xref: /dragonfly/sys/dev/drm/i915/intel_panel.c (revision aeaecd48)
1 /*
2  * Copyright © 2006-2010 Intel Corporation
3  * Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice (including the next
13  * paragraph) shall be included in all copies or substantial portions of the
14  * Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22  * DEALINGS IN THE SOFTWARE.
23  *
24  * Authors:
25  *	Eric Anholt <eric@anholt.net>
26  *      Dave Airlie <airlied@linux.ie>
27  *      Jesse Barnes <jesse.barnes@intel.com>
28  *      Chris Wilson <chris@chris-wilson.co.uk>
29  */
30 
31 #include <linux/moduleparam.h>
32 #include "intel_drv.h"
33 
34 void
35 intel_fixed_panel_mode(const struct drm_display_mode *fixed_mode,
36 		       struct drm_display_mode *adjusted_mode)
37 {
38 	drm_mode_copy(adjusted_mode, fixed_mode);
39 
40 	drm_mode_set_crtcinfo(adjusted_mode, 0);
41 }
42 
43 /**
44  * intel_find_panel_downclock - find the reduced downclock for LVDS in EDID
45  * @dev: drm device
46  * @fixed_mode : panel native mode
47  * @connector: LVDS/eDP connector
48  *
49  * Return downclock_avail
50  * Find the reduced downclock for LVDS/eDP in EDID.
51  */
52 struct drm_display_mode *
53 intel_find_panel_downclock(struct drm_device *dev,
54 			struct drm_display_mode *fixed_mode,
55 			struct drm_connector *connector)
56 {
57 	struct drm_display_mode *scan, *tmp_mode;
58 	int temp_downclock;
59 
60 	temp_downclock = fixed_mode->clock;
61 	tmp_mode = NULL;
62 
63 	list_for_each_entry(scan, &connector->probed_modes, head) {
64 		/*
65 		 * If one mode has the same resolution with the fixed_panel
66 		 * mode while they have the different refresh rate, it means
67 		 * that the reduced downclock is found. In such
68 		 * case we can set the different FPx0/1 to dynamically select
69 		 * between low and high frequency.
70 		 */
71 		if (scan->hdisplay == fixed_mode->hdisplay &&
72 		    scan->hsync_start == fixed_mode->hsync_start &&
73 		    scan->hsync_end == fixed_mode->hsync_end &&
74 		    scan->htotal == fixed_mode->htotal &&
75 		    scan->vdisplay == fixed_mode->vdisplay &&
76 		    scan->vsync_start == fixed_mode->vsync_start &&
77 		    scan->vsync_end == fixed_mode->vsync_end &&
78 		    scan->vtotal == fixed_mode->vtotal) {
79 			if (scan->clock < temp_downclock) {
80 				/*
81 				 * The downclock is already found. But we
82 				 * expect to find the lower downclock.
83 				 */
84 				temp_downclock = scan->clock;
85 				tmp_mode = scan;
86 			}
87 		}
88 	}
89 
90 	if (temp_downclock < fixed_mode->clock)
91 		return drm_mode_duplicate(dev, tmp_mode);
92 	else
93 		return NULL;
94 }
95 
96 /* adjusted_mode has been preset to be the panel's fixed mode */
97 void
98 intel_pch_panel_fitting(struct intel_crtc *intel_crtc,
99 			struct intel_crtc_state *pipe_config,
100 			int fitting_mode)
101 {
102 	struct drm_display_mode *adjusted_mode;
103 	int x, y, width, height;
104 
105 	adjusted_mode = &pipe_config->base.adjusted_mode;
106 
107 	x = y = width = height = 0;
108 
109 	/* Native modes don't need fitting */
110 	if (adjusted_mode->hdisplay == pipe_config->pipe_src_w &&
111 	    adjusted_mode->vdisplay == pipe_config->pipe_src_h)
112 		goto done;
113 
114 	switch (fitting_mode) {
115 	case DRM_MODE_SCALE_CENTER:
116 		width = pipe_config->pipe_src_w;
117 		height = pipe_config->pipe_src_h;
118 		x = (adjusted_mode->hdisplay - width + 1)/2;
119 		y = (adjusted_mode->vdisplay - height + 1)/2;
120 		break;
121 
122 	case DRM_MODE_SCALE_ASPECT:
123 		/* Scale but preserve the aspect ratio */
124 		{
125 			u32 scaled_width = adjusted_mode->hdisplay
126 				* pipe_config->pipe_src_h;
127 			u32 scaled_height = pipe_config->pipe_src_w
128 				* adjusted_mode->vdisplay;
129 			if (scaled_width > scaled_height) { /* pillar */
130 				width = scaled_height / pipe_config->pipe_src_h;
131 				if (width & 1)
132 					width++;
133 				x = (adjusted_mode->hdisplay - width + 1) / 2;
134 				y = 0;
135 				height = adjusted_mode->vdisplay;
136 			} else if (scaled_width < scaled_height) { /* letter */
137 				height = scaled_width / pipe_config->pipe_src_w;
138 				if (height & 1)
139 				    height++;
140 				y = (adjusted_mode->vdisplay - height + 1) / 2;
141 				x = 0;
142 				width = adjusted_mode->hdisplay;
143 			} else {
144 				x = y = 0;
145 				width = adjusted_mode->hdisplay;
146 				height = adjusted_mode->vdisplay;
147 			}
148 		}
149 		break;
150 
151 	case DRM_MODE_SCALE_FULLSCREEN:
152 		x = y = 0;
153 		width = adjusted_mode->hdisplay;
154 		height = adjusted_mode->vdisplay;
155 		break;
156 
157 	default:
158 		WARN(1, "bad panel fit mode: %d\n", fitting_mode);
159 		return;
160 	}
161 
162 done:
163 	pipe_config->pch_pfit.pos = (x << 16) | y;
164 	pipe_config->pch_pfit.size = (width << 16) | height;
165 	pipe_config->pch_pfit.enabled = pipe_config->pch_pfit.size != 0;
166 }
167 
168 static void
169 centre_horizontally(struct drm_display_mode *mode,
170 		    int width)
171 {
172 	u32 border, sync_pos, blank_width, sync_width;
173 
174 	/* keep the hsync and hblank widths constant */
175 	sync_width = mode->crtc_hsync_end - mode->crtc_hsync_start;
176 	blank_width = mode->crtc_hblank_end - mode->crtc_hblank_start;
177 	sync_pos = (blank_width - sync_width + 1) / 2;
178 
179 	border = (mode->hdisplay - width + 1) / 2;
180 	border += border & 1; /* make the border even */
181 
182 	mode->crtc_hdisplay = width;
183 	mode->crtc_hblank_start = width + border;
184 	mode->crtc_hblank_end = mode->crtc_hblank_start + blank_width;
185 
186 	mode->crtc_hsync_start = mode->crtc_hblank_start + sync_pos;
187 	mode->crtc_hsync_end = mode->crtc_hsync_start + sync_width;
188 }
189 
190 static void
191 centre_vertically(struct drm_display_mode *mode,
192 		  int height)
193 {
194 	u32 border, sync_pos, blank_width, sync_width;
195 
196 	/* keep the vsync and vblank widths constant */
197 	sync_width = mode->crtc_vsync_end - mode->crtc_vsync_start;
198 	blank_width = mode->crtc_vblank_end - mode->crtc_vblank_start;
199 	sync_pos = (blank_width - sync_width + 1) / 2;
200 
201 	border = (mode->vdisplay - height + 1) / 2;
202 
203 	mode->crtc_vdisplay = height;
204 	mode->crtc_vblank_start = height + border;
205 	mode->crtc_vblank_end = mode->crtc_vblank_start + blank_width;
206 
207 	mode->crtc_vsync_start = mode->crtc_vblank_start + sync_pos;
208 	mode->crtc_vsync_end = mode->crtc_vsync_start + sync_width;
209 }
210 
211 static inline u32 panel_fitter_scaling(u32 source, u32 target)
212 {
213 	/*
214 	 * Floating point operation is not supported. So the FACTOR
215 	 * is defined, which can avoid the floating point computation
216 	 * when calculating the panel ratio.
217 	 */
218 #define ACCURACY 12
219 #define FACTOR (1 << ACCURACY)
220 	u32 ratio = source * FACTOR / target;
221 	return (FACTOR * ratio + FACTOR/2) / FACTOR;
222 }
223 
224 static void i965_scale_aspect(struct intel_crtc_state *pipe_config,
225 			      u32 *pfit_control)
226 {
227 	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
228 	u32 scaled_width = adjusted_mode->hdisplay *
229 		pipe_config->pipe_src_h;
230 	u32 scaled_height = pipe_config->pipe_src_w *
231 		adjusted_mode->vdisplay;
232 
233 	/* 965+ is easy, it does everything in hw */
234 	if (scaled_width > scaled_height)
235 		*pfit_control |= PFIT_ENABLE |
236 			PFIT_SCALING_PILLAR;
237 	else if (scaled_width < scaled_height)
238 		*pfit_control |= PFIT_ENABLE |
239 			PFIT_SCALING_LETTER;
240 	else if (adjusted_mode->hdisplay != pipe_config->pipe_src_w)
241 		*pfit_control |= PFIT_ENABLE | PFIT_SCALING_AUTO;
242 }
243 
244 static void i9xx_scale_aspect(struct intel_crtc_state *pipe_config,
245 			      u32 *pfit_control, u32 *pfit_pgm_ratios,
246 			      u32 *border)
247 {
248 	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
249 	u32 scaled_width = adjusted_mode->hdisplay *
250 		pipe_config->pipe_src_h;
251 	u32 scaled_height = pipe_config->pipe_src_w *
252 		adjusted_mode->vdisplay;
253 	u32 bits;
254 
255 	/*
256 	 * For earlier chips we have to calculate the scaling
257 	 * ratio by hand and program it into the
258 	 * PFIT_PGM_RATIO register
259 	 */
260 	if (scaled_width > scaled_height) { /* pillar */
261 		centre_horizontally(adjusted_mode,
262 				    scaled_height /
263 				    pipe_config->pipe_src_h);
264 
265 		*border = LVDS_BORDER_ENABLE;
266 		if (pipe_config->pipe_src_h != adjusted_mode->vdisplay) {
267 			bits = panel_fitter_scaling(pipe_config->pipe_src_h,
268 						    adjusted_mode->vdisplay);
269 
270 			*pfit_pgm_ratios |= (bits << PFIT_HORIZ_SCALE_SHIFT |
271 					     bits << PFIT_VERT_SCALE_SHIFT);
272 			*pfit_control |= (PFIT_ENABLE |
273 					  VERT_INTERP_BILINEAR |
274 					  HORIZ_INTERP_BILINEAR);
275 		}
276 	} else if (scaled_width < scaled_height) { /* letter */
277 		centre_vertically(adjusted_mode,
278 				  scaled_width /
279 				  pipe_config->pipe_src_w);
280 
281 		*border = LVDS_BORDER_ENABLE;
282 		if (pipe_config->pipe_src_w != adjusted_mode->hdisplay) {
283 			bits = panel_fitter_scaling(pipe_config->pipe_src_w,
284 						    adjusted_mode->hdisplay);
285 
286 			*pfit_pgm_ratios |= (bits << PFIT_HORIZ_SCALE_SHIFT |
287 					     bits << PFIT_VERT_SCALE_SHIFT);
288 			*pfit_control |= (PFIT_ENABLE |
289 					  VERT_INTERP_BILINEAR |
290 					  HORIZ_INTERP_BILINEAR);
291 		}
292 	} else {
293 		/* Aspects match, Let hw scale both directions */
294 		*pfit_control |= (PFIT_ENABLE |
295 				  VERT_AUTO_SCALE | HORIZ_AUTO_SCALE |
296 				  VERT_INTERP_BILINEAR |
297 				  HORIZ_INTERP_BILINEAR);
298 	}
299 }
300 
301 void intel_gmch_panel_fitting(struct intel_crtc *intel_crtc,
302 			      struct intel_crtc_state *pipe_config,
303 			      int fitting_mode)
304 {
305 	struct drm_device *dev = intel_crtc->base.dev;
306 	u32 pfit_control = 0, pfit_pgm_ratios = 0, border = 0;
307 	struct drm_display_mode *adjusted_mode;
308 
309 	adjusted_mode = &pipe_config->base.adjusted_mode;
310 
311 	/* Native modes don't need fitting */
312 	if (adjusted_mode->hdisplay == pipe_config->pipe_src_w &&
313 	    adjusted_mode->vdisplay == pipe_config->pipe_src_h)
314 		goto out;
315 
316 	switch (fitting_mode) {
317 	case DRM_MODE_SCALE_CENTER:
318 		/*
319 		 * For centered modes, we have to calculate border widths &
320 		 * heights and modify the values programmed into the CRTC.
321 		 */
322 		centre_horizontally(adjusted_mode, pipe_config->pipe_src_w);
323 		centre_vertically(adjusted_mode, pipe_config->pipe_src_h);
324 		border = LVDS_BORDER_ENABLE;
325 		break;
326 	case DRM_MODE_SCALE_ASPECT:
327 		/* Scale but preserve the aspect ratio */
328 		if (INTEL_INFO(dev)->gen >= 4)
329 			i965_scale_aspect(pipe_config, &pfit_control);
330 		else
331 			i9xx_scale_aspect(pipe_config, &pfit_control,
332 					  &pfit_pgm_ratios, &border);
333 		break;
334 	case DRM_MODE_SCALE_FULLSCREEN:
335 		/*
336 		 * Full scaling, even if it changes the aspect ratio.
337 		 * Fortunately this is all done for us in hw.
338 		 */
339 		if (pipe_config->pipe_src_h != adjusted_mode->vdisplay ||
340 		    pipe_config->pipe_src_w != adjusted_mode->hdisplay) {
341 			pfit_control |= PFIT_ENABLE;
342 			if (INTEL_INFO(dev)->gen >= 4)
343 				pfit_control |= PFIT_SCALING_AUTO;
344 			else
345 				pfit_control |= (VERT_AUTO_SCALE |
346 						 VERT_INTERP_BILINEAR |
347 						 HORIZ_AUTO_SCALE |
348 						 HORIZ_INTERP_BILINEAR);
349 		}
350 		break;
351 	default:
352 		WARN(1, "bad panel fit mode: %d\n", fitting_mode);
353 		return;
354 	}
355 
356 	/* 965+ wants fuzzy fitting */
357 	/* FIXME: handle multiple panels by failing gracefully */
358 	if (INTEL_INFO(dev)->gen >= 4)
359 		pfit_control |= ((intel_crtc->pipe << PFIT_PIPE_SHIFT) |
360 				 PFIT_FILTER_FUZZY);
361 
362 out:
363 	if ((pfit_control & PFIT_ENABLE) == 0) {
364 		pfit_control = 0;
365 		pfit_pgm_ratios = 0;
366 	}
367 
368 	/* Make sure pre-965 set dither correctly for 18bpp panels. */
369 	if (INTEL_INFO(dev)->gen < 4 && pipe_config->pipe_bpp == 18)
370 		pfit_control |= PANEL_8TO6_DITHER_ENABLE;
371 
372 	pipe_config->gmch_pfit.control = pfit_control;
373 	pipe_config->gmch_pfit.pgm_ratios = pfit_pgm_ratios;
374 	pipe_config->gmch_pfit.lvds_border_bits = border;
375 }
376 
377 enum drm_connector_status
378 intel_panel_detect(struct drm_device *dev)
379 {
380 	struct drm_i915_private *dev_priv = dev->dev_private;
381 
382 	/* Assume that the BIOS does not lie through the OpRegion... */
383 	if (!i915.panel_ignore_lid && dev_priv->opregion.lid_state) {
384 		return ioread32(dev_priv->opregion.lid_state) & 0x1 ?
385 			connector_status_connected :
386 			connector_status_disconnected;
387 	}
388 
389 	switch (i915.panel_ignore_lid) {
390 	case -2:
391 		return connector_status_connected;
392 	case -1:
393 		return connector_status_disconnected;
394 	default:
395 		return connector_status_unknown;
396 	}
397 }
398 
399 /**
400  * scale - scale values from one range to another
401  *
402  * @source_val: value in range [@source_min..@source_max]
403  *
404  * Return @source_val in range [@source_min..@source_max] scaled to range
405  * [@target_min..@target_max].
406  */
407 static uint32_t scale(uint32_t source_val,
408 		      uint32_t source_min, uint32_t source_max,
409 		      uint32_t target_min, uint32_t target_max)
410 {
411 	uint64_t target_val;
412 
413 	WARN_ON(source_min > source_max);
414 	WARN_ON(target_min > target_max);
415 
416 	/* defensive */
417 	source_val = clamp(source_val, source_min, source_max);
418 
419 	/* avoid overflows */
420 	target_val = DIV_ROUND_CLOSEST_ULL((uint64_t)(source_val - source_min) *
421 			(target_max - target_min), source_max - source_min);
422 	target_val += target_min;
423 
424 	return target_val;
425 }
426 
427 /* Scale user_level in range [0..user_max] to [hw_min..hw_max]. */
428 static inline u32 scale_user_to_hw(struct intel_connector *connector,
429 				   u32 user_level, u32 user_max)
430 {
431 	struct intel_panel *panel = &connector->panel;
432 
433 	return scale(user_level, 0, user_max,
434 		     panel->backlight.min, panel->backlight.max);
435 }
436 
437 /* Scale user_level in range [0..user_max] to [0..hw_max], clamping the result
438  * to [hw_min..hw_max]. */
439 static inline u32 clamp_user_to_hw(struct intel_connector *connector,
440 				   u32 user_level, u32 user_max)
441 {
442 	struct intel_panel *panel = &connector->panel;
443 	u32 hw_level;
444 
445 	hw_level = scale(user_level, 0, user_max, 0, panel->backlight.max);
446 	hw_level = clamp(hw_level, panel->backlight.min, panel->backlight.max);
447 
448 	return hw_level;
449 }
450 
451 /* Scale hw_level in range [hw_min..hw_max] to [0..user_max]. */
452 static inline u32 scale_hw_to_user(struct intel_connector *connector,
453 				   u32 hw_level, u32 user_max)
454 {
455 	struct intel_panel *panel = &connector->panel;
456 
457 	return scale(hw_level, panel->backlight.min, panel->backlight.max,
458 		     0, user_max);
459 }
460 
461 static u32 intel_panel_compute_brightness(struct intel_connector *connector,
462 					  u32 val)
463 {
464 	struct drm_device *dev = connector->base.dev;
465 	struct drm_i915_private *dev_priv = dev->dev_private;
466 	struct intel_panel *panel = &connector->panel;
467 
468 	WARN_ON(panel->backlight.max == 0);
469 
470 	if (i915.invert_brightness < 0)
471 		return val;
472 
473 	if (i915.invert_brightness > 0 ||
474 	    dev_priv->quirks & QUIRK_INVERT_BRIGHTNESS) {
475 		return panel->backlight.max - val;
476 	}
477 
478 	return val;
479 }
480 
481 static u32 bdw_get_backlight(struct intel_connector *connector)
482 {
483 	struct drm_device *dev = connector->base.dev;
484 	struct drm_i915_private *dev_priv = dev->dev_private;
485 
486 	return I915_READ(BLC_PWM_PCH_CTL2) & BACKLIGHT_DUTY_CYCLE_MASK;
487 }
488 
489 static u32 pch_get_backlight(struct intel_connector *connector)
490 {
491 	struct drm_device *dev = connector->base.dev;
492 	struct drm_i915_private *dev_priv = dev->dev_private;
493 
494 	return I915_READ(BLC_PWM_CPU_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
495 }
496 
497 static u32 i9xx_get_backlight(struct intel_connector *connector)
498 {
499 	struct drm_device *dev = connector->base.dev;
500 	struct drm_i915_private *dev_priv = dev->dev_private;
501 	struct intel_panel *panel = &connector->panel;
502 	u32 val;
503 
504 	val = I915_READ(BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
505 	if (INTEL_INFO(dev)->gen < 4)
506 		val >>= 1;
507 
508 	if (panel->backlight.combination_mode) {
509 		u8 lbpc;
510 
511 		pci_read_config_byte(dev->pdev, PCI_LBPC, &lbpc);
512 		val *= lbpc;
513 	}
514 
515 	return val;
516 }
517 
518 static u32 _vlv_get_backlight(struct drm_device *dev, enum i915_pipe pipe)
519 {
520 	struct drm_i915_private *dev_priv = dev->dev_private;
521 
522 	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
523 		return 0;
524 
525 	return I915_READ(VLV_BLC_PWM_CTL(pipe)) & BACKLIGHT_DUTY_CYCLE_MASK;
526 }
527 
528 static u32 vlv_get_backlight(struct intel_connector *connector)
529 {
530 	struct drm_device *dev = connector->base.dev;
531 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
532 
533 	return _vlv_get_backlight(dev, pipe);
534 }
535 
536 #if 0
537 static u32 intel_panel_get_backlight(struct intel_connector *connector)
538 {
539 	struct drm_device *dev = connector->base.dev;
540 	struct drm_i915_private *dev_priv = dev->dev_private;
541 	struct intel_panel *panel = &connector->panel;
542 	u32 val = 0;
543 
544 	mutex_lock(&dev_priv->backlight_lock);
545 
546 	if (panel->backlight.enabled) {
547 		val = dev_priv->display.get_backlight(connector);
548 		val = intel_panel_compute_brightness(connector, val);
549 	}
550 
551 	mutex_unlock(&dev_priv->backlight_lock);
552 
553 	DRM_DEBUG_DRIVER("get backlight PWM = %d\n", val);
554 	return val;
555 }
556 #endif
557 
558 static void bdw_set_backlight(struct intel_connector *connector, u32 level)
559 {
560 	struct drm_device *dev = connector->base.dev;
561 	struct drm_i915_private *dev_priv = dev->dev_private;
562 	u32 val = I915_READ(BLC_PWM_PCH_CTL2) & ~BACKLIGHT_DUTY_CYCLE_MASK;
563 	I915_WRITE(BLC_PWM_PCH_CTL2, val | level);
564 }
565 
566 static void pch_set_backlight(struct intel_connector *connector, u32 level)
567 {
568 	struct drm_device *dev = connector->base.dev;
569 	struct drm_i915_private *dev_priv = dev->dev_private;
570 	u32 tmp;
571 
572 	tmp = I915_READ(BLC_PWM_CPU_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
573 	I915_WRITE(BLC_PWM_CPU_CTL, tmp | level);
574 }
575 
576 static void i9xx_set_backlight(struct intel_connector *connector, u32 level)
577 {
578 	struct drm_device *dev = connector->base.dev;
579 	struct drm_i915_private *dev_priv = dev->dev_private;
580 	struct intel_panel *panel = &connector->panel;
581 	u32 tmp, mask;
582 
583 	WARN_ON(panel->backlight.max == 0);
584 
585 	if (panel->backlight.combination_mode) {
586 		u8 lbpc;
587 
588 		lbpc = level * 0xfe / panel->backlight.max + 1;
589 		level /= lbpc;
590 		pci_write_config_byte(dev->pdev, PCI_LBPC, lbpc);
591 	}
592 
593 	if (IS_GEN4(dev)) {
594 		mask = BACKLIGHT_DUTY_CYCLE_MASK;
595 	} else {
596 		level <<= 1;
597 		mask = BACKLIGHT_DUTY_CYCLE_MASK_PNV;
598 	}
599 
600 	tmp = I915_READ(BLC_PWM_CTL) & ~mask;
601 	I915_WRITE(BLC_PWM_CTL, tmp | level);
602 }
603 
604 static void vlv_set_backlight(struct intel_connector *connector, u32 level)
605 {
606 	struct drm_device *dev = connector->base.dev;
607 	struct drm_i915_private *dev_priv = dev->dev_private;
608 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
609 	u32 tmp;
610 
611 	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
612 		return;
613 
614 	tmp = I915_READ(VLV_BLC_PWM_CTL(pipe)) & ~BACKLIGHT_DUTY_CYCLE_MASK;
615 	I915_WRITE(VLV_BLC_PWM_CTL(pipe), tmp | level);
616 }
617 
618 static void
619 intel_panel_actually_set_backlight(struct intel_connector *connector, u32 level)
620 {
621 	struct drm_device *dev = connector->base.dev;
622 	struct drm_i915_private *dev_priv = dev->dev_private;
623 
624 	DRM_DEBUG_DRIVER("set backlight PWM = %d\n", level);
625 
626 	level = intel_panel_compute_brightness(connector, level);
627 	dev_priv->display.set_backlight(connector, level);
628 }
629 
630 /* set backlight brightness to level in range [0..max], scaling wrt hw min */
631 static void intel_panel_set_backlight(struct intel_connector *connector,
632 				      u32 user_level, u32 user_max)
633 {
634 	struct drm_device *dev = connector->base.dev;
635 	struct drm_i915_private *dev_priv = dev->dev_private;
636 	struct intel_panel *panel = &connector->panel;
637 	u32 hw_level;
638 
639 	if (!panel->backlight.present)
640 		return;
641 
642 	mutex_lock(&dev_priv->backlight_lock);
643 
644 	WARN_ON(panel->backlight.max == 0);
645 
646 	hw_level = scale_user_to_hw(connector, user_level, user_max);
647 	panel->backlight.level = hw_level;
648 
649 	if (panel->backlight.enabled)
650 		intel_panel_actually_set_backlight(connector, hw_level);
651 
652 	mutex_unlock(&dev_priv->backlight_lock);
653 }
654 
655 /* set backlight brightness to level in range [0..max], assuming hw min is
656  * respected.
657  */
658 void intel_panel_set_backlight_acpi(struct intel_connector *connector,
659 				    u32 user_level, u32 user_max)
660 {
661 	struct drm_device *dev = connector->base.dev;
662 	struct drm_i915_private *dev_priv = dev->dev_private;
663 	struct intel_panel *panel = &connector->panel;
664 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
665 	u32 hw_level;
666 
667 	/*
668 	 * INVALID_PIPE may occur during driver init because
669 	 * connection_mutex isn't held across the entire backlight
670 	 * setup + modeset readout, and the BIOS can issue the
671 	 * requests at any time.
672 	 */
673 	if (!panel->backlight.present || pipe == INVALID_PIPE)
674 		return;
675 
676 	mutex_lock(&dev_priv->backlight_lock);
677 
678 	WARN_ON(panel->backlight.max == 0);
679 
680 	hw_level = clamp_user_to_hw(connector, user_level, user_max);
681 	panel->backlight.level = hw_level;
682 
683 	if (panel->backlight.device)
684 		panel->backlight.device->props.brightness =
685 			scale_hw_to_user(connector,
686 					 panel->backlight.level,
687 					 panel->backlight.device->props.max_brightness);
688 
689 	if (panel->backlight.enabled)
690 		intel_panel_actually_set_backlight(connector, hw_level);
691 
692 	mutex_unlock(&dev_priv->backlight_lock);
693 }
694 
695 static void pch_disable_backlight(struct intel_connector *connector)
696 {
697 	struct drm_device *dev = connector->base.dev;
698 	struct drm_i915_private *dev_priv = dev->dev_private;
699 	u32 tmp;
700 
701 	intel_panel_actually_set_backlight(connector, 0);
702 
703 	tmp = I915_READ(BLC_PWM_CPU_CTL2);
704 	I915_WRITE(BLC_PWM_CPU_CTL2, tmp & ~BLM_PWM_ENABLE);
705 
706 	tmp = I915_READ(BLC_PWM_PCH_CTL1);
707 	I915_WRITE(BLC_PWM_PCH_CTL1, tmp & ~BLM_PCH_PWM_ENABLE);
708 }
709 
710 static void i9xx_disable_backlight(struct intel_connector *connector)
711 {
712 	intel_panel_actually_set_backlight(connector, 0);
713 }
714 
715 static void i965_disable_backlight(struct intel_connector *connector)
716 {
717 	struct drm_device *dev = connector->base.dev;
718 	struct drm_i915_private *dev_priv = dev->dev_private;
719 	u32 tmp;
720 
721 	intel_panel_actually_set_backlight(connector, 0);
722 
723 	tmp = I915_READ(BLC_PWM_CTL2);
724 	I915_WRITE(BLC_PWM_CTL2, tmp & ~BLM_PWM_ENABLE);
725 }
726 
727 static void vlv_disable_backlight(struct intel_connector *connector)
728 {
729 	struct drm_device *dev = connector->base.dev;
730 	struct drm_i915_private *dev_priv = dev->dev_private;
731 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
732 	u32 tmp;
733 
734 	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
735 		return;
736 
737 	intel_panel_actually_set_backlight(connector, 0);
738 
739 	tmp = I915_READ(VLV_BLC_PWM_CTL2(pipe));
740 	I915_WRITE(VLV_BLC_PWM_CTL2(pipe), tmp & ~BLM_PWM_ENABLE);
741 }
742 
743 void intel_panel_disable_backlight(struct intel_connector *connector)
744 {
745 	struct drm_device *dev = connector->base.dev;
746 	struct drm_i915_private *dev_priv = dev->dev_private;
747 	struct intel_panel *panel = &connector->panel;
748 
749 	if (!panel->backlight.present)
750 		return;
751 
752 	/*
753 	 * Do not disable backlight on the vgaswitcheroo path. When switching
754 	 * away from i915, the other client may depend on i915 to handle the
755 	 * backlight. This will leave the backlight on unnecessarily when
756 	 * another client is not activated.
757 	 */
758 	if (dev->switch_power_state == DRM_SWITCH_POWER_CHANGING) {
759 		DRM_DEBUG_DRIVER("Skipping backlight disable on vga switch\n");
760 		return;
761 	}
762 
763 	mutex_lock(&dev_priv->backlight_lock);
764 
765 	if (panel->backlight.device)
766 		panel->backlight.device->props.power = FB_BLANK_POWERDOWN;
767 	panel->backlight.enabled = false;
768 	dev_priv->display.disable_backlight(connector);
769 
770 	mutex_unlock(&dev_priv->backlight_lock);
771 }
772 
773 static void bdw_enable_backlight(struct intel_connector *connector)
774 {
775 	struct drm_device *dev = connector->base.dev;
776 	struct drm_i915_private *dev_priv = dev->dev_private;
777 	struct intel_panel *panel = &connector->panel;
778 	u32 pch_ctl1, pch_ctl2;
779 
780 	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
781 	if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
782 		DRM_DEBUG_KMS("pch backlight already enabled\n");
783 		pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
784 		I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
785 	}
786 
787 	pch_ctl2 = panel->backlight.max << 16;
788 	I915_WRITE(BLC_PWM_PCH_CTL2, pch_ctl2);
789 
790 	pch_ctl1 = 0;
791 	if (panel->backlight.active_low_pwm)
792 		pch_ctl1 |= BLM_PCH_POLARITY;
793 
794 	/* After LPT, override is the default. */
795 	if (HAS_PCH_LPT(dev_priv))
796 		pch_ctl1 |= BLM_PCH_OVERRIDE_ENABLE;
797 
798 	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
799 	POSTING_READ(BLC_PWM_PCH_CTL1);
800 	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_PWM_ENABLE);
801 
802 	/* This won't stick until the above enable. */
803 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
804 }
805 
806 static void pch_enable_backlight(struct intel_connector *connector)
807 {
808 	struct drm_device *dev = connector->base.dev;
809 	struct drm_i915_private *dev_priv = dev->dev_private;
810 	struct intel_panel *panel = &connector->panel;
811 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
812 	enum transcoder cpu_transcoder =
813 		intel_pipe_to_cpu_transcoder(dev_priv, pipe);
814 	u32 cpu_ctl2, pch_ctl1, pch_ctl2;
815 
816 	cpu_ctl2 = I915_READ(BLC_PWM_CPU_CTL2);
817 	if (cpu_ctl2 & BLM_PWM_ENABLE) {
818 		DRM_DEBUG_KMS("cpu backlight already enabled\n");
819 		cpu_ctl2 &= ~BLM_PWM_ENABLE;
820 		I915_WRITE(BLC_PWM_CPU_CTL2, cpu_ctl2);
821 	}
822 
823 	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
824 	if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
825 		DRM_DEBUG_KMS("pch backlight already enabled\n");
826 		pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
827 		I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
828 	}
829 
830 	if (cpu_transcoder == TRANSCODER_EDP)
831 		cpu_ctl2 = BLM_TRANSCODER_EDP;
832 	else
833 		cpu_ctl2 = BLM_PIPE(cpu_transcoder);
834 	I915_WRITE(BLC_PWM_CPU_CTL2, cpu_ctl2);
835 	POSTING_READ(BLC_PWM_CPU_CTL2);
836 	I915_WRITE(BLC_PWM_CPU_CTL2, cpu_ctl2 | BLM_PWM_ENABLE);
837 
838 	/* This won't stick until the above enable. */
839 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
840 
841 	pch_ctl2 = panel->backlight.max << 16;
842 	I915_WRITE(BLC_PWM_PCH_CTL2, pch_ctl2);
843 
844 	pch_ctl1 = 0;
845 	if (panel->backlight.active_low_pwm)
846 		pch_ctl1 |= BLM_PCH_POLARITY;
847 
848 	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
849 	POSTING_READ(BLC_PWM_PCH_CTL1);
850 	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_PWM_ENABLE);
851 }
852 
853 static void i9xx_enable_backlight(struct intel_connector *connector)
854 {
855 	struct drm_device *dev = connector->base.dev;
856 	struct drm_i915_private *dev_priv = dev->dev_private;
857 	struct intel_panel *panel = &connector->panel;
858 	u32 ctl, freq;
859 
860 	ctl = I915_READ(BLC_PWM_CTL);
861 	if (ctl & BACKLIGHT_DUTY_CYCLE_MASK_PNV) {
862 		DRM_DEBUG_KMS("backlight already enabled\n");
863 		I915_WRITE(BLC_PWM_CTL, 0);
864 	}
865 
866 	freq = panel->backlight.max;
867 	if (panel->backlight.combination_mode)
868 		freq /= 0xff;
869 
870 	ctl = freq << 17;
871 	if (panel->backlight.combination_mode)
872 		ctl |= BLM_LEGACY_MODE;
873 	if (IS_PINEVIEW(dev) && panel->backlight.active_low_pwm)
874 		ctl |= BLM_POLARITY_PNV;
875 
876 	I915_WRITE(BLC_PWM_CTL, ctl);
877 	POSTING_READ(BLC_PWM_CTL);
878 
879 	/* XXX: combine this into above write? */
880 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
881 }
882 
883 static void i965_enable_backlight(struct intel_connector *connector)
884 {
885 	struct drm_device *dev = connector->base.dev;
886 	struct drm_i915_private *dev_priv = dev->dev_private;
887 	struct intel_panel *panel = &connector->panel;
888 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
889 	u32 ctl, ctl2, freq;
890 
891 	ctl2 = I915_READ(BLC_PWM_CTL2);
892 	if (ctl2 & BLM_PWM_ENABLE) {
893 		DRM_DEBUG_KMS("backlight already enabled\n");
894 		ctl2 &= ~BLM_PWM_ENABLE;
895 		I915_WRITE(BLC_PWM_CTL2, ctl2);
896 	}
897 
898 	freq = panel->backlight.max;
899 	if (panel->backlight.combination_mode)
900 		freq /= 0xff;
901 
902 	ctl = freq << 16;
903 	I915_WRITE(BLC_PWM_CTL, ctl);
904 
905 	ctl2 = BLM_PIPE(pipe);
906 	if (panel->backlight.combination_mode)
907 		ctl2 |= BLM_COMBINATION_MODE;
908 	if (panel->backlight.active_low_pwm)
909 		ctl2 |= BLM_POLARITY_I965;
910 	I915_WRITE(BLC_PWM_CTL2, ctl2);
911 	POSTING_READ(BLC_PWM_CTL2);
912 	I915_WRITE(BLC_PWM_CTL2, ctl2 | BLM_PWM_ENABLE);
913 
914 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
915 }
916 
917 static void vlv_enable_backlight(struct intel_connector *connector)
918 {
919 	struct drm_device *dev = connector->base.dev;
920 	struct drm_i915_private *dev_priv = dev->dev_private;
921 	struct intel_panel *panel = &connector->panel;
922 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
923 	u32 ctl, ctl2;
924 
925 	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
926 		return;
927 
928 	ctl2 = I915_READ(VLV_BLC_PWM_CTL2(pipe));
929 	if (ctl2 & BLM_PWM_ENABLE) {
930 		DRM_DEBUG_KMS("backlight already enabled\n");
931 		ctl2 &= ~BLM_PWM_ENABLE;
932 		I915_WRITE(VLV_BLC_PWM_CTL2(pipe), ctl2);
933 	}
934 
935 	ctl = panel->backlight.max << 16;
936 	I915_WRITE(VLV_BLC_PWM_CTL(pipe), ctl);
937 
938 	/* XXX: combine this into above write? */
939 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
940 
941 	ctl2 = 0;
942 	if (panel->backlight.active_low_pwm)
943 		ctl2 |= BLM_POLARITY_I965;
944 	I915_WRITE(VLV_BLC_PWM_CTL2(pipe), ctl2);
945 	POSTING_READ(VLV_BLC_PWM_CTL2(pipe));
946 	I915_WRITE(VLV_BLC_PWM_CTL2(pipe), ctl2 | BLM_PWM_ENABLE);
947 }
948 
949 void intel_panel_enable_backlight(struct intel_connector *connector)
950 {
951 	struct drm_device *dev = connector->base.dev;
952 	struct drm_i915_private *dev_priv = dev->dev_private;
953 	struct intel_panel *panel = &connector->panel;
954 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
955 
956 	if (!panel->backlight.present)
957 		return;
958 
959 	DRM_DEBUG_KMS("pipe %c\n", pipe_name(pipe));
960 
961 	mutex_lock(&dev_priv->backlight_lock);
962 
963 	WARN_ON(panel->backlight.max == 0);
964 
965 	if (panel->backlight.level <= panel->backlight.min) {
966 		panel->backlight.level = panel->backlight.max;
967 		if (panel->backlight.device)
968 			panel->backlight.device->props.brightness =
969 				scale_hw_to_user(connector,
970 						 panel->backlight.level,
971 						 panel->backlight.device->props.max_brightness);
972 	}
973 
974 	dev_priv->display.enable_backlight(connector);
975 	panel->backlight.enabled = true;
976 	if (panel->backlight.device)
977 		panel->backlight.device->props.power = FB_BLANK_UNBLANK;
978 
979 	mutex_unlock(&dev_priv->backlight_lock);
980 }
981 
982 #if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
983 static int intel_backlight_device_update_status(struct backlight_device *bd)
984 {
985 #if 0
986 	struct intel_connector *connector = bl_get_data(bd);
987 	struct intel_panel *panel = &connector->panel;
988 	struct drm_device *dev = connector->base.dev;
989 
990 	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
991 	DRM_DEBUG_KMS("updating intel_backlight, brightness=%d/%d\n",
992 		      bd->props.brightness, bd->props.max_brightness);
993 	intel_panel_set_backlight(connector, bd->props.brightness,
994 				  bd->props.max_brightness);
995 
996 	/*
997 	 * Allow flipping bl_power as a sub-state of enabled. Sadly the
998 	 * backlight class device does not make it easy to to differentiate
999 	 * between callbacks for brightness and bl_power, so our backlight_power
1000 	 * callback needs to take this into account.
1001 	 */
1002 	if (panel->backlight.enabled) {
1003 		if (panel->backlight_power) {
1004 			bool enable = bd->props.power == FB_BLANK_UNBLANK &&
1005 				bd->props.brightness != 0;
1006 			panel->backlight_power(connector, enable);
1007 		}
1008 	} else {
1009 		bd->props.power = FB_BLANK_POWERDOWN;
1010 	}
1011 
1012 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
1013 #endif
1014 	return 0;
1015 }
1016 
1017 static int intel_backlight_device_get_brightness(struct backlight_device *bd)
1018 {
1019 #if 0
1020 	struct intel_connector *connector = bl_get_data(bd);
1021 	struct drm_device *dev = connector->base.dev;
1022 	struct drm_i915_private *dev_priv = dev->dev_private;
1023 	u32 hw_level;
1024 	int ret;
1025 
1026 	intel_runtime_pm_get(dev_priv);
1027 	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
1028 
1029 	hw_level = intel_panel_get_backlight(connector);
1030 	ret = scale_hw_to_user(connector, hw_level, bd->props.max_brightness);
1031 
1032 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
1033 	intel_runtime_pm_put(dev_priv);
1034 
1035 	return ret;
1036 #endif
1037 	return 0;
1038 }
1039 
1040 static const struct backlight_ops intel_backlight_device_ops = {
1041 	.update_status = intel_backlight_device_update_status,
1042 	.get_brightness = intel_backlight_device_get_brightness,
1043 };
1044 
1045 static int intel_backlight_device_register(struct intel_connector *connector)
1046 {
1047 	struct intel_panel *panel = &connector->panel;
1048 	struct backlight_properties props;
1049 
1050 	if (WARN_ON(panel->backlight.device))
1051 		return -ENODEV;
1052 
1053 	if (!panel->backlight.present)
1054 		return 0;
1055 
1056 	WARN_ON(panel->backlight.max == 0);
1057 
1058 	memset(&props, 0, sizeof(props));
1059 	props.type = BACKLIGHT_RAW;
1060 
1061 	/*
1062 	 * Note: Everything should work even if the backlight device max
1063 	 * presented to the userspace is arbitrarily chosen.
1064 	 */
1065 	props.max_brightness = panel->backlight.max;
1066 	props.brightness = scale_hw_to_user(connector,
1067 					    panel->backlight.level,
1068 					    props.max_brightness);
1069 
1070 	if (panel->backlight.enabled)
1071 		props.power = FB_BLANK_UNBLANK;
1072 	else
1073 		props.power = FB_BLANK_POWERDOWN;
1074 
1075 	/*
1076 	 * Note: using the same name independent of the connector prevents
1077 	 * registration of multiple backlight devices in the driver.
1078 	 */
1079 #if 0
1080 	panel->backlight.device =
1081 		backlight_device_register("intel_backlight",
1082 					  connector->base.kdev,
1083 					  connector,
1084 					  &intel_backlight_device_ops, &props);
1085 
1086 	if (IS_ERR(panel->backlight.device)) {
1087 		DRM_ERROR("Failed to register backlight: %ld\n",
1088 			  PTR_ERR(panel->backlight.device));
1089 		panel->backlight.device = NULL;
1090 		return -ENODEV;
1091 	}
1092 #endif
1093 
1094 	DRM_DEBUG_KMS("Connector %s backlight sysfs interface registered\n",
1095 		      connector->base.name);
1096 
1097 	return 0;
1098 }
1099 
1100 static void intel_backlight_device_unregister(struct intel_connector *connector)
1101 {
1102 #if 0
1103 	struct intel_panel *panel = &connector->panel;
1104 
1105 	if (panel->backlight.device) {
1106 		backlight_device_unregister(panel->backlight.device);
1107 		panel->backlight.device = NULL;
1108 	}
1109 #endif
1110 }
1111 #else /* CONFIG_BACKLIGHT_CLASS_DEVICE */
1112 static int intel_backlight_device_register(struct intel_connector *connector)
1113 {
1114 	return 0;
1115 }
1116 static void intel_backlight_device_unregister(struct intel_connector *connector)
1117 {
1118 }
1119 #endif /* CONFIG_BACKLIGHT_CLASS_DEVICE */
1120 
1121 /*
1122  * Note: The setup hooks can't assume pipe is set!
1123  *
1124  * XXX: Query mode clock or hardware clock and program PWM modulation frequency
1125  * appropriately when it's 0. Use VBT and/or sane defaults.
1126  */
1127 static u32 get_backlight_min_vbt(struct intel_connector *connector)
1128 {
1129 	struct drm_device *dev = connector->base.dev;
1130 	struct drm_i915_private *dev_priv = dev->dev_private;
1131 	struct intel_panel *panel = &connector->panel;
1132 	int min;
1133 
1134 	WARN_ON(panel->backlight.max == 0);
1135 
1136 	/*
1137 	 * XXX: If the vbt value is 255, it makes min equal to max, which leads
1138 	 * to problems. There are such machines out there. Either our
1139 	 * interpretation is wrong or the vbt has bogus data. Or both. Safeguard
1140 	 * against this by letting the minimum be at most (arbitrarily chosen)
1141 	 * 25% of the max.
1142 	 */
1143 	min = clamp_t(int, dev_priv->vbt.backlight.min_brightness, 0, 64);
1144 	if (min != dev_priv->vbt.backlight.min_brightness) {
1145 		DRM_DEBUG_KMS("clamping VBT min backlight %d/255 to %d/255\n",
1146 			      dev_priv->vbt.backlight.min_brightness, min);
1147 	}
1148 
1149 	/* vbt value is a coefficient in range [0..255] */
1150 	return scale(min, 0, 255, 0, panel->backlight.max);
1151 }
1152 
1153 static int bdw_setup_backlight(struct intel_connector *connector, enum i915_pipe unused)
1154 {
1155 	struct drm_device *dev = connector->base.dev;
1156 	struct drm_i915_private *dev_priv = dev->dev_private;
1157 	struct intel_panel *panel = &connector->panel;
1158 	u32 pch_ctl1, pch_ctl2, val;
1159 
1160 	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
1161 	panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
1162 
1163 	pch_ctl2 = I915_READ(BLC_PWM_PCH_CTL2);
1164 	panel->backlight.max = pch_ctl2 >> 16;
1165 	if (!panel->backlight.max)
1166 		return -ENODEV;
1167 
1168 	panel->backlight.min = get_backlight_min_vbt(connector);
1169 
1170 	val = bdw_get_backlight(connector);
1171 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
1172 
1173 	panel->backlight.enabled = (pch_ctl1 & BLM_PCH_PWM_ENABLE) &&
1174 		panel->backlight.level != 0;
1175 
1176 	return 0;
1177 }
1178 
1179 static int pch_setup_backlight(struct intel_connector *connector, enum i915_pipe unused)
1180 {
1181 	struct drm_device *dev = connector->base.dev;
1182 	struct drm_i915_private *dev_priv = dev->dev_private;
1183 	struct intel_panel *panel = &connector->panel;
1184 	u32 cpu_ctl2, pch_ctl1, pch_ctl2, val;
1185 
1186 	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
1187 	panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
1188 
1189 	pch_ctl2 = I915_READ(BLC_PWM_PCH_CTL2);
1190 	panel->backlight.max = pch_ctl2 >> 16;
1191 	if (!panel->backlight.max)
1192 		return -ENODEV;
1193 
1194 	panel->backlight.min = get_backlight_min_vbt(connector);
1195 
1196 	val = pch_get_backlight(connector);
1197 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
1198 
1199 	cpu_ctl2 = I915_READ(BLC_PWM_CPU_CTL2);
1200 	panel->backlight.enabled = (cpu_ctl2 & BLM_PWM_ENABLE) &&
1201 		(pch_ctl1 & BLM_PCH_PWM_ENABLE) && panel->backlight.level != 0;
1202 
1203 	return 0;
1204 }
1205 
1206 static int i9xx_setup_backlight(struct intel_connector *connector, enum i915_pipe unused)
1207 {
1208 	struct drm_device *dev = connector->base.dev;
1209 	struct drm_i915_private *dev_priv = dev->dev_private;
1210 	struct intel_panel *panel = &connector->panel;
1211 	u32 ctl, val;
1212 
1213 	ctl = I915_READ(BLC_PWM_CTL);
1214 
1215 	if (IS_GEN2(dev) || IS_I915GM(dev) || IS_I945GM(dev))
1216 		panel->backlight.combination_mode = ctl & BLM_LEGACY_MODE;
1217 
1218 	if (IS_PINEVIEW(dev))
1219 		panel->backlight.active_low_pwm = ctl & BLM_POLARITY_PNV;
1220 
1221 	panel->backlight.max = ctl >> 17;
1222 	if (panel->backlight.combination_mode)
1223 		panel->backlight.max *= 0xff;
1224 
1225 	if (!panel->backlight.max)
1226 		return -ENODEV;
1227 
1228 	panel->backlight.min = get_backlight_min_vbt(connector);
1229 
1230 	val = i9xx_get_backlight(connector);
1231 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
1232 
1233 	panel->backlight.enabled = panel->backlight.level != 0;
1234 
1235 	return 0;
1236 }
1237 
1238 static int i965_setup_backlight(struct intel_connector *connector, enum i915_pipe unused)
1239 {
1240 	struct drm_device *dev = connector->base.dev;
1241 	struct drm_i915_private *dev_priv = dev->dev_private;
1242 	struct intel_panel *panel = &connector->panel;
1243 	u32 ctl, ctl2, val;
1244 
1245 	ctl2 = I915_READ(BLC_PWM_CTL2);
1246 	panel->backlight.combination_mode = ctl2 & BLM_COMBINATION_MODE;
1247 	panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;
1248 
1249 	ctl = I915_READ(BLC_PWM_CTL);
1250 	panel->backlight.max = ctl >> 16;
1251 	if (panel->backlight.combination_mode)
1252 		panel->backlight.max *= 0xff;
1253 
1254 	if (!panel->backlight.max)
1255 		return -ENODEV;
1256 
1257 	panel->backlight.min = get_backlight_min_vbt(connector);
1258 
1259 	val = i9xx_get_backlight(connector);
1260 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
1261 
1262 	panel->backlight.enabled = (ctl2 & BLM_PWM_ENABLE) &&
1263 		panel->backlight.level != 0;
1264 
1265 	return 0;
1266 }
1267 
1268 static int vlv_setup_backlight(struct intel_connector *connector, enum i915_pipe pipe)
1269 {
1270 	struct drm_device *dev = connector->base.dev;
1271 	struct drm_i915_private *dev_priv = dev->dev_private;
1272 	struct intel_panel *panel = &connector->panel;
1273 	enum i915_pipe p;
1274 	u32 ctl, ctl2, val;
1275 
1276 	for_each_pipe(dev_priv, p) {
1277 		u32 cur_val = I915_READ(VLV_BLC_PWM_CTL(p));
1278 
1279 		/* Skip if the modulation freq is already set */
1280 		if (cur_val & ~BACKLIGHT_DUTY_CYCLE_MASK)
1281 			continue;
1282 
1283 		cur_val &= BACKLIGHT_DUTY_CYCLE_MASK;
1284 		I915_WRITE(VLV_BLC_PWM_CTL(p), (0xf42 << 16) |
1285 			   cur_val);
1286 	}
1287 
1288 	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
1289 		return -ENODEV;
1290 
1291 	ctl2 = I915_READ(VLV_BLC_PWM_CTL2(pipe));
1292 	panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;
1293 
1294 	ctl = I915_READ(VLV_BLC_PWM_CTL(pipe));
1295 	panel->backlight.max = ctl >> 16;
1296 	if (!panel->backlight.max)
1297 		return -ENODEV;
1298 
1299 	panel->backlight.min = get_backlight_min_vbt(connector);
1300 
1301 	val = _vlv_get_backlight(dev, pipe);
1302 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
1303 
1304 	panel->backlight.enabled = (ctl2 & BLM_PWM_ENABLE) &&
1305 		panel->backlight.level != 0;
1306 
1307 	return 0;
1308 }
1309 
1310 #ifdef __DragonFly__
1311 /*
1312  * Read max backlight level
1313  */
1314 static int
1315 sysctl_backlight_max(SYSCTL_HANDLER_ARGS)
1316 {
1317 	int err, val;
1318 	struct intel_connector *connector = arg1;
1319 	struct drm_device *dev = connector->base.dev;
1320 	struct drm_i915_private *dev_priv = dev->dev_private;
1321 	struct intel_panel *panel = &connector->panel;
1322 
1323 	mutex_lock(&dev_priv->backlight_lock);
1324 	val = panel->backlight.max;
1325 	mutex_unlock(&dev_priv->backlight_lock);
1326 
1327 	err = sysctl_handle_int(oidp, &val, 0, req);
1328 	return(err);
1329 }
1330 
1331 /*
1332  * Read/write backlight level
1333  */
1334 static int
1335 sysctl_backlight_handler(SYSCTL_HANDLER_ARGS)
1336 {
1337 	struct intel_connector *connector = arg1;
1338 	struct drm_device *dev = connector->base.dev;
1339 	struct drm_i915_private *dev_priv = dev->dev_private;
1340 	struct intel_panel *panel = &connector->panel;
1341 	int err, val;
1342 	u32 user_level, max_brightness;
1343 
1344 	mutex_lock(&dev_priv->backlight_lock);
1345 	max_brightness = panel->backlight.max;
1346 	user_level = scale_hw_to_user(connector, panel->backlight.level,
1347 	    max_brightness);
1348 	mutex_unlock(&dev_priv->backlight_lock);
1349 
1350 	val = user_level;
1351 	err = sysctl_handle_int(oidp, &val, 0, req);
1352 	if (err != 0 || req->newptr == NULL) {
1353 		return(err);
1354 	}
1355 
1356 	if (val != user_level && val >= 0 && val <= max_brightness) {
1357 		drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
1358 		intel_panel_set_backlight(arg1, val, max_brightness);
1359 		drm_modeset_unlock(&dev->mode_config.connection_mutex);
1360 	}
1361 
1362 	return(err);
1363 }
1364 #endif /* __DragonFly__ */
1365 
1366 int intel_panel_setup_backlight(struct drm_connector *connector, enum i915_pipe pipe)
1367 {
1368 	struct drm_device *dev = connector->dev;
1369 	struct drm_i915_private *dev_priv = dev->dev_private;
1370 	struct intel_connector *intel_connector = to_intel_connector(connector);
1371 	struct intel_panel *panel = &intel_connector->panel;
1372 	int ret;
1373 
1374 	if (!dev_priv->vbt.backlight.present) {
1375 		if (dev_priv->quirks & QUIRK_BACKLIGHT_PRESENT) {
1376 			DRM_DEBUG_KMS("no backlight present per VBT, but present per quirk\n");
1377 		} else {
1378 			DRM_DEBUG_KMS("no backlight present per VBT\n");
1379 			return 0;
1380 		}
1381 	}
1382 
1383 	/* set level and max in panel struct */
1384 	mutex_lock(&dev_priv->backlight_lock);
1385 	ret = dev_priv->display.setup_backlight(intel_connector, pipe);
1386 	mutex_unlock(&dev_priv->backlight_lock);
1387 
1388 	if (ret) {
1389 		DRM_DEBUG_KMS("failed to setup backlight for connector %s\n",
1390 			      connector->name);
1391 		return ret;
1392 	}
1393 
1394 	panel->backlight.present = true;
1395 
1396 #ifdef __DragonFly__
1397 	SYSCTL_ADD_PROC(&connector->dev->sysctl->ctx, &sysctl__hw_children,
1398 			OID_AUTO, "backlight_max",
1399 			CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_ANYBODY,
1400 			connector, sizeof(int),
1401 			sysctl_backlight_max,
1402 			"I", "Max backlight level");
1403 	SYSCTL_ADD_PROC(&connector->dev->sysctl->ctx, &sysctl__hw_children,
1404 			OID_AUTO, "backlight_level",
1405 			CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY,
1406 			connector, sizeof(int),
1407 			sysctl_backlight_handler,
1408 			"I", "Backlight level");
1409 #endif
1410 
1411 	DRM_DEBUG_KMS("Connector %s backlight initialized, %s, brightness %u/%u\n",
1412 		      connector->name,
1413 		      panel->backlight.enabled ? "enabled" : "disabled",
1414 		      panel->backlight.level, panel->backlight.max);
1415 
1416 	return 0;
1417 }
1418 
1419 void intel_panel_destroy_backlight(struct drm_connector *connector)
1420 {
1421 	struct intel_connector *intel_connector = to_intel_connector(connector);
1422 	struct intel_panel *panel = &intel_connector->panel;
1423 
1424 	panel->backlight.present = false;
1425 }
1426 
1427 /* Set up chip specific backlight functions */
1428 void intel_panel_init_backlight_funcs(struct drm_device *dev)
1429 {
1430 	struct drm_i915_private *dev_priv = dev->dev_private;
1431 
1432 	if (IS_BROADWELL(dev) || (INTEL_INFO(dev)->gen >= 9)) {
1433 		dev_priv->display.setup_backlight = bdw_setup_backlight;
1434 		dev_priv->display.enable_backlight = bdw_enable_backlight;
1435 		dev_priv->display.disable_backlight = pch_disable_backlight;
1436 		dev_priv->display.set_backlight = bdw_set_backlight;
1437 		dev_priv->display.get_backlight = bdw_get_backlight;
1438 	} else if (HAS_PCH_SPLIT(dev)) {
1439 		dev_priv->display.setup_backlight = pch_setup_backlight;
1440 		dev_priv->display.enable_backlight = pch_enable_backlight;
1441 		dev_priv->display.disable_backlight = pch_disable_backlight;
1442 		dev_priv->display.set_backlight = pch_set_backlight;
1443 		dev_priv->display.get_backlight = pch_get_backlight;
1444 	} else if (IS_VALLEYVIEW(dev)) {
1445 		dev_priv->display.setup_backlight = vlv_setup_backlight;
1446 		dev_priv->display.enable_backlight = vlv_enable_backlight;
1447 		dev_priv->display.disable_backlight = vlv_disable_backlight;
1448 		dev_priv->display.set_backlight = vlv_set_backlight;
1449 		dev_priv->display.get_backlight = vlv_get_backlight;
1450 	} else if (IS_GEN4(dev)) {
1451 		dev_priv->display.setup_backlight = i965_setup_backlight;
1452 		dev_priv->display.enable_backlight = i965_enable_backlight;
1453 		dev_priv->display.disable_backlight = i965_disable_backlight;
1454 		dev_priv->display.set_backlight = i9xx_set_backlight;
1455 		dev_priv->display.get_backlight = i9xx_get_backlight;
1456 	} else {
1457 		dev_priv->display.setup_backlight = i9xx_setup_backlight;
1458 		dev_priv->display.enable_backlight = i9xx_enable_backlight;
1459 		dev_priv->display.disable_backlight = i9xx_disable_backlight;
1460 		dev_priv->display.set_backlight = i9xx_set_backlight;
1461 		dev_priv->display.get_backlight = i9xx_get_backlight;
1462 	}
1463 }
1464 
1465 int intel_panel_init(struct intel_panel *panel,
1466 		     struct drm_display_mode *fixed_mode,
1467 		     struct drm_display_mode *downclock_mode)
1468 {
1469 	panel->fixed_mode = fixed_mode;
1470 	panel->downclock_mode = downclock_mode;
1471 
1472 	return 0;
1473 }
1474 
1475 void intel_panel_fini(struct intel_panel *panel)
1476 {
1477 	struct intel_connector *intel_connector =
1478 		container_of(panel, struct intel_connector, panel);
1479 
1480 	if (panel->fixed_mode)
1481 		drm_mode_destroy(intel_connector->base.dev, panel->fixed_mode);
1482 
1483 	if (panel->downclock_mode)
1484 		drm_mode_destroy(intel_connector->base.dev,
1485 				panel->downclock_mode);
1486 }
1487 
1488 void intel_backlight_register(struct drm_device *dev)
1489 {
1490 	struct intel_connector *connector;
1491 
1492 	list_for_each_entry(connector, &dev->mode_config.connector_list, base.head)
1493 		intel_backlight_device_register(connector);
1494 }
1495 
1496 void intel_backlight_unregister(struct drm_device *dev)
1497 {
1498 	struct intel_connector *connector;
1499 
1500 	list_for_each_entry(connector, &dev->mode_config.connector_list, base.head)
1501 		intel_backlight_device_unregister(connector);
1502 }
1503