state;
}
bdata->count = 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];
gpio_keys_polled_check_state(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 irqreturn_t button_handle_irq(int irq, void *_bdata)
{
struct gpio_keys_button_data *bdata = (struct gpio_keys_button_data *) _bdata;
button_hotplug_event(bdata, bdata->b->type ?: EV_KEY, gpio_button_get_value(bdata));
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 = &pdata->buttons[i++];
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;
}
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;
}
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;
if (bdev->polled)
bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
pdata->poll_interval);
else
bdata->threshold = 1;
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++) {
struct gpio_keys_button *button = &pdata->buttons[i];
struct gpio_keys_button_data *bdata = &bdev->data[i];
if (!button->irq)
button->irq = gpio_to_irq(button->gpio);
if (button->irq < 0) {
dev_err(&pdev->dev, "failed to get irq for gpio:%d\n", button->gpio);
continue;
}
ret = devm_request_threaded_irq(&pdev->dev, button->irq, NULL, button_handle_irq,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
dev_name(&pdev->dev), bdata);
if (ret < 0)
dev_err(&pdev->dev, "failed to request irq:%d for gpio:%d\n", button->irq, button->gpio);
else
dev_dbg(&pdev->dev, "gpio:%d has irq:%d\n", button->gpio, button->irq);
if (bdata->b->type == EV_SW)
button_hotplug_event(bdata, EV_SW, gpio_button_get_value(bdata));
}
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;
int i;
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);
for (i = 0; i < pdata->nbuttons; i++)
gpio_keys_polled_check_state(&bdev->data[i]);
gpio_keys_polled_queue_work(bdev);
return ret;
}
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);
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 <juhosg@openwrt.org>");
MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRV_NAME);