x86: provide platform-devices for boot-framebuffers
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>hifive-unleashed-5.1
David Herrmann
H. Peter Anvin
parent
df0960ab2d
commit
e3263ab389
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@ -2270,6 +2270,32 @@ config RAPIDIO
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source "drivers/rapidio/Kconfig"
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config X86_SYSFB
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bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
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help
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Firmwares often provide initial graphics framebuffers so the BIOS,
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bootloader or kernel can show basic video-output during boot for
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user-guidance and debugging. Historically, x86 used the VESA BIOS
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Extensions and EFI-framebuffers for this, which are mostly limited
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to x86.
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This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
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framebuffers so the new generic system-framebuffer drivers can be
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used on x86. If the framebuffer is not compatible with the generic
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modes, it is adverticed as fallback platform framebuffer so legacy
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drivers like efifb, vesafb and uvesafb can pick it up.
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If this option is not selected, all system framebuffers are always
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marked as fallback platform framebuffers as usual.
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Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
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not be able to pick up generic system framebuffers if this option
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is selected. You are highly encouraged to enable simplefb as
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replacement if you select this option. simplefb can correctly deal
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with generic system framebuffers. But you should still keep vesafb
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and others enabled as fallback if a system framebuffer is
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incompatible with simplefb.
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If unsure, say Y.
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endmenu
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@ -0,0 +1,41 @@
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#ifndef _ARCH_X86_KERNEL_SYSFB_H
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#define _ARCH_X86_KERNEL_SYSFB_H
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/*
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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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#include <linux/kernel.h>
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#include <linux/platform_data/simplefb.h>
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#include <linux/screen_info.h>
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#ifdef CONFIG_X86_SYSFB
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bool parse_mode(const struct screen_info *si,
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struct simplefb_platform_data *mode);
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int create_simplefb(const struct screen_info *si,
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const struct simplefb_platform_data *mode);
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#else /* CONFIG_X86_SYSFB */
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static inline 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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return false;
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}
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static inline 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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return -EINVAL;
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}
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#endif /* CONFIG_X86_SYSFB */
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#endif /* _ARCH_X86_KERNEL_SYSFB_H */
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@ -103,6 +103,8 @@ obj-$(CONFIG_X86_CHECK_BIOS_CORRUPTION) += check.o
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obj-$(CONFIG_SWIOTLB) += pci-swiotlb.o
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obj-$(CONFIG_OF) += devicetree.o
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obj-$(CONFIG_UPROBES) += uprobes.o
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obj-y += sysfb.o
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obj-$(CONFIG_X86_SYSFB) += sysfb_simplefb.o
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obj-$(CONFIG_PERF_EVENTS) += perf_regs.o
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obj-$(CONFIG_TRACING) += tracepoint.o
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@ -0,0 +1,71 @@
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/*
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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 support for x86 systems
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* Create a platform-device for any available boot framebuffer. The
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* simple-framebuffer platform device is already available on DT systems, so
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* this module parses the global "screen_info" object and creates a suitable
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* platform device compatible with the "simple-framebuffer" DT object. If
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* the framebuffer is incompatible, we instead create a legacy
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* "vesa-framebuffer", "efi-framebuffer" or "platform-framebuffer" device and
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* pass the screen_info as platform_data. This allows legacy drivers
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* to pick these devices up without messing with simple-framebuffer drivers.
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* The global "screen_info" is still valid at all times.
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*
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* If CONFIG_X86_SYSFB is not selected, we never register "simple-framebuffer"
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* platform devices, but only use legacy framebuffer devices for
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* backwards compatibility.
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*
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* TODO: We set the dev_id field of all platform-devices to 0. This allows
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* other x86 OF/DT parsers to create such devices, too. However, they must
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* start at offset 1 for this to work.
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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 __init int sysfb_init(void)
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{
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struct screen_info *si = &screen_info;
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struct simplefb_platform_data mode;
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struct platform_device *pd;
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const char *name;
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bool compatible;
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int ret;
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/* try to create a simple-framebuffer device */
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compatible = parse_mode(si, &mode);
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if (compatible) {
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ret = create_simplefb(si, &mode);
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if (!ret)
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return 0;
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}
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/* if the FB is incompatible, create a legacy framebuffer device */
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if (si->orig_video_isVGA == VIDEO_TYPE_EFI)
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name = "efi-framebuffer";
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else if (si->orig_video_isVGA == VIDEO_TYPE_VLFB)
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name = "vesa-framebuffer";
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else
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name = "platform-framebuffer";
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pd = platform_device_register_resndata(NULL, name, 0,
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NULL, 0, si, sizeof(*si));
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return IS_ERR(pd) ? PTR_ERR(pd) : 0;
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}
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device_initcall(sysfb_init);
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@ -0,0 +1,95 @@
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/*
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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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