linux/drivers/firmware/sysfb_simplefb.c
Javier Martinez Canillas 8633ef82f1 drivers/firmware: consolidate EFI framebuffer setup for all arches
The register_gop_device() function registers an "efi-framebuffer" platform
device to match against the efifb driver, to have an early framebuffer for
EFI platforms.

But there is already support to do exactly the same by the Generic System
Framebuffers (sysfb) driver. This used to be only for X86 but it has been
moved to drivers/firmware and could be reused by other architectures.

Also, besides supporting registering an "efi-framebuffer", this driver can
register a "simple-framebuffer" allowing to use the siple{fb,drm} drivers
on non-X86 EFI platforms. For example, on aarch64 these drivers can only
be used with DT and doesn't have code to register a "simple-frambuffer"
platform device when booting with EFI.

For these reasons, let's remove the register_gop_device() duplicated code
and instead move the platform specific logic that's there to sysfb driver.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210625131359.1804394-1-javierm@redhat.com
2021-07-21 12:04:56 +02:00

125 lines
3.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Generic System Framebuffers
* Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com>
*/
/*
* 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 <linux/sysfb.h>
static const char simplefb_resname[] = "BOOTFB";
static const struct simplefb_format formats[] = SIMPLEFB_FORMATS;
/* try parsing screen_info into a simple-framebuffer mode struct */
__init bool sysfb_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 sysfb_create_simplefb(const struct screen_info *si,
const struct simplefb_platform_data *mode)
{
struct platform_device *pd;
struct resource res;
u64 base, size;
u32 length;
int ret;
/*
* If the 64BIT_BASE capability is set, ext_lfb_base will contain the
* upper half of the base address. Assemble the address, then make sure
* it is valid and we can actually access it.
*/
base = si->lfb_base;
if (si->capabilities & VIDEO_CAPABILITY_64BIT_BASE)
base |= (u64)si->ext_lfb_base << 32;
if (!base || (u64)(resource_size_t)base != base) {
printk(KERN_DEBUG "sysfb: inaccessible VRAM base\n");
return -EINVAL;
}
/*
* Don't use lfb_size as IORESOURCE size, since it may contain the
* entire VMEM, and thus require huge mappings. Use just the part we
* need, that is, the part where the framebuffer is located. But verify
* that it does not exceed the advertised VMEM.
* Note that in case of VBE, the lfb_size is shifted by 16 bits for
* historical reasons.
*/
size = si->lfb_size;
if (si->orig_video_isVGA == VIDEO_TYPE_VLFB)
size <<= 16;
length = mode->height * mode->stride;
if (length > size) {
printk(KERN_WARNING "sysfb: VRAM smaller than advertised\n");
return -EINVAL;
}
length = PAGE_ALIGN(length);
/* setup IORESOURCE_MEM as framebuffer memory */
memset(&res, 0, sizeof(res));
res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
res.name = simplefb_resname;
res.start = base;
res.end = res.start + length - 1;
if (res.end <= res.start)
return -EINVAL;
pd = platform_device_alloc("simple-framebuffer", 0);
if (!pd)
return -ENOMEM;
sysfb_apply_efi_quirks(pd);
ret = platform_device_add_resources(pd, &res, 1);
if (ret)
return ret;
ret = platform_device_add_data(pd, mode, sizeof(*mode));
if (ret)
return ret;
return platform_device_add(pd);
}