2 * Copyright (c) 2012 The Chromium OS Authors.
5 * Petr Stetiar <ynezz@true.cz>
7 * SPDX-License-Identifier: GPL-2.0+
9 * Contains stolen code from ddcprobe project which is:
10 * Copyright (C) Nalin Dahyabhai <bigfun@pobox.com>
16 #include <linux/ctype.h>
17 #include <linux/string.h>
19 int edid_check_info(struct edid1_info
*edid_info
)
21 if ((edid_info
== NULL
) || (edid_info
->version
== 0))
24 if (memcmp(edid_info
->header
, "\x0\xff\xff\xff\xff\xff\xff\x0", 8))
27 if (edid_info
->version
== 0xff && edid_info
->revision
== 0xff)
33 int edid_check_checksum(u8
*edid_block
)
38 for (i
= 0; i
< 128; i
++)
39 checksum
+= edid_block
[i
];
41 return (checksum
== 0) ? 0 : -EINVAL
;
44 int edid_get_ranges(struct edid1_info
*edid
, unsigned int *hmin
,
45 unsigned int *hmax
, unsigned int *vmin
,
49 struct edid_monitor_descriptor
*monitor
;
51 *hmin
= *hmax
= *vmin
= *vmax
= 0;
52 if (edid_check_info(edid
))
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
;
69 * Snip the tailing whitespace/return of a string.
71 * @param string The string to be snipped
72 * @return the snipped string
74 static char *snip(char *string
)
79 * This is always a 13 character buffer
80 * and it's not always terminated.
83 s
= &string
[strlen(string
) - 1];
85 while (s
>= string
&& (isspace(*s
) || *s
== '\n' || *s
== '\r' ||
93 * Print an EDID monitor descriptor block
95 * @param monitor The EDID monitor descriptor block
96 * @have_timing Modifies to 1 if the desciptor contains timing info
98 static void edid_print_dtd(struct edid_monitor_descriptor
*monitor
,
99 unsigned int *have_timing
)
101 unsigned char *bytes
= (unsigned char *)monitor
;
102 struct edid_detailed_timing
*timing
=
103 (struct edid_detailed_timing
*)monitor
;
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: "
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);
126 uint32_t pixclock
, h_active
, h_blanking
, v_active
, v_blanking
;
127 uint32_t h_total
, v_total
, vfreq
;
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
);
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
);
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
);
148 * Get the manufacturer name from an EDID info.
150 * @param edid_info The EDID info to be printed
151 * @param name Returns the string of the manufacturer name
153 static void edid_get_manufacturer_name(struct edid1_info
*edid
, char *name
)
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;
161 void edid_print_info(struct edid1_info
*edid_info
)
164 char manufacturer
[4];
165 unsigned int have_timing
= 0;
166 uint32_t serial_number
;
168 if (edid_check_info(edid_info
)) {
169 printf("Not a valid EDID\n");
173 printf("EDID version: %d.%d\n",
174 edid_info
->version
, edid_info
->revision
);
176 printf("Product ID code: %04x\n", EDID1_INFO_PRODUCT_CODE(*edid_info
));
178 edid_get_manufacturer_name(edid_info
, manufacturer
);
179 printf("Manufacturer: %s\n", manufacturer
);
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;
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);
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" : "");
209 printf("Monitor is %s\n",
210 EDID1_INFO_FEATURE_RGB(*edid_info
) ? "RGB" : "non-RGB");
212 printf("Maximum visible display size: %d cm x %d cm\n",
213 edid_info
->max_size_horizontal
,
214 edid_info
->max_size_vertical
);
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");
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");
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;
263 unsigned char xres
, vfreq
;
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
,
286 y
= x
* aspect
/ 10000;
287 printf("\t%dx%d%c\t%d Hz\n", x
, y
,
288 x
> 1000 ? ' ' : '\t', (vfreq
& 0x3f) + 60);
293 /* Detailed timing information. */
294 for (i
= 0; i
< ARRAY_SIZE(edid_info
->monitor_details
.descriptor
);
296 edid_print_dtd(&edid_info
->monitor_details
.descriptor
[i
],