drm/i915/gt: Ignore forcewake acquisition for posting_reads
[sfrench/cifs-2.6.git] / drivers / gpu / drm / omapdrm / omap_crtc.c
1 /*
2  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
3  * Author: Rob Clark <rob@ti.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17
18 #include <drm/drm_atomic.h>
19 #include <drm/drm_atomic_helper.h>
20 #include <drm/drm_crtc.h>
21 #include <drm/drm_mode.h>
22 #include <drm/drm_plane_helper.h>
23 #include <linux/math64.h>
24
25 #include "omap_drv.h"
26
27 #define to_omap_crtc_state(x) container_of(x, struct omap_crtc_state, base)
28
29 struct omap_crtc_state {
30         /* Must be first. */
31         struct drm_crtc_state base;
32         /* Shadow values for legacy userspace support. */
33         unsigned int rotation;
34         unsigned int zpos;
35 };
36
37 #define to_omap_crtc(x) container_of(x, struct omap_crtc, base)
38
39 struct omap_crtc {
40         struct drm_crtc base;
41
42         const char *name;
43         struct omap_drm_pipeline *pipe;
44         enum omap_channel channel;
45
46         struct videomode vm;
47
48         bool ignore_digit_sync_lost;
49
50         bool enabled;
51         bool pending;
52         wait_queue_head_t pending_wait;
53         struct drm_pending_vblank_event *event;
54 };
55
56 /* -----------------------------------------------------------------------------
57  * Helper Functions
58  */
59
60 struct videomode *omap_crtc_timings(struct drm_crtc *crtc)
61 {
62         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
63         return &omap_crtc->vm;
64 }
65
66 enum omap_channel omap_crtc_channel(struct drm_crtc *crtc)
67 {
68         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
69         return omap_crtc->channel;
70 }
71
72 static bool omap_crtc_is_pending(struct drm_crtc *crtc)
73 {
74         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
75         unsigned long flags;
76         bool pending;
77
78         spin_lock_irqsave(&crtc->dev->event_lock, flags);
79         pending = omap_crtc->pending;
80         spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
81
82         return pending;
83 }
84
85 int omap_crtc_wait_pending(struct drm_crtc *crtc)
86 {
87         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
88
89         /*
90          * Timeout is set to a "sufficiently" high value, which should cover
91          * a single frame refresh even on slower displays.
92          */
93         return wait_event_timeout(omap_crtc->pending_wait,
94                                   !omap_crtc_is_pending(crtc),
95                                   msecs_to_jiffies(250));
96 }
97
98 /* -----------------------------------------------------------------------------
99  * DSS Manager Functions
100  */
101
102 /*
103  * Manager-ops, callbacks from output when they need to configure
104  * the upstream part of the video pipe.
105  *
106  * Most of these we can ignore until we add support for command-mode
107  * panels.. for video-mode the crtc-helpers already do an adequate
108  * job of sequencing the setup of the video pipe in the proper order
109  */
110
111 /* we can probably ignore these until we support command-mode panels: */
112 static void omap_crtc_dss_start_update(struct omap_drm_private *priv,
113                                        enum omap_channel channel)
114 {
115 }
116
117 /* Called only from the encoder enable/disable and suspend/resume handlers. */
118 static void omap_crtc_set_enabled(struct drm_crtc *crtc, bool enable)
119 {
120         struct drm_device *dev = crtc->dev;
121         struct omap_drm_private *priv = dev->dev_private;
122         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
123         enum omap_channel channel = omap_crtc->channel;
124         struct omap_irq_wait *wait;
125         u32 framedone_irq, vsync_irq;
126         int ret;
127
128         if (WARN_ON(omap_crtc->enabled == enable))
129                 return;
130
131         if (omap_crtc->pipe->output->type == OMAP_DISPLAY_TYPE_HDMI) {
132                 priv->dispc_ops->mgr_enable(priv->dispc, channel, enable);
133                 omap_crtc->enabled = enable;
134                 return;
135         }
136
137         if (omap_crtc->channel == OMAP_DSS_CHANNEL_DIGIT) {
138                 /*
139                  * Digit output produces some sync lost interrupts during the
140                  * first frame when enabling, so we need to ignore those.
141                  */
142                 omap_crtc->ignore_digit_sync_lost = true;
143         }
144
145         framedone_irq = priv->dispc_ops->mgr_get_framedone_irq(priv->dispc,
146                                                                channel);
147         vsync_irq = priv->dispc_ops->mgr_get_vsync_irq(priv->dispc, channel);
148
149         if (enable) {
150                 wait = omap_irq_wait_init(dev, vsync_irq, 1);
151         } else {
152                 /*
153                  * When we disable the digit output, we need to wait for
154                  * FRAMEDONE to know that DISPC has finished with the output.
155                  *
156                  * OMAP2/3 does not have FRAMEDONE irq for digit output, and in
157                  * that case we need to use vsync interrupt, and wait for both
158                  * even and odd frames.
159                  */
160
161                 if (framedone_irq)
162                         wait = omap_irq_wait_init(dev, framedone_irq, 1);
163                 else
164                         wait = omap_irq_wait_init(dev, vsync_irq, 2);
165         }
166
167         priv->dispc_ops->mgr_enable(priv->dispc, channel, enable);
168         omap_crtc->enabled = enable;
169
170         ret = omap_irq_wait(dev, wait, msecs_to_jiffies(100));
171         if (ret) {
172                 dev_err(dev->dev, "%s: timeout waiting for %s\n",
173                                 omap_crtc->name, enable ? "enable" : "disable");
174         }
175
176         if (omap_crtc->channel == OMAP_DSS_CHANNEL_DIGIT) {
177                 omap_crtc->ignore_digit_sync_lost = false;
178                 /* make sure the irq handler sees the value above */
179                 mb();
180         }
181 }
182
183
184 static int omap_crtc_dss_enable(struct omap_drm_private *priv,
185                                 enum omap_channel channel)
186 {
187         struct drm_crtc *crtc = priv->channels[channel]->crtc;
188         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
189
190         priv->dispc_ops->mgr_set_timings(priv->dispc, omap_crtc->channel,
191                                          &omap_crtc->vm);
192         omap_crtc_set_enabled(&omap_crtc->base, true);
193
194         return 0;
195 }
196
197 static void omap_crtc_dss_disable(struct omap_drm_private *priv,
198                                   enum omap_channel channel)
199 {
200         struct drm_crtc *crtc = priv->channels[channel]->crtc;
201         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
202
203         omap_crtc_set_enabled(&omap_crtc->base, false);
204 }
205
206 static void omap_crtc_dss_set_timings(struct omap_drm_private *priv,
207                 enum omap_channel channel,
208                 const struct videomode *vm)
209 {
210         struct drm_crtc *crtc = priv->channels[channel]->crtc;
211         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
212
213         DBG("%s", omap_crtc->name);
214         omap_crtc->vm = *vm;
215 }
216
217 static void omap_crtc_dss_set_lcd_config(struct omap_drm_private *priv,
218                 enum omap_channel channel,
219                 const struct dss_lcd_mgr_config *config)
220 {
221         struct drm_crtc *crtc = priv->channels[channel]->crtc;
222         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
223
224         DBG("%s", omap_crtc->name);
225         priv->dispc_ops->mgr_set_lcd_config(priv->dispc, omap_crtc->channel,
226                                             config);
227 }
228
229 static int omap_crtc_dss_register_framedone(
230                 struct omap_drm_private *priv, enum omap_channel channel,
231                 void (*handler)(void *), void *data)
232 {
233         return 0;
234 }
235
236 static void omap_crtc_dss_unregister_framedone(
237                 struct omap_drm_private *priv, enum omap_channel channel,
238                 void (*handler)(void *), void *data)
239 {
240 }
241
242 static const struct dss_mgr_ops mgr_ops = {
243         .start_update = omap_crtc_dss_start_update,
244         .enable = omap_crtc_dss_enable,
245         .disable = omap_crtc_dss_disable,
246         .set_timings = omap_crtc_dss_set_timings,
247         .set_lcd_config = omap_crtc_dss_set_lcd_config,
248         .register_framedone_handler = omap_crtc_dss_register_framedone,
249         .unregister_framedone_handler = omap_crtc_dss_unregister_framedone,
250 };
251
252 /* -----------------------------------------------------------------------------
253  * Setup, Flush and Page Flip
254  */
255
256 void omap_crtc_error_irq(struct drm_crtc *crtc, u32 irqstatus)
257 {
258         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
259
260         if (omap_crtc->ignore_digit_sync_lost) {
261                 irqstatus &= ~DISPC_IRQ_SYNC_LOST_DIGIT;
262                 if (!irqstatus)
263                         return;
264         }
265
266         DRM_ERROR_RATELIMITED("%s: errors: %08x\n", omap_crtc->name, irqstatus);
267 }
268
269 void omap_crtc_vblank_irq(struct drm_crtc *crtc)
270 {
271         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
272         struct drm_device *dev = omap_crtc->base.dev;
273         struct omap_drm_private *priv = dev->dev_private;
274         bool pending;
275
276         spin_lock(&crtc->dev->event_lock);
277         /*
278          * If the dispc is busy we're racing the flush operation. Try again on
279          * the next vblank interrupt.
280          */
281         if (priv->dispc_ops->mgr_go_busy(priv->dispc, omap_crtc->channel)) {
282                 spin_unlock(&crtc->dev->event_lock);
283                 return;
284         }
285
286         /* Send the vblank event if one has been requested. */
287         if (omap_crtc->event) {
288                 drm_crtc_send_vblank_event(crtc, omap_crtc->event);
289                 omap_crtc->event = NULL;
290         }
291
292         pending = omap_crtc->pending;
293         omap_crtc->pending = false;
294         spin_unlock(&crtc->dev->event_lock);
295
296         if (pending)
297                 drm_crtc_vblank_put(crtc);
298
299         /* Wake up omap_atomic_complete. */
300         wake_up(&omap_crtc->pending_wait);
301
302         DBG("%s: apply done", omap_crtc->name);
303 }
304
305 static void omap_crtc_write_crtc_properties(struct drm_crtc *crtc)
306 {
307         struct omap_drm_private *priv = crtc->dev->dev_private;
308         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
309         struct omap_overlay_manager_info info;
310
311         memset(&info, 0, sizeof(info));
312
313         info.default_color = 0x000000;
314         info.trans_enabled = false;
315         info.partial_alpha_enabled = false;
316         info.cpr_enable = false;
317
318         priv->dispc_ops->mgr_setup(priv->dispc, omap_crtc->channel, &info);
319 }
320
321 /* -----------------------------------------------------------------------------
322  * CRTC Functions
323  */
324
325 static void omap_crtc_destroy(struct drm_crtc *crtc)
326 {
327         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
328
329         DBG("%s", omap_crtc->name);
330
331         drm_crtc_cleanup(crtc);
332
333         kfree(omap_crtc);
334 }
335
336 static void omap_crtc_arm_event(struct drm_crtc *crtc)
337 {
338         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
339
340         WARN_ON(omap_crtc->pending);
341         omap_crtc->pending = true;
342
343         if (crtc->state->event) {
344                 omap_crtc->event = crtc->state->event;
345                 crtc->state->event = NULL;
346         }
347 }
348
349 static void omap_crtc_atomic_enable(struct drm_crtc *crtc,
350                                     struct drm_crtc_state *old_state)
351 {
352         struct omap_drm_private *priv = crtc->dev->dev_private;
353         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
354         int ret;
355
356         DBG("%s", omap_crtc->name);
357
358         priv->dispc_ops->runtime_get(priv->dispc);
359
360         spin_lock_irq(&crtc->dev->event_lock);
361         drm_crtc_vblank_on(crtc);
362         ret = drm_crtc_vblank_get(crtc);
363         WARN_ON(ret != 0);
364
365         omap_crtc_arm_event(crtc);
366         spin_unlock_irq(&crtc->dev->event_lock);
367 }
368
369 static void omap_crtc_atomic_disable(struct drm_crtc *crtc,
370                                      struct drm_crtc_state *old_state)
371 {
372         struct omap_drm_private *priv = crtc->dev->dev_private;
373         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
374
375         DBG("%s", omap_crtc->name);
376
377         spin_lock_irq(&crtc->dev->event_lock);
378         if (crtc->state->event) {
379                 drm_crtc_send_vblank_event(crtc, crtc->state->event);
380                 crtc->state->event = NULL;
381         }
382         spin_unlock_irq(&crtc->dev->event_lock);
383
384         drm_crtc_vblank_off(crtc);
385
386         priv->dispc_ops->runtime_put(priv->dispc);
387 }
388
389 static enum drm_mode_status omap_crtc_mode_valid(struct drm_crtc *crtc,
390                                         const struct drm_display_mode *mode)
391 {
392         struct omap_drm_private *priv = crtc->dev->dev_private;
393         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
394         struct videomode vm = {0};
395         int r;
396
397         drm_display_mode_to_videomode(mode, &vm);
398         r = priv->dispc_ops->mgr_check_timings(priv->dispc, omap_crtc->channel,
399                                                &vm);
400         if (r)
401                 return r;
402
403         /* Check for bandwidth limit */
404         if (priv->max_bandwidth) {
405                 /*
406                  * Estimation for the bandwidth need of a given mode with one
407                  * full screen plane:
408                  * bandwidth = resolution * 32bpp * (pclk / (vtotal * htotal))
409                  *                                      ^^ Refresh rate ^^
410                  *
411                  * The interlaced mode is taken into account by using the
412                  * pixelclock in the calculation.
413                  *
414                  * The equation is rearranged for 64bit arithmetic.
415                  */
416                 uint64_t bandwidth = mode->clock * 1000;
417                 unsigned int bpp = 4;
418
419                 bandwidth = bandwidth * mode->hdisplay * mode->vdisplay * bpp;
420                 bandwidth = div_u64(bandwidth, mode->htotal * mode->vtotal);
421
422                 /*
423                  * Reject modes which would need more bandwidth if used with one
424                  * full resolution plane (most common use case).
425                  */
426                 if (priv->max_bandwidth < bandwidth)
427                         return MODE_BAD;
428         }
429
430         return MODE_OK;
431 }
432
433 static void omap_crtc_mode_set_nofb(struct drm_crtc *crtc)
434 {
435         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
436         struct drm_display_mode *mode = &crtc->state->adjusted_mode;
437
438         DBG("%s: set mode: " DRM_MODE_FMT,
439             omap_crtc->name, DRM_MODE_ARG(mode));
440
441         drm_display_mode_to_videomode(mode, &omap_crtc->vm);
442 }
443
444 static int omap_crtc_atomic_check(struct drm_crtc *crtc,
445                                 struct drm_crtc_state *state)
446 {
447         struct drm_plane_state *pri_state;
448
449         if (state->color_mgmt_changed && state->gamma_lut) {
450                 unsigned int length = state->gamma_lut->length /
451                         sizeof(struct drm_color_lut);
452
453                 if (length < 2)
454                         return -EINVAL;
455         }
456
457         pri_state = drm_atomic_get_new_plane_state(state->state, crtc->primary);
458         if (pri_state) {
459                 struct omap_crtc_state *omap_crtc_state =
460                         to_omap_crtc_state(state);
461
462                 /* Mirror new values for zpos and rotation in omap_crtc_state */
463                 omap_crtc_state->zpos = pri_state->zpos;
464                 omap_crtc_state->rotation = pri_state->rotation;
465         }
466
467         return 0;
468 }
469
470 static void omap_crtc_atomic_begin(struct drm_crtc *crtc,
471                                    struct drm_crtc_state *old_crtc_state)
472 {
473 }
474
475 static void omap_crtc_atomic_flush(struct drm_crtc *crtc,
476                                    struct drm_crtc_state *old_crtc_state)
477 {
478         struct omap_drm_private *priv = crtc->dev->dev_private;
479         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
480         int ret;
481
482         if (crtc->state->color_mgmt_changed) {
483                 struct drm_color_lut *lut = NULL;
484                 unsigned int length = 0;
485
486                 if (crtc->state->gamma_lut) {
487                         lut = (struct drm_color_lut *)
488                                 crtc->state->gamma_lut->data;
489                         length = crtc->state->gamma_lut->length /
490                                 sizeof(*lut);
491                 }
492                 priv->dispc_ops->mgr_set_gamma(priv->dispc, omap_crtc->channel,
493                                                lut, length);
494         }
495
496         omap_crtc_write_crtc_properties(crtc);
497
498         /* Only flush the CRTC if it is currently enabled. */
499         if (!omap_crtc->enabled)
500                 return;
501
502         DBG("%s: GO", omap_crtc->name);
503
504         ret = drm_crtc_vblank_get(crtc);
505         WARN_ON(ret != 0);
506
507         spin_lock_irq(&crtc->dev->event_lock);
508         priv->dispc_ops->mgr_go(priv->dispc, omap_crtc->channel);
509         omap_crtc_arm_event(crtc);
510         spin_unlock_irq(&crtc->dev->event_lock);
511 }
512
513 static int omap_crtc_atomic_set_property(struct drm_crtc *crtc,
514                                          struct drm_crtc_state *state,
515                                          struct drm_property *property,
516                                          u64 val)
517 {
518         struct omap_drm_private *priv = crtc->dev->dev_private;
519         struct drm_plane_state *plane_state;
520
521         /*
522          * Delegate property set to the primary plane. Get the plane state and
523          * set the property directly, the shadow copy will be assigned in the
524          * omap_crtc_atomic_check callback. This way updates to plane state will
525          * always be mirrored in the crtc state correctly.
526          */
527         plane_state = drm_atomic_get_plane_state(state->state, crtc->primary);
528         if (IS_ERR(plane_state))
529                 return PTR_ERR(plane_state);
530
531         if (property == crtc->primary->rotation_property)
532                 plane_state->rotation = val;
533         else if (property == priv->zorder_prop)
534                 plane_state->zpos = val;
535         else
536                 return -EINVAL;
537
538         return 0;
539 }
540
541 static int omap_crtc_atomic_get_property(struct drm_crtc *crtc,
542                                          const struct drm_crtc_state *state,
543                                          struct drm_property *property,
544                                          u64 *val)
545 {
546         struct omap_drm_private *priv = crtc->dev->dev_private;
547         struct omap_crtc_state *omap_state = to_omap_crtc_state(state);
548
549         if (property == crtc->primary->rotation_property)
550                 *val = omap_state->rotation;
551         else if (property == priv->zorder_prop)
552                 *val = omap_state->zpos;
553         else
554                 return -EINVAL;
555
556         return 0;
557 }
558
559 static void omap_crtc_reset(struct drm_crtc *crtc)
560 {
561         if (crtc->state)
562                 __drm_atomic_helper_crtc_destroy_state(crtc->state);
563
564         kfree(crtc->state);
565         crtc->state = kzalloc(sizeof(struct omap_crtc_state), GFP_KERNEL);
566
567         if (crtc->state)
568                 crtc->state->crtc = crtc;
569 }
570
571 static struct drm_crtc_state *
572 omap_crtc_duplicate_state(struct drm_crtc *crtc)
573 {
574         struct omap_crtc_state *state, *current_state;
575
576         if (WARN_ON(!crtc->state))
577                 return NULL;
578
579         current_state = to_omap_crtc_state(crtc->state);
580
581         state = kmalloc(sizeof(*state), GFP_KERNEL);
582         if (!state)
583                 return NULL;
584
585         __drm_atomic_helper_crtc_duplicate_state(crtc, &state->base);
586
587         state->zpos = current_state->zpos;
588         state->rotation = current_state->rotation;
589
590         return &state->base;
591 }
592
593 static const struct drm_crtc_funcs omap_crtc_funcs = {
594         .reset = omap_crtc_reset,
595         .set_config = drm_atomic_helper_set_config,
596         .destroy = omap_crtc_destroy,
597         .page_flip = drm_atomic_helper_page_flip,
598         .gamma_set = drm_atomic_helper_legacy_gamma_set,
599         .atomic_duplicate_state = omap_crtc_duplicate_state,
600         .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
601         .atomic_set_property = omap_crtc_atomic_set_property,
602         .atomic_get_property = omap_crtc_atomic_get_property,
603         .enable_vblank = omap_irq_enable_vblank,
604         .disable_vblank = omap_irq_disable_vblank,
605 };
606
607 static const struct drm_crtc_helper_funcs omap_crtc_helper_funcs = {
608         .mode_set_nofb = omap_crtc_mode_set_nofb,
609         .atomic_check = omap_crtc_atomic_check,
610         .atomic_begin = omap_crtc_atomic_begin,
611         .atomic_flush = omap_crtc_atomic_flush,
612         .atomic_enable = omap_crtc_atomic_enable,
613         .atomic_disable = omap_crtc_atomic_disable,
614         .mode_valid = omap_crtc_mode_valid,
615 };
616
617 /* -----------------------------------------------------------------------------
618  * Init and Cleanup
619  */
620
621 static const char *channel_names[] = {
622         [OMAP_DSS_CHANNEL_LCD] = "lcd",
623         [OMAP_DSS_CHANNEL_DIGIT] = "tv",
624         [OMAP_DSS_CHANNEL_LCD2] = "lcd2",
625         [OMAP_DSS_CHANNEL_LCD3] = "lcd3",
626 };
627
628 void omap_crtc_pre_init(struct omap_drm_private *priv)
629 {
630         dss_install_mgr_ops(priv->dss, &mgr_ops, priv);
631 }
632
633 void omap_crtc_pre_uninit(struct omap_drm_private *priv)
634 {
635         dss_uninstall_mgr_ops(priv->dss);
636 }
637
638 /* initialize crtc */
639 struct drm_crtc *omap_crtc_init(struct drm_device *dev,
640                                 struct omap_drm_pipeline *pipe,
641                                 struct drm_plane *plane)
642 {
643         struct omap_drm_private *priv = dev->dev_private;
644         struct drm_crtc *crtc = NULL;
645         struct omap_crtc *omap_crtc;
646         enum omap_channel channel;
647         int ret;
648
649         channel = pipe->output->dispc_channel;
650
651         DBG("%s", channel_names[channel]);
652
653         omap_crtc = kzalloc(sizeof(*omap_crtc), GFP_KERNEL);
654         if (!omap_crtc)
655                 return ERR_PTR(-ENOMEM);
656
657         crtc = &omap_crtc->base;
658
659         init_waitqueue_head(&omap_crtc->pending_wait);
660
661         omap_crtc->pipe = pipe;
662         omap_crtc->channel = channel;
663         omap_crtc->name = channel_names[channel];
664
665         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
666                                         &omap_crtc_funcs, NULL);
667         if (ret < 0) {
668                 dev_err(dev->dev, "%s(): could not init crtc for: %s\n",
669                         __func__, pipe->output->name);
670                 kfree(omap_crtc);
671                 return ERR_PTR(ret);
672         }
673
674         drm_crtc_helper_add(crtc, &omap_crtc_helper_funcs);
675
676         /* The dispc API adapts to what ever size, but the HW supports
677          * 256 element gamma table for LCDs and 1024 element table for
678          * OMAP_DSS_CHANNEL_DIGIT. X server assumes 256 element gamma
679          * tables so lets use that. Size of HW gamma table can be
680          * extracted with dispc_mgr_gamma_size(). If it returns 0
681          * gamma table is not supprted.
682          */
683         if (priv->dispc_ops->mgr_gamma_size(priv->dispc, channel)) {
684                 unsigned int gamma_lut_size = 256;
685
686                 drm_crtc_enable_color_mgmt(crtc, 0, false, gamma_lut_size);
687                 drm_mode_crtc_set_gamma_size(crtc, gamma_lut_size);
688         }
689
690         omap_plane_install_properties(crtc->primary, &crtc->base);
691
692         return crtc;
693 }