mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
111 lines
3.2 KiB
111 lines
3.2 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* Generic System Framebuffers on x86 |
|
* Copyright (c) 2012-2013 David Herrmann <[email protected]> |
|
*/ |
|
|
|
/* |
|
* 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 <asm/sysfb.h> |
|
|
|
static const char simplefb_resname[] = "BOOTFB"; |
|
static const struct simplefb_format formats[] = SIMPLEFB_FORMATS; |
|
|
|
/* try parsing x86 screen_info into a simple-framebuffer mode struct */ |
|
__init bool 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 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; |
|
|
|
/* |
|
* 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_register_resndata(NULL, "simple-framebuffer", 0, |
|
&res, 1, mode, sizeof(*mode)); |
|
return PTR_ERR_OR_ZERO(pd); |
|
}
|
|
|