Merge tag 'md-3.9' of git://neil.brown.name/md
[firefly-linux-kernel-4.4.55.git] / drivers / gpu / drm / i915 / intel_bios.c
1 /*
2  * Copyright © 2006 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21  * SOFTWARE.
22  *
23  * Authors:
24  *    Eric Anholt <eric@anholt.net>
25  *
26  */
27 #include <linux/dmi.h>
28 #include <drm/drm_dp_helper.h>
29 #include <drm/drmP.h>
30 #include <drm/i915_drm.h>
31 #include "i915_drv.h"
32 #include "intel_bios.h"
33
34 #define SLAVE_ADDR1     0x70
35 #define SLAVE_ADDR2     0x72
36
37 static int panel_type;
38
39 static void *
40 find_section(struct bdb_header *bdb, int section_id)
41 {
42         u8 *base = (u8 *)bdb;
43         int index = 0;
44         u16 total, current_size;
45         u8 current_id;
46
47         /* skip to first section */
48         index += bdb->header_size;
49         total = bdb->bdb_size;
50
51         /* walk the sections looking for section_id */
52         while (index < total) {
53                 current_id = *(base + index);
54                 index++;
55                 current_size = *((u16 *)(base + index));
56                 index += 2;
57                 if (current_id == section_id)
58                         return base + index;
59                 index += current_size;
60         }
61
62         return NULL;
63 }
64
65 static u16
66 get_blocksize(void *p)
67 {
68         u16 *block_ptr, block_size;
69
70         block_ptr = (u16 *)((char *)p - 2);
71         block_size = *block_ptr;
72         return block_size;
73 }
74
75 static void
76 fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
77                         const struct lvds_dvo_timing *dvo_timing)
78 {
79         panel_fixed_mode->hdisplay = (dvo_timing->hactive_hi << 8) |
80                 dvo_timing->hactive_lo;
81         panel_fixed_mode->hsync_start = panel_fixed_mode->hdisplay +
82                 ((dvo_timing->hsync_off_hi << 8) | dvo_timing->hsync_off_lo);
83         panel_fixed_mode->hsync_end = panel_fixed_mode->hsync_start +
84                 dvo_timing->hsync_pulse_width;
85         panel_fixed_mode->htotal = panel_fixed_mode->hdisplay +
86                 ((dvo_timing->hblank_hi << 8) | dvo_timing->hblank_lo);
87
88         panel_fixed_mode->vdisplay = (dvo_timing->vactive_hi << 8) |
89                 dvo_timing->vactive_lo;
90         panel_fixed_mode->vsync_start = panel_fixed_mode->vdisplay +
91                 dvo_timing->vsync_off;
92         panel_fixed_mode->vsync_end = panel_fixed_mode->vsync_start +
93                 dvo_timing->vsync_pulse_width;
94         panel_fixed_mode->vtotal = panel_fixed_mode->vdisplay +
95                 ((dvo_timing->vblank_hi << 8) | dvo_timing->vblank_lo);
96         panel_fixed_mode->clock = dvo_timing->clock * 10;
97         panel_fixed_mode->type = DRM_MODE_TYPE_PREFERRED;
98
99         if (dvo_timing->hsync_positive)
100                 panel_fixed_mode->flags |= DRM_MODE_FLAG_PHSYNC;
101         else
102                 panel_fixed_mode->flags |= DRM_MODE_FLAG_NHSYNC;
103
104         if (dvo_timing->vsync_positive)
105                 panel_fixed_mode->flags |= DRM_MODE_FLAG_PVSYNC;
106         else
107                 panel_fixed_mode->flags |= DRM_MODE_FLAG_NVSYNC;
108
109         /* Some VBTs have bogus h/vtotal values */
110         if (panel_fixed_mode->hsync_end > panel_fixed_mode->htotal)
111                 panel_fixed_mode->htotal = panel_fixed_mode->hsync_end + 1;
112         if (panel_fixed_mode->vsync_end > panel_fixed_mode->vtotal)
113                 panel_fixed_mode->vtotal = panel_fixed_mode->vsync_end + 1;
114
115         drm_mode_set_name(panel_fixed_mode);
116 }
117
118 static bool
119 lvds_dvo_timing_equal_size(const struct lvds_dvo_timing *a,
120                            const struct lvds_dvo_timing *b)
121 {
122         if (a->hactive_hi != b->hactive_hi ||
123             a->hactive_lo != b->hactive_lo)
124                 return false;
125
126         if (a->hsync_off_hi != b->hsync_off_hi ||
127             a->hsync_off_lo != b->hsync_off_lo)
128                 return false;
129
130         if (a->hsync_pulse_width != b->hsync_pulse_width)
131                 return false;
132
133         if (a->hblank_hi != b->hblank_hi ||
134             a->hblank_lo != b->hblank_lo)
135                 return false;
136
137         if (a->vactive_hi != b->vactive_hi ||
138             a->vactive_lo != b->vactive_lo)
139                 return false;
140
141         if (a->vsync_off != b->vsync_off)
142                 return false;
143
144         if (a->vsync_pulse_width != b->vsync_pulse_width)
145                 return false;
146
147         if (a->vblank_hi != b->vblank_hi ||
148             a->vblank_lo != b->vblank_lo)
149                 return false;
150
151         return true;
152 }
153
154 static const struct lvds_dvo_timing *
155 get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,
156                     const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,
157                     int index)
158 {
159         /*
160          * the size of fp_timing varies on the different platform.
161          * So calculate the DVO timing relative offset in LVDS data
162          * entry to get the DVO timing entry
163          */
164
165         int lfp_data_size =
166                 lvds_lfp_data_ptrs->ptr[1].dvo_timing_offset -
167                 lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset;
168         int dvo_timing_offset =
169                 lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset -
170                 lvds_lfp_data_ptrs->ptr[0].fp_timing_offset;
171         char *entry = (char *)lvds_lfp_data->data + lfp_data_size * index;
172
173         return (struct lvds_dvo_timing *)(entry + dvo_timing_offset);
174 }
175
176 /* get lvds_fp_timing entry
177  * this function may return NULL if the corresponding entry is invalid
178  */
179 static const struct lvds_fp_timing *
180 get_lvds_fp_timing(const struct bdb_header *bdb,
181                    const struct bdb_lvds_lfp_data *data,
182                    const struct bdb_lvds_lfp_data_ptrs *ptrs,
183                    int index)
184 {
185         size_t data_ofs = (const u8 *)data - (const u8 *)bdb;
186         u16 data_size = ((const u16 *)data)[-1]; /* stored in header */
187         size_t ofs;
188
189         if (index >= ARRAY_SIZE(ptrs->ptr))
190                 return NULL;
191         ofs = ptrs->ptr[index].fp_timing_offset;
192         if (ofs < data_ofs ||
193             ofs + sizeof(struct lvds_fp_timing) > data_ofs + data_size)
194                 return NULL;
195         return (const struct lvds_fp_timing *)((const u8 *)bdb + ofs);
196 }
197
198 /* Try to find integrated panel data */
199 static void
200 parse_lfp_panel_data(struct drm_i915_private *dev_priv,
201                             struct bdb_header *bdb)
202 {
203         const struct bdb_lvds_options *lvds_options;
204         const struct bdb_lvds_lfp_data *lvds_lfp_data;
205         const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs;
206         const struct lvds_dvo_timing *panel_dvo_timing;
207         const struct lvds_fp_timing *fp_timing;
208         struct drm_display_mode *panel_fixed_mode;
209         int i, downclock;
210
211         lvds_options = find_section(bdb, BDB_LVDS_OPTIONS);
212         if (!lvds_options)
213                 return;
214
215         dev_priv->lvds_dither = lvds_options->pixel_dither;
216         if (lvds_options->panel_type == 0xff)
217                 return;
218
219         panel_type = lvds_options->panel_type;
220
221         lvds_lfp_data = find_section(bdb, BDB_LVDS_LFP_DATA);
222         if (!lvds_lfp_data)
223                 return;
224
225         lvds_lfp_data_ptrs = find_section(bdb, BDB_LVDS_LFP_DATA_PTRS);
226         if (!lvds_lfp_data_ptrs)
227                 return;
228
229         dev_priv->lvds_vbt = 1;
230
231         panel_dvo_timing = get_lvds_dvo_timing(lvds_lfp_data,
232                                                lvds_lfp_data_ptrs,
233                                                lvds_options->panel_type);
234
235         panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode), GFP_KERNEL);
236         if (!panel_fixed_mode)
237                 return;
238
239         fill_detail_timing_data(panel_fixed_mode, panel_dvo_timing);
240
241         dev_priv->lfp_lvds_vbt_mode = panel_fixed_mode;
242
243         DRM_DEBUG_KMS("Found panel mode in BIOS VBT tables:\n");
244         drm_mode_debug_printmodeline(panel_fixed_mode);
245
246         /*
247          * Iterate over the LVDS panel timing info to find the lowest clock
248          * for the native resolution.
249          */
250         downclock = panel_dvo_timing->clock;
251         for (i = 0; i < 16; i++) {
252                 const struct lvds_dvo_timing *dvo_timing;
253
254                 dvo_timing = get_lvds_dvo_timing(lvds_lfp_data,
255                                                  lvds_lfp_data_ptrs,
256                                                  i);
257                 if (lvds_dvo_timing_equal_size(dvo_timing, panel_dvo_timing) &&
258                     dvo_timing->clock < downclock)
259                         downclock = dvo_timing->clock;
260         }
261
262         if (downclock < panel_dvo_timing->clock && i915_lvds_downclock) {
263                 dev_priv->lvds_downclock_avail = 1;
264                 dev_priv->lvds_downclock = downclock * 10;
265                 DRM_DEBUG_KMS("LVDS downclock is found in VBT. "
266                               "Normal Clock %dKHz, downclock %dKHz\n",
267                               panel_fixed_mode->clock, 10*downclock);
268         }
269
270         fp_timing = get_lvds_fp_timing(bdb, lvds_lfp_data,
271                                        lvds_lfp_data_ptrs,
272                                        lvds_options->panel_type);
273         if (fp_timing) {
274                 /* check the resolution, just to be sure */
275                 if (fp_timing->x_res == panel_fixed_mode->hdisplay &&
276                     fp_timing->y_res == panel_fixed_mode->vdisplay) {
277                         dev_priv->bios_lvds_val = fp_timing->lvds_reg_val;
278                         DRM_DEBUG_KMS("VBT initial LVDS value %x\n",
279                                       dev_priv->bios_lvds_val);
280                 }
281         }
282 }
283
284 /* Try to find sdvo panel data */
285 static void
286 parse_sdvo_panel_data(struct drm_i915_private *dev_priv,
287                       struct bdb_header *bdb)
288 {
289         struct lvds_dvo_timing *dvo_timing;
290         struct drm_display_mode *panel_fixed_mode;
291         int index;
292
293         index = i915_vbt_sdvo_panel_type;
294         if (index == -2) {
295                 DRM_DEBUG_KMS("Ignore SDVO panel mode from BIOS VBT tables.\n");
296                 return;
297         }
298
299         if (index == -1) {
300                 struct bdb_sdvo_lvds_options *sdvo_lvds_options;
301
302                 sdvo_lvds_options = find_section(bdb, BDB_SDVO_LVDS_OPTIONS);
303                 if (!sdvo_lvds_options)
304                         return;
305
306                 index = sdvo_lvds_options->panel_type;
307         }
308
309         dvo_timing = find_section(bdb, BDB_SDVO_PANEL_DTDS);
310         if (!dvo_timing)
311                 return;
312
313         panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode), GFP_KERNEL);
314         if (!panel_fixed_mode)
315                 return;
316
317         fill_detail_timing_data(panel_fixed_mode, dvo_timing + index);
318
319         dev_priv->sdvo_lvds_vbt_mode = panel_fixed_mode;
320
321         DRM_DEBUG_KMS("Found SDVO panel mode in BIOS VBT tables:\n");
322         drm_mode_debug_printmodeline(panel_fixed_mode);
323 }
324
325 static int intel_bios_ssc_frequency(struct drm_device *dev,
326                                     bool alternate)
327 {
328         switch (INTEL_INFO(dev)->gen) {
329         case 2:
330                 return alternate ? 66 : 48;
331         case 3:
332         case 4:
333                 return alternate ? 100 : 96;
334         default:
335                 return alternate ? 100 : 120;
336         }
337 }
338
339 static void
340 parse_general_features(struct drm_i915_private *dev_priv,
341                        struct bdb_header *bdb)
342 {
343         struct drm_device *dev = dev_priv->dev;
344         struct bdb_general_features *general;
345
346         general = find_section(bdb, BDB_GENERAL_FEATURES);
347         if (general) {
348                 dev_priv->int_tv_support = general->int_tv_support;
349                 dev_priv->int_crt_support = general->int_crt_support;
350                 dev_priv->lvds_use_ssc = general->enable_ssc;
351                 dev_priv->lvds_ssc_freq =
352                         intel_bios_ssc_frequency(dev, general->ssc_freq);
353                 dev_priv->display_clock_mode = general->display_clock_mode;
354                 DRM_DEBUG_KMS("BDB_GENERAL_FEATURES int_tv_support %d int_crt_support %d lvds_use_ssc %d lvds_ssc_freq %d display_clock_mode %d\n",
355                               dev_priv->int_tv_support,
356                               dev_priv->int_crt_support,
357                               dev_priv->lvds_use_ssc,
358                               dev_priv->lvds_ssc_freq,
359                               dev_priv->display_clock_mode);
360         }
361 }
362
363 static void
364 parse_general_definitions(struct drm_i915_private *dev_priv,
365                           struct bdb_header *bdb)
366 {
367         struct bdb_general_definitions *general;
368
369         general = find_section(bdb, BDB_GENERAL_DEFINITIONS);
370         if (general) {
371                 u16 block_size = get_blocksize(general);
372                 if (block_size >= sizeof(*general)) {
373                         int bus_pin = general->crt_ddc_gmbus_pin;
374                         DRM_DEBUG_KMS("crt_ddc_bus_pin: %d\n", bus_pin);
375                         if (intel_gmbus_is_port_valid(bus_pin))
376                                 dev_priv->crt_ddc_pin = bus_pin;
377                 } else {
378                         DRM_DEBUG_KMS("BDB_GD too small (%d). Invalid.\n",
379                                       block_size);
380                 }
381         }
382 }
383
384 static void
385 parse_sdvo_device_mapping(struct drm_i915_private *dev_priv,
386                           struct bdb_header *bdb)
387 {
388         struct sdvo_device_mapping *p_mapping;
389         struct bdb_general_definitions *p_defs;
390         struct child_device_config *p_child;
391         int i, child_device_num, count;
392         u16     block_size;
393
394         p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
395         if (!p_defs) {
396                 DRM_DEBUG_KMS("No general definition block is found, unable to construct sdvo mapping.\n");
397                 return;
398         }
399         /* judge whether the size of child device meets the requirements.
400          * If the child device size obtained from general definition block
401          * is different with sizeof(struct child_device_config), skip the
402          * parsing of sdvo device info
403          */
404         if (p_defs->child_dev_size != sizeof(*p_child)) {
405                 /* different child dev size . Ignore it */
406                 DRM_DEBUG_KMS("different child size is found. Invalid.\n");
407                 return;
408         }
409         /* get the block size of general definitions */
410         block_size = get_blocksize(p_defs);
411         /* get the number of child device */
412         child_device_num = (block_size - sizeof(*p_defs)) /
413                                 sizeof(*p_child);
414         count = 0;
415         for (i = 0; i < child_device_num; i++) {
416                 p_child = &(p_defs->devices[i]);
417                 if (!p_child->device_type) {
418                         /* skip the device block if device type is invalid */
419                         continue;
420                 }
421                 if (p_child->slave_addr != SLAVE_ADDR1 &&
422                         p_child->slave_addr != SLAVE_ADDR2) {
423                         /*
424                          * If the slave address is neither 0x70 nor 0x72,
425                          * it is not a SDVO device. Skip it.
426                          */
427                         continue;
428                 }
429                 if (p_child->dvo_port != DEVICE_PORT_DVOB &&
430                         p_child->dvo_port != DEVICE_PORT_DVOC) {
431                         /* skip the incorrect SDVO port */
432                         DRM_DEBUG_KMS("Incorrect SDVO port. Skip it\n");
433                         continue;
434                 }
435                 DRM_DEBUG_KMS("the SDVO device with slave addr %2x is found on"
436                                 " %s port\n",
437                                 p_child->slave_addr,
438                                 (p_child->dvo_port == DEVICE_PORT_DVOB) ?
439                                         "SDVOB" : "SDVOC");
440                 p_mapping = &(dev_priv->sdvo_mappings[p_child->dvo_port - 1]);
441                 if (!p_mapping->initialized) {
442                         p_mapping->dvo_port = p_child->dvo_port;
443                         p_mapping->slave_addr = p_child->slave_addr;
444                         p_mapping->dvo_wiring = p_child->dvo_wiring;
445                         p_mapping->ddc_pin = p_child->ddc_pin;
446                         p_mapping->i2c_pin = p_child->i2c_pin;
447                         p_mapping->initialized = 1;
448                         DRM_DEBUG_KMS("SDVO device: dvo=%x, addr=%x, wiring=%d, ddc_pin=%d, i2c_pin=%d\n",
449                                       p_mapping->dvo_port,
450                                       p_mapping->slave_addr,
451                                       p_mapping->dvo_wiring,
452                                       p_mapping->ddc_pin,
453                                       p_mapping->i2c_pin);
454                 } else {
455                         DRM_DEBUG_KMS("Maybe one SDVO port is shared by "
456                                          "two SDVO device.\n");
457                 }
458                 if (p_child->slave2_addr) {
459                         /* Maybe this is a SDVO device with multiple inputs */
460                         /* And the mapping info is not added */
461                         DRM_DEBUG_KMS("there exists the slave2_addr. Maybe this"
462                                 " is a SDVO device with multiple inputs.\n");
463                 }
464                 count++;
465         }
466
467         if (!count) {
468                 /* No SDVO device info is found */
469                 DRM_DEBUG_KMS("No SDVO device info is found in VBT\n");
470         }
471         return;
472 }
473
474 static void
475 parse_driver_features(struct drm_i915_private *dev_priv,
476                        struct bdb_header *bdb)
477 {
478         struct drm_device *dev = dev_priv->dev;
479         struct bdb_driver_features *driver;
480
481         driver = find_section(bdb, BDB_DRIVER_FEATURES);
482         if (!driver)
483                 return;
484
485         if (SUPPORTS_EDP(dev) &&
486             driver->lvds_config == BDB_DRIVER_FEATURE_EDP)
487                 dev_priv->edp.support = 1;
488
489         if (driver->dual_frequency)
490                 dev_priv->render_reclock_avail = true;
491 }
492
493 static void
494 parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
495 {
496         struct bdb_edp *edp;
497         struct edp_power_seq *edp_pps;
498         struct edp_link_params *edp_link_params;
499
500         edp = find_section(bdb, BDB_EDP);
501         if (!edp) {
502                 if (SUPPORTS_EDP(dev_priv->dev) && dev_priv->edp.support)
503                         DRM_DEBUG_KMS("No eDP BDB found but eDP panel supported.\n");
504                 return;
505         }
506
507         switch ((edp->color_depth >> (panel_type * 2)) & 3) {
508         case EDP_18BPP:
509                 dev_priv->edp.bpp = 18;
510                 break;
511         case EDP_24BPP:
512                 dev_priv->edp.bpp = 24;
513                 break;
514         case EDP_30BPP:
515                 dev_priv->edp.bpp = 30;
516                 break;
517         }
518
519         /* Get the eDP sequencing and link info */
520         edp_pps = &edp->power_seqs[panel_type];
521         edp_link_params = &edp->link_params[panel_type];
522
523         dev_priv->edp.pps = *edp_pps;
524
525         dev_priv->edp.rate = edp_link_params->rate ? DP_LINK_BW_2_7 :
526                 DP_LINK_BW_1_62;
527         switch (edp_link_params->lanes) {
528         case 0:
529                 dev_priv->edp.lanes = 1;
530                 break;
531         case 1:
532                 dev_priv->edp.lanes = 2;
533                 break;
534         case 3:
535         default:
536                 dev_priv->edp.lanes = 4;
537                 break;
538         }
539         switch (edp_link_params->preemphasis) {
540         case 0:
541                 dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_0;
542                 break;
543         case 1:
544                 dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_3_5;
545                 break;
546         case 2:
547                 dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_6;
548                 break;
549         case 3:
550                 dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_9_5;
551                 break;
552         }
553         switch (edp_link_params->vswing) {
554         case 0:
555                 dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_400;
556                 break;
557         case 1:
558                 dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_600;
559                 break;
560         case 2:
561                 dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_800;
562                 break;
563         case 3:
564                 dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_1200;
565                 break;
566         }
567 }
568
569 static void
570 parse_device_mapping(struct drm_i915_private *dev_priv,
571                        struct bdb_header *bdb)
572 {
573         struct bdb_general_definitions *p_defs;
574         struct child_device_config *p_child, *child_dev_ptr;
575         int i, child_device_num, count;
576         u16     block_size;
577
578         p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
579         if (!p_defs) {
580                 DRM_DEBUG_KMS("No general definition block is found, no devices defined.\n");
581                 return;
582         }
583         /* judge whether the size of child device meets the requirements.
584          * If the child device size obtained from general definition block
585          * is different with sizeof(struct child_device_config), skip the
586          * parsing of sdvo device info
587          */
588         if (p_defs->child_dev_size != sizeof(*p_child)) {
589                 /* different child dev size . Ignore it */
590                 DRM_DEBUG_KMS("different child size is found. Invalid.\n");
591                 return;
592         }
593         /* get the block size of general definitions */
594         block_size = get_blocksize(p_defs);
595         /* get the number of child device */
596         child_device_num = (block_size - sizeof(*p_defs)) /
597                                 sizeof(*p_child);
598         count = 0;
599         /* get the number of child device that is present */
600         for (i = 0; i < child_device_num; i++) {
601                 p_child = &(p_defs->devices[i]);
602                 if (!p_child->device_type) {
603                         /* skip the device block if device type is invalid */
604                         continue;
605                 }
606                 count++;
607         }
608         if (!count) {
609                 DRM_DEBUG_KMS("no child dev is parsed from VBT\n");
610                 return;
611         }
612         dev_priv->child_dev = kcalloc(count, sizeof(*p_child), GFP_KERNEL);
613         if (!dev_priv->child_dev) {
614                 DRM_DEBUG_KMS("No memory space for child device\n");
615                 return;
616         }
617
618         dev_priv->child_dev_num = count;
619         count = 0;
620         for (i = 0; i < child_device_num; i++) {
621                 p_child = &(p_defs->devices[i]);
622                 if (!p_child->device_type) {
623                         /* skip the device block if device type is invalid */
624                         continue;
625                 }
626                 child_dev_ptr = dev_priv->child_dev + count;
627                 count++;
628                 memcpy((void *)child_dev_ptr, (void *)p_child,
629                                         sizeof(*p_child));
630         }
631         return;
632 }
633
634 static void
635 init_vbt_defaults(struct drm_i915_private *dev_priv)
636 {
637         struct drm_device *dev = dev_priv->dev;
638
639         dev_priv->crt_ddc_pin = GMBUS_PORT_VGADDC;
640
641         /* LFP panel data */
642         dev_priv->lvds_dither = 1;
643         dev_priv->lvds_vbt = 0;
644
645         /* SDVO panel data */
646         dev_priv->sdvo_lvds_vbt_mode = NULL;
647
648         /* general features */
649         dev_priv->int_tv_support = 1;
650         dev_priv->int_crt_support = 1;
651
652         /* Default to using SSC */
653         dev_priv->lvds_use_ssc = 1;
654         dev_priv->lvds_ssc_freq = intel_bios_ssc_frequency(dev, 1);
655         DRM_DEBUG_KMS("Set default to SSC at %dMHz\n", dev_priv->lvds_ssc_freq);
656 }
657
658 static int __init intel_no_opregion_vbt_callback(const struct dmi_system_id *id)
659 {
660         DRM_DEBUG_KMS("Falling back to manually reading VBT from "
661                       "VBIOS ROM for %s\n",
662                       id->ident);
663         return 1;
664 }
665
666 static const struct dmi_system_id intel_no_opregion_vbt[] = {
667         {
668                 .callback = intel_no_opregion_vbt_callback,
669                 .ident = "ThinkCentre A57",
670                 .matches = {
671                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
672                         DMI_MATCH(DMI_PRODUCT_NAME, "97027RG"),
673                 },
674         },
675         { }
676 };
677
678 /**
679  * intel_parse_bios - find VBT and initialize settings from the BIOS
680  * @dev: DRM device
681  *
682  * Loads the Video BIOS and checks that the VBT exists.  Sets scratch registers
683  * to appropriate values.
684  *
685  * Returns 0 on success, nonzero on failure.
686  */
687 int
688 intel_parse_bios(struct drm_device *dev)
689 {
690         struct drm_i915_private *dev_priv = dev->dev_private;
691         struct pci_dev *pdev = dev->pdev;
692         struct bdb_header *bdb = NULL;
693         u8 __iomem *bios = NULL;
694
695         init_vbt_defaults(dev_priv);
696
697         /* XXX Should this validation be moved to intel_opregion.c? */
698         if (!dmi_check_system(intel_no_opregion_vbt) && dev_priv->opregion.vbt) {
699                 struct vbt_header *vbt = dev_priv->opregion.vbt;
700                 if (memcmp(vbt->signature, "$VBT", 4) == 0) {
701                         DRM_DEBUG_KMS("Using VBT from OpRegion: %20s\n",
702                                          vbt->signature);
703                         bdb = (struct bdb_header *)((char *)vbt + vbt->bdb_offset);
704                 } else
705                         dev_priv->opregion.vbt = NULL;
706         }
707
708         if (bdb == NULL) {
709                 struct vbt_header *vbt = NULL;
710                 size_t size;
711                 int i;
712
713                 bios = pci_map_rom(pdev, &size);
714                 if (!bios)
715                         return -1;
716
717                 /* Scour memory looking for the VBT signature */
718                 for (i = 0; i + 4 < size; i++) {
719                         if (!memcmp(bios + i, "$VBT", 4)) {
720                                 vbt = (struct vbt_header *)(bios + i);
721                                 break;
722                         }
723                 }
724
725                 if (!vbt) {
726                         DRM_DEBUG_DRIVER("VBT signature missing\n");
727                         pci_unmap_rom(pdev, bios);
728                         return -1;
729                 }
730
731                 bdb = (struct bdb_header *)(bios + i + vbt->bdb_offset);
732         }
733
734         /* Grab useful general definitions */
735         parse_general_features(dev_priv, bdb);
736         parse_general_definitions(dev_priv, bdb);
737         parse_lfp_panel_data(dev_priv, bdb);
738         parse_sdvo_panel_data(dev_priv, bdb);
739         parse_sdvo_device_mapping(dev_priv, bdb);
740         parse_device_mapping(dev_priv, bdb);
741         parse_driver_features(dev_priv, bdb);
742         parse_edp(dev_priv, bdb);
743
744         if (bios)
745                 pci_unmap_rom(pdev, bios);
746
747         return 0;
748 }
749
750 /* Ensure that vital registers have been initialised, even if the BIOS
751  * is absent or just failing to do its job.
752  */
753 void intel_setup_bios(struct drm_device *dev)
754 {
755         struct drm_i915_private *dev_priv = dev->dev_private;
756
757          /* Set the Panel Power On/Off timings if uninitialized. */
758         if (!HAS_PCH_SPLIT(dev) &&
759             I915_READ(PP_ON_DELAYS) == 0 && I915_READ(PP_OFF_DELAYS) == 0) {
760                 /* Set T2 to 40ms and T5 to 200ms */
761                 I915_WRITE(PP_ON_DELAYS, 0x019007d0);
762
763                 /* Set T3 to 35ms and Tx to 200ms */
764                 I915_WRITE(PP_OFF_DELAYS, 0x015e07d0);
765         }
766 }