fbmem.c

 *
 *	Registers a frame buffer device @fb_info.
 *
 *	Returns negative errno on error, or zero for success.
 *
 */

int
register_framebuffer(struct fb_info *fb_info)
{
	int i;
	struct fb_event event;

	if (num_registered_fb == FB_MAX)
		return -ENXIO;
	num_registered_fb++;
	for (i = 0 ; i < FB_MAX; i++)
		if (!registered_fb[i])
			break;
	fb_info->node = i;

	fb_info->class_device = class_device_create(fb_class, MKDEV(FB_MAJOR, i),
				    fb_info->device, "fb%d", i);
	if (IS_ERR(fb_info->class_device)) {
		/* Not fatal */
		printk(KERN_WARNING "Unable to create class_device for framebuffer %d; errno = %ld\n", i, PTR_ERR(fb_info->class_device));
		fb_info->class_device = NULL;
	} else
		fb_init_class_device(fb_info);

	if (fb_info->pixmap.addr == NULL) {
		fb_info->pixmap.addr = kmalloc(FBPIXMAPSIZE, GFP_KERNEL);
		if (fb_info->pixmap.addr) {
			fb_info->pixmap.size = FBPIXMAPSIZE;
			fb_info->pixmap.buf_align = 1;
			fb_info->pixmap.scan_align = 1;
			fb_info->pixmap.access_align = 4;
			fb_info->pixmap.flags = FB_PIXMAP_DEFAULT;
		}
	}	
	fb_info->pixmap.offset = 0;

	if (!fb_info->modelist.prev ||
	    !fb_info->modelist.next ||
	    list_empty(&fb_info->modelist)) {
	        struct fb_videomode mode;

		INIT_LIST_HEAD(&fb_info->modelist);
		fb_var_to_videomode(&mode, &fb_info->var);
		fb_add_videomode(&mode, &fb_info->modelist);
	}

	registered_fb[i] = fb_info;

	devfs_mk_cdev(MKDEV(FB_MAJOR, i),
			S_IFCHR | S_IRUGO | S_IWUGO, "fb/%d", i);
	event.info = fb_info;
	notifier_call_chain(&fb_notifier_list,
			    FB_EVENT_FB_REGISTERED, &event);
	return 0;
}


/**
 *	unregister_framebuffer - releases a frame buffer device
 *	@fb_info: frame buffer info structure
 *
 *	Unregisters a frame buffer device @fb_info.
 *
 *	Returns negative errno on error, or zero for success.
 *
 */

int
unregister_framebuffer(struct fb_info *fb_info)
{
	int i;

	i = fb_info->node;
	if (!registered_fb[i])
		return -EINVAL;
	devfs_remove("fb/%d", i);

	if (fb_info->pixmap.addr && (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT))
		kfree(fb_info->pixmap.addr);
	fb_destroy_modelist(&fb_info->modelist);
	registered_fb[i]=NULL;
	num_registered_fb--;
	fb_cleanup_class_device(fb_info);
	class_device_destroy(fb_class, MKDEV(FB_MAJOR, i));
	return 0;
}

/**
 *	fb_register_client - register a client notifier
 *	@nb: notifier block to callback on events
 */
int fb_register_client(struct notifier_block *nb)
{
	return notifier_chain_register(&fb_notifier_list, nb);
}

/**
 *	fb_unregister_client - unregister a client notifier
 *	@nb: notifier block to callback on events
 */
int fb_unregister_client(struct notifier_block *nb)
{
	return notifier_chain_unregister(&fb_notifier_list, nb);
}

/**
 *	fb_set_suspend - low level driver signals suspend
 *	@info: framebuffer affected
 *	@state: 0 = resuming, !=0 = suspending
 *
 *	This is meant to be used by low level drivers to
 * 	signal suspend/resume to the core & clients.
 *	It must be called with the console semaphore held
 */
void fb_set_suspend(struct fb_info *info, int state)
{
	struct fb_event event;

	event.info = info;
	if (state) {
		notifier_call_chain(&fb_notifier_list, FB_EVENT_SUSPEND, &event);
		info->state = FBINFO_STATE_SUSPENDED;
	} else {
		info->state = FBINFO_STATE_RUNNING;
		notifier_call_chain(&fb_notifier_list, FB_EVENT_RESUME, &event);
	}
}

/**
 *	fbmem_init - init frame buffer subsystem
 *
 *	Initialize the frame buffer subsystem.
 *
 *	NOTE: This function is _only_ to be called by drivers/char/mem.c.
 *
 */

static int __init
fbmem_init(void)
{
	create_proc_read_entry("fb", 0, NULL, fbmem_read_proc, NULL);

	devfs_mk_dir("fb");
	if (register_chrdev(FB_MAJOR,"fb",&fb_fops))
		printk("unable to get major %d for fb devs\n", FB_MAJOR);

	fb_class = class_create(THIS_MODULE, "graphics");
	if (IS_ERR(fb_class)) {
		printk(KERN_WARNING "Unable to create fb class; errno = %ld\n", PTR_ERR(fb_class));
		fb_class = NULL;
	}
	return 0;
}

#ifdef MODULE
module_init(fbmem_init);
static void __exit
fbmem_exit(void)
{
	class_destroy(fb_class);
}

module_exit(fbmem_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Framebuffer base");
#else
subsys_initcall(fbmem_init);
#endif

int fb_new_modelist(struct fb_info *info)
{
	struct fb_event event;
	struct fb_var_screeninfo var = info->var;
	struct list_head *pos, *n;
	struct fb_modelist *modelist;
	struct fb_videomode *m, mode;
	int err = 1;

	list_for_each_safe(pos, n, &info->modelist) {
		modelist = list_entry(pos, struct fb_modelist, list);
		m = &modelist->mode;
		fb_videomode_to_var(&var, m);
		var.activate = FB_ACTIVATE_TEST;
		err = fb_set_var(info, &var);
		fb_var_to_videomode(&mode, &var);
		if (err || !fb_mode_is_equal(m, &mode)) {
			list_del(pos);
			kfree(pos);
		}
	}

	err = 1;

	if (!list_empty(&info->modelist)) {
		event.info = info;
		err = notifier_call_chain(&fb_notifier_list,
					   FB_EVENT_NEW_MODELIST,
					   &event);
	}

	return err;
}

static char *video_options[FB_MAX];
static int ofonly;

extern const char *global_mode_option;

/**
 * fb_get_options - get kernel boot parameters
 * @name:   framebuffer name as it would appear in
 *          the boot parameter line
 *          (video=<name>:<options>)
 * @option: the option will be stored here
 *
 * NOTE: Needed to maintain backwards compatibility
 */
int fb_get_options(char *name, char **option)
{
	char *opt, *options = NULL;
	int opt_len, retval = 0;
	int name_len = strlen(name), i;

	if (name_len && ofonly && strncmp(name, "offb", 4))
		retval = 1;

	if (name_len && !retval) {
		for (i = 0; i < FB_MAX; i++) {
			if (video_options[i] == NULL)
				continue;
			opt_len = strlen(video_options[i]);
			if (!opt_len)
				continue;
			opt = video_options[i];
			if (!strncmp(name, opt, name_len) &&
			    opt[name_len] == ':')
				options = opt + name_len + 1;
		}
	}
	if (options && !strncmp(options, "off", 3))
		retval = 1;

	if (option)
		*option = options;

	return retval;
}

/**
 *	video_setup - process command line options
 *	@options: string of options
 *
 *	Process command line options for frame buffer subsystem.
 *
 *	NOTE: This function is a __setup and __init function.
 *            It only stores the options.  Drivers have to call
 *            fb_get_options() as necessary.
 *
 *	Returns zero.
 *
 */
static int __init video_setup(char *options)
{
	int i, global = 0;

	if (!options || !*options)
 		global = 1;

 	if (!global && !strncmp(options, "ofonly", 6)) {
 		ofonly = 1;
 		global = 1;
 	}

 	if (!global && !strstr(options, "fb:")) {
 		global_mode_option = options;
 		global = 1;
 	}

 	if (!global) {
 		for (i = 0; i < FB_MAX; i++) {
 			if (video_options[i] == NULL) {
 				video_options[i] = options;
 				break;
 			}

		}
	}

	return 0;
}
__setup("video=", video_setup);

    /*
     *  Visible symbols for modules
     */

EXPORT_SYMBOL(register_framebuffer);
EXPORT_SYMBOL(unregister_framebuffer);
EXPORT_SYMBOL(num_registered_fb);
EXPORT_SYMBOL(registered_fb);
EXPORT_SYMBOL(fb_prepare_logo);
EXPORT_SYMBOL(fb_show_logo);
EXPORT_SYMBOL(fb_set_var);
EXPORT_SYMBOL(fb_blank);
EXPORT_SYMBOL(fb_pan_display);
EXPORT_SYMBOL(fb_get_buffer_offset);
EXPORT_SYMBOL(fb_set_suspend);
EXPORT_SYMBOL(fb_register_client);
EXPORT_SYMBOL(fb_unregister_client);
EXPORT_SYMBOL(fb_get_options);
EXPORT_SYMBOL(fb_new_modelist);

MODULE_LICENSE("GPL");