fbmem.c

Linux环境下视频显示卡设备的驱动程序源代码

	if (copy_in_user(&cmap->start, &cmap32->start, 2 * sizeof(__u32)))
		return -EFAULT;

	if (get_user(data, &cmap32->red) ||
	    put_user(compat_ptr(data), &cmap->red) ||
	    get_user(data, &cmap32->green) ||
	    put_user(compat_ptr(data), &cmap->green) ||
	    get_user(data, &cmap32->blue) ||
	    put_user(compat_ptr(data), &cmap->blue) ||
	    get_user(data, &cmap32->transp) ||
	    put_user(compat_ptr(data), &cmap->transp))
		return -EFAULT;

	err = do_fb_ioctl(info, cmd, (unsigned long) cmap);

	if (!err) {
		if (copy_in_user(&cmap32->start,
				 &cmap->start,
				 2 * sizeof(__u32)))
			err = -EFAULT;
	}
	return err;
}

static int do_fscreeninfo_to_user(struct fb_fix_screeninfo *fix,
				  struct fb_fix_screeninfo32 __user *fix32)
{
	__u32 data;
	int err;

	err = copy_to_user(&fix32->id, &fix->id, sizeof(fix32->id));

	data = (__u32) (unsigned long) fix->smem_start;
	err |= put_user(data, &fix32->smem_start);

	err |= put_user(fix->smem_len, &fix32->smem_len);
	err |= put_user(fix->type, &fix32->type);
	err |= put_user(fix->type_aux, &fix32->type_aux);
	err |= put_user(fix->visual, &fix32->visual);
	err |= put_user(fix->xpanstep, &fix32->xpanstep);
	err |= put_user(fix->ypanstep, &fix32->ypanstep);
	err |= put_user(fix->ywrapstep, &fix32->ywrapstep);
	err |= put_user(fix->line_length, &fix32->line_length);

	data = (__u32) (unsigned long) fix->mmio_start;
	err |= put_user(data, &fix32->mmio_start);

	err |= put_user(fix->mmio_len, &fix32->mmio_len);
	err |= put_user(fix->accel, &fix32->accel);
	err |= copy_to_user(fix32->reserved, fix->reserved,
			    sizeof(fix->reserved));

	return err;
}

static int fb_get_fscreeninfo(struct fb_info *info, unsigned int cmd,
			      unsigned long arg)
{
	mm_segment_t old_fs;
	struct fb_fix_screeninfo fix;
	struct fb_fix_screeninfo32 __user *fix32;
	int err;

	fix32 = compat_ptr(arg);

	old_fs = get_fs();
	set_fs(KERNEL_DS);
	err = do_fb_ioctl(info, cmd, (unsigned long) &fix);
	set_fs(old_fs);

	if (!err)
		err = do_fscreeninfo_to_user(&fix, fix32);

	return err;
}

static long fb_compat_ioctl(struct file *file, unsigned int cmd,
			    unsigned long arg)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	int fbidx = iminor(inode);
	struct fb_info *info = registered_fb[fbidx];
	struct fb_ops *fb = info->fbops;
	long ret = -ENOIOCTLCMD;

	switch(cmd) {
	case FBIOGET_VSCREENINFO:
	case FBIOPUT_VSCREENINFO:
	case FBIOPAN_DISPLAY:
	case FBIOGET_CON2FBMAP:
	case FBIOPUT_CON2FBMAP:
		arg = (unsigned long) compat_ptr(arg);
	case FBIOBLANK:
		ret = do_fb_ioctl(info, cmd, arg);
		break;

	case FBIOGET_FSCREENINFO:
		ret = fb_get_fscreeninfo(info, cmd, arg);
		break;

	case FBIOGETCMAP:
	case FBIOPUTCMAP:
		ret = fb_getput_cmap(info, cmd, arg);
		break;

	default:
		if (fb->fb_compat_ioctl)
			ret = fb->fb_compat_ioctl(info, cmd, arg);
		break;
	}
	return ret;
}
#endif

static int
fb_mmap(struct file *file, struct vm_area_struct * vma)
__acquires(&info->lock)
__releases(&info->lock)
{
	int fbidx = iminor(file->f_path.dentry->d_inode);
	struct fb_info *info = registered_fb[fbidx];
	struct fb_ops *fb = info->fbops;
	unsigned long off;
	unsigned long start;
	u32 len;

	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
		return -EINVAL;
	off = vma->vm_pgoff << PAGE_SHIFT;
	if (!fb)
		return -ENODEV;
	if (fb->fb_mmap) {
		int res;
		mutex_lock(&info->lock);
		res = fb->fb_mmap(info, vma);
		mutex_unlock(&info->lock);
		return res;
	}

	mutex_lock(&info->lock);

	/* frame buffer memory */
	start = info->fix.smem_start;
	len = PAGE_ALIGN((start & ~PAGE_MASK) + info->fix.smem_len);
	if (off >= len) {
		/* memory mapped io */
		off -= len;
		if (info->var.accel_flags) {
			mutex_unlock(&info->lock);
			return -EINVAL;
		}
		start = info->fix.mmio_start;
		len = PAGE_ALIGN((start & ~PAGE_MASK) + info->fix.mmio_len);
	}
	mutex_unlock(&info->lock);
	start &= PAGE_MASK;
	if ((vma->vm_end - vma->vm_start + off) > len)
		return -EINVAL;
	off += start;
	vma->vm_pgoff = off >> PAGE_SHIFT;
	/* This is an IO map - tell maydump to skip this VMA */
	vma->vm_flags |= VM_IO | VM_RESERVED;
	fb_pgprotect(file, vma, off);
	if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
			     vma->vm_end - vma->vm_start, vma->vm_page_prot))
		return -EAGAIN;
	return 0;
}

static int
fb_open(struct inode *inode, struct file *file)
__acquires(&info->lock)
__releases(&info->lock)
{
	int fbidx = iminor(inode);
	struct fb_info *info;
	int res = 0;

	if (fbidx >= FB_MAX)
		return -ENODEV;
	info = registered_fb[fbidx];
	if (!info)
		request_module("fb%d", fbidx);
	info = registered_fb[fbidx];
	if (!info)
		return -ENODEV;
	mutex_lock(&info->lock);
	if (!try_module_get(info->fbops->owner)) {
		res = -ENODEV;
		goto out;
	}
	file->private_data = info;
	if (info->fbops->fb_open) {
		res = info->fbops->fb_open(info,1);
		if (res)
			module_put(info->fbops->owner);
	}
#ifdef CONFIG_FB_DEFERRED_IO
	if (info->fbdefio)
		fb_deferred_io_open(info, inode, file);
#endif
out:
	mutex_unlock(&info->lock);
	return res;
}

static int 
fb_release(struct inode *inode, struct file *file)
__acquires(&info->lock)
__releases(&info->lock)
{
	struct fb_info * const info = file->private_data;

	mutex_lock(&info->lock);
	if (info->fbops->fb_release)
		info->fbops->fb_release(info,1);
	module_put(info->fbops->owner);
	mutex_unlock(&info->lock);
	return 0;
}

static const struct file_operations fb_fops = {
	.owner =	THIS_MODULE,
	.read =		fb_read,
	.write =	fb_write,
	.unlocked_ioctl = fb_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl = fb_compat_ioctl,
#endif
	.mmap =		fb_mmap,
	.open =		fb_open,
	.release =	fb_release,
#ifdef HAVE_ARCH_FB_UNMAPPED_AREA
	.get_unmapped_area = get_fb_unmapped_area,
#endif
#ifdef CONFIG_FB_DEFERRED_IO
	.fsync =	fb_deferred_io_fsync,
#endif
};

struct class *fb_class;
EXPORT_SYMBOL(fb_class);

static int fb_check_foreignness(struct fb_info *fi)
{
	const bool foreign_endian = fi->flags & FBINFO_FOREIGN_ENDIAN;

	fi->flags &= ~FBINFO_FOREIGN_ENDIAN;

#ifdef __BIG_ENDIAN
	fi->flags |= foreign_endian ? 0 : FBINFO_BE_MATH;
#else
	fi->flags |= foreign_endian ? FBINFO_BE_MATH : 0;
#endif /* __BIG_ENDIAN */

	if (fi->flags & FBINFO_BE_MATH && !fb_be_math(fi)) {
		pr_err("%s: enable CONFIG_FB_BIG_ENDIAN to "
		       "support this framebuffer\n", fi->fix.id);
		return -ENOSYS;
	} else if (!(fi->flags & FBINFO_BE_MATH) && fb_be_math(fi)) {
		pr_err("%s: enable CONFIG_FB_LITTLE_ENDIAN to "
		       "support this framebuffer\n", fi->fix.id);
		return -ENOSYS;
	}

	return 0;
}

/**
 *	register_framebuffer - registers a frame buffer device
 *	@fb_info: frame buffer info structure
 *
 *	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;
	struct fb_videomode mode;

	if (num_registered_fb == FB_MAX)
		return -ENXIO;

	if (fb_check_foreignness(fb_info))
		return -ENOSYS;

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

	fb_info->dev = device_create(fb_class, fb_info->device,
				     MKDEV(FB_MAJOR, i), NULL, "fb%d", i);
	if (IS_ERR(fb_info->dev)) {
		/* Not fatal */
		printk(KERN_WARNING "Unable to create device for framebuffer %d; errno = %ld\n", i, PTR_ERR(fb_info->dev));
		fb_info->dev = NULL;
	} else
		fb_init_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 = 32;
			fb_info->pixmap.flags = FB_PIXMAP_DEFAULT;
		}
	}	
	fb_info->pixmap.offset = 0;

	if (!fb_info->pixmap.blit_x)
		fb_info->pixmap.blit_x = ~(u32)0;

	if (!fb_info->pixmap.blit_y)
		fb_info->pixmap.blit_y = ~(u32)0;

	if (!fb_info->modelist.prev || !fb_info->modelist.next)
		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;

	event.info = fb_info;
	fb_notifier_call_chain(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.
 *
 *      This function will also notify the framebuffer console
 *      to release the driver.
 *
 *      This is meant to be called within a driver's module_exit()
 *      function. If this is called outside module_exit(), ensure
 *      that the driver implements fb_open() and fb_release() to
 *      check that no processes are using the device.
 */

int
unregister_framebuffer(struct fb_info *fb_info)
{
	struct fb_event event;
	int i, ret = 0;

	i = fb_info->node;
	if (!registered_fb[i]) {
		ret = -EINVAL;
		goto done;
	}

	event.info = fb_info;
	ret = fb_notifier_call_chain(FB_EVENT_FB_UNBIND, &event);

	if (ret) {
		ret = -EINVAL;
		goto done;
	}

	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_device(fb_info);
	device_destroy(fb_class, MKDEV(FB_MAJOR, i));
	event.info = fb_info;
	fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
done:
	return ret;
}

/**
 *	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) {
		fb_notifier_call_chain(FB_EVENT_SUSPEND, &event);
		info->state = FBINFO_STATE_SUSPENDED;
	} else {
		info->state = FBINFO_STATE_RUNNING;
		fb_notifier_call_chain(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)
{
	proc_create("fb", 0, NULL, &fb_proc_fops);

	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)
{
	remove_proc_entry("fb", NULL);
	class_destroy(fb_class);
	unregister_chrdev(FB_MAJOR, "fb");
}

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 = fb_notifier_call_chain(FB_EVENT_NEW_MODELIST, &event);
	}

	return err;
}

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

/**
 * 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;
}

#ifndef MODULE
/**
 *	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:")) {
 		fb_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 1;
}
__setup("video=", video_setup);
#endif

    /*
     *  Visible symbols for modules
     */

EXPORT_SYMBOL(register_framebuffer);
EXPORT_SYMBOL(unregister_framebuffer);
EXPORT_SYMBOL(num_registered_fb);
EXPORT_SYMBOL(registered_fb);
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_get_options);

MODULE_LICENSE("GPL");