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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141// 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){ __u8 type; u32 bits_per_pixel; unsigned int i;
type = si->orig_video_isVGA; if (type != VIDEO_TYPE_VLFB && type != VIDEO_TYPE_EFI) return false;
bits_per_pixel = __screen_info_lfb_bits_per_pixel(si);
for (i = 0; i < ARRAY_SIZE(formats); ++i) { const struct simplefb_format *f = &formats[i];
if (f->transp.length) continue; /* transparent formats are unsupported by VESA/EFI */
if (bits_per_pixel == 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) { mode->format = f->name; mode->width = si->lfb_width; mode->height = si->lfb_height; mode->stride = si->lfb_linelength; return true; } }
return false;}
__init struct platform_device *sysfb_create_simplefb(const struct screen_info *si, const struct simplefb_platform_data *mode, struct device *parent){ 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 ERR_PTR(-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 ERR_PTR(-EINVAL); } length = PAGE_ALIGN(length);
/* setup IORESOURCE_MEM as framebuffer memory */ memset(&res, 0, sizeof(res)); res.flags = IORESOURCE_MEM; res.name = simplefb_resname; res.start = base; res.end = res.start + length - 1; if (res.end <= res.start) return ERR_PTR(-EINVAL);
pd = platform_device_alloc("simple-framebuffer", 0); if (!pd) return ERR_PTR(-ENOMEM);
pd->dev.parent = parent;
sysfb_set_efifb_fwnode(si, pd);
ret = platform_device_add_resources(pd, &res, 1); if (ret) goto err_put_device;
ret = platform_device_add_data(pd, mode, sizeof(*mode)); if (ret) goto err_put_device;
ret = platform_device_add(pd); if (ret) goto err_put_device;
return pd;
err_put_device: platform_device_put(pd);
return ERR_PTR(ret);}