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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/video/backlight/backlight.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/video/backlight/backlight.c')
-rw-r--r-- | drivers/video/backlight/backlight.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c new file mode 100644 index 000000000000..acc81cb01d56 --- /dev/null +++ b/drivers/video/backlight/backlight.c @@ -0,0 +1,264 @@ +/* + * Backlight Lowlevel Control Abstraction + * + * Copyright (C) 2003,2004 Hewlett-Packard Company + * + */ + +#include <linux/version.h> +#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 <asm/bug.h> + +static ssize_t backlight_show_power(struct class_device *cdev, char *buf) +{ + int rc; + struct backlight_device *bd = to_backlight_device(cdev); + + down(&bd->sem); + if (likely(bd->props && bd->props->get_power)) + rc = sprintf(buf, "%d\n", bd->props->get_power(bd)); + else + rc = -ENXIO; + up(&bd->sem); + + return rc; +} + +static ssize_t backlight_store_power(struct class_device *cdev, const char *buf, size_t count) +{ + int rc, power; + char *endp; + struct backlight_device *bd = to_backlight_device(cdev); + + power = simple_strtoul(buf, &endp, 0); + if (*endp && !isspace(*endp)) + return -EINVAL; + + down(&bd->sem); + if (likely(bd->props && bd->props->set_power)) { + pr_debug("backlight: set power to %d\n", power); + bd->props->set_power(bd, power); + rc = count; + } else + rc = -ENXIO; + up(&bd->sem); + + return rc; +} + +static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf) +{ + int rc; + 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)); + else + rc = -ENXIO; + up(&bd->sem); + + return rc; +} + +static ssize_t backlight_store_brightness(struct class_device *cdev, const char *buf, size_t count) +{ + int rc, brightness; + char *endp; + struct backlight_device *bd = to_backlight_device(cdev); + + brightness = simple_strtoul(buf, &endp, 0); + if (*endp && !isspace(*endp)) + return -EINVAL; + + down(&bd->sem); + if (likely(bd->props && bd->props->set_brightness)) { + pr_debug("backlight: set brightness to %d\n", brightness); + bd->props->set_brightness(bd, brightness); + rc = count; + } else + rc = -ENXIO; + up(&bd->sem); + + return rc; +} + +static ssize_t backlight_show_max_brightness(struct class_device *cdev, char *buf) +{ + int rc; + struct backlight_device *bd = to_backlight_device(cdev); + + down(&bd->sem); + if (likely(bd->props)) + rc = sprintf(buf, "%d\n", bd->props->max_brightness); + else + rc = -ENXIO; + 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(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->set_power(bd, *(int *)evdata->data); + 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, 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; + 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); + 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"); |