linux-sg2042/drivers/video/backlight/backlight.c

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/*
* Backlight Lowlevel Control Abstraction
*
* Copyright (C) 2003,2004 Hewlett-Packard Company
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#ifdef CONFIG_PMAC_BACKLIGHT
#include <asm/backlight.h>
#endif
static const char *const backlight_types[] = {
[BACKLIGHT_RAW] = "raw",
[BACKLIGHT_PLATFORM] = "platform",
[BACKLIGHT_FIRMWARE] = "firmware",
};
#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(bd, 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 = kstrtoul(buf, 0, &power);
if (rc)
return rc;
rc = -ENXIO;
mutex_lock(&bd->ops_lock);
if (bd->ops) {
pr_debug("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 = kstrtoul(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("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_type(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct backlight_device *bd = to_backlight_device(dev);
return sprintf(buf, "%s\n", backlight_types[bd->props.type]);
}
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);
mutex_lock(&bd->ops_lock);
if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) {
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);
mutex_lock(&bd->ops_lock);
if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) {
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(type, 0444, backlight_show_type, 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,
struct device *parent, void *devdata, const struct backlight_ops *ops,
const struct backlight_properties *props)
{
struct backlight_device *new_bd;
int rc;
pr_debug("backlight_device_register: name=%s\n", name);
new_bd = kzalloc(sizeof(struct backlight_device), GFP_KERNEL);
if (!new_bd)
return ERR_PTR(-ENOMEM);
mutex_init(&new_bd->update_lock);
mutex_init(&new_bd->ops_lock);
new_bd->dev.class = backlight_class;
new_bd->dev.parent = parent;
new_bd->dev.release = bl_device_release;
dev_set_name(&new_bd->dev, name);
dev_set_drvdata(&new_bd->dev, devdata);
/* Set default properties */
if (props) {
memcpy(&new_bd->props, props,
sizeof(struct backlight_properties));
if (props->type <= 0 || props->type >= BACKLIGHT_TYPE_MAX) {
WARN(1, "%s: invalid backlight type", name);
new_bd->props.type = BACKLIGHT_RAW;
}
} else {
new_bd->props.type = BACKLIGHT_RAW;
}
rc = device_register(&new_bd->dev);
if (rc) {
kfree(new_bd);
return ERR_PTR(rc);
}
rc = backlight_register_fb(new_bd);
if (rc) {
device_unregister(&new_bd->dev);
return ERR_PTR(rc);
}
new_bd->ops = ops;
#ifdef CONFIG_PMAC_BACKLIGHT
mutex_lock(&pmac_backlight_mutex);
if (!pmac_backlight)
pmac_backlight = new_bd;
mutex_unlock(&pmac_backlight_mutex);
#endif
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)
{
if (!bd)
return;
#ifdef CONFIG_PMAC_BACKLIGHT
mutex_lock(&pmac_backlight_mutex);
if (pmac_backlight == bd)
pmac_backlight = NULL;
mutex_unlock(&pmac_backlight_mutex);
#endif
mutex_lock(&bd->ops_lock);
bd->ops = NULL;
mutex_unlock(&bd->ops_lock);
backlight_unregister_fb(bd);
device_unregister(&bd->dev);
}
EXPORT_SYMBOL(backlight_device_unregister);
static void __exit backlight_class_exit(void)
{
class_destroy(backlight_class);
}
static int __init backlight_class_init(void)
{
backlight_class = class_create(THIS_MODULE, "backlight");
if (IS_ERR(backlight_class)) {
pr_warn("Unable to create backlight class; errno = %ld\n",
PTR_ERR(backlight_class));
return PTR_ERR(backlight_class);
}
backlight_class->dev_attrs = bl_device_attributes;
backlight_class->suspend = backlight_suspend;
backlight_class->resume = backlight_resume;
return 0;
}
/*
* 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");