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 37 static __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; 77 err: 78 platform_device_put(pd); 79 return ret; 80 } 81 82 /* must execute after PCI subsystem for EFI quirks */ 83 device_initcall(sysfb_init); 84