Line data    Source code

       1             : // SPDX-License-Identifier: GPL-2.0-or-later
       2             : /*
       3             :  * Generic System Framebuffers on x86
       4             :  * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com>
       5             :  */
       6             : 
       7             : /*
       8             :  * Simple-Framebuffer support for x86 systems
       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_X86_SYSFB is not selected, we 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 x86 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 <asm/sysfb.h>
      36             : 
      37           1 : static __init int sysfb_init(void)
      38             : {
      39           1 :         struct screen_info *si = &screen_info;
      40           1 :         struct simplefb_platform_data mode;
      41           1 :         struct platform_device *pd;
      42           1 :         const char *name;
      43           1 :         bool compatible;
      44           1 :         int ret;
      45             : 
      46           1 :         sysfb_apply_efi_quirks();
      47             : 
      48             :         /* try to create a simple-framebuffer device */
      49           1 :         compatible = parse_mode(si, &mode);
      50           1 :         if (compatible) {
      51             :                 ret = create_simplefb(si, &mode);
      52             :                 if (!ret)
      53             :                         return 0;
      54             :         }
      55             : 
      56             :         /* if the FB is incompatible, create a legacy framebuffer device */
      57           1 :         if (si->orig_video_isVGA == VIDEO_TYPE_EFI)
      58             :                 name = "efi-framebuffer";
      59           1 :         else if (si->orig_video_isVGA == VIDEO_TYPE_VLFB)
      60             :                 name = "vesa-framebuffer";
      61             :         else
      62           1 :                 name = "platform-framebuffer";
      63             : 
      64           1 :         pd = platform_device_register_resndata(NULL, name, 0,
      65             :                                                NULL, 0, si, sizeof(*si));
      66           1 :         return PTR_ERR_OR_ZERO(pd);
      67             : }
      68             : 
      69             : /* must execute after PCI subsystem for EFI quirks */
      70             : device_initcall(sysfb_init);