mirror of https://gitee.com/openkylin/linux.git
96 lines
2.7 KiB
C
96 lines
2.7 KiB
C
/*
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* Generic System Framebuffers on x86
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* Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*/
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/*
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* simple-framebuffer probing
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* Try to convert "screen_info" into a "simple-framebuffer" compatible mode.
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* If the mode is incompatible, we return "false" and let the caller create
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* legacy nodes instead.
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*/
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/platform_data/simplefb.h>
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#include <linux/platform_device.h>
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#include <linux/screen_info.h>
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#include <asm/sysfb.h>
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static const char simplefb_resname[] = "BOOTFB";
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static const struct simplefb_format formats[] = SIMPLEFB_FORMATS;
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/* try parsing x86 screen_info into a simple-framebuffer mode struct */
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__init bool parse_mode(const struct screen_info *si,
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struct simplefb_platform_data *mode)
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{
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const struct simplefb_format *f;
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__u8 type;
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unsigned int i;
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type = si->orig_video_isVGA;
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if (type != VIDEO_TYPE_VLFB && type != VIDEO_TYPE_EFI)
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return false;
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for (i = 0; i < ARRAY_SIZE(formats); ++i) {
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f = &formats[i];
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if (si->lfb_depth == f->bits_per_pixel &&
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si->red_size == f->red.length &&
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si->red_pos == f->red.offset &&
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si->green_size == f->green.length &&
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si->green_pos == f->green.offset &&
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si->blue_size == f->blue.length &&
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si->blue_pos == f->blue.offset &&
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si->rsvd_size == f->transp.length &&
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si->rsvd_pos == f->transp.offset) {
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mode->format = f->name;
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mode->width = si->lfb_width;
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mode->height = si->lfb_height;
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mode->stride = si->lfb_linelength;
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return true;
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}
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}
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return false;
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}
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__init int create_simplefb(const struct screen_info *si,
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const struct simplefb_platform_data *mode)
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{
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struct platform_device *pd;
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struct resource res;
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unsigned long len;
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/* don't use lfb_size as it may contain the whole VMEM instead of only
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* the part that is occupied by the framebuffer */
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len = mode->height * mode->stride;
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len = PAGE_ALIGN(len);
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if (len > si->lfb_size << 16) {
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printk(KERN_WARNING "sysfb: VRAM smaller than advertised\n");
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return -EINVAL;
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}
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/* setup IORESOURCE_MEM as framebuffer memory */
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memset(&res, 0, sizeof(res));
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res.flags = IORESOURCE_MEM;
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res.name = simplefb_resname;
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res.start = si->lfb_base;
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res.end = si->lfb_base + len - 1;
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if (res.end <= res.start)
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return -EINVAL;
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pd = platform_device_register_resndata(NULL, "simple-framebuffer", 0,
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&res, 1, mode, sizeof(*mode));
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if (IS_ERR(pd))
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return PTR_ERR(pd);
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return 0;
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}
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