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authorDavid Herrmann <dh.herrmann@gmail.com>2013-08-02 14:05:22 +0200
committerH. Peter Anvin <hpa@linux.intel.com>2013-08-02 16:17:46 -0700
commite3263ab389a7bc9398c3d366819d6f39b9cfd677 (patch)
treeaa42182804337d3a491f16a5d581e1102a110858 /arch/x86/include/asm/sysfb.h
parentdf0960ab2d95543a7c162b04b2064991666adbad (diff)
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>
Diffstat (limited to 'arch/x86/include/asm/sysfb.h')
-rw-r--r--arch/x86/include/asm/sysfb.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/x86/include/asm/sysfb.h b/arch/x86/include/asm/sysfb.h
new file mode 100644
index 000000000000..2395fe03f56b
--- /dev/null
+++ b/arch/x86/include/asm/sysfb.h
@@ -0,0 +1,41 @@
+#ifndef _ARCH_X86_KERNEL_SYSFB_H
+#define _ARCH_X86_KERNEL_SYSFB_H
+
+/*
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/platform_data/simplefb.h>
+#include <linux/screen_info.h>
+
+#ifdef CONFIG_X86_SYSFB
+
+bool parse_mode(const struct screen_info *si,
+ struct simplefb_platform_data *mode);
+int create_simplefb(const struct screen_info *si,
+ const struct simplefb_platform_data *mode);
+
+#else /* CONFIG_X86_SYSFB */
+
+static inline bool parse_mode(const struct screen_info *si,
+ struct simplefb_platform_data *mode)
+{
+ return false;
+}
+
+static inline int create_simplefb(const struct screen_info *si,
+ const struct simplefb_platform_data *mode)
+{
+ return -EINVAL;
+}
+
+#endif /* CONFIG_X86_SYSFB */
+
+#endif /* _ARCH_X86_KERNEL_SYSFB_H */