xref: /dragonfly/sys/dev/drm/i915/intel_bios.c (revision b29f78b5)
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 <drm/drmP.h>
28 #include <drm/drm_dp_helper.h>
29 #include <drm/i915_drm.h>
30 #include "i915_drv.h"
31 #include "intel_bios.h"
32 
33 #define	SLAVE_ADDR1	0x70
34 #define	SLAVE_ADDR2	0x72
35 
36 static int panel_type;
37 
38 static void *
39 find_section(struct bdb_header *bdb, int section_id)
40 {
41 	u8 *base = (u8 *)bdb;
42 	int index = 0;
43 	u16 total, current_size;
44 	u8 current_id;
45 
46 	/* skip to first section */
47 	index += bdb->header_size;
48 	total = bdb->bdb_size;
49 
50 	/* walk the sections looking for section_id */
51 	while (index < total) {
52 		current_id = *(base + index);
53 		index++;
54 		current_size = *((u16 *)(base + index));
55 		index += 2;
56 		if (current_id == section_id)
57 			return base + index;
58 		index += current_size;
59 	}
60 
61 	return NULL;
62 }
63 
64 static u16
65 get_blocksize(void *p)
66 {
67 	u16 *block_ptr, block_size;
68 
69 	block_ptr = (u16 *)((char *)p - 2);
70 	block_size = *block_ptr;
71 	return block_size;
72 }
73 
74 static void
75 fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
76 			const struct lvds_dvo_timing *dvo_timing)
77 {
78 	panel_fixed_mode->hdisplay = (dvo_timing->hactive_hi << 8) |
79 		dvo_timing->hactive_lo;
80 	panel_fixed_mode->hsync_start = panel_fixed_mode->hdisplay +
81 		((dvo_timing->hsync_off_hi << 8) | dvo_timing->hsync_off_lo);
82 	panel_fixed_mode->hsync_end = panel_fixed_mode->hsync_start +
83 		dvo_timing->hsync_pulse_width;
84 	panel_fixed_mode->htotal = panel_fixed_mode->hdisplay +
85 		((dvo_timing->hblank_hi << 8) | dvo_timing->hblank_lo);
86 
87 	panel_fixed_mode->vdisplay = (dvo_timing->vactive_hi << 8) |
88 		dvo_timing->vactive_lo;
89 	panel_fixed_mode->vsync_start = panel_fixed_mode->vdisplay +
90 		dvo_timing->vsync_off;
91 	panel_fixed_mode->vsync_end = panel_fixed_mode->vsync_start +
92 		dvo_timing->vsync_pulse_width;
93 	panel_fixed_mode->vtotal = panel_fixed_mode->vdisplay +
94 		((dvo_timing->vblank_hi << 8) | dvo_timing->vblank_lo);
95 	panel_fixed_mode->clock = dvo_timing->clock * 10;
96 	panel_fixed_mode->type = DRM_MODE_TYPE_PREFERRED;
97 
98 	if (dvo_timing->hsync_positive)
99 		panel_fixed_mode->flags |= DRM_MODE_FLAG_PHSYNC;
100 	else
101 		panel_fixed_mode->flags |= DRM_MODE_FLAG_NHSYNC;
102 
103 	if (dvo_timing->vsync_positive)
104 		panel_fixed_mode->flags |= DRM_MODE_FLAG_PVSYNC;
105 	else
106 		panel_fixed_mode->flags |= DRM_MODE_FLAG_NVSYNC;
107 
108 	/* Some VBTs have bogus h/vtotal values */
109 	if (panel_fixed_mode->hsync_end > panel_fixed_mode->htotal)
110 		panel_fixed_mode->htotal = panel_fixed_mode->hsync_end + 1;
111 	if (panel_fixed_mode->vsync_end > panel_fixed_mode->vtotal)
112 		panel_fixed_mode->vtotal = panel_fixed_mode->vsync_end + 1;
113 
114 	drm_mode_set_name(panel_fixed_mode);
115 }
116 
117 static bool
118 lvds_dvo_timing_equal_size(const struct lvds_dvo_timing *a,
119 			   const struct lvds_dvo_timing *b)
120 {
121 	if (a->hactive_hi != b->hactive_hi ||
122 	    a->hactive_lo != b->hactive_lo)
123 		return false;
124 
125 	if (a->hsync_off_hi != b->hsync_off_hi ||
126 	    a->hsync_off_lo != b->hsync_off_lo)
127 		return false;
128 
129 	if (a->hsync_pulse_width != b->hsync_pulse_width)
130 		return false;
131 
132 	if (a->hblank_hi != b->hblank_hi ||
133 	    a->hblank_lo != b->hblank_lo)
134 		return false;
135 
136 	if (a->vactive_hi != b->vactive_hi ||
137 	    a->vactive_lo != b->vactive_lo)
138 		return false;
139 
140 	if (a->vsync_off != b->vsync_off)
141 		return false;
142 
143 	if (a->vsync_pulse_width != b->vsync_pulse_width)
144 		return false;
145 
146 	if (a->vblank_hi != b->vblank_hi ||
147 	    a->vblank_lo != b->vblank_lo)
148 		return false;
149 
150 	return true;
151 }
152 
153 static const struct lvds_dvo_timing *
154 get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,
155 		    const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,
156 		    int index)
157 {
158 	/*
159 	 * the size of fp_timing varies on the different platform.
160 	 * So calculate the DVO timing relative offset in LVDS data
161 	 * entry to get the DVO timing entry
162 	 */
163 
164 	int lfp_data_size =
165 		lvds_lfp_data_ptrs->ptr[1].dvo_timing_offset -
166 		lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset;
167 	int dvo_timing_offset =
168 		lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset -
169 		lvds_lfp_data_ptrs->ptr[0].fp_timing_offset;
170 	const char *entry = (const char *)lvds_lfp_data->data + lfp_data_size * index;
171 
172 	return (const struct lvds_dvo_timing *)(entry + dvo_timing_offset);
173 }
174 
175 /* get lvds_fp_timing entry
176  * this function may return NULL if the corresponding entry is invalid
177  */
178 static const struct lvds_fp_timing *
179 get_lvds_fp_timing(const struct bdb_header *bdb,
180 		   const struct bdb_lvds_lfp_data *data,
181 		   const struct bdb_lvds_lfp_data_ptrs *ptrs,
182 		   int index)
183 {
184 	size_t data_ofs = (const u8 *)data - (const u8 *)bdb;
185 	u16 data_size = ((const u16 *)data)[-1]; /* stored in header */
186 	size_t ofs;
187 
188 	if (index >= ARRAY_SIZE(ptrs->ptr))
189 		return NULL;
190 	ofs = ptrs->ptr[index].fp_timing_offset;
191 	if (ofs < data_ofs ||
192 	    ofs + sizeof(struct lvds_fp_timing) > data_ofs + data_size)
193 		return NULL;
194 	return (const struct lvds_fp_timing *)((const u8 *)bdb + ofs);
195 }
196 
197 /* Try to find integrated panel data */
198 static void
199 parse_lfp_panel_data(struct drm_i915_private *dev_priv,
200 			    struct bdb_header *bdb)
201 {
202 	const struct bdb_lvds_options *lvds_options;
203 	const struct bdb_lvds_lfp_data *lvds_lfp_data;
204 	const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs;
205 	const struct lvds_dvo_timing *panel_dvo_timing;
206 	const struct lvds_fp_timing *fp_timing;
207 	struct drm_display_mode *panel_fixed_mode;
208 	int i, downclock;
209 
210 	lvds_options = find_section(bdb, BDB_LVDS_OPTIONS);
211 	if (!lvds_options)
212 		return;
213 
214 	dev_priv->vbt.lvds_dither = lvds_options->pixel_dither;
215 	if (lvds_options->panel_type == 0xff)
216 		return;
217 
218 	panel_type = lvds_options->panel_type;
219 
220 	lvds_lfp_data = find_section(bdb, BDB_LVDS_LFP_DATA);
221 	if (!lvds_lfp_data)
222 		return;
223 
224 	lvds_lfp_data_ptrs = find_section(bdb, BDB_LVDS_LFP_DATA_PTRS);
225 	if (!lvds_lfp_data_ptrs)
226 		return;
227 
228 	dev_priv->vbt.lvds_vbt = 1;
229 
230 	panel_dvo_timing = get_lvds_dvo_timing(lvds_lfp_data,
231 					       lvds_lfp_data_ptrs,
232 					       lvds_options->panel_type);
233 
234 	panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode), GFP_KERNEL);
235 	if (!panel_fixed_mode)
236 		return;
237 
238 	fill_detail_timing_data(panel_fixed_mode, panel_dvo_timing);
239 
240 	dev_priv->vbt.lfp_lvds_vbt_mode = panel_fixed_mode;
241 
242 	DRM_DEBUG_KMS("Found panel mode in BIOS VBT tables:\n");
243 	drm_mode_debug_printmodeline(panel_fixed_mode);
244 
245 	/*
246 	 * Iterate over the LVDS panel timing info to find the lowest clock
247 	 * for the native resolution.
248 	 */
249 	downclock = panel_dvo_timing->clock;
250 	for (i = 0; i < 16; i++) {
251 		const struct lvds_dvo_timing *dvo_timing;
252 
253 		dvo_timing = get_lvds_dvo_timing(lvds_lfp_data,
254 						 lvds_lfp_data_ptrs,
255 						 i);
256 		if (lvds_dvo_timing_equal_size(dvo_timing, panel_dvo_timing) &&
257 		    dvo_timing->clock < downclock)
258 			downclock = dvo_timing->clock;
259 	}
260 
261 	if (downclock < panel_dvo_timing->clock && i915_lvds_downclock) {
262 		dev_priv->lvds_downclock_avail = 1;
263 		dev_priv->lvds_downclock = downclock * 10;
264 		DRM_DEBUG_KMS("LVDS downclock is found in VBT. "
265 			      "Normal Clock %dKHz, downclock %dKHz\n",
266 			      panel_fixed_mode->clock, 10*downclock);
267 	}
268 
269 	fp_timing = get_lvds_fp_timing(bdb, lvds_lfp_data,
270 				       lvds_lfp_data_ptrs,
271 				       lvds_options->panel_type);
272 	if (fp_timing) {
273 		/* check the resolution, just to be sure */
274 		if (fp_timing->x_res == panel_fixed_mode->hdisplay &&
275 		    fp_timing->y_res == panel_fixed_mode->vdisplay) {
276 			dev_priv->vbt.bios_lvds_val = fp_timing->lvds_reg_val;
277 			DRM_DEBUG_KMS("VBT initial LVDS value %x\n",
278 				      dev_priv->vbt.bios_lvds_val);
279 		}
280 	}
281 }
282 
283 /* Try to find sdvo panel data */
284 static void
285 parse_sdvo_panel_data(struct drm_i915_private *dev_priv,
286 		      struct bdb_header *bdb)
287 {
288 	struct lvds_dvo_timing *dvo_timing;
289 	struct drm_display_mode *panel_fixed_mode;
290 	int index;
291 
292 	index = i915_vbt_sdvo_panel_type;
293 	if (index == -2) {
294 		DRM_DEBUG_KMS("Ignore SDVO panel mode from BIOS VBT tables.\n");
295 		return;
296 	}
297 
298 	if (index == -1) {
299 		struct bdb_sdvo_lvds_options *sdvo_lvds_options;
300 
301 		sdvo_lvds_options = find_section(bdb, BDB_SDVO_LVDS_OPTIONS);
302 		if (!sdvo_lvds_options)
303 			return;
304 
305 		index = sdvo_lvds_options->panel_type;
306 	}
307 
308 	dvo_timing = find_section(bdb, BDB_SDVO_PANEL_DTDS);
309 	if (!dvo_timing)
310 		return;
311 
312 	panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode), GFP_KERNEL);
313 	if (!panel_fixed_mode)
314 		return;
315 
316 	fill_detail_timing_data(panel_fixed_mode, dvo_timing + index);
317 
318 	dev_priv->vbt.sdvo_lvds_vbt_mode = panel_fixed_mode;
319 
320 	DRM_DEBUG_KMS("Found SDVO panel mode in BIOS VBT tables:\n");
321 	drm_mode_debug_printmodeline(panel_fixed_mode);
322 }
323 
324 static int intel_bios_ssc_frequency(struct drm_device *dev,
325 				    bool alternate)
326 {
327 	switch (INTEL_INFO(dev)->gen) {
328 	case 2:
329 		return alternate ? 66 : 48;
330 	case 3:
331 	case 4:
332 		return alternate ? 100 : 96;
333 	default:
334 		return alternate ? 100 : 120;
335 	}
336 }
337 
338 static void
339 parse_general_features(struct drm_i915_private *dev_priv,
340 		       struct bdb_header *bdb)
341 {
342 	struct drm_device *dev = dev_priv->dev;
343 	struct bdb_general_features *general;
344 
345 	general = find_section(bdb, BDB_GENERAL_FEATURES);
346 	if (general) {
347 		dev_priv->vbt.int_tv_support = general->int_tv_support;
348 		dev_priv->vbt.int_crt_support = general->int_crt_support;
349 		dev_priv->vbt.lvds_use_ssc = general->enable_ssc;
350 		dev_priv->vbt.lvds_ssc_freq =
351 			intel_bios_ssc_frequency(dev, general->ssc_freq);
352 		dev_priv->vbt.display_clock_mode = general->display_clock_mode;
353 		dev_priv->vbt.fdi_rx_polarity_inverted = general->fdi_rx_polarity_inverted;
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 fdi_rx_polarity_inverted %d\n",
355 			      dev_priv->vbt.int_tv_support,
356 			      dev_priv->vbt.int_crt_support,
357 			      dev_priv->vbt.lvds_use_ssc,
358 			      dev_priv->vbt.lvds_ssc_freq,
359 			      dev_priv->vbt.display_clock_mode,
360 			      dev_priv->vbt.fdi_rx_polarity_inverted);
361 	}
362 }
363 
364 static void
365 parse_general_definitions(struct drm_i915_private *dev_priv,
366 			  struct bdb_header *bdb)
367 {
368 	struct bdb_general_definitions *general;
369 
370 	general = find_section(bdb, BDB_GENERAL_DEFINITIONS);
371 	if (general) {
372 		u16 block_size = get_blocksize(general);
373 		if (block_size >= sizeof(*general)) {
374 			int bus_pin = general->crt_ddc_gmbus_pin;
375 			DRM_DEBUG_KMS("crt_ddc_bus_pin: %d\n", bus_pin);
376 			if (intel_gmbus_is_port_valid(bus_pin))
377 				dev_priv->vbt.crt_ddc_pin = bus_pin;
378 		} else {
379 			DRM_DEBUG_KMS("BDB_GD too small (%d). Invalid.\n",
380 				      block_size);
381 		}
382 	}
383 }
384 
385 static void
386 parse_sdvo_device_mapping(struct drm_i915_private *dev_priv,
387 			  struct bdb_header *bdb)
388 {
389 	struct sdvo_device_mapping *p_mapping;
390 	struct bdb_general_definitions *p_defs;
391 	struct child_device_config *p_child;
392 	int i, child_device_num, count;
393 	u16	block_size;
394 
395 	p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
396 	if (!p_defs) {
397 		DRM_DEBUG_KMS("No general definition block is found, unable to construct sdvo mapping.\n");
398 		return;
399 	}
400 	/* judge whether the size of child device meets the requirements.
401 	 * If the child device size obtained from general definition block
402 	 * is different with sizeof(struct child_device_config), skip the
403 	 * parsing of sdvo device info
404 	 */
405 	if (p_defs->child_dev_size != sizeof(*p_child)) {
406 		/* different child dev size . Ignore it */
407 		DRM_DEBUG_KMS("different child size is found. Invalid.\n");
408 		return;
409 	}
410 	/* get the block size of general definitions */
411 	block_size = get_blocksize(p_defs);
412 	/* get the number of child device */
413 	child_device_num = (block_size - sizeof(*p_defs)) /
414 				sizeof(*p_child);
415 	count = 0;
416 	for (i = 0; i < child_device_num; i++) {
417 		p_child = &(p_defs->devices[i]);
418 		if (!p_child->device_type) {
419 			/* skip the device block if device type is invalid */
420 			continue;
421 		}
422 		if (p_child->slave_addr != SLAVE_ADDR1 &&
423 			p_child->slave_addr != SLAVE_ADDR2) {
424 			/*
425 			 * If the slave address is neither 0x70 nor 0x72,
426 			 * it is not a SDVO device. Skip it.
427 			 */
428 			continue;
429 		}
430 		if (p_child->dvo_port != DEVICE_PORT_DVOB &&
431 			p_child->dvo_port != DEVICE_PORT_DVOC) {
432 			/* skip the incorrect SDVO port */
433 			DRM_DEBUG_KMS("Incorrect SDVO port. Skip it\n");
434 			continue;
435 		}
436 		DRM_DEBUG_KMS("the SDVO device with slave addr %2x is found on"
437 				" %s port\n",
438 				p_child->slave_addr,
439 				(p_child->dvo_port == DEVICE_PORT_DVOB) ?
440 					"SDVOB" : "SDVOC");
441 		p_mapping = &(dev_priv->sdvo_mappings[p_child->dvo_port - 1]);
442 		if (!p_mapping->initialized) {
443 			p_mapping->dvo_port = p_child->dvo_port;
444 			p_mapping->slave_addr = p_child->slave_addr;
445 			p_mapping->dvo_wiring = p_child->dvo_wiring;
446 			p_mapping->ddc_pin = p_child->ddc_pin;
447 			p_mapping->i2c_pin = p_child->i2c_pin;
448 			p_mapping->initialized = 1;
449 			DRM_DEBUG_KMS("SDVO device: dvo=%x, addr=%x, wiring=%d, ddc_pin=%d, i2c_pin=%d\n",
450 				      p_mapping->dvo_port,
451 				      p_mapping->slave_addr,
452 				      p_mapping->dvo_wiring,
453 				      p_mapping->ddc_pin,
454 				      p_mapping->i2c_pin);
455 		} else {
456 			DRM_DEBUG_KMS("Maybe one SDVO port is shared by "
457 					 "two SDVO device.\n");
458 		}
459 		if (p_child->slave2_addr) {
460 			/* Maybe this is a SDVO device with multiple inputs */
461 			/* And the mapping info is not added */
462 			DRM_DEBUG_KMS("there exists the slave2_addr. Maybe this"
463 				" is a SDVO device with multiple inputs.\n");
464 		}
465 		count++;
466 	}
467 
468 	if (!count) {
469 		/* No SDVO device info is found */
470 		DRM_DEBUG_KMS("No SDVO device info is found in VBT\n");
471 	}
472 	return;
473 }
474 
475 static void
476 parse_driver_features(struct drm_i915_private *dev_priv,
477 		       struct bdb_header *bdb)
478 {
479 	struct drm_device *dev = dev_priv->dev;
480 	struct bdb_driver_features *driver;
481 
482 	driver = find_section(bdb, BDB_DRIVER_FEATURES);
483 	if (!driver)
484 		return;
485 
486 	if (SUPPORTS_EDP(dev) &&
487 	    driver->lvds_config == BDB_DRIVER_FEATURE_EDP)
488 		dev_priv->vbt.edp_support = 1;
489 
490 	if (driver->dual_frequency)
491 		dev_priv->render_reclock_avail = true;
492 }
493 
494 static void
495 parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
496 {
497 	struct bdb_edp *edp;
498 	struct edp_power_seq *edp_pps;
499 	struct edp_link_params *edp_link_params;
500 
501 	edp = find_section(bdb, BDB_EDP);
502 	if (!edp) {
503 		if (SUPPORTS_EDP(dev_priv->dev) && dev_priv->vbt.edp_support)
504 			DRM_DEBUG_KMS("No eDP BDB found but eDP panel supported.\n");
505 		return;
506 	}
507 
508 	switch ((edp->color_depth >> (panel_type * 2)) & 3) {
509 	case EDP_18BPP:
510 		dev_priv->vbt.edp_bpp = 18;
511 		break;
512 	case EDP_24BPP:
513 		dev_priv->vbt.edp_bpp = 24;
514 		break;
515 	case EDP_30BPP:
516 		dev_priv->vbt.edp_bpp = 30;
517 		break;
518 	}
519 
520 	/* Get the eDP sequencing and link info */
521 	edp_pps = &edp->power_seqs[panel_type];
522 	edp_link_params = &edp->link_params[panel_type];
523 
524 	dev_priv->vbt.edp_pps = *edp_pps;
525 
526 	dev_priv->vbt.edp_rate = edp_link_params->rate ? DP_LINK_BW_2_7 :
527 		DP_LINK_BW_1_62;
528 	switch (edp_link_params->lanes) {
529 	case 0:
530 		dev_priv->vbt.edp_lanes = 1;
531 		break;
532 	case 1:
533 		dev_priv->vbt.edp_lanes = 2;
534 		break;
535 	case 3:
536 	default:
537 		dev_priv->vbt.edp_lanes = 4;
538 		break;
539 	}
540 	switch (edp_link_params->preemphasis) {
541 	case 0:
542 		dev_priv->vbt.edp_preemphasis = DP_TRAIN_PRE_EMPHASIS_0;
543 		break;
544 	case 1:
545 		dev_priv->vbt.edp_preemphasis = DP_TRAIN_PRE_EMPHASIS_3_5;
546 		break;
547 	case 2:
548 		dev_priv->vbt.edp_preemphasis = DP_TRAIN_PRE_EMPHASIS_6;
549 		break;
550 	case 3:
551 		dev_priv->vbt.edp_preemphasis = DP_TRAIN_PRE_EMPHASIS_9_5;
552 		break;
553 	}
554 	switch (edp_link_params->vswing) {
555 	case 0:
556 		dev_priv->vbt.edp_vswing = DP_TRAIN_VOLTAGE_SWING_400;
557 		break;
558 	case 1:
559 		dev_priv->vbt.edp_vswing = DP_TRAIN_VOLTAGE_SWING_600;
560 		break;
561 	case 2:
562 		dev_priv->vbt.edp_vswing = DP_TRAIN_VOLTAGE_SWING_800;
563 		break;
564 	case 3:
565 		dev_priv->vbt.edp_vswing = DP_TRAIN_VOLTAGE_SWING_1200;
566 		break;
567 	}
568 }
569 
570 static void
571 parse_device_mapping(struct drm_i915_private *dev_priv,
572 		       struct bdb_header *bdb)
573 {
574 	struct bdb_general_definitions *p_defs;
575 	struct child_device_config *p_child, *child_dev_ptr;
576 	int i, child_device_num, count;
577 	u16	block_size;
578 
579 	p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
580 	if (!p_defs) {
581 		DRM_DEBUG_KMS("No general definition block is found, no devices defined.\n");
582 		return;
583 	}
584 	/* judge whether the size of child device meets the requirements.
585 	 * If the child device size obtained from general definition block
586 	 * is different with sizeof(struct child_device_config), skip the
587 	 * parsing of sdvo device info
588 	 */
589 	if (p_defs->child_dev_size != sizeof(*p_child)) {
590 		/* different child dev size . Ignore it */
591 		DRM_DEBUG_KMS("different child size is found. Invalid.\n");
592 		return;
593 	}
594 	/* get the block size of general definitions */
595 	block_size = get_blocksize(p_defs);
596 	/* get the number of child device */
597 	child_device_num = (block_size - sizeof(*p_defs)) /
598 				sizeof(*p_child);
599 	count = 0;
600 	/* get the number of child device that is present */
601 	for (i = 0; i < child_device_num; i++) {
602 		p_child = &(p_defs->devices[i]);
603 		if (!p_child->device_type) {
604 			/* skip the device block if device type is invalid */
605 			continue;
606 		}
607 		count++;
608 	}
609 	if (!count) {
610 		DRM_DEBUG_KMS("no child dev is parsed from VBT\n");
611 		return;
612 	}
613 	dev_priv->vbt.child_dev = kmalloc(sizeof(*p_child) * count, M_DRM,
614 	    M_WAITOK | M_ZERO);
615 	if (!dev_priv->vbt.child_dev) {
616 		DRM_DEBUG_KMS("No memory space for child device\n");
617 		return;
618 	}
619 
620 	dev_priv->vbt.child_dev_num = count;
621 	count = 0;
622 	for (i = 0; i < child_device_num; i++) {
623 		p_child = &(p_defs->devices[i]);
624 		if (!p_child->device_type) {
625 			/* skip the device block if device type is invalid */
626 			continue;
627 		}
628 		child_dev_ptr = dev_priv->vbt.child_dev + count;
629 		count++;
630 		memcpy((void *)child_dev_ptr, (void *)p_child,
631 					sizeof(*p_child));
632 	}
633 	return;
634 }
635 
636 static void
637 init_vbt_defaults(struct drm_i915_private *dev_priv)
638 {
639 	struct drm_device *dev = dev_priv->dev;
640 
641 	dev_priv->vbt.crt_ddc_pin = GMBUS_PORT_VGADDC;
642 
643 	/* LFP panel data */
644 	dev_priv->vbt.lvds_dither = 1;
645 	dev_priv->vbt.lvds_vbt = 0;
646 
647 	/* SDVO panel data */
648 	dev_priv->vbt.sdvo_lvds_vbt_mode = NULL;
649 
650 	/* general features */
651 	dev_priv->vbt.int_tv_support = 1;
652 	dev_priv->vbt.int_crt_support = 1;
653 
654 	/* Default to using SSC */
655 	dev_priv->vbt.lvds_use_ssc = 1;
656 	dev_priv->vbt.lvds_ssc_freq = intel_bios_ssc_frequency(dev, 1);
657 	DRM_DEBUG_KMS("Set default to SSC at %dMHz\n", dev_priv->vbt.lvds_ssc_freq);
658 }
659 
660 static int __init intel_no_opregion_vbt_callback(const struct dmi_system_id *id)
661 {
662 	DRM_DEBUG_KMS("Falling back to manually reading VBT from "
663 		      "VBIOS ROM for %s\n",
664 		      id->ident);
665 	return 1;
666 }
667 
668 static const struct dmi_system_id intel_no_opregion_vbt[] = {
669 	{
670 		.callback = intel_no_opregion_vbt_callback,
671 		.ident = "ThinkCentre A57",
672 		.matches = {
673 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
674 			DMI_MATCH(DMI_PRODUCT_NAME, "97027RG"),
675 		},
676 	},
677 	{ }
678 };
679 
680 /**
681  * intel_parse_bios - find VBT and initialize settings from the BIOS
682  * @dev: DRM device
683  *
684  * Loads the Video BIOS and checks that the VBT exists.  Sets scratch registers
685  * to appropriate values.
686  *
687  * Returns 0 on success, nonzero on failure.
688  */
689 int
690 intel_parse_bios(struct drm_device *dev)
691 {
692 	struct drm_i915_private *dev_priv = dev->dev_private;
693 	struct bdb_header *bdb = NULL;
694 	u8 __iomem *bios = NULL;
695 
696 	if (HAS_PCH_NOP(dev))
697 		return -ENODEV;
698 
699 	init_vbt_defaults(dev_priv);
700 
701 	/* XXX Should this validation be moved to intel_opregion.c? */
702 	if (!dmi_check_system(intel_no_opregion_vbt) && dev_priv->opregion.vbt) {
703 		struct vbt_header *vbt = dev_priv->opregion.vbt;
704 		if (memcmp(vbt->signature, "$VBT", 4) == 0) {
705 			DRM_DEBUG_KMS("Using VBT from OpRegion: %20s\n",
706 					 vbt->signature);
707 			bdb = (struct bdb_header *)((char *)vbt + vbt->bdb_offset);
708 		} else
709 			dev_priv->opregion.vbt = NULL;
710 	}
711 	bios = NULL;
712 
713 #if 1
714 	if (bdb == NULL) {
715 		KIB_NOTYET();
716 		return (-1);
717 	}
718 #else
719 	if (bdb == NULL) {
720 		struct vbt_header *vbt = NULL;
721 		size_t size;
722 		int i;
723 
724 		bios = pci_map_rom(pdev, &size);
725 		if (!bios)
726 			return -1;
727 
728 		/* Scour memory looking for the VBT signature */
729 		for (i = 0; i + 4 < size; i++) {
730 			if (!memcmp(bios + i, "$VBT", 4)) {
731 				vbt = (struct vbt_header *)(bios + i);
732 				break;
733 			}
734 		}
735 
736 		if (!vbt) {
737 			DRM_DEBUG_DRIVER("VBT signature missing\n");
738 			pci_unmap_rom(pdev, bios);
739 			return -1;
740 		}
741 
742 		bdb = (struct bdb_header *)(bios + i + vbt->bdb_offset);
743 	}
744 #endif
745 
746 	/* Grab useful general definitions */
747 	parse_general_features(dev_priv, bdb);
748 	parse_general_definitions(dev_priv, bdb);
749 	parse_lfp_panel_data(dev_priv, bdb);
750 	parse_sdvo_panel_data(dev_priv, bdb);
751 	parse_sdvo_device_mapping(dev_priv, bdb);
752 	parse_device_mapping(dev_priv, bdb);
753 	parse_driver_features(dev_priv, bdb);
754 	parse_edp(dev_priv, bdb);
755 
756 #if 0
757 	if (bios)
758 		pci_unmap_rom(pdev, bios);
759 #endif
760 
761 	return 0;
762 }
763 
764 /* Ensure that vital registers have been initialised, even if the BIOS
765  * is absent or just failing to do its job.
766  */
767 void intel_setup_bios(struct drm_device *dev)
768 {
769 	struct drm_i915_private *dev_priv = dev->dev_private;
770 
771 	 /* Set the Panel Power On/Off timings if uninitialized. */
772 	if (!HAS_PCH_SPLIT(dev) &&
773 	    I915_READ(PP_ON_DELAYS) == 0 && I915_READ(PP_OFF_DELAYS) == 0) {
774 		/* Set T2 to 40ms and T5 to 200ms */
775 		I915_WRITE(PP_ON_DELAYS, 0x019007d0);
776 
777 		/* Set T3 to 35ms and Tx to 200ms */
778 		I915_WRITE(PP_OFF_DELAYS, 0x015e07d0);
779 	}
780 }
781