| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 1 | /* |
| 2 | * Generic System Framebuffers on x86 |
| 3 | * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License as published by the Free |
| 7 | * Software Foundation; either version 2 of the License, or (at your option) |
| 8 | * any later version. |
| 9 | */ |
| 10 | |
| 11 | /* |
| 12 | * simple-framebuffer probing |
| 13 | * Try to convert "screen_info" into a "simple-framebuffer" compatible mode. |
| 14 | * If the mode is incompatible, we return "false" and let the caller create |
| 15 | * legacy nodes instead. |
| 16 | */ |
| 17 | |
| 18 | #include <linux/err.h> |
| 19 | #include <linux/init.h> |
| 20 | #include <linux/kernel.h> |
| 21 | #include <linux/mm.h> |
| 22 | #include <linux/platform_data/simplefb.h> |
| 23 | #include <linux/platform_device.h> |
| 24 | #include <linux/screen_info.h> |
| 25 | #include <asm/sysfb.h> |
| 26 | |
| 27 | static const char simplefb_resname[] = "BOOTFB"; |
| 28 | static const struct simplefb_format formats[] = SIMPLEFB_FORMATS; |
| 29 | |
| 30 | /* try parsing x86 screen_info into a simple-framebuffer mode struct */ |
| 31 | __init bool parse_mode(const struct screen_info *si, |
| 32 | struct simplefb_platform_data *mode) |
| 33 | { |
| 34 | const struct simplefb_format *f; |
| 35 | __u8 type; |
| 36 | unsigned int i; |
| 37 | |
| 38 | type = si->orig_video_isVGA; |
| 39 | if (type != VIDEO_TYPE_VLFB && type != VIDEO_TYPE_EFI) |
| 40 | return false; |
| 41 | |
| 42 | for (i = 0; i < ARRAY_SIZE(formats); ++i) { |
| 43 | f = &formats[i]; |
| 44 | if (si->lfb_depth == f->bits_per_pixel && |
| 45 | si->red_size == f->red.length && |
| 46 | si->red_pos == f->red.offset && |
| 47 | si->green_size == f->green.length && |
| 48 | si->green_pos == f->green.offset && |
| 49 | si->blue_size == f->blue.length && |
| 50 | si->blue_pos == f->blue.offset && |
| 51 | si->rsvd_size == f->transp.length && |
| 52 | si->rsvd_pos == f->transp.offset) { |
| 53 | mode->format = f->name; |
| 54 | mode->width = si->lfb_width; |
| 55 | mode->height = si->lfb_height; |
| 56 | mode->stride = si->lfb_linelength; |
| 57 | return true; |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | return false; |
| 62 | } |
| 63 | |
| 64 | __init int create_simplefb(const struct screen_info *si, |
| 65 | const struct simplefb_platform_data *mode) |
| 66 | { |
| 67 | struct platform_device *pd; |
| 68 | struct resource res; |
| 69 | unsigned long len; |
| 70 | |
| 71 | /* don't use lfb_size as it may contain the whole VMEM instead of only |
| 72 | * the part that is occupied by the framebuffer */ |
| 73 | len = mode->height * mode->stride; |
| 74 | len = PAGE_ALIGN(len); |
| 75 | if (len > (u64)si->lfb_size << 16) { |
| 76 | printk(KERN_WARNING "sysfb: VRAM smaller than advertised\n"); |
| 77 | return -EINVAL; |
| 78 | } |
| 79 | |
| 80 | /* setup IORESOURCE_MEM as framebuffer memory */ |
| 81 | memset(&res, 0, sizeof(res)); |
| 82 | res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; |
| 83 | res.name = simplefb_resname; |
| 84 | res.start = si->lfb_base; |
| 85 | res.end = si->lfb_base + len - 1; |
| 86 | if (res.end <= res.start) |
| 87 | return -EINVAL; |
| 88 | |
| 89 | pd = platform_device_register_resndata(NULL, "simple-framebuffer", 0, |
| 90 | &res, 1, mode, sizeof(*mode)); |
| 91 | return PTR_ERR_OR_ZERO(pd); |
| 92 | } |