xref: /openbmc/linux/drivers/firmware/efi/libstub/gop.c (revision ecf53091)
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_graphics_output_protocol_t *
89 find_gop(efi_guid_t *proto, 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_status_t status;
95 	efi_handle_t h;
96 	int i;
97 
98 	first_gop = NULL;
99 
100 	for_each_efi_handle(h, handles, size, i) {
101 		efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
102 		bool conout_found = false;
103 		void *dummy = NULL;
104 
105 		status = efi_bs_call(handle_protocol, h, proto, (void **)&gop);
106 		if (status != EFI_SUCCESS)
107 			continue;
108 
109 		mode = efi_table_attr(gop, mode);
110 		info = efi_table_attr(mode, info);
111 		if (info->pixel_format == PIXEL_BLT_ONLY)
112 			continue;
113 
114 		status = efi_bs_call(handle_protocol, h, &conout_proto, &dummy);
115 		if (status == EFI_SUCCESS)
116 			conout_found = true;
117 
118 		if (!first_gop || conout_found) {
119 			/*
120 			 * Systems that use the UEFI Console Splitter may
121 			 * provide multiple GOP devices, not all of which are
122 			 * backed by real hardware. The workaround is to search
123 			 * for a GOP implementing the ConOut protocol, and if
124 			 * one isn't found, to just fall back to the first GOP.
125 			 *
126 			 * Once we've found a GOP supporting ConOut,
127 			 * don't bother looking any further.
128 			 */
129 			first_gop = gop;
130 			if (conout_found)
131 				break;
132 		}
133 	}
134 
135 	return first_gop;
136 }
137 
138 static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto,
139 			      unsigned long size, void **handles)
140 {
141 	efi_graphics_output_protocol_t *gop;
142 	efi_graphics_output_protocol_mode_t *mode;
143 	efi_graphics_output_mode_info_t *info = NULL;
144 	efi_physical_addr_t fb_base;
145 
146 	gop = find_gop(proto, size, handles);
147 
148 	/* Did we find any GOPs? */
149 	if (!gop)
150 		return EFI_NOT_FOUND;
151 
152 	/* EFI framebuffer */
153 	mode = efi_table_attr(gop, mode);
154 	info = efi_table_attr(mode, info);
155 
156 	si->orig_video_isVGA = VIDEO_TYPE_EFI;
157 
158 	si->lfb_width  = info->horizontal_resolution;
159 	si->lfb_height = info->vertical_resolution;
160 
161 	fb_base		 = efi_table_attr(mode, frame_buffer_base);
162 	si->lfb_base	 = fb_base;
163 	si->ext_lfb_base = (u64)(unsigned long)fb_base >> 32;
164 	if (si->ext_lfb_base)
165 		si->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
166 
167 	si->pages = 1;
168 
169 	setup_pixel_info(si, info->pixels_per_scan_line,
170 			     info->pixel_information, info->pixel_format);
171 
172 	si->lfb_size = si->lfb_linelength * si->lfb_height;
173 
174 	si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
175 
176 	return EFI_SUCCESS;
177 }
178 
179 /*
180  * See if we have Graphics Output Protocol
181  */
182 efi_status_t efi_setup_gop(struct screen_info *si, efi_guid_t *proto,
183 			   unsigned long size)
184 {
185 	efi_status_t status;
186 	void **gop_handle = NULL;
187 
188 	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
189 			     (void **)&gop_handle);
190 	if (status != EFI_SUCCESS)
191 		return status;
192 
193 	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, proto, NULL,
194 			     &size, gop_handle);
195 	if (status != EFI_SUCCESS)
196 		goto free_handle;
197 
198 	status = setup_gop(si, proto, size, gop_handle);
199 
200 free_handle:
201 	efi_bs_call(free_pool, gop_handle);
202 	return status;
203 }
204