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linux-next/drivers/video/backlight/backlight.c
Yu Luming 519ab5f2be ACPI: video: Add dev argument for backlight_device_register
This patch set adds generic abstract layer support for acpi video driver to
have generic user interface to control backlight and output switch control by
leveraging the existing backlight sysfs class driver, and by adding a new
video output sysfs class driver.

This patch:

Add dev argument for backlight_device_register to link the class device to
real device object.  The platform specific driver should find a way to get the
real device object for their video device.

[akpm@osdl.org: build fix]
[akpm@osdl.org: fix msi-laptop.c]
Signed-off-by: Luming Yu <Luming.yu@intel.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>
2006-12-20 01:42:19 -05:00

300 lines
7.7 KiB
C

/*
* 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>
static ssize_t backlight_show_power(struct class_device *cdev, char *buf)
{
int rc = -ENXIO;
struct backlight_device *bd = to_backlight_device(cdev);
down(&bd->sem);
if (likely(bd->props))
rc = sprintf(buf, "%d\n", bd->props->power);
up(&bd->sem);
return rc;
}
static ssize_t backlight_store_power(struct class_device *cdev, const char *buf, size_t count)
{
int rc = -ENXIO;
char *endp;
struct backlight_device *bd = to_backlight_device(cdev);
int power = simple_strtoul(buf, &endp, 0);
size_t size = endp - buf;
if (*endp && isspace(*endp))
size++;
if (size != count)
return -EINVAL;
down(&bd->sem);
if (likely(bd->props)) {
pr_debug("backlight: set power to %d\n", power);
bd->props->power = power;
if (likely(bd->props->update_status))
bd->props->update_status(bd);
rc = count;
}
up(&bd->sem);
return rc;
}
static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf)
{
int rc = -ENXIO;
struct backlight_device *bd = to_backlight_device(cdev);
down(&bd->sem);
if (likely(bd->props))
rc = sprintf(buf, "%d\n", bd->props->brightness);
up(&bd->sem);
return rc;
}
static ssize_t backlight_store_brightness(struct class_device *cdev, const char *buf, size_t count)
{
int rc = -ENXIO;
char *endp;
struct backlight_device *bd = to_backlight_device(cdev);
int brightness = simple_strtoul(buf, &endp, 0);
size_t size = endp - buf;
if (*endp && isspace(*endp))
size++;
if (size != count)
return -EINVAL;
down(&bd->sem);
if (likely(bd->props)) {
if (brightness > bd->props->max_brightness)
rc = -EINVAL;
else {
pr_debug("backlight: set brightness to %d\n",
brightness);
bd->props->brightness = brightness;
if (likely(bd->props->update_status))
bd->props->update_status(bd);
rc = count;
}
}
up(&bd->sem);
return rc;
}
static ssize_t backlight_show_max_brightness(struct class_device *cdev, char *buf)
{
int rc = -ENXIO;
struct backlight_device *bd = to_backlight_device(cdev);
down(&bd->sem);
if (likely(bd->props))
rc = sprintf(buf, "%d\n", bd->props->max_brightness);
up(&bd->sem);
return rc;
}
static ssize_t backlight_show_actual_brightness(struct class_device *cdev,
char *buf)
{
int rc = -ENXIO;
struct backlight_device *bd = to_backlight_device(cdev);
down(&bd->sem);
if (likely(bd->props && bd->props->get_brightness))
rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd));
up(&bd->sem);
return rc;
}
static void backlight_class_release(struct class_device *dev)
{
struct backlight_device *bd = to_backlight_device(dev);
kfree(bd);
}
static struct class backlight_class = {
.name = "backlight",
.release = backlight_class_release,
};
#define DECLARE_ATTR(_name,_mode,_show,_store) \
{ \
.attr = { .name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE }, \
.show = _show, \
.store = _store, \
}
static struct class_device_attribute bl_class_device_attributes[] = {
DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power),
DECLARE_ATTR(brightness, 0644, backlight_show_brightness,
backlight_store_brightness),
DECLARE_ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
NULL),
DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
};
/* 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 =(struct fb_event *)data;
/* If we aren't interested in this event, skip it immediately ... */
if (event != FB_EVENT_BLANK)
return 0;
bd = container_of(self, struct backlight_device, fb_notif);
down(&bd->sem);
if (bd->props)
if (!bd->props->check_fb ||
bd->props->check_fb(evdata->info)) {
bd->props->fb_blank = *(int *)evdata->data;
if (likely(bd->props && bd->props->update_status))
bd->props->update_status(bd);
}
up(&bd->sem);
return 0;
}
/**
* 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).
* @devdata: an optional pointer to be stored in the class_device. The
* methods may retrieve it by using class_get_devdata(&bd->class_dev).
* @bp: the backlight properties structure.
*
* Creates and registers new backlight class_device. Returns either an
* ERR_PTR() or a pointer to the newly allocated device.
*/
struct backlight_device *backlight_device_register(const char *name,
struct device *dev,
void *devdata,
struct backlight_properties *bp)
{
int i, rc;
struct backlight_device *new_bd;
pr_debug("backlight_device_alloc: name=%s\n", name);
new_bd = kmalloc(sizeof(struct backlight_device), GFP_KERNEL);
if (unlikely(!new_bd))
return ERR_PTR(-ENOMEM);
init_MUTEX(&new_bd->sem);
new_bd->props = bp;
memset(&new_bd->class_dev, 0, sizeof(new_bd->class_dev));
new_bd->class_dev.class = &backlight_class;
new_bd->class_dev.dev = dev;
strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN);
class_set_devdata(&new_bd->class_dev, devdata);
rc = class_device_register(&new_bd->class_dev);
if (unlikely(rc)) {
error: kfree(new_bd);
return ERR_PTR(rc);
}
memset(&new_bd->fb_notif, 0, sizeof(new_bd->fb_notif));
new_bd->fb_notif.notifier_call = fb_notifier_callback;
rc = fb_register_client(&new_bd->fb_notif);
if (unlikely(rc))
goto error;
for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) {
rc = class_device_create_file(&new_bd->class_dev,
&bl_class_device_attributes[i]);
if (unlikely(rc)) {
while (--i >= 0)
class_device_remove_file(&new_bd->class_dev,
&bl_class_device_attributes[i]);
class_device_unregister(&new_bd->class_dev);
/* No need to kfree(new_bd) since release() method was called */
return ERR_PTR(rc);
}
}
return new_bd;
}
EXPORT_SYMBOL(backlight_device_register);
/**
* backlight_device_unregister - unregisters a backlight device object.
* @bd: the backlight device object to be unregistered and freed.
*
* Unregisters a previously registered via backlight_device_register object.
*/
void backlight_device_unregister(struct backlight_device *bd)
{
int i;
if (!bd)
return;
pr_debug("backlight_device_unregister: name=%s\n", bd->class_dev.class_id);
for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++)
class_device_remove_file(&bd->class_dev,
&bl_class_device_attributes[i]);
down(&bd->sem);
if (likely(bd->props && bd->props->update_status)) {
bd->props->brightness = 0;
bd->props->power = 0;
bd->props->update_status(bd);
}
bd->props = NULL;
up(&bd->sem);
fb_unregister_client(&bd->fb_notif);
class_device_unregister(&bd->class_dev);
}
EXPORT_SYMBOL(backlight_device_unregister);
static void __exit backlight_class_exit(void)
{
class_unregister(&backlight_class);
}
static int __init backlight_class_init(void)
{
return class_register(&backlight_class);
}
/*
* if this is compiled into the kernel, we need to ensure that the
* class is registered before users of the class try to register lcd's
*/
postcore_initcall(backlight_class_init);
module_exit(backlight_class_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");