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>
17 #include <linux/ctype.h>
18 #include <linux/string.h>
20 int edid_check_info(struct edid1_info
*edid_info
)
22 if ((edid_info
== NULL
) || (edid_info
->version
== 0))
25 if (memcmp(edid_info
->header
, "\x0\xff\xff\xff\xff\xff\xff\x0", 8))
28 if (edid_info
->version
== 0xff && edid_info
->revision
== 0xff)
34 int edid_check_checksum(u8
*edid_block
)
39 for (i
= 0; i
< 128; i
++)
40 checksum
+= edid_block
[i
];
42 return (checksum
== 0) ? 0 : -EINVAL
;
45 int edid_get_ranges(struct edid1_info
*edid
, unsigned int *hmin
,
46 unsigned int *hmax
, unsigned int *vmin
,
50 struct edid_monitor_descriptor
*monitor
;
52 *hmin
= *hmax
= *vmin
= *vmax
= 0;
53 if (edid_check_info(edid
))
56 for (i
= 0; i
< ARRAY_SIZE(edid
->monitor_details
.descriptor
); i
++) {
57 monitor
= &edid
->monitor_details
.descriptor
[i
];
58 if (monitor
->type
== EDID_MONITOR_DESCRIPTOR_RANGE
) {
59 *hmin
= monitor
->data
.range_data
.horizontal_min
;
60 *hmax
= monitor
->data
.range_data
.horizontal_max
;
61 *vmin
= monitor
->data
.range_data
.vertical_min
;
62 *vmax
= monitor
->data
.range_data
.vertical_max
;
69 /* Set all parts of a timing entry to the same value */
70 static void set_entry(struct timing_entry
*entry
, u32 value
)
78 * decode_timing() - Decoding an 18-byte detailed timing record
80 * @buf: Pointer to EDID detailed timing record
81 * @timing: Place to put timing
83 static void decode_timing(u8
*buf
, struct display_timing
*timing
)
86 unsigned int ha
, hbl
, hso
, hspw
, hborder
;
87 unsigned int va
, vbl
, vso
, vspw
, vborder
;
89 /* Edid contains pixel clock in terms of 10KHz */
90 set_entry(&timing
->pixelclock
, (buf
[0] + (buf
[1] << 8)) * 10000);
91 x_mm
= (buf
[12] + ((buf
[14] & 0xf0) << 4));
92 y_mm
= (buf
[13] + ((buf
[14] & 0x0f) << 8));
93 ha
= (buf
[2] + ((buf
[4] & 0xf0) << 4));
94 hbl
= (buf
[3] + ((buf
[4] & 0x0f) << 8));
95 hso
= (buf
[8] + ((buf
[11] & 0xc0) << 2));
96 hspw
= (buf
[9] + ((buf
[11] & 0x30) << 4));
98 va
= (buf
[5] + ((buf
[7] & 0xf0) << 4));
99 vbl
= (buf
[6] + ((buf
[7] & 0x0f) << 8));
100 vso
= ((buf
[10] >> 4) + ((buf
[11] & 0x0c) << 2));
101 vspw
= ((buf
[10] & 0x0f) + ((buf
[11] & 0x03) << 4));
104 set_entry(&timing
->hactive
, ha
);
105 set_entry(&timing
->hfront_porch
, hso
);
106 set_entry(&timing
->hback_porch
, hbl
- hso
- hspw
);
107 set_entry(&timing
->hsync_len
, hspw
);
109 set_entry(&timing
->vactive
, va
);
110 set_entry(&timing
->vfront_porch
, vso
);
111 set_entry(&timing
->vback_porch
, vbl
- vso
- vspw
);
112 set_entry(&timing
->vsync_len
, vspw
);
114 debug("Detailed mode clock %u Hz, %d mm x %d mm\n"
115 " %04x %04x %04x %04x hborder %x\n"
116 " %04x %04x %04x %04x vborder %x\n",
117 timing
->pixelclock
.typ
,
119 ha
, ha
+ hso
, ha
+ hso
+ hspw
,
121 va
, va
+ vso
, va
+ vso
+ vspw
,
125 int edid_get_timing(u8
*buf
, int buf_size
, struct display_timing
*timing
,
126 int *panel_bits_per_colourp
)
128 struct edid1_info
*edid
= (struct edid1_info
*)buf
;
132 if (buf_size
< sizeof(*edid
) || edid_check_info(edid
)) {
133 debug("%s: Invalid buffer\n", __func__
);
137 if (!EDID1_INFO_FEATURE_PREFERRED_TIMING_MODE(*edid
)) {
138 debug("%s: No preferred timing\n", __func__
);
142 /* Look for detailed timing */
144 for (i
= 0; i
< 4; i
++) {
145 struct edid_monitor_descriptor
*desc
;
147 desc
= &edid
->monitor_details
.descriptor
[i
];
148 if (desc
->zero_flag_1
!= 0) {
149 decode_timing((u8
*)desc
, timing
);
157 if (!EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid
)) {
158 debug("%s: Not a digital display\n", __func__
);
161 if (edid
->version
!= 1 || edid
->revision
< 4) {
162 debug("%s: EDID version %d.%d does not have required info\n",
163 __func__
, edid
->version
, edid
->revision
);
164 *panel_bits_per_colourp
= -1;
166 *panel_bits_per_colourp
=
167 ((edid
->video_input_definition
& 0x70) >> 3) + 4;
174 * Snip the tailing whitespace/return of a string.
176 * @param string The string to be snipped
177 * @return the snipped string
179 static char *snip(char *string
)
184 * This is always a 13 character buffer
185 * and it's not always terminated.
188 s
= &string
[strlen(string
) - 1];
190 while (s
>= string
&& (isspace(*s
) || *s
== '\n' || *s
== '\r' ||
198 * Print an EDID monitor descriptor block
200 * @param monitor The EDID monitor descriptor block
201 * @have_timing Modifies to 1 if the desciptor contains timing info
203 static void edid_print_dtd(struct edid_monitor_descriptor
*monitor
,
204 unsigned int *have_timing
)
206 unsigned char *bytes
= (unsigned char *)monitor
;
207 struct edid_detailed_timing
*timing
=
208 (struct edid_detailed_timing
*)monitor
;
210 if (bytes
[0] == 0 && bytes
[1] == 0) {
211 if (monitor
->type
== EDID_MONITOR_DESCRIPTOR_SERIAL
)
212 printf("Monitor serial number: %s\n",
213 snip(monitor
->data
.string
));
214 else if (monitor
->type
== EDID_MONITOR_DESCRIPTOR_ASCII
)
215 printf("Monitor ID: %s\n",
216 snip(monitor
->data
.string
));
217 else if (monitor
->type
== EDID_MONITOR_DESCRIPTOR_NAME
)
218 printf("Monitor name: %s\n",
219 snip(monitor
->data
.string
));
220 else if (monitor
->type
== EDID_MONITOR_DESCRIPTOR_RANGE
)
221 printf("Monitor range limits, horizontal sync: "
222 "%d-%d kHz, vertical refresh: "
223 "%d-%d Hz, max pixel clock: "
225 monitor
->data
.range_data
.horizontal_min
,
226 monitor
->data
.range_data
.horizontal_max
,
227 monitor
->data
.range_data
.vertical_min
,
228 monitor
->data
.range_data
.vertical_max
,
229 monitor
->data
.range_data
.pixel_clock_max
* 10);
231 uint32_t pixclock
, h_active
, h_blanking
, v_active
, v_blanking
;
232 uint32_t h_total
, v_total
, vfreq
;
234 pixclock
= EDID_DETAILED_TIMING_PIXEL_CLOCK(*timing
);
235 h_active
= EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(*timing
);
236 h_blanking
= EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(*timing
);
237 v_active
= EDID_DETAILED_TIMING_VERTICAL_ACTIVE(*timing
);
238 v_blanking
= EDID_DETAILED_TIMING_VERTICAL_BLANKING(*timing
);
240 h_total
= h_active
+ h_blanking
;
241 v_total
= v_active
+ v_blanking
;
242 if (v_total
* h_total
)
243 vfreq
= pixclock
/ (v_total
* h_total
);
245 vfreq
= 1; /* Error case */
246 printf("\t%dx%d\%c\t%d Hz (detailed)\n", h_active
,
247 v_active
, h_active
> 1000 ? ' ' : '\t', vfreq
);
253 * Get the manufacturer name from an EDID info.
255 * @param edid_info The EDID info to be printed
256 * @param name Returns the string of the manufacturer name
258 static void edid_get_manufacturer_name(struct edid1_info
*edid
, char *name
)
260 name
[0] = EDID1_INFO_MANUFACTURER_NAME_CHAR1(*edid
) + 'A' - 1;
261 name
[1] = EDID1_INFO_MANUFACTURER_NAME_CHAR2(*edid
) + 'A' - 1;
262 name
[2] = EDID1_INFO_MANUFACTURER_NAME_CHAR3(*edid
) + 'A' - 1;
266 void edid_print_info(struct edid1_info
*edid_info
)
269 char manufacturer
[4];
270 unsigned int have_timing
= 0;
271 uint32_t serial_number
;
273 if (edid_check_info(edid_info
)) {
274 printf("Not a valid EDID\n");
278 printf("EDID version: %d.%d\n",
279 edid_info
->version
, edid_info
->revision
);
281 printf("Product ID code: %04x\n", EDID1_INFO_PRODUCT_CODE(*edid_info
));
283 edid_get_manufacturer_name(edid_info
, manufacturer
);
284 printf("Manufacturer: %s\n", manufacturer
);
286 serial_number
= EDID1_INFO_SERIAL_NUMBER(*edid_info
);
287 if (serial_number
!= 0xffffffff) {
288 if (strcmp(manufacturer
, "MAG") == 0)
289 serial_number
-= 0x7000000;
290 if (strcmp(manufacturer
, "OQI") == 0)
291 serial_number
-= 456150000;
292 if (strcmp(manufacturer
, "VSC") == 0)
293 serial_number
-= 640000000;
295 printf("Serial number: %08x\n", serial_number
);
296 printf("Manufactured in week: %d year: %d\n",
297 edid_info
->week
, edid_info
->year
+ 1990);
299 printf("Video input definition: %svoltage level %d%s%s%s%s%s\n",
300 EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid_info
) ?
301 "digital signal, " : "analog signal, ",
302 EDID1_INFO_VIDEO_INPUT_VOLTAGE_LEVEL(*edid_info
),
303 EDID1_INFO_VIDEO_INPUT_BLANK_TO_BLACK(*edid_info
) ?
304 ", blank to black" : "",
305 EDID1_INFO_VIDEO_INPUT_SEPARATE_SYNC(*edid_info
) ?
306 ", separate sync" : "",
307 EDID1_INFO_VIDEO_INPUT_COMPOSITE_SYNC(*edid_info
) ?
308 ", composite sync" : "",
309 EDID1_INFO_VIDEO_INPUT_SYNC_ON_GREEN(*edid_info
) ?
310 ", sync on green" : "",
311 EDID1_INFO_VIDEO_INPUT_SERRATION_V(*edid_info
) ?
312 ", serration v" : "");
314 printf("Monitor is %s\n",
315 EDID1_INFO_FEATURE_RGB(*edid_info
) ? "RGB" : "non-RGB");
317 printf("Maximum visible display size: %d cm x %d cm\n",
318 edid_info
->max_size_horizontal
,
319 edid_info
->max_size_vertical
);
321 printf("Power management features: %s%s, %s%s, %s%s\n",
322 EDID1_INFO_FEATURE_ACTIVE_OFF(*edid_info
) ?
323 "" : "no ", "active off",
324 EDID1_INFO_FEATURE_SUSPEND(*edid_info
) ? "" : "no ", "suspend",
325 EDID1_INFO_FEATURE_STANDBY(*edid_info
) ? "" : "no ", "standby");
327 printf("Estabilished timings:\n");
328 if (EDID1_INFO_ESTABLISHED_TIMING_720X400_70(*edid_info
))
329 printf("\t720x400\t\t70 Hz (VGA 640x400, IBM)\n");
330 if (EDID1_INFO_ESTABLISHED_TIMING_720X400_88(*edid_info
))
331 printf("\t720x400\t\t88 Hz (XGA2)\n");
332 if (EDID1_INFO_ESTABLISHED_TIMING_640X480_60(*edid_info
))
333 printf("\t640x480\t\t60 Hz (VGA)\n");
334 if (EDID1_INFO_ESTABLISHED_TIMING_640X480_67(*edid_info
))
335 printf("\t640x480\t\t67 Hz (Mac II, Apple)\n");
336 if (EDID1_INFO_ESTABLISHED_TIMING_640X480_72(*edid_info
))
337 printf("\t640x480\t\t72 Hz (VESA)\n");
338 if (EDID1_INFO_ESTABLISHED_TIMING_640X480_75(*edid_info
))
339 printf("\t640x480\t\t75 Hz (VESA)\n");
340 if (EDID1_INFO_ESTABLISHED_TIMING_800X600_56(*edid_info
))
341 printf("\t800x600\t\t56 Hz (VESA)\n");
342 if (EDID1_INFO_ESTABLISHED_TIMING_800X600_60(*edid_info
))
343 printf("\t800x600\t\t60 Hz (VESA)\n");
344 if (EDID1_INFO_ESTABLISHED_TIMING_800X600_72(*edid_info
))
345 printf("\t800x600\t\t72 Hz (VESA)\n");
346 if (EDID1_INFO_ESTABLISHED_TIMING_800X600_75(*edid_info
))
347 printf("\t800x600\t\t75 Hz (VESA)\n");
348 if (EDID1_INFO_ESTABLISHED_TIMING_832X624_75(*edid_info
))
349 printf("\t832x624\t\t75 Hz (Mac II)\n");
350 if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_87I(*edid_info
))
351 printf("\t1024x768\t87 Hz Interlaced (8514A)\n");
352 if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_60(*edid_info
))
353 printf("\t1024x768\t60 Hz (VESA)\n");
354 if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_70(*edid_info
))
355 printf("\t1024x768\t70 Hz (VESA)\n");
356 if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_75(*edid_info
))
357 printf("\t1024x768\t75 Hz (VESA)\n");
358 if (EDID1_INFO_ESTABLISHED_TIMING_1280X1024_75(*edid_info
))
359 printf("\t1280x1024\t75 (VESA)\n");
360 if (EDID1_INFO_ESTABLISHED_TIMING_1152X870_75(*edid_info
))
361 printf("\t1152x870\t75 (Mac II)\n");
363 /* Standard timings. */
364 printf("Standard timings:\n");
365 for (i
= 0; i
< ARRAY_SIZE(edid_info
->standard_timings
); i
++) {
366 unsigned int aspect
= 10000;
368 unsigned char xres
, vfreq
;
370 xres
= EDID1_INFO_STANDARD_TIMING_XRESOLUTION(*edid_info
, i
);
371 vfreq
= EDID1_INFO_STANDARD_TIMING_VFREQ(*edid_info
, i
);
372 if ((xres
!= vfreq
) ||
373 ((xres
!= 0) && (xres
!= 1)) ||
374 ((vfreq
!= 0) && (vfreq
!= 1))) {
375 switch (EDID1_INFO_STANDARD_TIMING_ASPECT(*edid_info
,
391 y
= x
* aspect
/ 10000;
392 printf("\t%dx%d%c\t%d Hz\n", x
, y
,
393 x
> 1000 ? ' ' : '\t', (vfreq
& 0x3f) + 60);
398 /* Detailed timing information. */
399 for (i
= 0; i
< ARRAY_SIZE(edid_info
->monitor_details
.descriptor
);
401 edid_print_dtd(&edid_info
->monitor_details
.descriptor
[i
],