96 lines
		
	
	
	
		
			2.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			96 lines
		
	
	
	
		
			2.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /*
 | ||
|  |  * Generic System Framebuffers on x86 | ||
|  |  * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com> | ||
|  |  * | ||
|  |  * 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. | ||
|  |  */ | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * simple-framebuffer probing | ||
|  |  * Try to convert "screen_info" into a "simple-framebuffer" compatible mode. | ||
|  |  * If the mode is incompatible, we return "false" and let the caller create | ||
|  |  * legacy nodes instead. | ||
|  |  */ | ||
|  | 
 | ||
|  | #include <linux/err.h>
 | ||
|  | #include <linux/init.h>
 | ||
|  | #include <linux/kernel.h>
 | ||
|  | #include <linux/mm.h>
 | ||
|  | #include <linux/platform_data/simplefb.h>
 | ||
|  | #include <linux/platform_device.h>
 | ||
|  | #include <linux/screen_info.h>
 | ||
|  | #include <asm/sysfb.h>
 | ||
|  | 
 | ||
|  | static const char simplefb_resname[] = "BOOTFB"; | ||
|  | static const struct simplefb_format formats[] = SIMPLEFB_FORMATS; | ||
|  | 
 | ||
|  | /* try parsing x86 screen_info into a simple-framebuffer mode struct */ | ||
|  | __init bool parse_mode(const struct screen_info *si, | ||
|  | 		       struct simplefb_platform_data *mode) | ||
|  | { | ||
|  | 	const struct simplefb_format *f; | ||
|  | 	__u8 type; | ||
|  | 	unsigned int i; | ||
|  | 
 | ||
|  | 	type = si->orig_video_isVGA; | ||
|  | 	if (type != VIDEO_TYPE_VLFB && type != VIDEO_TYPE_EFI) | ||
|  | 		return false; | ||
|  | 
 | ||
|  | 	for (i = 0; i < ARRAY_SIZE(formats); ++i) { | ||
|  | 		f = &formats[i]; | ||
|  | 		if (si->lfb_depth == f->bits_per_pixel && | ||
|  | 		    si->red_size == f->red.length && | ||
|  | 		    si->red_pos == f->red.offset && | ||
|  | 		    si->green_size == f->green.length && | ||
|  | 		    si->green_pos == f->green.offset && | ||
|  | 		    si->blue_size == f->blue.length && | ||
|  | 		    si->blue_pos == f->blue.offset && | ||
|  | 		    si->rsvd_size == f->transp.length && | ||
|  | 		    si->rsvd_pos == f->transp.offset) { | ||
|  | 			mode->format = f->name; | ||
|  | 			mode->width = si->lfb_width; | ||
|  | 			mode->height = si->lfb_height; | ||
|  | 			mode->stride = si->lfb_linelength; | ||
|  | 			return true; | ||
|  | 		} | ||
|  | 	} | ||
|  | 
 | ||
|  | 	return false; | ||
|  | } | ||
|  | 
 | ||
|  | __init int create_simplefb(const struct screen_info *si, | ||
|  | 			   const struct simplefb_platform_data *mode) | ||
|  | { | ||
|  | 	struct platform_device *pd; | ||
|  | 	struct resource res; | ||
|  | 	unsigned long len; | ||
|  | 
 | ||
|  | 	/* don't use lfb_size as it may contain the whole VMEM instead of only
 | ||
|  | 	 * the part that is occupied by the framebuffer */ | ||
|  | 	len = mode->height * mode->stride; | ||
|  | 	len = PAGE_ALIGN(len); | ||
|  | 	if (len > si->lfb_size << 16) { | ||
|  | 		printk(KERN_WARNING "sysfb: VRAM smaller than advertised\n"); | ||
|  | 		return -EINVAL; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	/* setup IORESOURCE_MEM as framebuffer memory */ | ||
|  | 	memset(&res, 0, sizeof(res)); | ||
|  | 	res.flags = IORESOURCE_MEM; | ||
|  | 	res.name = simplefb_resname; | ||
|  | 	res.start = si->lfb_base; | ||
|  | 	res.end = si->lfb_base + len - 1; | ||
|  | 	if (res.end <= res.start) | ||
|  | 		return -EINVAL; | ||
|  | 
 | ||
|  | 	pd = platform_device_register_resndata(NULL, "simple-framebuffer", 0, | ||
|  | 					       &res, 1, mode, sizeof(*mode)); | ||
|  | 	if (IS_ERR(pd)) | ||
|  | 		return PTR_ERR(pd); | ||
|  | 
 | ||
|  | 	return 0; | ||
|  | } |