e3263ab389
The current situation regarding boot-framebuffers (VGA, VESA/VBE, EFI) on x86 causes troubles when loading multiple fbdev drivers. The global "struct screen_info" does not provide any state-tracking about which drivers use the FBs. request_mem_region() theoretically works, but unfortunately vesafb/efifb ignore it due to quirks for broken boards. Avoid this by creating a platform framebuffer devices with a pointer to the "struct screen_info" as platform-data. Drivers can now create platform-drivers and the driver-core will refuse multiple drivers being active simultaneously. We keep the screen_info available for backwards-compatibility. Drivers can be converted in follow-up patches. Different devices are created for VGA/VESA/EFI FBs to allow multiple drivers to be loaded on distro kernels. We create: - "vesa-framebuffer" for VBE/VESA graphics FBs - "efi-framebuffer" for EFI FBs - "platform-framebuffer" for everything else This allows to load vesafb, efifb and others simultaneously and each picks up only the supported FB types. Apart from platform-framebuffer devices, this also introduces a compatibility option for "simple-framebuffer" drivers which recently got introduced for OF based systems. If CONFIG_X86_SYSFB is selected, we try to match the screen_info against a simple-framebuffer supported format. If we succeed, we create a "simple-framebuffer" device instead of a platform-framebuffer. This allows to reuse the simplefb.c driver across architectures and also to introduce a SimpleDRM driver. There is no need to have vesafb.c, efifb.c, simplefb.c and more just to have architecture specific quirks in their setup-routines. Instead, we now move the architecture specific quirks into x86-setup and provide a generic simple-framebuffer. For backwards-compatibility (if strange formats are used), we still allow vesafb/efifb to be loaded simultaneously and pick up all remaining devices. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Link: http://lkml.kernel.org/r/1375445127-15480-4-git-send-email-dh.herrmann@gmail.com Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
95 lines
2.7 KiB
C
95 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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