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/*
* Backlight Lowlevel Control Abstraction
*
* Copyright (C) 2003,2004 Hewlett-Packard Company
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/backlight.h>
#include <linux/notifier.h>
#include <linux/ctype.h>
#include <linux/err.h>
#include <linux/fb.h>
#ifdef CONFIG_PMAC_BACKLIGHT
#include <asm/backlight.h>
#endif
#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
/* This callback gets called when something important happens inside a
* framebuffer driver. We're looking if that important event is blanking,
* and if it is, we're switching backlight power as well ...
*/
static int fb_notifier_callback(struct notifier_block *self,
unsigned long event, void *data)
{
struct backlight_device *bd;
struct fb_event *evdata = data;
/* If we aren't interested in this event, skip it immediately ... */
if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
return 0;
bd = container_of(self, struct backlight_device, fb_notif);
mutex_lock(&bd->ops_lock);
if (bd->ops)
if (!bd->ops->check_fb ||
bd->ops->check_fb(evdata->info)) {
bd->props.fb_blank = *(int *)evdata->data;
if (bd->props.fb_blank == FB_BLANK_UNBLANK)
bd->props.state &= ~BL_CORE_FBBLANK;
else
bd->props.state |= BL_CORE_FBBLANK;
backlight_update_status(bd);
}
mutex_unlock(&bd->ops_lock);
return 0;
}
static int backlight_register_fb(struct backlight_device *bd)
{
memset(&bd->fb_notif, 0, sizeof(bd->fb_notif));
bd->fb_notif.notifier_call = fb_notifier_callback;
return fb_register_client(&bd->fb_notif);
}
static void backlight_unregister_fb(struct backlight_device *bd)
{
fb_unregister_client(&bd->fb_notif);
}
#else
static inline int backlight_register_fb(struct backlight_device *bd)
{
return 0;
}
static inline void backlight_unregister_fb(struct backlight_device *bd)
{
}
#endif /* CONFIG_FB */
static void backlight_generate_event(struct backlight_device *bd,
enum backlight_update_reason reason)
{
char *envp[2];
switch (reason) {
case BACKLIGHT_UPDATE_SYSFS:
envp[0] = "SOURCE=sysfs";
break;
case BACKLIGHT_UPDATE_HOTKEY:
envp[0] = "SOURCE=hotkey";
break;
default:
envp[0] = "SOURCE=unknown";
break;
}
envp[1] = NULL;
kobject_uevent_env(&bd->dev.kobj, KOBJ_CHANGE, envp);
sysfs_notify(&bd->dev.kobj, NULL, "actual_brightness");
}
static ssize_t backlight_show_power(struct device *dev,
struct device_attribute *attr,char *buf)
{
struct backlight_device *bd = to_backlight_device(dev);
return sprintf(buf, "%d\n", bd->props.power);
}
static ssize_t backlight_store_power(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
int rc;
struct backlight_device *bd = to_backlight_device(dev);
unsigned long power;
rc = strict_strtoul(buf, 0, &power);
if (rc)
return rc;
rc = -ENXIO;
mutex_lock(&bd->ops_lock);
if (bd->ops) {
pr_debug("backlight: set power to %lu\n", power);
if (bd->props.power != power) {
bd->props.power = power;
backlight_update_status(bd);
}
rc = count;
}
mutex_unlock(&bd->ops_lock);
return rc;
}
static ssize_t backlight_show_brightness(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct backlight_device *bd = to_backlight_device(dev);
return sprintf(buf, "%d\n", bd->props.brightness);
}
static ssize_t backlight_store_brightness(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
int rc;
struct backlight_device *bd = to_backlight_device(dev);
unsigned long brightness;
rc = strict_strtoul(buf, 0, &brightness);
if (rc)
return rc;
rc = -ENXIO;
mutex_lock(&bd->ops_lock);
if (bd->ops) {
if (brightness > bd->props.max_brightness)
rc = -EINVAL;
else {
pr_debug("backlight: set brightness to %lu\n",
brightness);
bd->props.brightness = brightness;
backlight_update_status(bd);
rc = count;
}
}
mutex_unlock(&bd->ops_lock);
backlight_generate_event(bd, BACKLIGHT_UPDATE_SYSFS);
return rc;
}
static ssize_t backlight_show_max_brightness(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct backlight_device *bd = to_backlight_device(dev);
return sprintf(buf, "%d\n", bd->props.max_brightness);
}
static ssize_t backlight_show_actual_brightness(struct device *dev,
struct device_attribute *attr, char *buf)
{
int rc = -ENXIO;
struct backlight_device *bd = to_backlight_device(dev);
mutex_lock(&bd->ops_lock);
if (bd->ops && bd->ops->get_brightness)
rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd));
mutex_unlock(&bd->ops_lock);
return rc;
}
static struct class *backlight_class;
static int backlight_suspend(struct device *dev, pm_message_t state)
{
struct backlight_device *bd = to_backlight_device(dev);
if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
mutex_lock(&bd->ops_lock);
bd->props.state |= BL_CORE_SUSPENDED;
backlight_update_status(bd);
mutex_unlock(&bd->ops_lock);
}
return 0;
}
static int backlight_resume(struct device *dev)
{
struct backlight_device *bd = to_backlight_device(dev);
if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
mutex_lock(&bd->ops_lock);
bd->props.state &= ~BL_CORE_SUSPENDED;
backlight_update_status(bd);
mutex_unlock(&bd->ops_lock);
}
return 0;
}
static void bl_device_release(struct device *dev)
{
struct backlight_device *bd = to_backlight_device(dev);
kfree(bd);
}
static struct device_attribute bl_device_attributes[] = {
__ATTR(bl_power, 0644, backlight_show_power, backlight_store_power),
__ATTR(brightness, 0644, backlight_show_brightness,
backlight_store_brightness),
__ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
NULL),
__ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
__ATTR_NULL,
};
/**
* backlight_force_update - tell the backlight subsystem that hardware state
* has changed
* @bd: the backlight device to update
*
* Updates the internal state of the backlight in response to a hardware event,
* and generate a uevent to notify userspace
*/
void backlight_force_update(struct backlight_device *bd,
enum backlight_update_reason reason)
{
mutex_lock(&bd->ops_lock);
if (bd->ops && bd->ops->get_brightness)
bd->props.brightness = bd->ops->get_brightness(bd);
mutex_unlock(&bd->ops_lock);
backlight_generate_event(bd, reason);
}
EXPORT_SYMBOL(backlight_force_update);
/**
* backlight_device_register - create and register a new object of
* backlight_device class.
* @name: the name of the new object(must be the same as the name of the
* respective framebuffer device).
* @parent: a pointer to the parent device
* @devdata: an optional pointer to be stored for private driver use. The
* methods may retrieve it by using bl_get_data(bd).
* @ops: the backlight operations structure.
*
* Creates and registers new backlight device. Returns either an
* ERR_PTR() or a pointer to the newly allocated device.
*/
struct backlight_device *backlight_device_register(const char *name
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