xref: /dragonfly/sys/dev/drm/i915/intel_bios.c (revision f2c43266)
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/drmP.h>
29 #include <drm/drm_dp_helper.h>
30 #include <drm/i915_drm.h>
31 #include "i915_drv.h"
32 #include "intel_bios.h"
33 #include <linux/string.h>
34 
35 #define	SLAVE_ADDR1	0x70
36 #define	SLAVE_ADDR2	0x72
37 
38 static int panel_type;
39 
40 static const void *
41 find_section(const void *_bdb, int section_id)
42 {
43 	const struct bdb_header *bdb = _bdb;
44 	const u8 *base = _bdb;
45 	int index = 0;
46 	u32 total, current_size;
47 	u8 current_id;
48 
49 	/* skip to first section */
50 	index += bdb->header_size;
51 	total = bdb->bdb_size;
52 
53 	/* walk the sections looking for section_id */
54 	while (index + 3 < total) {
55 		current_id = *(base + index);
56 		index++;
57 
58 		current_size = *((const u16 *)(base + index));
59 		index += 2;
60 
61 		/* The MIPI Sequence Block v3+ has a separate size field. */
62 		if (current_id == BDB_MIPI_SEQUENCE && *(base + index) >= 3)
63 			current_size = *((const u32 *)(base + index + 1));
64 
65 		if (index + current_size > total)
66 			return NULL;
67 
68 		if (current_id == section_id)
69 			return base + index;
70 
71 		index += current_size;
72 	}
73 
74 	return NULL;
75 }
76 
77 #pragma GCC diagnostic ignored "-Wcast-qual"
78 static u16
79 get_blocksize(const void *p)
80 {
81 	u16 *block_ptr, block_size;
82 
83 	block_ptr = (u16 *)((char *)p - 2);
84 	block_size = *block_ptr;
85 	return block_size;
86 }
87 #pragma GCC diagnostic pop
88 
89 static void
90 fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
91 			const struct lvds_dvo_timing *dvo_timing)
92 {
93 	panel_fixed_mode->hdisplay = (dvo_timing->hactive_hi << 8) |
94 		dvo_timing->hactive_lo;
95 	panel_fixed_mode->hsync_start = panel_fixed_mode->hdisplay +
96 		((dvo_timing->hsync_off_hi << 8) | dvo_timing->hsync_off_lo);
97 	panel_fixed_mode->hsync_end = panel_fixed_mode->hsync_start +
98 		dvo_timing->hsync_pulse_width;
99 	panel_fixed_mode->htotal = panel_fixed_mode->hdisplay +
100 		((dvo_timing->hblank_hi << 8) | dvo_timing->hblank_lo);
101 
102 	panel_fixed_mode->vdisplay = (dvo_timing->vactive_hi << 8) |
103 		dvo_timing->vactive_lo;
104 	panel_fixed_mode->vsync_start = panel_fixed_mode->vdisplay +
105 		dvo_timing->vsync_off;
106 	panel_fixed_mode->vsync_end = panel_fixed_mode->vsync_start +
107 		dvo_timing->vsync_pulse_width;
108 	panel_fixed_mode->vtotal = panel_fixed_mode->vdisplay +
109 		((dvo_timing->vblank_hi << 8) | dvo_timing->vblank_lo);
110 	panel_fixed_mode->clock = dvo_timing->clock * 10;
111 	panel_fixed_mode->type = DRM_MODE_TYPE_PREFERRED;
112 
113 	if (dvo_timing->hsync_positive)
114 		panel_fixed_mode->flags |= DRM_MODE_FLAG_PHSYNC;
115 	else
116 		panel_fixed_mode->flags |= DRM_MODE_FLAG_NHSYNC;
117 
118 	if (dvo_timing->vsync_positive)
119 		panel_fixed_mode->flags |= DRM_MODE_FLAG_PVSYNC;
120 	else
121 		panel_fixed_mode->flags |= DRM_MODE_FLAG_NVSYNC;
122 
123 	/* Some VBTs have bogus h/vtotal values */
124 	if (panel_fixed_mode->hsync_end > panel_fixed_mode->htotal)
125 		panel_fixed_mode->htotal = panel_fixed_mode->hsync_end + 1;
126 	if (panel_fixed_mode->vsync_end > panel_fixed_mode->vtotal)
127 		panel_fixed_mode->vtotal = panel_fixed_mode->vsync_end + 1;
128 
129 	drm_mode_set_name(panel_fixed_mode);
130 }
131 
132 static const struct lvds_dvo_timing *
133 get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,
134 		    const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,
135 		    int index)
136 {
137 	/*
138 	 * the size of fp_timing varies on the different platform.
139 	 * So calculate the DVO timing relative offset in LVDS data
140 	 * entry to get the DVO timing entry
141 	 */
142 
143 	int lfp_data_size =
144 		lvds_lfp_data_ptrs->ptr[1].dvo_timing_offset -
145 		lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset;
146 	int dvo_timing_offset =
147 		lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset -
148 		lvds_lfp_data_ptrs->ptr[0].fp_timing_offset;
149 	const char *entry = (const char *)lvds_lfp_data->data + lfp_data_size * index;
150 
151 	return (const struct lvds_dvo_timing *)(entry + dvo_timing_offset);
152 }
153 
154 /* get lvds_fp_timing entry
155  * this function may return NULL if the corresponding entry is invalid
156  */
157 static const struct lvds_fp_timing *
158 get_lvds_fp_timing(const struct bdb_header *bdb,
159 		   const struct bdb_lvds_lfp_data *data,
160 		   const struct bdb_lvds_lfp_data_ptrs *ptrs,
161 		   int index)
162 {
163 	size_t data_ofs = (const u8 *)data - (const u8 *)bdb;
164 	u16 data_size = ((const u16 *)data)[-1]; /* stored in header */
165 	size_t ofs;
166 
167 	if (index >= ARRAY_SIZE(ptrs->ptr))
168 		return NULL;
169 	ofs = ptrs->ptr[index].fp_timing_offset;
170 	if (ofs < data_ofs ||
171 	    ofs + sizeof(struct lvds_fp_timing) > data_ofs + data_size)
172 		return NULL;
173 	return (const struct lvds_fp_timing *)((const u8 *)bdb + ofs);
174 }
175 
176 /* Try to find integrated panel data */
177 static void
178 parse_lfp_panel_data(struct drm_i915_private *dev_priv,
179 		     const struct bdb_header *bdb)
180 {
181 	const struct bdb_lvds_options *lvds_options;
182 	const struct bdb_lvds_lfp_data *lvds_lfp_data;
183 	const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs;
184 	const struct lvds_dvo_timing *panel_dvo_timing;
185 	const struct lvds_fp_timing *fp_timing;
186 	struct drm_display_mode *panel_fixed_mode;
187 	int drrs_mode;
188 
189 	lvds_options = find_section(bdb, BDB_LVDS_OPTIONS);
190 	if (!lvds_options)
191 		return;
192 
193 	dev_priv->vbt.lvds_dither = lvds_options->pixel_dither;
194 	if (lvds_options->panel_type == 0xff)
195 		return;
196 
197 	panel_type = lvds_options->panel_type;
198 
199 	drrs_mode = (lvds_options->dps_panel_type_bits
200 				>> (panel_type * 2)) & MODE_MASK;
201 	/*
202 	 * VBT has static DRRS = 0 and seamless DRRS = 2.
203 	 * The below piece of code is required to adjust vbt.drrs_type
204 	 * to match the enum drrs_support_type.
205 	 */
206 	switch (drrs_mode) {
207 	case 0:
208 		dev_priv->vbt.drrs_type = STATIC_DRRS_SUPPORT;
209 		DRM_DEBUG_KMS("DRRS supported mode is static\n");
210 		break;
211 	case 2:
212 		dev_priv->vbt.drrs_type = SEAMLESS_DRRS_SUPPORT;
213 		DRM_DEBUG_KMS("DRRS supported mode is seamless\n");
214 		break;
215 	default:
216 		dev_priv->vbt.drrs_type = DRRS_NOT_SUPPORTED;
217 		DRM_DEBUG_KMS("DRRS not supported (VBT input)\n");
218 		break;
219 	}
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->vbt.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->vbt.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 	fp_timing = get_lvds_fp_timing(bdb, lvds_lfp_data,
247 				       lvds_lfp_data_ptrs,
248 				       lvds_options->panel_type);
249 	if (fp_timing) {
250 		/* check the resolution, just to be sure */
251 		if (fp_timing->x_res == panel_fixed_mode->hdisplay &&
252 		    fp_timing->y_res == panel_fixed_mode->vdisplay) {
253 			dev_priv->vbt.bios_lvds_val = fp_timing->lvds_reg_val;
254 			DRM_DEBUG_KMS("VBT initial LVDS value %x\n",
255 				      dev_priv->vbt.bios_lvds_val);
256 		}
257 	}
258 }
259 
260 static void
261 parse_lfp_backlight(struct drm_i915_private *dev_priv,
262 		    const struct bdb_header *bdb)
263 {
264 	const struct bdb_lfp_backlight_data *backlight_data;
265 	const struct bdb_lfp_backlight_data_entry *entry;
266 
267 	backlight_data = find_section(bdb, BDB_LVDS_BACKLIGHT);
268 	if (!backlight_data)
269 		return;
270 
271 	if (backlight_data->entry_size != sizeof(backlight_data->data[0])) {
272 		DRM_DEBUG_KMS("Unsupported backlight data entry size %u\n",
273 			      backlight_data->entry_size);
274 		return;
275 	}
276 
277 	entry = &backlight_data->data[panel_type];
278 
279 	dev_priv->vbt.backlight.present = entry->type == BDB_BACKLIGHT_TYPE_PWM;
280 	if (!dev_priv->vbt.backlight.present) {
281 		DRM_DEBUG_KMS("PWM backlight not present in VBT (type %u)\n",
282 			      entry->type);
283 		return;
284 	}
285 
286 	dev_priv->vbt.backlight.pwm_freq_hz = entry->pwm_freq_hz;
287 	dev_priv->vbt.backlight.active_low_pwm = entry->active_low_pwm;
288 	dev_priv->vbt.backlight.min_brightness = entry->min_brightness;
289 	DRM_DEBUG_KMS("VBT backlight PWM modulation frequency %u Hz, "
290 		      "active %s, min brightness %u, level %u\n",
291 		      dev_priv->vbt.backlight.pwm_freq_hz,
292 		      dev_priv->vbt.backlight.active_low_pwm ? "low" : "high",
293 		      dev_priv->vbt.backlight.min_brightness,
294 		      backlight_data->level[panel_type]);
295 }
296 
297 /* Try to find sdvo panel data */
298 static void
299 parse_sdvo_panel_data(struct drm_i915_private *dev_priv,
300 		      const struct bdb_header *bdb)
301 {
302 	const struct lvds_dvo_timing *dvo_timing;
303 	struct drm_display_mode *panel_fixed_mode;
304 	int index;
305 
306 	index = i915.vbt_sdvo_panel_type;
307 	if (index == -2) {
308 		DRM_DEBUG_KMS("Ignore SDVO panel mode from BIOS VBT tables.\n");
309 		return;
310 	}
311 
312 	if (index == -1) {
313 		const struct bdb_sdvo_lvds_options *sdvo_lvds_options;
314 
315 		sdvo_lvds_options = find_section(bdb, BDB_SDVO_LVDS_OPTIONS);
316 		if (!sdvo_lvds_options)
317 			return;
318 
319 		index = sdvo_lvds_options->panel_type;
320 	}
321 
322 	dvo_timing = find_section(bdb, BDB_SDVO_PANEL_DTDS);
323 	if (!dvo_timing)
324 		return;
325 
326 	panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode), GFP_KERNEL);
327 	if (!panel_fixed_mode)
328 		return;
329 
330 	fill_detail_timing_data(panel_fixed_mode, dvo_timing + index);
331 
332 	dev_priv->vbt.sdvo_lvds_vbt_mode = panel_fixed_mode;
333 
334 	DRM_DEBUG_KMS("Found SDVO panel mode in BIOS VBT tables:\n");
335 	drm_mode_debug_printmodeline(panel_fixed_mode);
336 }
337 
338 static int intel_bios_ssc_frequency(struct drm_device *dev,
339 				    bool alternate)
340 {
341 	switch (INTEL_INFO(dev)->gen) {
342 	case 2:
343 		return alternate ? 66667 : 48000;
344 	case 3:
345 	case 4:
346 		return alternate ? 100000 : 96000;
347 	default:
348 		return alternate ? 100000 : 120000;
349 	}
350 }
351 
352 static void
353 parse_general_features(struct drm_i915_private *dev_priv,
354 		       const struct bdb_header *bdb)
355 {
356 	struct drm_device *dev = dev_priv->dev;
357 	const struct bdb_general_features *general;
358 
359 	general = find_section(bdb, BDB_GENERAL_FEATURES);
360 	if (general) {
361 		dev_priv->vbt.int_tv_support = general->int_tv_support;
362 		dev_priv->vbt.int_crt_support = general->int_crt_support;
363 		dev_priv->vbt.lvds_use_ssc = general->enable_ssc;
364 		dev_priv->vbt.lvds_ssc_freq =
365 			intel_bios_ssc_frequency(dev, general->ssc_freq);
366 		dev_priv->vbt.display_clock_mode = general->display_clock_mode;
367 		dev_priv->vbt.fdi_rx_polarity_inverted = general->fdi_rx_polarity_inverted;
368 		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",
369 			      dev_priv->vbt.int_tv_support,
370 			      dev_priv->vbt.int_crt_support,
371 			      dev_priv->vbt.lvds_use_ssc,
372 			      dev_priv->vbt.lvds_ssc_freq,
373 			      dev_priv->vbt.display_clock_mode,
374 			      dev_priv->vbt.fdi_rx_polarity_inverted);
375 	}
376 }
377 
378 static void
379 parse_general_definitions(struct drm_i915_private *dev_priv,
380 			  const struct bdb_header *bdb)
381 {
382 	const struct bdb_general_definitions *general;
383 
384 	general = find_section(bdb, BDB_GENERAL_DEFINITIONS);
385 	if (general) {
386 		u16 block_size = get_blocksize(general);
387 		if (block_size >= sizeof(*general)) {
388 			int bus_pin = general->crt_ddc_gmbus_pin;
389 			DRM_DEBUG_KMS("crt_ddc_bus_pin: %d\n", bus_pin);
390 			if (intel_gmbus_is_valid_pin(dev_priv, bus_pin))
391 				dev_priv->vbt.crt_ddc_pin = bus_pin;
392 		} else {
393 			DRM_DEBUG_KMS("BDB_GD too small (%d). Invalid.\n",
394 				      block_size);
395 		}
396 	}
397 }
398 
399 static const union child_device_config *
400 child_device_ptr(const struct bdb_general_definitions *p_defs, int i)
401 {
402 	return (const void *) &p_defs->devices[i * p_defs->child_dev_size];
403 }
404 
405 static void
406 parse_sdvo_device_mapping(struct drm_i915_private *dev_priv,
407 			  const struct bdb_header *bdb)
408 {
409 	struct sdvo_device_mapping *p_mapping;
410 	const struct bdb_general_definitions *p_defs;
411 	const struct old_child_dev_config *child; /* legacy */
412 	int i, child_device_num, count;
413 	u16	block_size;
414 
415 	p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
416 	if (!p_defs) {
417 		DRM_DEBUG_KMS("No general definition block is found, unable to construct sdvo mapping.\n");
418 		return;
419 	}
420 
421 	/*
422 	 * Only parse SDVO mappings when the general definitions block child
423 	 * device size matches that of the *legacy* child device config
424 	 * struct. Thus, SDVO mapping will be skipped for newer VBT.
425 	 */
426 	if (p_defs->child_dev_size != sizeof(*child)) {
427 		DRM_DEBUG_KMS("Unsupported child device size for SDVO mapping.\n");
428 		return;
429 	}
430 	/* get the block size of general definitions */
431 	block_size = get_blocksize(p_defs);
432 	/* get the number of child device */
433 	child_device_num = (block_size - sizeof(*p_defs)) /
434 		p_defs->child_dev_size;
435 	count = 0;
436 	for (i = 0; i < child_device_num; i++) {
437 		child = &child_device_ptr(p_defs, i)->old;
438 		if (!child->device_type) {
439 			/* skip the device block if device type is invalid */
440 			continue;
441 		}
442 		if (child->slave_addr != SLAVE_ADDR1 &&
443 		    child->slave_addr != SLAVE_ADDR2) {
444 			/*
445 			 * If the slave address is neither 0x70 nor 0x72,
446 			 * it is not a SDVO device. Skip it.
447 			 */
448 			continue;
449 		}
450 		if (child->dvo_port != DEVICE_PORT_DVOB &&
451 		    child->dvo_port != DEVICE_PORT_DVOC) {
452 			/* skip the incorrect SDVO port */
453 			DRM_DEBUG_KMS("Incorrect SDVO port. Skip it\n");
454 			continue;
455 		}
456 		DRM_DEBUG_KMS("the SDVO device with slave addr %2x is found on"
457 			      " %s port\n",
458 			      child->slave_addr,
459 			      (child->dvo_port == DEVICE_PORT_DVOB) ?
460 			      "SDVOB" : "SDVOC");
461 		p_mapping = &(dev_priv->sdvo_mappings[child->dvo_port - 1]);
462 		if (!p_mapping->initialized) {
463 			p_mapping->dvo_port = child->dvo_port;
464 			p_mapping->slave_addr = child->slave_addr;
465 			p_mapping->dvo_wiring = child->dvo_wiring;
466 			p_mapping->ddc_pin = child->ddc_pin;
467 			p_mapping->i2c_pin = child->i2c_pin;
468 			p_mapping->initialized = 1;
469 			DRM_DEBUG_KMS("SDVO device: dvo=%x, addr=%x, wiring=%d, ddc_pin=%d, i2c_pin=%d\n",
470 				      p_mapping->dvo_port,
471 				      p_mapping->slave_addr,
472 				      p_mapping->dvo_wiring,
473 				      p_mapping->ddc_pin,
474 				      p_mapping->i2c_pin);
475 		} else {
476 			DRM_DEBUG_KMS("Maybe one SDVO port is shared by "
477 					 "two SDVO device.\n");
478 		}
479 		if (child->slave2_addr) {
480 			/* Maybe this is a SDVO device with multiple inputs */
481 			/* And the mapping info is not added */
482 			DRM_DEBUG_KMS("there exists the slave2_addr. Maybe this"
483 				" is a SDVO device with multiple inputs.\n");
484 		}
485 		count++;
486 	}
487 
488 	if (!count) {
489 		/* No SDVO device info is found */
490 		DRM_DEBUG_KMS("No SDVO device info is found in VBT\n");
491 	}
492 	return;
493 }
494 
495 static void
496 parse_driver_features(struct drm_i915_private *dev_priv,
497 		      const struct bdb_header *bdb)
498 {
499 	const struct bdb_driver_features *driver;
500 
501 	driver = find_section(bdb, BDB_DRIVER_FEATURES);
502 	if (!driver)
503 		return;
504 
505 	if (driver->lvds_config == BDB_DRIVER_FEATURE_EDP)
506 		dev_priv->vbt.edp_support = 1;
507 
508 	if (driver->dual_frequency)
509 		dev_priv->render_reclock_avail = true;
510 
511 	DRM_DEBUG_KMS("DRRS State Enabled:%d\n", driver->drrs_enabled);
512 	/*
513 	 * If DRRS is not supported, drrs_type has to be set to 0.
514 	 * This is because, VBT is configured in such a way that
515 	 * static DRRS is 0 and DRRS not supported is represented by
516 	 * driver->drrs_enabled=false
517 	 */
518 	if (!driver->drrs_enabled)
519 		dev_priv->vbt.drrs_type = DRRS_NOT_SUPPORTED;
520 }
521 
522 static void
523 parse_edp(struct drm_i915_private *dev_priv, const struct bdb_header *bdb)
524 {
525 	const struct bdb_edp *edp;
526 	const struct edp_power_seq *edp_pps;
527 	const struct edp_link_params *edp_link_params;
528 
529 	edp = find_section(bdb, BDB_EDP);
530 	if (!edp) {
531 		if (dev_priv->vbt.edp_support)
532 			DRM_DEBUG_KMS("No eDP BDB found but eDP panel supported.\n");
533 		return;
534 	}
535 
536 	switch ((edp->color_depth >> (panel_type * 2)) & 3) {
537 	case EDP_18BPP:
538 		dev_priv->vbt.edp_bpp = 18;
539 		break;
540 	case EDP_24BPP:
541 		dev_priv->vbt.edp_bpp = 24;
542 		break;
543 	case EDP_30BPP:
544 		dev_priv->vbt.edp_bpp = 30;
545 		break;
546 	}
547 
548 	/* Get the eDP sequencing and link info */
549 	edp_pps = &edp->power_seqs[panel_type];
550 	edp_link_params = &edp->link_params[panel_type];
551 
552 	dev_priv->vbt.edp_pps = *edp_pps;
553 
554 	switch (edp_link_params->rate) {
555 	case EDP_RATE_1_62:
556 		dev_priv->vbt.edp_rate = DP_LINK_BW_1_62;
557 		break;
558 	case EDP_RATE_2_7:
559 		dev_priv->vbt.edp_rate = DP_LINK_BW_2_7;
560 		break;
561 	default:
562 		DRM_DEBUG_KMS("VBT has unknown eDP link rate value %u\n",
563 			      edp_link_params->rate);
564 		break;
565 	}
566 
567 	switch (edp_link_params->lanes) {
568 	case EDP_LANE_1:
569 		dev_priv->vbt.edp_lanes = 1;
570 		break;
571 	case EDP_LANE_2:
572 		dev_priv->vbt.edp_lanes = 2;
573 		break;
574 	case EDP_LANE_4:
575 		dev_priv->vbt.edp_lanes = 4;
576 		break;
577 	default:
578 		DRM_DEBUG_KMS("VBT has unknown eDP lane count value %u\n",
579 			      edp_link_params->lanes);
580 		break;
581 	}
582 
583 	switch (edp_link_params->preemphasis) {
584 	case EDP_PREEMPHASIS_NONE:
585 		dev_priv->vbt.edp_preemphasis = DP_TRAIN_PRE_EMPH_LEVEL_0;
586 		break;
587 	case EDP_PREEMPHASIS_3_5dB:
588 		dev_priv->vbt.edp_preemphasis = DP_TRAIN_PRE_EMPH_LEVEL_1;
589 		break;
590 	case EDP_PREEMPHASIS_6dB:
591 		dev_priv->vbt.edp_preemphasis = DP_TRAIN_PRE_EMPH_LEVEL_2;
592 		break;
593 	case EDP_PREEMPHASIS_9_5dB:
594 		dev_priv->vbt.edp_preemphasis = DP_TRAIN_PRE_EMPH_LEVEL_3;
595 		break;
596 	default:
597 		DRM_DEBUG_KMS("VBT has unknown eDP pre-emphasis value %u\n",
598 			      edp_link_params->preemphasis);
599 		break;
600 	}
601 
602 	switch (edp_link_params->vswing) {
603 	case EDP_VSWING_0_4V:
604 		dev_priv->vbt.edp_vswing = DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
605 		break;
606 	case EDP_VSWING_0_6V:
607 		dev_priv->vbt.edp_vswing = DP_TRAIN_VOLTAGE_SWING_LEVEL_1;
608 		break;
609 	case EDP_VSWING_0_8V:
610 		dev_priv->vbt.edp_vswing = DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
611 		break;
612 	case EDP_VSWING_1_2V:
613 		dev_priv->vbt.edp_vswing = DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
614 		break;
615 	default:
616 		DRM_DEBUG_KMS("VBT has unknown eDP voltage swing value %u\n",
617 			      edp_link_params->vswing);
618 		break;
619 	}
620 
621 	if (bdb->version >= 173) {
622 		uint8_t vswing;
623 
624 		/* Don't read from VBT if module parameter has valid value*/
625 		if (i915.edp_vswing) {
626 			dev_priv->edp_low_vswing = i915.edp_vswing == 1;
627 		} else {
628 			vswing = (edp->edp_vswing_preemph >> (panel_type * 4)) & 0xF;
629 			dev_priv->edp_low_vswing = vswing == 0;
630 		}
631 	}
632 }
633 
634 static void
635 parse_psr(struct drm_i915_private *dev_priv, const struct bdb_header *bdb)
636 {
637 	const struct bdb_psr *psr;
638 	const struct psr_table *psr_table;
639 
640 	psr = find_section(bdb, BDB_PSR);
641 	if (!psr) {
642 		DRM_DEBUG_KMS("No PSR BDB found.\n");
643 		return;
644 	}
645 
646 	psr_table = &psr->psr_table[panel_type];
647 
648 	dev_priv->vbt.psr.full_link = psr_table->full_link;
649 	dev_priv->vbt.psr.require_aux_wakeup = psr_table->require_aux_to_wakeup;
650 
651 	/* Allowed VBT values goes from 0 to 15 */
652 	dev_priv->vbt.psr.idle_frames = psr_table->idle_frames < 0 ? 0 :
653 		psr_table->idle_frames > 15 ? 15 : psr_table->idle_frames;
654 
655 	switch (psr_table->lines_to_wait) {
656 	case 0:
657 		dev_priv->vbt.psr.lines_to_wait = PSR_0_LINES_TO_WAIT;
658 		break;
659 	case 1:
660 		dev_priv->vbt.psr.lines_to_wait = PSR_1_LINE_TO_WAIT;
661 		break;
662 	case 2:
663 		dev_priv->vbt.psr.lines_to_wait = PSR_4_LINES_TO_WAIT;
664 		break;
665 	case 3:
666 		dev_priv->vbt.psr.lines_to_wait = PSR_8_LINES_TO_WAIT;
667 		break;
668 	default:
669 		DRM_DEBUG_KMS("VBT has unknown PSR lines to wait %u\n",
670 			      psr_table->lines_to_wait);
671 		break;
672 	}
673 
674 	dev_priv->vbt.psr.tp1_wakeup_time = psr_table->tp1_wakeup_time;
675 	dev_priv->vbt.psr.tp2_tp3_wakeup_time = psr_table->tp2_tp3_wakeup_time;
676 }
677 
678 static u8 *goto_next_sequence(u8 *data, int *size)
679 {
680 	u16 len;
681 	int tmp = *size;
682 
683 	if (--tmp < 0)
684 		return NULL;
685 
686 	/* goto first element */
687 	data++;
688 	while (1) {
689 		switch (*data) {
690 		case MIPI_SEQ_ELEM_SEND_PKT:
691 			/*
692 			 * skip by this element payload size
693 			 * skip elem id, command flag and data type
694 			 */
695 			tmp -= 5;
696 			if (tmp < 0)
697 				return NULL;
698 
699 			data += 3;
700 			len = *((u16 *)data);
701 
702 			tmp -= len;
703 			if (tmp < 0)
704 				return NULL;
705 
706 			/* skip by len */
707 			data = data + 2 + len;
708 			break;
709 		case MIPI_SEQ_ELEM_DELAY:
710 			/* skip by elem id, and delay is 4 bytes */
711 			tmp -= 5;
712 			if (tmp < 0)
713 				return NULL;
714 
715 			data += 5;
716 			break;
717 		case MIPI_SEQ_ELEM_GPIO:
718 			tmp -= 3;
719 			if (tmp < 0)
720 				return NULL;
721 
722 			data += 3;
723 			break;
724 		default:
725 			DRM_ERROR("Unknown element\n");
726 			return NULL;
727 		}
728 
729 		/* end of sequence ? */
730 		if (*data == 0)
731 			break;
732 	}
733 
734 	/* goto next sequence or end of block byte */
735 	if (--tmp < 0)
736 		return NULL;
737 
738 	data++;
739 
740 	/* update amount of data left for the sequence block to be parsed */
741 	*size = tmp;
742 	return data;
743 }
744 
745 static void
746 parse_mipi(struct drm_i915_private *dev_priv, const struct bdb_header *bdb)
747 {
748 	const struct bdb_mipi_config *start;
749 	const struct bdb_mipi_sequence *sequence;
750 	const struct mipi_config *config;
751 	const struct mipi_pps_data *pps;
752 	u8 *data;
753 	const u8 *seq_data;
754 	int i, panel_id, seq_size;
755 	u16 block_size;
756 
757 	/* parse MIPI blocks only if LFP type is MIPI */
758 	if (!dev_priv->vbt.has_mipi)
759 		return;
760 
761 	/* Initialize this to undefined indicating no generic MIPI support */
762 	dev_priv->vbt.dsi.panel_id = MIPI_DSI_UNDEFINED_PANEL_ID;
763 
764 	/* Block #40 is already parsed and panel_fixed_mode is
765 	 * stored in dev_priv->lfp_lvds_vbt_mode
766 	 * resuse this when needed
767 	 */
768 
769 	/* Parse #52 for panel index used from panel_type already
770 	 * parsed
771 	 */
772 	start = find_section(bdb, BDB_MIPI_CONFIG);
773 	if (!start) {
774 		DRM_DEBUG_KMS("No MIPI config BDB found");
775 		return;
776 	}
777 
778 	DRM_DEBUG_DRIVER("Found MIPI Config block, panel index = %d\n",
779 								panel_type);
780 
781 	/*
782 	 * get hold of the correct configuration block and pps data as per
783 	 * the panel_type as index
784 	 */
785 	config = &start->config[panel_type];
786 	pps = &start->pps[panel_type];
787 
788 	/* store as of now full data. Trim when we realise all is not needed */
789 	dev_priv->vbt.dsi.config = kmemdup(config, sizeof(struct mipi_config), GFP_KERNEL);
790 	if (!dev_priv->vbt.dsi.config)
791 		return;
792 
793 	dev_priv->vbt.dsi.pps = kmemdup(pps, sizeof(struct mipi_pps_data), GFP_KERNEL);
794 	if (!dev_priv->vbt.dsi.pps) {
795 		kfree(dev_priv->vbt.dsi.config);
796 		return;
797 	}
798 
799 	/* We have mandatory mipi config blocks. Initialize as generic panel */
800 	dev_priv->vbt.dsi.panel_id = MIPI_DSI_GENERIC_PANEL_ID;
801 
802 	/* Check if we have sequence block as well */
803 	sequence = find_section(bdb, BDB_MIPI_SEQUENCE);
804 	if (!sequence) {
805 		DRM_DEBUG_KMS("No MIPI Sequence found, parsing complete\n");
806 		return;
807 	}
808 
809 	/* Fail gracefully for forward incompatible sequence block. */
810 	if (sequence->version >= 3) {
811 		DRM_ERROR("Unable to parse MIPI Sequence Block v3+\n");
812 		return;
813 	}
814 
815 	DRM_DEBUG_DRIVER("Found MIPI sequence block\n");
816 
817 	block_size = get_blocksize(sequence);
818 
819 	/*
820 	 * parse the sequence block for individual sequences
821 	 */
822 	dev_priv->vbt.dsi.seq_version = sequence->version;
823 
824 	seq_data = &sequence->data[0];
825 
826 	/*
827 	 * sequence block is variable length and hence we need to parse and
828 	 * get the sequence data for specific panel id
829 	 */
830 	for (i = 0; i < MAX_MIPI_CONFIGURATIONS; i++) {
831 		panel_id = *seq_data;
832 #pragma GCC diagnostic ignored "-Wcast-qual"
833 		seq_size = *((u16 *) (seq_data + 1));
834 #pragma GCC diagnostic pop
835 		if (panel_id == panel_type)
836 			break;
837 
838 		/* skip the sequence including seq header of 3 bytes */
839 		seq_data = seq_data + 3 + seq_size;
840 		if ((seq_data - &sequence->data[0]) > block_size) {
841 			DRM_ERROR("Sequence start is beyond sequence block size, corrupted sequence block\n");
842 			return;
843 		}
844 	}
845 
846 	if (i == MAX_MIPI_CONFIGURATIONS) {
847 		DRM_ERROR("Sequence block detected but no valid configuration\n");
848 		return;
849 	}
850 
851 	/* check if found sequence is completely within the sequence block
852 	 * just being paranoid */
853 	if (seq_size > block_size) {
854 		DRM_ERROR("Corrupted sequence/size, bailing out\n");
855 		return;
856 	}
857 
858 	/* skip the panel id(1 byte) and seq size(2 bytes) */
859 	dev_priv->vbt.dsi.data = kmemdup(seq_data + 3, seq_size, GFP_KERNEL);
860 	if (!dev_priv->vbt.dsi.data)
861 		return;
862 
863 	/*
864 	 * loop into the sequence data and split into multiple sequneces
865 	 * There are only 5 types of sequences as of now
866 	 */
867 	data = dev_priv->vbt.dsi.data;
868 	dev_priv->vbt.dsi.size = seq_size;
869 
870 	/* two consecutive 0x00 indicate end of all sequences */
871 	while (1) {
872 		int seq_id = *data;
873 		if (MIPI_SEQ_MAX > seq_id && seq_id > MIPI_SEQ_UNDEFINED) {
874 			dev_priv->vbt.dsi.sequence[seq_id] = data;
875 			DRM_DEBUG_DRIVER("Found mipi sequence - %d\n", seq_id);
876 		} else {
877 			DRM_ERROR("undefined sequence\n");
878 			goto err;
879 		}
880 
881 		/* partial parsing to skip elements */
882 		data = goto_next_sequence(data, &seq_size);
883 
884 		if (data == NULL) {
885 			DRM_ERROR("Sequence elements going beyond block itself. Sequence block parsing failed\n");
886 			goto err;
887 		}
888 
889 		if (*data == 0)
890 			break; /* end of sequence reached */
891 	}
892 
893 	DRM_DEBUG_DRIVER("MIPI related vbt parsing complete\n");
894 	return;
895 err:
896 	kfree(dev_priv->vbt.dsi.data);
897 	dev_priv->vbt.dsi.data = NULL;
898 
899 	/* error during parsing so set all pointers to null
900 	 * because of partial parsing */
901 	memset(dev_priv->vbt.dsi.sequence, 0, sizeof(dev_priv->vbt.dsi.sequence));
902 }
903 
904 static u8 translate_iboost(u8 val)
905 {
906 	static const u8 mapping[] = { 1, 3, 7 }; /* See VBT spec */
907 
908 	if (val >= ARRAY_SIZE(mapping)) {
909 		DRM_DEBUG_KMS("Unsupported I_boost value found in VBT (%d), display may not work properly\n", val);
910 		return 0;
911 	}
912 	return mapping[val];
913 }
914 
915 static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
916 			   const struct bdb_header *bdb)
917 {
918 	union child_device_config *it, *child = NULL;
919 	struct ddi_vbt_port_info *info = &dev_priv->vbt.ddi_port_info[port];
920 	uint8_t hdmi_level_shift;
921 	int i, j;
922 	bool is_dvi, is_hdmi, is_dp, is_edp, is_crt;
923 	uint8_t aux_channel, ddc_pin;
924 	/* Each DDI port can have more than one value on the "DVO Port" field,
925 	 * so look for all the possible values for each port and abort if more
926 	 * than one is found. */
927 	int dvo_ports[][3] = {
928 		{DVO_PORT_HDMIA, DVO_PORT_DPA, -1},
929 		{DVO_PORT_HDMIB, DVO_PORT_DPB, -1},
930 		{DVO_PORT_HDMIC, DVO_PORT_DPC, -1},
931 		{DVO_PORT_HDMID, DVO_PORT_DPD, -1},
932 		{DVO_PORT_CRT, DVO_PORT_HDMIE, DVO_PORT_DPE},
933 	};
934 
935 	/* Find the child device to use, abort if more than one found. */
936 	for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
937 		it = dev_priv->vbt.child_dev + i;
938 
939 		for (j = 0; j < 3; j++) {
940 			if (dvo_ports[port][j] == -1)
941 				break;
942 
943 			if (it->common.dvo_port == dvo_ports[port][j]) {
944 				if (child) {
945 					DRM_DEBUG_KMS("More than one child device for port %c in VBT.\n",
946 						      port_name(port));
947 					return;
948 				}
949 				child = it;
950 			}
951 		}
952 	}
953 	if (!child)
954 		return;
955 
956 	aux_channel = child->raw[25];
957 	ddc_pin = child->common.ddc_pin;
958 
959 	is_dvi = child->common.device_type & DEVICE_TYPE_TMDS_DVI_SIGNALING;
960 	is_dp = child->common.device_type & DEVICE_TYPE_DISPLAYPORT_OUTPUT;
961 	is_crt = child->common.device_type & DEVICE_TYPE_ANALOG_OUTPUT;
962 	is_hdmi = is_dvi && (child->common.device_type & DEVICE_TYPE_NOT_HDMI_OUTPUT) == 0;
963 	is_edp = is_dp && (child->common.device_type & DEVICE_TYPE_INTERNAL_CONNECTOR);
964 
965 	info->supports_dvi = is_dvi;
966 	info->supports_hdmi = is_hdmi;
967 	info->supports_dp = is_dp;
968 
969 	DRM_DEBUG_KMS("Port %c VBT info: DP:%d HDMI:%d DVI:%d EDP:%d CRT:%d\n",
970 		      port_name(port), is_dp, is_hdmi, is_dvi, is_edp, is_crt);
971 
972 	if (is_edp && is_dvi)
973 		DRM_DEBUG_KMS("Internal DP port %c is TMDS compatible\n",
974 			      port_name(port));
975 	if (is_crt && port != PORT_E)
976 		DRM_DEBUG_KMS("Port %c is analog\n", port_name(port));
977 	if (is_crt && (is_dvi || is_dp))
978 		DRM_DEBUG_KMS("Analog port %c is also DP or TMDS compatible\n",
979 			      port_name(port));
980 	if (is_dvi && (port == PORT_A || port == PORT_E))
981 		DRM_DEBUG_KMS("Port %c is TMDS compatible\n", port_name(port));
982 	if (!is_dvi && !is_dp && !is_crt)
983 		DRM_DEBUG_KMS("Port %c is not DP/TMDS/CRT compatible\n",
984 			      port_name(port));
985 	if (is_edp && (port == PORT_B || port == PORT_C || port == PORT_E))
986 		DRM_DEBUG_KMS("Port %c is internal DP\n", port_name(port));
987 
988 	if (is_dvi) {
989 		if (port == PORT_E) {
990 			info->alternate_ddc_pin = ddc_pin;
991 			/* if DDIE share ddc pin with other port, then
992 			 * dvi/hdmi couldn't exist on the shared port.
993 			 * Otherwise they share the same ddc bin and system
994 			 * couldn't communicate with them seperately. */
995 			if (ddc_pin == DDC_PIN_B) {
996 				dev_priv->vbt.ddi_port_info[PORT_B].supports_dvi = 0;
997 				dev_priv->vbt.ddi_port_info[PORT_B].supports_hdmi = 0;
998 			} else if (ddc_pin == DDC_PIN_C) {
999 				dev_priv->vbt.ddi_port_info[PORT_C].supports_dvi = 0;
1000 				dev_priv->vbt.ddi_port_info[PORT_C].supports_hdmi = 0;
1001 			} else if (ddc_pin == DDC_PIN_D) {
1002 				dev_priv->vbt.ddi_port_info[PORT_D].supports_dvi = 0;
1003 				dev_priv->vbt.ddi_port_info[PORT_D].supports_hdmi = 0;
1004 			}
1005 		} else if (ddc_pin == DDC_PIN_B && port != PORT_B)
1006 			DRM_DEBUG_KMS("Unexpected DDC pin for port B\n");
1007 		else if (ddc_pin == DDC_PIN_C && port != PORT_C)
1008 			DRM_DEBUG_KMS("Unexpected DDC pin for port C\n");
1009 		else if (ddc_pin == DDC_PIN_D && port != PORT_D)
1010 			DRM_DEBUG_KMS("Unexpected DDC pin for port D\n");
1011 	}
1012 
1013 	if (is_dp) {
1014 		if (port == PORT_E) {
1015 			info->alternate_aux_channel = aux_channel;
1016 			/* if DDIE share aux channel with other port, then
1017 			 * DP couldn't exist on the shared port. Otherwise
1018 			 * they share the same aux channel and system
1019 			 * couldn't communicate with them seperately. */
1020 			if (aux_channel == DP_AUX_A)
1021 				dev_priv->vbt.ddi_port_info[PORT_A].supports_dp = 0;
1022 			else if (aux_channel == DP_AUX_B)
1023 				dev_priv->vbt.ddi_port_info[PORT_B].supports_dp = 0;
1024 			else if (aux_channel == DP_AUX_C)
1025 				dev_priv->vbt.ddi_port_info[PORT_C].supports_dp = 0;
1026 			else if (aux_channel == DP_AUX_D)
1027 				dev_priv->vbt.ddi_port_info[PORT_D].supports_dp = 0;
1028 		}
1029 		else if (aux_channel == DP_AUX_A && port != PORT_A)
1030 			DRM_DEBUG_KMS("Unexpected AUX channel for port A\n");
1031 		else if (aux_channel == DP_AUX_B && port != PORT_B)
1032 			DRM_DEBUG_KMS("Unexpected AUX channel for port B\n");
1033 		else if (aux_channel == DP_AUX_C && port != PORT_C)
1034 			DRM_DEBUG_KMS("Unexpected AUX channel for port C\n");
1035 		else if (aux_channel == DP_AUX_D && port != PORT_D)
1036 			DRM_DEBUG_KMS("Unexpected AUX channel for port D\n");
1037 	}
1038 
1039 	if (bdb->version >= 158) {
1040 		/* The VBT HDMI level shift values match the table we have. */
1041 		hdmi_level_shift = child->raw[7] & 0xF;
1042 		DRM_DEBUG_KMS("VBT HDMI level shift for port %c: %d\n",
1043 			      port_name(port),
1044 			      hdmi_level_shift);
1045 		info->hdmi_level_shift = hdmi_level_shift;
1046 	}
1047 
1048 	/* Parse the I_boost config for SKL and above */
1049 	if (bdb->version >= 196 && (child->common.flags_1 & IBOOST_ENABLE)) {
1050 		info->dp_boost_level = translate_iboost(child->common.iboost_level & 0xF);
1051 		DRM_DEBUG_KMS("VBT (e)DP boost level for port %c: %d\n",
1052 			      port_name(port), info->dp_boost_level);
1053 		info->hdmi_boost_level = translate_iboost(child->common.iboost_level >> 4);
1054 		DRM_DEBUG_KMS("VBT HDMI boost level for port %c: %d\n",
1055 			      port_name(port), info->hdmi_boost_level);
1056 	}
1057 }
1058 
1059 static void parse_ddi_ports(struct drm_i915_private *dev_priv,
1060 			    const struct bdb_header *bdb)
1061 {
1062 	struct drm_device *dev = dev_priv->dev;
1063 	enum port port;
1064 
1065 	if (!HAS_DDI(dev))
1066 		return;
1067 
1068 	if (!dev_priv->vbt.child_dev_num)
1069 		return;
1070 
1071 	if (bdb->version < 155)
1072 		return;
1073 
1074 	for (port = PORT_A; port < I915_MAX_PORTS; port++)
1075 		parse_ddi_port(dev_priv, port, bdb);
1076 }
1077 
1078 static void
1079 parse_device_mapping(struct drm_i915_private *dev_priv,
1080 		     const struct bdb_header *bdb)
1081 {
1082 	const struct bdb_general_definitions *p_defs;
1083 	const union child_device_config *p_child;
1084 	union child_device_config *child_dev_ptr;
1085 	int i, child_device_num, count;
1086 	u8 expected_size;
1087 	u16 block_size;
1088 
1089 	p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
1090 	if (!p_defs) {
1091 		DRM_DEBUG_KMS("No general definition block is found, no devices defined.\n");
1092 		return;
1093 	}
1094 	if (bdb->version < 195) {
1095 		expected_size = sizeof(struct old_child_dev_config);
1096 	} else if (bdb->version == 195) {
1097 		expected_size = 37;
1098 	} else if (bdb->version <= 197) {
1099 		expected_size = 38;
1100 	} else {
1101 		expected_size = 38;
1102 		BUILD_BUG_ON(sizeof(*p_child) < 38);
1103 		DRM_DEBUG_DRIVER("Expected child device config size for VBT version %u not known; assuming %u\n",
1104 				 bdb->version, expected_size);
1105 	}
1106 
1107 	/* The legacy sized child device config is the minimum we need. */
1108 	if (p_defs->child_dev_size < sizeof(struct old_child_dev_config)) {
1109 		DRM_ERROR("Child device config size %u is too small.\n",
1110 			  p_defs->child_dev_size);
1111 		return;
1112 	}
1113 
1114 	/* Flag an error for unexpected size, but continue anyway. */
1115 	if (p_defs->child_dev_size != expected_size)
1116 		DRM_ERROR("Unexpected child device config size %u (expected %u for VBT version %u)\n",
1117 			  p_defs->child_dev_size, expected_size, bdb->version);
1118 
1119 	/* get the block size of general definitions */
1120 	block_size = get_blocksize(p_defs);
1121 	/* get the number of child device */
1122 	child_device_num = (block_size - sizeof(*p_defs)) /
1123 				p_defs->child_dev_size;
1124 	count = 0;
1125 	/* get the number of child device that is present */
1126 	for (i = 0; i < child_device_num; i++) {
1127 		p_child = child_device_ptr(p_defs, i);
1128 		if (!p_child->common.device_type) {
1129 			/* skip the device block if device type is invalid */
1130 			continue;
1131 		}
1132 		count++;
1133 	}
1134 	if (!count) {
1135 		DRM_DEBUG_KMS("no child dev is parsed from VBT\n");
1136 		return;
1137 	}
1138 	dev_priv->vbt.child_dev = kcalloc(count, sizeof(*p_child), GFP_KERNEL);
1139 	if (!dev_priv->vbt.child_dev) {
1140 		DRM_DEBUG_KMS("No memory space for child device\n");
1141 		return;
1142 	}
1143 
1144 	dev_priv->vbt.child_dev_num = count;
1145 	count = 0;
1146 	for (i = 0; i < child_device_num; i++) {
1147 		p_child = child_device_ptr(p_defs, i);
1148 		if (!p_child->common.device_type) {
1149 			/* skip the device block if device type is invalid */
1150 			continue;
1151 		}
1152 
1153 		if (p_child->common.dvo_port >= DVO_PORT_MIPIA
1154 		    && p_child->common.dvo_port <= DVO_PORT_MIPID
1155 		    &&p_child->common.device_type & DEVICE_TYPE_MIPI_OUTPUT) {
1156 			DRM_DEBUG_KMS("Found MIPI as LFP\n");
1157 			dev_priv->vbt.has_mipi = 1;
1158 			dev_priv->vbt.dsi.port = p_child->common.dvo_port;
1159 		}
1160 
1161 		child_dev_ptr = dev_priv->vbt.child_dev + count;
1162 		count++;
1163 
1164 		/*
1165 		 * Copy as much as we know (sizeof) and is available
1166 		 * (child_dev_size) of the child device. Accessing the data must
1167 		 * depend on VBT version.
1168 		 */
1169 		memcpy(child_dev_ptr, p_child,
1170 		       min_t(size_t, p_defs->child_dev_size, sizeof(*p_child)));
1171 	}
1172 	return;
1173 }
1174 
1175 static void
1176 init_vbt_defaults(struct drm_i915_private *dev_priv)
1177 {
1178 	struct drm_device *dev = dev_priv->dev;
1179 	enum port port;
1180 
1181 	dev_priv->vbt.crt_ddc_pin = GMBUS_PIN_VGADDC;
1182 
1183 	/* Default to having backlight */
1184 	dev_priv->vbt.backlight.present = true;
1185 
1186 	/* LFP panel data */
1187 	dev_priv->vbt.lvds_dither = 1;
1188 	dev_priv->vbt.lvds_vbt = 0;
1189 
1190 	/* SDVO panel data */
1191 	dev_priv->vbt.sdvo_lvds_vbt_mode = NULL;
1192 
1193 	/* general features */
1194 	dev_priv->vbt.int_tv_support = 1;
1195 	dev_priv->vbt.int_crt_support = 1;
1196 
1197 	/* Default to using SSC */
1198 	dev_priv->vbt.lvds_use_ssc = 1;
1199 	/*
1200 	 * Core/SandyBridge/IvyBridge use alternative (120MHz) reference
1201 	 * clock for LVDS.
1202 	 */
1203 	dev_priv->vbt.lvds_ssc_freq = intel_bios_ssc_frequency(dev,
1204 			!HAS_PCH_SPLIT(dev));
1205 	DRM_DEBUG_KMS("Set default to SSC at %d kHz\n", dev_priv->vbt.lvds_ssc_freq);
1206 
1207 	for (port = PORT_A; port < I915_MAX_PORTS; port++) {
1208 		struct ddi_vbt_port_info *info =
1209 			&dev_priv->vbt.ddi_port_info[port];
1210 
1211 		info->hdmi_level_shift = HDMI_LEVEL_SHIFT_UNKNOWN;
1212 
1213 		info->supports_dvi = (port != PORT_A && port != PORT_E);
1214 		info->supports_hdmi = info->supports_dvi;
1215 		info->supports_dp = (port != PORT_E);
1216 	}
1217 }
1218 
1219 static int intel_no_opregion_vbt_callback(const struct dmi_system_id *id)
1220 {
1221 	DRM_DEBUG_KMS("Falling back to manually reading VBT from "
1222 		      "VBIOS ROM for %s\n",
1223 		      id->ident);
1224 	return 1;
1225 }
1226 
1227 static const struct dmi_system_id intel_no_opregion_vbt[] = {
1228 	{
1229 		.callback = intel_no_opregion_vbt_callback,
1230 		.ident = "ThinkCentre A57",
1231 		.matches = {
1232 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
1233 			DMI_MATCH(DMI_PRODUCT_NAME, "97027RG"),
1234 		},
1235 	},
1236 	{ }
1237 };
1238 
1239 static const struct bdb_header *validate_vbt(const void __iomem *_base,
1240 					     size_t size,
1241 					     const void __iomem *_vbt,
1242 					     const char *source)
1243 {
1244 	/*
1245 	 * This is the one place where we explicitly discard the address space
1246 	 * (__iomem) of the BIOS/VBT. (And this will cause a sparse complaint.)
1247 	 * From now on everything is based on 'base', and treated as regular
1248 	 * memory.
1249 	 */
1250 	const char *base = (const void *) _base;
1251 	size_t offset = (const char *)_vbt - (const char*)_base;
1252 	const struct vbt_header *vbt = (const struct vbt_header *)(base + offset);
1253 	const struct bdb_header *bdb;
1254 
1255 	if (offset + sizeof(struct vbt_header) > size) {
1256 		DRM_DEBUG_DRIVER("VBT header incomplete\n");
1257 		return NULL;
1258 	}
1259 
1260 	if (memcmp(vbt->signature, "$VBT", 4)) {
1261 		DRM_DEBUG_DRIVER("VBT invalid signature\n");
1262 		return NULL;
1263 	}
1264 
1265 	offset += vbt->bdb_offset;
1266 	if (offset + sizeof(struct bdb_header) > size) {
1267 		DRM_DEBUG_DRIVER("BDB header incomplete\n");
1268 		return NULL;
1269 	}
1270 
1271 	bdb = (const struct bdb_header*)(base + offset);
1272 	if (offset + bdb->bdb_size > size) {
1273 		DRM_DEBUG_DRIVER("BDB incomplete\n");
1274 		return NULL;
1275 	}
1276 
1277 	DRM_DEBUG_KMS("Using VBT from %s: %20s\n",
1278 		      source, vbt->signature);
1279 	return bdb;
1280 }
1281 
1282 static const struct bdb_header *find_vbt(void __iomem *bios, size_t size)
1283 {
1284 	const struct bdb_header *bdb = NULL;
1285 	size_t i;
1286 
1287 	/* Scour memory looking for the VBT signature. */
1288 	for (i = 0; i + 4 < size; i++) {
1289 		if (ioread32(bios + i) == *((const u32 *) "$VBT")) {
1290 			bdb = validate_vbt((char *)bios, size, (char *)bios + i, "PCI ROM");
1291 			break;
1292 		}
1293 	}
1294 
1295 	return bdb;
1296 }
1297 
1298 /**
1299  * intel_parse_bios - find VBT and initialize settings from the BIOS
1300  * @dev: DRM device
1301  *
1302  * Loads the Video BIOS and checks that the VBT exists.  Sets scratch registers
1303  * to appropriate values.
1304  *
1305  * Returns 0 on success, nonzero on failure.
1306  */
1307 int
1308 intel_parse_bios(struct drm_device *dev)
1309 {
1310 	struct drm_i915_private *dev_priv = dev->dev_private;
1311 #if 0
1312 	struct pci_dev *pdev = dev->pdev;
1313 #endif
1314 	const struct bdb_header *bdb = NULL;
1315 	u8 __iomem *bios = NULL;
1316 
1317 	if (HAS_PCH_NOP(dev))
1318 		return -ENODEV;
1319 
1320 	init_vbt_defaults(dev_priv);
1321 
1322 	/* XXX Should this validation be moved to intel_opregion.c? */
1323 	if (!dmi_check_system(intel_no_opregion_vbt) && dev_priv->opregion.vbt)
1324 		bdb = validate_vbt(dev_priv->opregion.header, OPREGION_SIZE,
1325 				   dev_priv->opregion.vbt, "OpRegion");
1326 
1327 	if (bdb == NULL) {
1328 		size_t size;
1329 
1330 #if 0
1331 		bios = pci_map_rom(pdev, &size);
1332 		if (!bios)
1333 #endif
1334 			return -1;
1335 
1336 		bdb = find_vbt(bios, size);
1337 		if (!bdb) {
1338 #if 0
1339 			pci_unmap_rom(pdev, bios);
1340 #endif
1341 			return -1;
1342 		}
1343 	}
1344 
1345 	/* Grab useful general definitions */
1346 	parse_general_features(dev_priv, bdb);
1347 	parse_general_definitions(dev_priv, bdb);
1348 	parse_lfp_panel_data(dev_priv, bdb);
1349 	parse_lfp_backlight(dev_priv, bdb);
1350 	parse_sdvo_panel_data(dev_priv, bdb);
1351 	parse_sdvo_device_mapping(dev_priv, bdb);
1352 	parse_device_mapping(dev_priv, bdb);
1353 	parse_driver_features(dev_priv, bdb);
1354 	parse_edp(dev_priv, bdb);
1355 	parse_psr(dev_priv, bdb);
1356 	parse_mipi(dev_priv, bdb);
1357 	parse_ddi_ports(dev_priv, bdb);
1358 
1359 #if 0
1360 	if (bios)
1361 		pci_unmap_rom(pdev, bios);
1362 #endif
1363 
1364 	return 0;
1365 }
1366 
1367 /* Ensure that vital registers have been initialised, even if the BIOS
1368  * is absent or just failing to do its job.
1369  */
1370 void intel_setup_bios(struct drm_device *dev)
1371 {
1372 	struct drm_i915_private *dev_priv = dev->dev_private;
1373 
1374 	 /* Set the Panel Power On/Off timings if uninitialized. */
1375 	if (!HAS_PCH_SPLIT(dev) &&
1376 	    I915_READ(PP_ON_DELAYS) == 0 && I915_READ(PP_OFF_DELAYS) == 0) {
1377 		/* Set T2 to 40ms and T5 to 200ms */
1378 		I915_WRITE(PP_ON_DELAYS, 0x019007d0);
1379 
1380 		/* Set T3 to 35ms and Tx to 200ms */
1381 		I915_WRITE(PP_OFF_DELAYS, 0x015e07d0);
1382 	}
1383 }
1384