LXR linux/drivers/firmware/sysfb.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Generic System Framebuffers
   4 * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com>
   5 */
   6
   7/*
   8 * Simple-Framebuffer support
   9 * Create a platform-device for any available boot framebuffer. The
  10 * simple-framebuffer platform device is already available on DT systems, so
  11 * this module parses the global "screen_info" object and creates a suitable
  12 * platform device compatible with the "simple-framebuffer" DT object. If
  13 * the framebuffer is incompatible, we instead create a legacy
  14 * "vesa-framebuffer", "efi-framebuffer" or "platform-framebuffer" device and
  15 * pass the screen_info as platform_data. This allows legacy drivers
  16 * to pick these devices up without messing with simple-framebuffer drivers.
  17 * The global "screen_info" is still valid at all times.
  18 *
  19 * If CONFIG_SYSFB_SIMPLEFB is not selected, never register "simple-framebuffer"
  20 * platform devices, but only use legacy framebuffer devices for
  21 * backwards compatibility.
  22 *
  23 * TODO: We set the dev_id field of all platform-devices to 0. This allows
  24 * other OF/DT parsers to create such devices, too. However, they must
  25 * start at offset 1 for this to work.
  26 */
  27
  28#include <linux/err.h>
  29#include <linux/init.h>
  30#include <linux/kernel.h>
  31#include <linux/mm.h>
  32#include <linux/platform_data/simplefb.h>
  33#include <linux/platform_device.h>
  34#include <linux/screen_info.h>
  35#include <linux/sysfb.h>
  36
  37static __init int sysfb_init(void)
  38{
  39        struct screen_info *si = &screen_info;
  40        struct simplefb_platform_data mode;
  41        struct platform_device *pd;
  42        const char *name;
  43        bool compatible;
  44        int ret;
  45
  46        /* try to create a simple-framebuffer device */
  47        compatible = sysfb_parse_mode(si, &mode);
  48        if (compatible) {
  49                ret = sysfb_create_simplefb(si, &mode);
  50                if (!ret)
  51                        return 0;
  52        }
  53
  54        /* if the FB is incompatible, create a legacy framebuffer device */
  55        if (si->orig_video_isVGA == VIDEO_TYPE_EFI)
  56                name = "efi-framebuffer";
  57        else if (si->orig_video_isVGA == VIDEO_TYPE_VLFB)
  58                name = "vesa-framebuffer";
  59        else
  60                name = "platform-framebuffer";
  61
  62        pd = platform_device_alloc(name, 0);
  63        if (!pd)
  64                return -ENOMEM;
  65
  66        sysfb_apply_efi_quirks(pd);
  67
  68        ret = platform_device_add_data(pd, si, sizeof(*si));
  69        if (ret)
  70                goto err;
  71
  72        ret = platform_device_add(pd);
  73        if (ret)
  74                goto err;
  75
  76        return 0;
  77err:
  78        platform_device_put(pd);
  79        return ret;
  80}
  81
  82/* must execute after PCI subsystem for EFI quirks */
  83device_initcall(sysfb_init);
  84