fbsysfs.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 75 行

/*
 * fbsysfs.c - framebuffer device class and attributes
 *
 * Copyright (c) 2004 James Simmons <[e-mail]>
 * 
 *	This program is free software you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */

/*
 * Note:  currently there's only stubs for framebuffer_alloc and
 * framebuffer_release here.  The reson for that is that until all drivers
 * are converted to use it a sysfsification will open OOPSable races.
 */

#include <linux/kernel.h>
#include <linux/fb.h>

/**
 * framebuffer_alloc - creates a new frame buffer info structure
 *
 * @size: size of driver private data, can be zero
 * @dev: pointer to the device for this fb, this can be NULL
 *
 * Creates a new frame buffer info structure. Also reserves @size bytes
 * for driver private data (info->par). info->par (if any) will be
 * aligned to sizeof(long).
 *
 * Returns the new structure, or NULL if an error occured.
 *
 */
struct fb_info *framebuffer_alloc(size_t size, struct device *dev)
{
#define BYTES_PER_LONG (BITS_PER_LONG/8)
#define PADDING (BYTES_PER_LONG - (sizeof(struct fb_info) % BYTES_PER_LONG))
	int fb_info_size = sizeof(struct fb_info);
	struct fb_info *info;
	char *p;

	if (size)
		fb_info_size += PADDING;

	p = kmalloc(fb_info_size + size, GFP_KERNEL);
	if (!p)
		return NULL;
	memset(p, 0, fb_info_size + size);
	info = (struct fb_info *) p;

	if (size)
		info->par = p + fb_info_size;

	return info;
#undef PADDING
#undef BYTES_PER_LONG
}

/**
 * framebuffer_release - marks the structure available for freeing
 *
 * @info: frame buffer info structure
 *
 * Drop the reference count of the class_device embedded in the
 * framebuffer info structure.
 *
 */
void framebuffer_release(struct fb_info *info)
{
	kfree(info);
}

EXPORT_SYMBOL(framebuffer_release);
EXPORT_SYMBOL(framebuffer_alloc);