xref: /openbmc/linux/drivers/firmware/efi/libstub/gop.c (revision 6327e6d0)
1 // SPDX-License-Identifier: GPL-2.0
2 /* -----------------------------------------------------------------------
3  *
4  *   Copyright 2011 Intel Corporation; author Matt Fleming
5  *
6  * ----------------------------------------------------------------------- */
7 
8 #include <linux/efi.h>
9 #include <linux/screen_info.h>
10 #include <asm/efi.h>
11 #include <asm/setup.h>
12 
13 #include "efistub.h"
14 
15 static void find_bits(unsigned long mask, u8 *pos, u8 *size)
16 {
17 	u8 first, len;
18 
19 	first = 0;
20 	len = 0;
21 
22 	if (mask) {
23 		while (!(mask & 0x1)) {
24 			mask = mask >> 1;
25 			first++;
26 		}
27 
28 		while (mask & 0x1) {
29 			mask = mask >> 1;
30 			len++;
31 		}
32 	}
33 
34 	*pos = first;
35 	*size = len;
36 }
37 
38 static void
39 setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line,
40 		 efi_pixel_bitmask_t pixel_info, int pixel_format)
41 {
42 	if (pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) {
43 		si->lfb_depth = 32;
44 		si->lfb_linelength = pixels_per_scan_line * 4;
45 		si->red_size = 8;
46 		si->red_pos = 0;
47 		si->green_size = 8;
48 		si->green_pos = 8;
49 		si->blue_size = 8;
50 		si->blue_pos = 16;
51 		si->rsvd_size = 8;
52 		si->rsvd_pos = 24;
53 	} else if (pixel_format == PIXEL_BGR_RESERVED_8BIT_PER_COLOR) {
54 		si->lfb_depth = 32;
55 		si->lfb_linelength = pixels_per_scan_line * 4;
56 		si->red_size = 8;
57 		si->red_pos = 16;
58 		si->green_size = 8;
59 		si->green_pos = 8;
60 		si->blue_size = 8;
61 		si->blue_pos = 0;
62 		si->rsvd_size = 8;
63 		si->rsvd_pos = 24;
64 	} else if (pixel_format == PIXEL_BIT_MASK) {
65 		find_bits(pixel_info.red_mask, &si->red_pos, &si->red_size);
66 		find_bits(pixel_info.green_mask, &si->green_pos,
67 			  &si->green_size);
68 		find_bits(pixel_info.blue_mask, &si->blue_pos, &si->blue_size);
69 		find_bits(pixel_info.reserved_mask, &si->rsvd_pos,
70 			  &si->rsvd_size);
71 		si->lfb_depth = si->red_size + si->green_size +
72 			si->blue_size + si->rsvd_size;
73 		si->lfb_linelength = (pixels_per_scan_line * si->lfb_depth) / 8;
74 	} else {
75 		si->lfb_depth = 4;
76 		si->lfb_linelength = si->lfb_width / 2;
77 		si->red_size = 0;
78 		si->red_pos = 0;
79 		si->green_size = 0;
80 		si->green_pos = 0;
81 		si->blue_size = 0;
82 		si->blue_pos = 0;
83 		si->rsvd_size = 0;
84 		si->rsvd_pos = 0;
85 	}
86 }
87 
88 static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto,
89 			      unsigned long size, void **handles)
90 {
91 	efi_graphics_output_protocol_t *gop, *first_gop;
92 	efi_graphics_output_protocol_mode_t *mode;
93 	efi_graphics_output_mode_info_t *info = NULL;
94 	efi_physical_addr_t fb_base;
95 	efi_status_t status;
96 	efi_handle_t h;
97 	int i;
98 
99 	first_gop = NULL;
100 	gop = NULL;
101 
102 	for_each_efi_handle(h, handles, size, i) {
103 		efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
104 		bool conout_found = false;
105 		void *dummy = NULL;
106 
107 		status = efi_bs_call(handle_protocol, h, proto, (void **)&gop);
108 		if (status != EFI_SUCCESS)
109 			continue;
110 
111 		mode = efi_table_attr(gop, mode);
112 		info = efi_table_attr(mode, info);
113 		if (info->pixel_format == PIXEL_BLT_ONLY)
114 			continue;
115 
116 		status = efi_bs_call(handle_protocol, h, &conout_proto, &dummy);
117 		if (status == EFI_SUCCESS)
118 			conout_found = true;
119 
120 		if (!first_gop || conout_found) {
121 			/*
122 			 * Systems that use the UEFI Console Splitter may
123 			 * provide multiple GOP devices, not all of which are
124 			 * backed by real hardware. The workaround is to search
125 			 * for a GOP implementing the ConOut protocol, and if
126 			 * one isn't found, to just fall back to the first GOP.
127 			 *
128 			 * Once we've found a GOP supporting ConOut,
129 			 * don't bother looking any further.
130 			 */
131 			first_gop = gop;
132 			if (conout_found)
133 				break;
134 		}
135 	}
136 
137 	/* Did we find any GOPs? */
138 	if (!first_gop)
139 		return EFI_NOT_FOUND;
140 
141 	/* EFI framebuffer */
142 	mode = efi_table_attr(first_gop, mode);
143 	info = efi_table_attr(mode, info);
144 
145 	si->orig_video_isVGA = VIDEO_TYPE_EFI;
146 
147 	si->lfb_width  = info->horizontal_resolution;
148 	si->lfb_height = info->vertical_resolution;
149 
150 	fb_base		 = efi_table_attr(mode, frame_buffer_base);
151 	si->lfb_base	 = fb_base;
152 	si->ext_lfb_base = (u64)(unsigned long)fb_base >> 32;
153 	if (si->ext_lfb_base)
154 		si->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
155 
156 	si->pages = 1;
157 
158 	setup_pixel_info(si, info->pixels_per_scan_line,
159 			     info->pixel_information, info->pixel_format);
160 
161 	si->lfb_size = si->lfb_linelength * si->lfb_height;
162 
163 	si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
164 
165 	return EFI_SUCCESS;
166 }
167 
168 /*
169  * See if we have Graphics Output Protocol
170  */
171 efi_status_t efi_setup_gop(struct screen_info *si, efi_guid_t *proto,
172 			   unsigned long size)
173 {
174 	efi_status_t status;
175 	void **gop_handle = NULL;
176 
177 	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
178 			     (void **)&gop_handle);
179 	if (status != EFI_SUCCESS)
180 		return status;
181 
182 	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, proto, NULL,
183 			     &size, gop_handle);
184 	if (status != EFI_SUCCESS)
185 		goto free_handle;
186 
187 	status = setup_gop(si, proto, size, gop_handle);
188 
189 free_handle:
190 	efi_bs_call(free_pool, gop_handle);
191 	return status;
192 }
193