edid: Add an edid_check_checksum() helper function
[platform/kernel/u-boot.git] / common / edid.c
1 /*
2  * Copyright (c) 2012 The Chromium OS Authors.
3  *
4  * (C) Copyright 2010
5  * Petr Stetiar <ynezz@true.cz>
6  *
7  * SPDX-License-Identifier:     GPL-2.0+
8  *
9  * Contains stolen code from ddcprobe project which is:
10  * Copyright (C) Nalin Dahyabhai <bigfun@pobox.com>
11  */
12
13 #include <common.h>
14 #include <edid.h>
15 #include <errno.h>
16 #include <linux/ctype.h>
17 #include <linux/string.h>
18
19 int edid_check_info(struct edid1_info *edid_info)
20 {
21         if ((edid_info == NULL) || (edid_info->version == 0))
22                 return -1;
23
24         if (memcmp(edid_info->header, "\x0\xff\xff\xff\xff\xff\xff\x0", 8))
25                 return -1;
26
27         if (edid_info->version == 0xff && edid_info->revision == 0xff)
28                 return -1;
29
30         return 0;
31 }
32
33 int edid_check_checksum(u8 *edid_block)
34 {
35         u8 checksum = 0;
36         int i;
37
38         for (i = 0; i < 128; i++)
39                 checksum += edid_block[i];
40
41         return (checksum == 0) ? 0 : -EINVAL;
42 }
43
44 int edid_get_ranges(struct edid1_info *edid, unsigned int *hmin,
45                     unsigned int *hmax, unsigned int *vmin,
46                     unsigned int *vmax)
47 {
48         int i;
49         struct edid_monitor_descriptor *monitor;
50
51         *hmin = *hmax = *vmin = *vmax = 0;
52         if (edid_check_info(edid))
53                 return -1;
54
55         for (i = 0; i < ARRAY_SIZE(edid->monitor_details.descriptor); i++) {
56                 monitor = &edid->monitor_details.descriptor[i];
57                 if (monitor->type == EDID_MONITOR_DESCRIPTOR_RANGE) {
58                         *hmin = monitor->data.range_data.horizontal_min;
59                         *hmax = monitor->data.range_data.horizontal_max;
60                         *vmin = monitor->data.range_data.vertical_min;
61                         *vmax = monitor->data.range_data.vertical_max;
62                         return 0;
63                 }
64         }
65         return -1;
66 }
67
68 /**
69  * Snip the tailing whitespace/return of a string.
70  *
71  * @param string        The string to be snipped
72  * @return the snipped string
73  */
74 static char *snip(char *string)
75 {
76         char *s;
77
78         /*
79          * This is always a 13 character buffer
80          * and it's not always terminated.
81          */
82         string[12] = '\0';
83         s = &string[strlen(string) - 1];
84
85         while (s >= string && (isspace(*s) || *s == '\n' || *s == '\r' ||
86                         *s == '\0'))
87                 *(s--) = '\0';
88
89         return string;
90 }
91
92 /**
93  * Print an EDID monitor descriptor block
94  *
95  * @param monitor       The EDID monitor descriptor block
96  * @have_timing         Modifies to 1 if the desciptor contains timing info
97  */
98 static void edid_print_dtd(struct edid_monitor_descriptor *monitor,
99                            unsigned int *have_timing)
100 {
101         unsigned char *bytes = (unsigned char *)monitor;
102         struct edid_detailed_timing *timing =
103                         (struct edid_detailed_timing *)monitor;
104
105         if (bytes[0] == 0 && bytes[1] == 0) {
106                 if (monitor->type == EDID_MONITOR_DESCRIPTOR_SERIAL)
107                         printf("Monitor serial number: %s\n",
108                                snip(monitor->data.string));
109                 else if (monitor->type == EDID_MONITOR_DESCRIPTOR_ASCII)
110                         printf("Monitor ID: %s\n",
111                                snip(monitor->data.string));
112                 else if (monitor->type == EDID_MONITOR_DESCRIPTOR_NAME)
113                         printf("Monitor name: %s\n",
114                                snip(monitor->data.string));
115                 else if (monitor->type == EDID_MONITOR_DESCRIPTOR_RANGE)
116                         printf("Monitor range limits, horizontal sync: "
117                                "%d-%d kHz, vertical refresh: "
118                                "%d-%d Hz, max pixel clock: "
119                                "%d MHz\n",
120                                monitor->data.range_data.horizontal_min,
121                                monitor->data.range_data.horizontal_max,
122                                monitor->data.range_data.vertical_min,
123                                monitor->data.range_data.vertical_max,
124                                monitor->data.range_data.pixel_clock_max * 10);
125         } else {
126                 uint32_t pixclock, h_active, h_blanking, v_active, v_blanking;
127                 uint32_t h_total, v_total, vfreq;
128
129                 pixclock = EDID_DETAILED_TIMING_PIXEL_CLOCK(*timing);
130                 h_active = EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(*timing);
131                 h_blanking = EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(*timing);
132                 v_active = EDID_DETAILED_TIMING_VERTICAL_ACTIVE(*timing);
133                 v_blanking = EDID_DETAILED_TIMING_VERTICAL_BLANKING(*timing);
134
135                 h_total = h_active + h_blanking;
136                 v_total = v_active + v_blanking;
137                 if (v_total * h_total)
138                         vfreq = pixclock / (v_total * h_total);
139                 else
140                         vfreq = 1; /* Error case */
141                 printf("\t%dx%d\%c\t%d Hz (detailed)\n", h_active,
142                        v_active, h_active > 1000 ? ' ' : '\t', vfreq);
143                 *have_timing = 1;
144         }
145 }
146
147 /**
148  * Get the manufacturer name from an EDID info.
149  *
150  * @param edid_info     The EDID info to be printed
151  * @param name          Returns the string of the manufacturer name
152  */
153 static void edid_get_manufacturer_name(struct edid1_info *edid, char *name)
154 {
155         name[0] = EDID1_INFO_MANUFACTURER_NAME_CHAR1(*edid) + 'A' - 1;
156         name[1] = EDID1_INFO_MANUFACTURER_NAME_CHAR2(*edid) + 'A' - 1;
157         name[2] = EDID1_INFO_MANUFACTURER_NAME_CHAR3(*edid) + 'A' - 1;
158         name[3] = '\0';
159 }
160
161 void edid_print_info(struct edid1_info *edid_info)
162 {
163         int i;
164         char manufacturer[4];
165         unsigned int have_timing = 0;
166         uint32_t serial_number;
167
168         if (edid_check_info(edid_info)) {
169                 printf("Not a valid EDID\n");
170                 return;
171         }
172
173         printf("EDID version: %d.%d\n",
174                edid_info->version, edid_info->revision);
175
176         printf("Product ID code: %04x\n", EDID1_INFO_PRODUCT_CODE(*edid_info));
177
178         edid_get_manufacturer_name(edid_info, manufacturer);
179         printf("Manufacturer: %s\n", manufacturer);
180
181         serial_number = EDID1_INFO_SERIAL_NUMBER(*edid_info);
182         if (serial_number != 0xffffffff) {
183                 if (strcmp(manufacturer, "MAG") == 0)
184                         serial_number -= 0x7000000;
185                 if (strcmp(manufacturer, "OQI") == 0)
186                         serial_number -= 456150000;
187                 if (strcmp(manufacturer, "VSC") == 0)
188                         serial_number -= 640000000;
189         }
190         printf("Serial number: %08x\n", serial_number);
191         printf("Manufactured in week: %d year: %d\n",
192                edid_info->week, edid_info->year + 1990);
193
194         printf("Video input definition: %svoltage level %d%s%s%s%s%s\n",
195                EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid_info) ?
196                "digital signal, " : "analog signal, ",
197                EDID1_INFO_VIDEO_INPUT_VOLTAGE_LEVEL(*edid_info),
198                EDID1_INFO_VIDEO_INPUT_BLANK_TO_BLACK(*edid_info) ?
199                ", blank to black" : "",
200                EDID1_INFO_VIDEO_INPUT_SEPARATE_SYNC(*edid_info) ?
201                ", separate sync" : "",
202                EDID1_INFO_VIDEO_INPUT_COMPOSITE_SYNC(*edid_info) ?
203                ", composite sync" : "",
204                EDID1_INFO_VIDEO_INPUT_SYNC_ON_GREEN(*edid_info) ?
205                ", sync on green" : "",
206                EDID1_INFO_VIDEO_INPUT_SERRATION_V(*edid_info) ?
207                ", serration v" : "");
208
209         printf("Monitor is %s\n",
210                EDID1_INFO_FEATURE_RGB(*edid_info) ? "RGB" : "non-RGB");
211
212         printf("Maximum visible display size: %d cm x %d cm\n",
213                edid_info->max_size_horizontal,
214                edid_info->max_size_vertical);
215
216         printf("Power management features: %s%s, %s%s, %s%s\n",
217                EDID1_INFO_FEATURE_ACTIVE_OFF(*edid_info) ?
218                "" : "no ", "active off",
219                EDID1_INFO_FEATURE_SUSPEND(*edid_info) ? "" : "no ", "suspend",
220                EDID1_INFO_FEATURE_STANDBY(*edid_info) ? "" : "no ", "standby");
221
222         printf("Estabilished timings:\n");
223         if (EDID1_INFO_ESTABLISHED_TIMING_720X400_70(*edid_info))
224                 printf("\t720x400\t\t70 Hz (VGA 640x400, IBM)\n");
225         if (EDID1_INFO_ESTABLISHED_TIMING_720X400_88(*edid_info))
226                 printf("\t720x400\t\t88 Hz (XGA2)\n");
227         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_60(*edid_info))
228                 printf("\t640x480\t\t60 Hz (VGA)\n");
229         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_67(*edid_info))
230                 printf("\t640x480\t\t67 Hz (Mac II, Apple)\n");
231         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_72(*edid_info))
232                 printf("\t640x480\t\t72 Hz (VESA)\n");
233         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_75(*edid_info))
234                 printf("\t640x480\t\t75 Hz (VESA)\n");
235         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_56(*edid_info))
236                 printf("\t800x600\t\t56 Hz (VESA)\n");
237         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_60(*edid_info))
238                 printf("\t800x600\t\t60 Hz (VESA)\n");
239         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_72(*edid_info))
240                 printf("\t800x600\t\t72 Hz (VESA)\n");
241         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_75(*edid_info))
242                 printf("\t800x600\t\t75 Hz (VESA)\n");
243         if (EDID1_INFO_ESTABLISHED_TIMING_832X624_75(*edid_info))
244                 printf("\t832x624\t\t75 Hz (Mac II)\n");
245         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_87I(*edid_info))
246                 printf("\t1024x768\t87 Hz Interlaced (8514A)\n");
247         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_60(*edid_info))
248                 printf("\t1024x768\t60 Hz (VESA)\n");
249         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_70(*edid_info))
250                 printf("\t1024x768\t70 Hz (VESA)\n");
251         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_75(*edid_info))
252                 printf("\t1024x768\t75 Hz (VESA)\n");
253         if (EDID1_INFO_ESTABLISHED_TIMING_1280X1024_75(*edid_info))
254                 printf("\t1280x1024\t75 (VESA)\n");
255         if (EDID1_INFO_ESTABLISHED_TIMING_1152X870_75(*edid_info))
256                 printf("\t1152x870\t75 (Mac II)\n");
257
258         /* Standard timings. */
259         printf("Standard timings:\n");
260         for (i = 0; i < ARRAY_SIZE(edid_info->standard_timings); i++) {
261                 unsigned int aspect = 10000;
262                 unsigned int x, y;
263                 unsigned char xres, vfreq;
264
265                 xres = EDID1_INFO_STANDARD_TIMING_XRESOLUTION(*edid_info, i);
266                 vfreq = EDID1_INFO_STANDARD_TIMING_VFREQ(*edid_info, i);
267                 if ((xres != vfreq) ||
268                     ((xres != 0) && (xres != 1)) ||
269                     ((vfreq != 0) && (vfreq != 1))) {
270                         switch (EDID1_INFO_STANDARD_TIMING_ASPECT(*edid_info,
271                                         i)) {
272                         case ASPECT_625:
273                                 aspect = 6250;
274                                 break;
275                         case ASPECT_75:
276                                 aspect = 7500;
277                                 break;
278                         case ASPECT_8:
279                                 aspect = 8000;
280                                 break;
281                         case ASPECT_5625:
282                                 aspect = 5625;
283                                 break;
284                         }
285                         x = (xres + 31) * 8;
286                         y = x * aspect / 10000;
287                         printf("\t%dx%d%c\t%d Hz\n", x, y,
288                                x > 1000 ? ' ' : '\t', (vfreq & 0x3f) + 60);
289                         have_timing = 1;
290                 }
291         }
292
293         /* Detailed timing information. */
294         for (i = 0; i < ARRAY_SIZE(edid_info->monitor_details.descriptor);
295                         i++) {
296                 edid_print_dtd(&edid_info->monitor_details.descriptor[i],
297                                &have_timing);
298         }
299
300         if (!have_timing)
301                 printf("\tNone\n");
302 }