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drm/i915: avoid brightness overflow when doing scale
[linux-imx.git] / drivers / gpu / drm / i915 / intel_panel.c
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32
33 #include <linux/moduleparam.h>
34 #include "intel_drv.h"
35
36 #define PCI_LBPC 0xf4 /* legacy/combination backlight modes */
37
38 void
39 intel_fixed_panel_mode(struct drm_display_mode *fixed_mode,
40                        struct drm_display_mode *adjusted_mode)
41 {
42         adjusted_mode->hdisplay = fixed_mode->hdisplay;
43         adjusted_mode->hsync_start = fixed_mode->hsync_start;
44         adjusted_mode->hsync_end = fixed_mode->hsync_end;
45         adjusted_mode->htotal = fixed_mode->htotal;
46
47         adjusted_mode->vdisplay = fixed_mode->vdisplay;
48         adjusted_mode->vsync_start = fixed_mode->vsync_start;
49         adjusted_mode->vsync_end = fixed_mode->vsync_end;
50         adjusted_mode->vtotal = fixed_mode->vtotal;
51
52         adjusted_mode->clock = fixed_mode->clock;
53 }
54
55 /* adjusted_mode has been preset to be the panel's fixed mode */
56 void
57 intel_pch_panel_fitting(struct intel_crtc *intel_crtc,
58                         struct intel_crtc_config *pipe_config,
59                         int fitting_mode)
60 {
61         struct drm_display_mode *mode, *adjusted_mode;
62         int x, y, width, height;
63
64         mode = &pipe_config->requested_mode;
65         adjusted_mode = &pipe_config->adjusted_mode;
66
67         x = y = width = height = 0;
68
69         /* Native modes don't need fitting */
70         if (adjusted_mode->hdisplay == mode->hdisplay &&
71             adjusted_mode->vdisplay == mode->vdisplay)
72                 goto done;
73
74         switch (fitting_mode) {
75         case DRM_MODE_SCALE_CENTER:
76                 width = mode->hdisplay;
77                 height = mode->vdisplay;
78                 x = (adjusted_mode->hdisplay - width + 1)/2;
79                 y = (adjusted_mode->vdisplay - height + 1)/2;
80                 break;
81
82         case DRM_MODE_SCALE_ASPECT:
83                 /* Scale but preserve the aspect ratio */
84                 {
85                         u32 scaled_width = adjusted_mode->hdisplay * mode->vdisplay;
86                         u32 scaled_height = mode->hdisplay * adjusted_mode->vdisplay;
87                         if (scaled_width > scaled_height) { /* pillar */
88                                 width = scaled_height / mode->vdisplay;
89                                 if (width & 1)
90                                         width++;
91                                 x = (adjusted_mode->hdisplay - width + 1) / 2;
92                                 y = 0;
93                                 height = adjusted_mode->vdisplay;
94                         } else if (scaled_width < scaled_height) { /* letter */
95                                 height = scaled_width / mode->hdisplay;
96                                 if (height & 1)
97                                     height++;
98                                 y = (adjusted_mode->vdisplay - height + 1) / 2;
99                                 x = 0;
100                                 width = adjusted_mode->hdisplay;
101                         } else {
102                                 x = y = 0;
103                                 width = adjusted_mode->hdisplay;
104                                 height = adjusted_mode->vdisplay;
105                         }
106                 }
107                 break;
108
109         case DRM_MODE_SCALE_FULLSCREEN:
110                 x = y = 0;
111                 width = adjusted_mode->hdisplay;
112                 height = adjusted_mode->vdisplay;
113                 break;
114
115         default:
116                 WARN(1, "bad panel fit mode: %d\n", fitting_mode);
117                 return;
118         }
119
120 done:
121         pipe_config->pch_pfit.pos = (x << 16) | y;
122         pipe_config->pch_pfit.size = (width << 16) | height;
123 }
124
125 static void
126 centre_horizontally(struct drm_display_mode *mode,
127                     int width)
128 {
129         u32 border, sync_pos, blank_width, sync_width;
130
131         /* keep the hsync and hblank widths constant */
132         sync_width = mode->crtc_hsync_end - mode->crtc_hsync_start;
133         blank_width = mode->crtc_hblank_end - mode->crtc_hblank_start;
134         sync_pos = (blank_width - sync_width + 1) / 2;
135
136         border = (mode->hdisplay - width + 1) / 2;
137         border += border & 1; /* make the border even */
138
139         mode->crtc_hdisplay = width;
140         mode->crtc_hblank_start = width + border;
141         mode->crtc_hblank_end = mode->crtc_hblank_start + blank_width;
142
143         mode->crtc_hsync_start = mode->crtc_hblank_start + sync_pos;
144         mode->crtc_hsync_end = mode->crtc_hsync_start + sync_width;
145 }
146
147 static void
148 centre_vertically(struct drm_display_mode *mode,
149                   int height)
150 {
151         u32 border, sync_pos, blank_width, sync_width;
152
153         /* keep the vsync and vblank widths constant */
154         sync_width = mode->crtc_vsync_end - mode->crtc_vsync_start;
155         blank_width = mode->crtc_vblank_end - mode->crtc_vblank_start;
156         sync_pos = (blank_width - sync_width + 1) / 2;
157
158         border = (mode->vdisplay - height + 1) / 2;
159
160         mode->crtc_vdisplay = height;
161         mode->crtc_vblank_start = height + border;
162         mode->crtc_vblank_end = mode->crtc_vblank_start + blank_width;
163
164         mode->crtc_vsync_start = mode->crtc_vblank_start + sync_pos;
165         mode->crtc_vsync_end = mode->crtc_vsync_start + sync_width;
166 }
167
168 static inline u32 panel_fitter_scaling(u32 source, u32 target)
169 {
170         /*
171          * Floating point operation is not supported. So the FACTOR
172          * is defined, which can avoid the floating point computation
173          * when calculating the panel ratio.
174          */
175 #define ACCURACY 12
176 #define FACTOR (1 << ACCURACY)
177         u32 ratio = source * FACTOR / target;
178         return (FACTOR * ratio + FACTOR/2) / FACTOR;
179 }
180
181 void intel_gmch_panel_fitting(struct intel_crtc *intel_crtc,
182                               struct intel_crtc_config *pipe_config,
183                               int fitting_mode)
184 {
185         struct drm_device *dev = intel_crtc->base.dev;
186         u32 pfit_control = 0, pfit_pgm_ratios = 0, border = 0;
187         struct drm_display_mode *mode, *adjusted_mode;
188
189         mode = &pipe_config->requested_mode;
190         adjusted_mode = &pipe_config->adjusted_mode;
191
192         /* Native modes don't need fitting */
193         if (adjusted_mode->hdisplay == mode->hdisplay &&
194             adjusted_mode->vdisplay == mode->vdisplay)
195                 goto out;
196
197         drm_mode_set_crtcinfo(adjusted_mode, 0);
198         pipe_config->timings_set = true;
199
200         switch (fitting_mode) {
201         case DRM_MODE_SCALE_CENTER:
202                 /*
203                  * For centered modes, we have to calculate border widths &
204                  * heights and modify the values programmed into the CRTC.
205                  */
206                 centre_horizontally(adjusted_mode, mode->hdisplay);
207                 centre_vertically(adjusted_mode, mode->vdisplay);
208                 border = LVDS_BORDER_ENABLE;
209                 break;
210         case DRM_MODE_SCALE_ASPECT:
211                 /* Scale but preserve the aspect ratio */
212                 if (INTEL_INFO(dev)->gen >= 4) {
213                         u32 scaled_width = adjusted_mode->hdisplay *
214                                 mode->vdisplay;
215                         u32 scaled_height = mode->hdisplay *
216                                 adjusted_mode->vdisplay;
217
218                         /* 965+ is easy, it does everything in hw */
219                         if (scaled_width > scaled_height)
220                                 pfit_control |= PFIT_ENABLE |
221                                         PFIT_SCALING_PILLAR;
222                         else if (scaled_width < scaled_height)
223                                 pfit_control |= PFIT_ENABLE |
224                                         PFIT_SCALING_LETTER;
225                         else if (adjusted_mode->hdisplay != mode->hdisplay)
226                                 pfit_control |= PFIT_ENABLE | PFIT_SCALING_AUTO;
227                 } else {
228                         u32 scaled_width = adjusted_mode->hdisplay *
229                                 mode->vdisplay;
230                         u32 scaled_height = mode->hdisplay *
231                                 adjusted_mode->vdisplay;
232                         /*
233                          * For earlier chips we have to calculate the scaling
234                          * ratio by hand and program it into the
235                          * PFIT_PGM_RATIO register
236                          */
237                         if (scaled_width > scaled_height) { /* pillar */
238                                 centre_horizontally(adjusted_mode,
239                                                     scaled_height /
240                                                     mode->vdisplay);
241
242                                 border = LVDS_BORDER_ENABLE;
243                                 if (mode->vdisplay != adjusted_mode->vdisplay) {
244                                         u32 bits = panel_fitter_scaling(mode->vdisplay, adjusted_mode->vdisplay);
245                                         pfit_pgm_ratios |= (bits << PFIT_HORIZ_SCALE_SHIFT |
246                                                             bits << PFIT_VERT_SCALE_SHIFT);
247                                         pfit_control |= (PFIT_ENABLE |
248                                                          VERT_INTERP_BILINEAR |
249                                                          HORIZ_INTERP_BILINEAR);
250                                 }
251                         } else if (scaled_width < scaled_height) { /* letter */
252                                 centre_vertically(adjusted_mode,
253                                                   scaled_width /
254                                                   mode->hdisplay);
255
256                                 border = LVDS_BORDER_ENABLE;
257                                 if (mode->hdisplay != adjusted_mode->hdisplay) {
258                                         u32 bits = panel_fitter_scaling(mode->hdisplay, adjusted_mode->hdisplay);
259                                         pfit_pgm_ratios |= (bits << PFIT_HORIZ_SCALE_SHIFT |
260                                                             bits << PFIT_VERT_SCALE_SHIFT);
261                                         pfit_control |= (PFIT_ENABLE |
262                                                          VERT_INTERP_BILINEAR |
263                                                          HORIZ_INTERP_BILINEAR);
264                                 }
265                         } else {
266                                 /* Aspects match, Let hw scale both directions */
267                                 pfit_control |= (PFIT_ENABLE |
268                                                  VERT_AUTO_SCALE | HORIZ_AUTO_SCALE |
269                                                  VERT_INTERP_BILINEAR |
270                                                  HORIZ_INTERP_BILINEAR);
271                         }
272                 }
273                 break;
274         case DRM_MODE_SCALE_FULLSCREEN:
275                 /*
276                  * Full scaling, even if it changes the aspect ratio.
277                  * Fortunately this is all done for us in hw.
278                  */
279                 if (mode->vdisplay != adjusted_mode->vdisplay ||
280                     mode->hdisplay != adjusted_mode->hdisplay) {
281                         pfit_control |= PFIT_ENABLE;
282                         if (INTEL_INFO(dev)->gen >= 4)
283                                 pfit_control |= PFIT_SCALING_AUTO;
284                         else
285                                 pfit_control |= (VERT_AUTO_SCALE |
286                                                  VERT_INTERP_BILINEAR |
287                                                  HORIZ_AUTO_SCALE |
288                                                  HORIZ_INTERP_BILINEAR);
289                 }
290                 break;
291         default:
292                 WARN(1, "bad panel fit mode: %d\n", fitting_mode);
293                 return;
294         }
295
296         /* 965+ wants fuzzy fitting */
297         /* FIXME: handle multiple panels by failing gracefully */
298         if (INTEL_INFO(dev)->gen >= 4)
299                 pfit_control |= ((intel_crtc->pipe << PFIT_PIPE_SHIFT) |
300                                  PFIT_FILTER_FUZZY);
301
302 out:
303         if ((pfit_control & PFIT_ENABLE) == 0) {
304                 pfit_control = 0;
305                 pfit_pgm_ratios = 0;
306         }
307
308         /* Make sure pre-965 set dither correctly for 18bpp panels. */
309         if (INTEL_INFO(dev)->gen < 4 && pipe_config->pipe_bpp == 18)
310                 pfit_control |= PANEL_8TO6_DITHER_ENABLE;
311
312         pipe_config->gmch_pfit.control = pfit_control;
313         pipe_config->gmch_pfit.pgm_ratios = pfit_pgm_ratios;
314         pipe_config->gmch_pfit.lvds_border_bits = border;
315 }
316
317 static int is_backlight_combination_mode(struct drm_device *dev)
318 {
319         struct drm_i915_private *dev_priv = dev->dev_private;
320
321         if (INTEL_INFO(dev)->gen >= 4)
322                 return I915_READ(BLC_PWM_CTL2) & BLM_COMBINATION_MODE;
323
324         if (IS_GEN2(dev))
325                 return I915_READ(BLC_PWM_CTL) & BLM_LEGACY_MODE;
326
327         return 0;
328 }
329
330 /* XXX: query mode clock or hardware clock and program max PWM appropriately
331  * when it's 0.
332  */
333 static u32 i915_read_blc_pwm_ctl(struct drm_device *dev)
334 {
335         struct drm_i915_private *dev_priv = dev->dev_private;
336         u32 val;
337
338         WARN_ON_SMP(!spin_is_locked(&dev_priv->backlight.lock));
339
340         /* Restore the CTL value if it lost, e.g. GPU reset */
341
342         if (HAS_PCH_SPLIT(dev_priv->dev)) {
343                 val = I915_READ(BLC_PWM_PCH_CTL2);
344                 if (dev_priv->regfile.saveBLC_PWM_CTL2 == 0) {
345                         dev_priv->regfile.saveBLC_PWM_CTL2 = val;
346                 } else if (val == 0) {
347                         val = dev_priv->regfile.saveBLC_PWM_CTL2;
348                         I915_WRITE(BLC_PWM_PCH_CTL2, val);
349                 }
350         } else {
351                 val = I915_READ(BLC_PWM_CTL);
352                 if (dev_priv->regfile.saveBLC_PWM_CTL == 0) {
353                         dev_priv->regfile.saveBLC_PWM_CTL = val;
354                         if (INTEL_INFO(dev)->gen >= 4)
355                                 dev_priv->regfile.saveBLC_PWM_CTL2 =
356                                         I915_READ(BLC_PWM_CTL2);
357                 } else if (val == 0) {
358                         val = dev_priv->regfile.saveBLC_PWM_CTL;
359                         I915_WRITE(BLC_PWM_CTL, val);
360                         if (INTEL_INFO(dev)->gen >= 4)
361                                 I915_WRITE(BLC_PWM_CTL2,
362                                            dev_priv->regfile.saveBLC_PWM_CTL2);
363                 }
364         }
365
366         return val;
367 }
368
369 static u32 intel_panel_get_max_backlight(struct drm_device *dev)
370 {
371         u32 max;
372
373         max = i915_read_blc_pwm_ctl(dev);
374
375         if (HAS_PCH_SPLIT(dev)) {
376                 max >>= 16;
377         } else {
378                 if (INTEL_INFO(dev)->gen < 4)
379                         max >>= 17;
380                 else
381                         max >>= 16;
382
383                 if (is_backlight_combination_mode(dev))
384                         max *= 0xff;
385         }
386
387         DRM_DEBUG_DRIVER("max backlight PWM = %d\n", max);
388
389         return max;
390 }
391
392 static int i915_panel_invert_brightness;
393 MODULE_PARM_DESC(invert_brightness, "Invert backlight brightness "
394         "(-1 force normal, 0 machine defaults, 1 force inversion), please "
395         "report PCI device ID, subsystem vendor and subsystem device ID "
396         "to dri-devel@lists.freedesktop.org, if your machine needs it. "
397         "It will then be included in an upcoming module version.");
398 module_param_named(invert_brightness, i915_panel_invert_brightness, int, 0600);
399 static u32 intel_panel_compute_brightness(struct drm_device *dev, u32 val)
400 {
401         struct drm_i915_private *dev_priv = dev->dev_private;
402
403         if (i915_panel_invert_brightness < 0)
404                 return val;
405
406         if (i915_panel_invert_brightness > 0 ||
407             dev_priv->quirks & QUIRK_INVERT_BRIGHTNESS) {
408                 u32 max = intel_panel_get_max_backlight(dev);
409                 if (max)
410                         return max - val;
411         }
412
413         return val;
414 }
415
416 static u32 intel_panel_get_backlight(struct drm_device *dev)
417 {
418         struct drm_i915_private *dev_priv = dev->dev_private;
419         u32 val;
420         unsigned long flags;
421
422         spin_lock_irqsave(&dev_priv->backlight.lock, flags);
423
424         if (HAS_PCH_SPLIT(dev)) {
425                 val = I915_READ(BLC_PWM_CPU_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
426         } else {
427                 val = I915_READ(BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
428                 if (INTEL_INFO(dev)->gen < 4)
429                         val >>= 1;
430
431                 if (is_backlight_combination_mode(dev)) {
432                         u8 lbpc;
433
434                         pci_read_config_byte(dev->pdev, PCI_LBPC, &lbpc);
435                         val *= lbpc;
436                 }
437         }
438
439         val = intel_panel_compute_brightness(dev, val);
440
441         spin_unlock_irqrestore(&dev_priv->backlight.lock, flags);
442
443         DRM_DEBUG_DRIVER("get backlight PWM = %d\n", val);
444         return val;
445 }
446
447 static void intel_pch_panel_set_backlight(struct drm_device *dev, u32 level)
448 {
449         struct drm_i915_private *dev_priv = dev->dev_private;
450         u32 val = I915_READ(BLC_PWM_CPU_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
451         I915_WRITE(BLC_PWM_CPU_CTL, val | level);
452 }
453
454 static void intel_panel_actually_set_backlight(struct drm_device *dev, u32 level)
455 {
456         struct drm_i915_private *dev_priv = dev->dev_private;
457         u32 tmp;
458
459         DRM_DEBUG_DRIVER("set backlight PWM = %d\n", level);
460         level = intel_panel_compute_brightness(dev, level);
461
462         if (HAS_PCH_SPLIT(dev))
463                 return intel_pch_panel_set_backlight(dev, level);
464
465         if (is_backlight_combination_mode(dev)) {
466                 u32 max = intel_panel_get_max_backlight(dev);
467                 u8 lbpc;
468
469                 /* we're screwed, but keep behaviour backwards compatible */
470                 if (!max)
471                         max = 1;
472
473                 lbpc = level * 0xfe / max + 1;
474                 level /= lbpc;
475                 pci_write_config_byte(dev->pdev, PCI_LBPC, lbpc);
476         }
477
478         tmp = I915_READ(BLC_PWM_CTL);
479         if (INTEL_INFO(dev)->gen < 4)
480                 level <<= 1;
481         tmp &= ~BACKLIGHT_DUTY_CYCLE_MASK;
482         I915_WRITE(BLC_PWM_CTL, tmp | level);
483 }
484
485 /* set backlight brightness to level in range [0..max] */
486 void intel_panel_set_backlight(struct drm_device *dev, u32 level, u32 max)
487 {
488         struct drm_i915_private *dev_priv = dev->dev_private;
489         u32 freq;
490         unsigned long flags;
491
492         spin_lock_irqsave(&dev_priv->backlight.lock, flags);
493
494         freq = intel_panel_get_max_backlight(dev);
495         if (!freq) {
496                 /* we are screwed, bail out */
497                 goto out;
498         }
499
500         /* scale to hardware, but be careful to not overflow */
501         if (freq < max)
502                 level = level * freq / max;
503         else
504                 level = freq / max * level;
505
506         dev_priv->backlight.level = level;
507         if (dev_priv->backlight.device)
508                 dev_priv->backlight.device->props.brightness = level;
509
510         if (dev_priv->backlight.enabled)
511                 intel_panel_actually_set_backlight(dev, level);
512 out:
513         spin_unlock_irqrestore(&dev_priv->backlight.lock, flags);
514 }
515
516 void intel_panel_disable_backlight(struct drm_device *dev)
517 {
518         struct drm_i915_private *dev_priv = dev->dev_private;
519         unsigned long flags;
520
521         spin_lock_irqsave(&dev_priv->backlight.lock, flags);
522
523         dev_priv->backlight.enabled = false;
524         intel_panel_actually_set_backlight(dev, 0);
525
526         if (INTEL_INFO(dev)->gen >= 4) {
527                 uint32_t reg, tmp;
528
529                 reg = HAS_PCH_SPLIT(dev) ? BLC_PWM_CPU_CTL2 : BLC_PWM_CTL2;
530
531                 I915_WRITE(reg, I915_READ(reg) & ~BLM_PWM_ENABLE);
532
533                 if (HAS_PCH_SPLIT(dev)) {
534                         tmp = I915_READ(BLC_PWM_PCH_CTL1);
535                         tmp &= ~BLM_PCH_PWM_ENABLE;
536                         I915_WRITE(BLC_PWM_PCH_CTL1, tmp);
537                 }
538         }
539
540         spin_unlock_irqrestore(&dev_priv->backlight.lock, flags);
541 }
542
543 void intel_panel_enable_backlight(struct drm_device *dev,
544                                   enum pipe pipe)
545 {
546         struct drm_i915_private *dev_priv = dev->dev_private;
547         enum transcoder cpu_transcoder =
548                 intel_pipe_to_cpu_transcoder(dev_priv, pipe);
549         unsigned long flags;
550
551         spin_lock_irqsave(&dev_priv->backlight.lock, flags);
552
553         if (dev_priv->backlight.level == 0) {
554                 dev_priv->backlight.level = intel_panel_get_max_backlight(dev);
555                 if (dev_priv->backlight.device)
556                         dev_priv->backlight.device->props.brightness =
557                                 dev_priv->backlight.level;
558         }
559
560         if (INTEL_INFO(dev)->gen >= 4) {
561                 uint32_t reg, tmp;
562
563                 reg = HAS_PCH_SPLIT(dev) ? BLC_PWM_CPU_CTL2 : BLC_PWM_CTL2;
564
565
566                 tmp = I915_READ(reg);
567
568                 /* Note that this can also get called through dpms changes. And
569                  * we don't track the backlight dpms state, hence check whether
570                  * we have to do anything first. */
571                 if (tmp & BLM_PWM_ENABLE)
572                         goto set_level;
573
574                 if (INTEL_INFO(dev)->num_pipes == 3)
575                         tmp &= ~BLM_PIPE_SELECT_IVB;
576                 else
577                         tmp &= ~BLM_PIPE_SELECT;
578
579                 if (cpu_transcoder == TRANSCODER_EDP)
580                         tmp |= BLM_TRANSCODER_EDP;
581                 else
582                         tmp |= BLM_PIPE(cpu_transcoder);
583                 tmp &= ~BLM_PWM_ENABLE;
584
585                 I915_WRITE(reg, tmp);
586                 POSTING_READ(reg);
587                 I915_WRITE(reg, tmp | BLM_PWM_ENABLE);
588
589                 if (HAS_PCH_SPLIT(dev) &&
590                     !(dev_priv->quirks & QUIRK_NO_PCH_PWM_ENABLE)) {
591                         tmp = I915_READ(BLC_PWM_PCH_CTL1);
592                         tmp |= BLM_PCH_PWM_ENABLE;
593                         tmp &= ~BLM_PCH_OVERRIDE_ENABLE;
594                         I915_WRITE(BLC_PWM_PCH_CTL1, tmp);
595                 }
596         }
597
598 set_level:
599         /* Call below after setting BLC_PWM_CPU_CTL2 and BLC_PWM_PCH_CTL1.
600          * BLC_PWM_CPU_CTL may be cleared to zero automatically when these
601          * registers are set.
602          */
603         dev_priv->backlight.enabled = true;
604         intel_panel_actually_set_backlight(dev, dev_priv->backlight.level);
605
606         spin_unlock_irqrestore(&dev_priv->backlight.lock, flags);
607 }
608
609 static void intel_panel_init_backlight(struct drm_device *dev)
610 {
611         struct drm_i915_private *dev_priv = dev->dev_private;
612
613         dev_priv->backlight.level = intel_panel_get_backlight(dev);
614         dev_priv->backlight.enabled = dev_priv->backlight.level != 0;
615 }
616
617 enum drm_connector_status
618 intel_panel_detect(struct drm_device *dev)
619 {
620         struct drm_i915_private *dev_priv = dev->dev_private;
621
622         /* Assume that the BIOS does not lie through the OpRegion... */
623         if (!i915_panel_ignore_lid && dev_priv->opregion.lid_state) {
624                 return ioread32(dev_priv->opregion.lid_state) & 0x1 ?
625                         connector_status_connected :
626                         connector_status_disconnected;
627         }
628
629         switch (i915_panel_ignore_lid) {
630         case -2:
631                 return connector_status_connected;
632         case -1:
633                 return connector_status_disconnected;
634         default:
635                 return connector_status_unknown;
636         }
637 }
638
639 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
640 static int intel_panel_update_status(struct backlight_device *bd)
641 {
642         struct drm_device *dev = bl_get_data(bd);
643         intel_panel_set_backlight(dev, bd->props.brightness,
644                                   bd->props.max_brightness);
645         return 0;
646 }
647
648 static int intel_panel_get_brightness(struct backlight_device *bd)
649 {
650         struct drm_device *dev = bl_get_data(bd);
651         return intel_panel_get_backlight(dev);
652 }
653
654 static const struct backlight_ops intel_panel_bl_ops = {
655         .update_status = intel_panel_update_status,
656         .get_brightness = intel_panel_get_brightness,
657 };
658
659 int intel_panel_setup_backlight(struct drm_connector *connector)
660 {
661         struct drm_device *dev = connector->dev;
662         struct drm_i915_private *dev_priv = dev->dev_private;
663         struct backlight_properties props;
664         unsigned long flags;
665
666         intel_panel_init_backlight(dev);
667
668         if (WARN_ON(dev_priv->backlight.device))
669                 return -ENODEV;
670
671         memset(&props, 0, sizeof(props));
672         props.type = BACKLIGHT_RAW;
673         props.brightness = dev_priv->backlight.level;
674
675         spin_lock_irqsave(&dev_priv->backlight.lock, flags);
676         props.max_brightness = intel_panel_get_max_backlight(dev);
677         spin_unlock_irqrestore(&dev_priv->backlight.lock, flags);
678
679         if (props.max_brightness == 0) {
680                 DRM_DEBUG_DRIVER("Failed to get maximum backlight value\n");
681                 return -ENODEV;
682         }
683         dev_priv->backlight.device =
684                 backlight_device_register("intel_backlight",
685                                           &connector->kdev, dev,
686                                           &intel_panel_bl_ops, &props);
687
688         if (IS_ERR(dev_priv->backlight.device)) {
689                 DRM_ERROR("Failed to register backlight: %ld\n",
690                           PTR_ERR(dev_priv->backlight.device));
691                 dev_priv->backlight.device = NULL;
692                 return -ENODEV;
693         }
694         return 0;
695 }
696
697 void intel_panel_destroy_backlight(struct drm_device *dev)
698 {
699         struct drm_i915_private *dev_priv = dev->dev_private;
700         if (dev_priv->backlight.device) {
701                 backlight_device_unregister(dev_priv->backlight.device);
702                 dev_priv->backlight.device = NULL;
703         }
704 }
705 #else
706 int intel_panel_setup_backlight(struct drm_connector *connector)
707 {
708         intel_panel_init_backlight(connector->dev);
709         return 0;
710 }
711
712 void intel_panel_destroy_backlight(struct drm_device *dev)
713 {
714         return;
715 }
716 #endif
717
718 int intel_panel_init(struct intel_panel *panel,
719                      struct drm_display_mode *fixed_mode)
720 {
721         panel->fixed_mode = fixed_mode;
722
723         return 0;
724 }
725
726 void intel_panel_fini(struct intel_panel *panel)
727 {
728         struct intel_connector *intel_connector =
729                 container_of(panel, struct intel_connector, panel);
730
731         if (panel->fixed_mode)
732                 drm_mode_destroy(intel_connector->base.dev, panel->fixed_mode);
733 }