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