Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[cris-mirror.git] / drivers / gpu / drm / omapdrm / omap_crtc.c
blob1b8154e58d1823e6e949a1448ac604cbe2ccf8aa
1 /*
2 * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
3 * Author: Rob Clark <rob@ti.com>
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.
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.
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/>.
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>
26 #include "omap_drv.h"
28 #define to_omap_crtc_state(x) container_of(x, struct omap_crtc_state, base)
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;
38 #define to_omap_crtc(x) container_of(x, struct omap_crtc, base)
40 struct omap_crtc {
41 struct drm_crtc base;
43 const char *name;
44 enum omap_channel channel;
46 struct videomode vm;
48 bool ignore_digit_sync_lost;
50 bool enabled;
51 bool pending;
52 wait_queue_head_t pending_wait;
53 struct drm_pending_vblank_event *event;
56 /* -----------------------------------------------------------------------------
57 * Helper Functions
60 struct videomode *omap_crtc_timings(struct drm_crtc *crtc)
62 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
63 return &omap_crtc->vm;
66 enum omap_channel omap_crtc_channel(struct drm_crtc *crtc)
68 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
69 return omap_crtc->channel;
72 static bool omap_crtc_is_pending(struct drm_crtc *crtc)
74 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
75 unsigned long flags;
76 bool pending;
78 spin_lock_irqsave(&crtc->dev->event_lock, flags);
79 pending = omap_crtc->pending;
80 spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
82 return pending;
85 int omap_crtc_wait_pending(struct drm_crtc *crtc)
87 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
90 * Timeout is set to a "sufficiently" high value, which should cover
91 * a single frame refresh even on slower displays.
93 return wait_event_timeout(omap_crtc->pending_wait,
94 !omap_crtc_is_pending(crtc),
95 msecs_to_jiffies(250));
98 /* -----------------------------------------------------------------------------
99 * DSS Manager Functions
103 * Manager-ops, callbacks from output when they need to configure
104 * the upstream part of the video pipe.
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
111 /* ovl-mgr-id -> crtc */
112 static struct omap_crtc *omap_crtcs[8];
113 static struct omap_dss_device *omap_crtc_output[8];
115 /* we can probably ignore these until we support command-mode panels: */
116 static int omap_crtc_dss_connect(enum omap_channel channel,
117 struct omap_dss_device *dst)
119 const struct dispc_ops *dispc_ops = dispc_get_ops();
121 if (omap_crtc_output[channel])
122 return -EINVAL;
124 if ((dispc_ops->mgr_get_supported_outputs(channel) & dst->id) == 0)
125 return -EINVAL;
127 omap_crtc_output[channel] = dst;
128 dst->dispc_channel_connected = true;
130 return 0;
133 static void omap_crtc_dss_disconnect(enum omap_channel channel,
134 struct omap_dss_device *dst)
136 omap_crtc_output[channel] = NULL;
137 dst->dispc_channel_connected = false;
140 static void omap_crtc_dss_start_update(enum omap_channel channel)
144 /* Called only from the encoder enable/disable and suspend/resume handlers. */
145 static void omap_crtc_set_enabled(struct drm_crtc *crtc, bool enable)
147 struct drm_device *dev = crtc->dev;
148 struct omap_drm_private *priv = dev->dev_private;
149 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
150 enum omap_channel channel = omap_crtc->channel;
151 struct omap_irq_wait *wait;
152 u32 framedone_irq, vsync_irq;
153 int ret;
155 if (WARN_ON(omap_crtc->enabled == enable))
156 return;
158 if (omap_crtc_output[channel]->output_type == OMAP_DISPLAY_TYPE_HDMI) {
159 priv->dispc_ops->mgr_enable(channel, enable);
160 omap_crtc->enabled = enable;
161 return;
164 if (omap_crtc->channel == OMAP_DSS_CHANNEL_DIGIT) {
166 * Digit output produces some sync lost interrupts during the
167 * first frame when enabling, so we need to ignore those.
169 omap_crtc->ignore_digit_sync_lost = true;
172 framedone_irq = priv->dispc_ops->mgr_get_framedone_irq(channel);
173 vsync_irq = priv->dispc_ops->mgr_get_vsync_irq(channel);
175 if (enable) {
176 wait = omap_irq_wait_init(dev, vsync_irq, 1);
177 } else {
179 * When we disable the digit output, we need to wait for
180 * FRAMEDONE to know that DISPC has finished with the output.
182 * OMAP2/3 does not have FRAMEDONE irq for digit output, and in
183 * that case we need to use vsync interrupt, and wait for both
184 * even and odd frames.
187 if (framedone_irq)
188 wait = omap_irq_wait_init(dev, framedone_irq, 1);
189 else
190 wait = omap_irq_wait_init(dev, vsync_irq, 2);
193 priv->dispc_ops->mgr_enable(channel, enable);
194 omap_crtc->enabled = enable;
196 ret = omap_irq_wait(dev, wait, msecs_to_jiffies(100));
197 if (ret) {
198 dev_err(dev->dev, "%s: timeout waiting for %s\n",
199 omap_crtc->name, enable ? "enable" : "disable");
202 if (omap_crtc->channel == OMAP_DSS_CHANNEL_DIGIT) {
203 omap_crtc->ignore_digit_sync_lost = false;
204 /* make sure the irq handler sees the value above */
205 mb();
210 static int omap_crtc_dss_enable(enum omap_channel channel)
212 struct omap_crtc *omap_crtc = omap_crtcs[channel];
213 struct omap_drm_private *priv = omap_crtc->base.dev->dev_private;
215 priv->dispc_ops->mgr_set_timings(omap_crtc->channel, &omap_crtc->vm);
216 omap_crtc_set_enabled(&omap_crtc->base, true);
218 return 0;
221 static void omap_crtc_dss_disable(enum omap_channel channel)
223 struct omap_crtc *omap_crtc = omap_crtcs[channel];
225 omap_crtc_set_enabled(&omap_crtc->base, false);
228 static void omap_crtc_dss_set_timings(enum omap_channel channel,
229 const struct videomode *vm)
231 struct omap_crtc *omap_crtc = omap_crtcs[channel];
232 DBG("%s", omap_crtc->name);
233 omap_crtc->vm = *vm;
236 static void omap_crtc_dss_set_lcd_config(enum omap_channel channel,
237 const struct dss_lcd_mgr_config *config)
239 struct omap_crtc *omap_crtc = omap_crtcs[channel];
240 struct omap_drm_private *priv = omap_crtc->base.dev->dev_private;
242 DBG("%s", omap_crtc->name);
243 priv->dispc_ops->mgr_set_lcd_config(omap_crtc->channel, config);
246 static int omap_crtc_dss_register_framedone(
247 enum omap_channel channel,
248 void (*handler)(void *), void *data)
250 return 0;
253 static void omap_crtc_dss_unregister_framedone(
254 enum omap_channel channel,
255 void (*handler)(void *), void *data)
259 static const struct dss_mgr_ops mgr_ops = {
260 .connect = omap_crtc_dss_connect,
261 .disconnect = omap_crtc_dss_disconnect,
262 .start_update = omap_crtc_dss_start_update,
263 .enable = omap_crtc_dss_enable,
264 .disable = omap_crtc_dss_disable,
265 .set_timings = omap_crtc_dss_set_timings,
266 .set_lcd_config = omap_crtc_dss_set_lcd_config,
267 .register_framedone_handler = omap_crtc_dss_register_framedone,
268 .unregister_framedone_handler = omap_crtc_dss_unregister_framedone,
271 /* -----------------------------------------------------------------------------
272 * Setup, Flush and Page Flip
275 void omap_crtc_error_irq(struct drm_crtc *crtc, uint32_t irqstatus)
277 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
279 if (omap_crtc->ignore_digit_sync_lost) {
280 irqstatus &= ~DISPC_IRQ_SYNC_LOST_DIGIT;
281 if (!irqstatus)
282 return;
285 DRM_ERROR_RATELIMITED("%s: errors: %08x\n", omap_crtc->name, irqstatus);
288 void omap_crtc_vblank_irq(struct drm_crtc *crtc)
290 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
291 struct drm_device *dev = omap_crtc->base.dev;
292 struct omap_drm_private *priv = dev->dev_private;
293 bool pending;
295 spin_lock(&crtc->dev->event_lock);
297 * If the dispc is busy we're racing the flush operation. Try again on
298 * the next vblank interrupt.
300 if (priv->dispc_ops->mgr_go_busy(omap_crtc->channel)) {
301 spin_unlock(&crtc->dev->event_lock);
302 return;
305 /* Send the vblank event if one has been requested. */
306 if (omap_crtc->event) {
307 drm_crtc_send_vblank_event(crtc, omap_crtc->event);
308 omap_crtc->event = NULL;
311 pending = omap_crtc->pending;
312 omap_crtc->pending = false;
313 spin_unlock(&crtc->dev->event_lock);
315 if (pending)
316 drm_crtc_vblank_put(crtc);
318 /* Wake up omap_atomic_complete. */
319 wake_up(&omap_crtc->pending_wait);
321 DBG("%s: apply done", omap_crtc->name);
324 static void omap_crtc_write_crtc_properties(struct drm_crtc *crtc)
326 struct omap_drm_private *priv = crtc->dev->dev_private;
327 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
328 struct omap_overlay_manager_info info;
330 memset(&info, 0, sizeof(info));
332 info.default_color = 0x000000;
333 info.trans_enabled = false;
334 info.partial_alpha_enabled = false;
335 info.cpr_enable = false;
337 priv->dispc_ops->mgr_setup(omap_crtc->channel, &info);
340 /* -----------------------------------------------------------------------------
341 * CRTC Functions
344 static void omap_crtc_destroy(struct drm_crtc *crtc)
346 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
348 DBG("%s", omap_crtc->name);
350 drm_crtc_cleanup(crtc);
352 kfree(omap_crtc);
355 static void omap_crtc_arm_event(struct drm_crtc *crtc)
357 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
359 WARN_ON(omap_crtc->pending);
360 omap_crtc->pending = true;
362 if (crtc->state->event) {
363 omap_crtc->event = crtc->state->event;
364 crtc->state->event = NULL;
368 static void omap_crtc_atomic_enable(struct drm_crtc *crtc,
369 struct drm_crtc_state *old_state)
371 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
372 int ret;
374 DBG("%s", omap_crtc->name);
376 spin_lock_irq(&crtc->dev->event_lock);
377 drm_crtc_vblank_on(crtc);
378 ret = drm_crtc_vblank_get(crtc);
379 WARN_ON(ret != 0);
381 omap_crtc_arm_event(crtc);
382 spin_unlock_irq(&crtc->dev->event_lock);
385 static void omap_crtc_atomic_disable(struct drm_crtc *crtc,
386 struct drm_crtc_state *old_state)
388 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
390 DBG("%s", omap_crtc->name);
392 spin_lock_irq(&crtc->dev->event_lock);
393 if (crtc->state->event) {
394 drm_crtc_send_vblank_event(crtc, crtc->state->event);
395 crtc->state->event = NULL;
397 spin_unlock_irq(&crtc->dev->event_lock);
399 drm_crtc_vblank_off(crtc);
402 static enum drm_mode_status omap_crtc_mode_valid(struct drm_crtc *crtc,
403 const struct drm_display_mode *mode)
405 struct omap_drm_private *priv = crtc->dev->dev_private;
407 /* Check for bandwidth limit */
408 if (priv->max_bandwidth) {
410 * Estimation for the bandwidth need of a given mode with one
411 * full screen plane:
412 * bandwidth = resolution * 32bpp * (pclk / (vtotal * htotal))
413 * ^^ Refresh rate ^^
415 * The interlaced mode is taken into account by using the
416 * pixelclock in the calculation.
418 * The equation is rearranged for 64bit arithmetic.
420 uint64_t bandwidth = mode->clock * 1000;
421 unsigned int bpp = 4;
423 bandwidth = bandwidth * mode->hdisplay * mode->vdisplay * bpp;
424 bandwidth = div_u64(bandwidth, mode->htotal * mode->vtotal);
427 * Reject modes which would need more bandwidth if used with one
428 * full resolution plane (most common use case).
430 if (priv->max_bandwidth < bandwidth)
431 return MODE_BAD;
434 return MODE_OK;
437 static void omap_crtc_mode_set_nofb(struct drm_crtc *crtc)
439 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
440 struct drm_display_mode *mode = &crtc->state->adjusted_mode;
441 struct omap_drm_private *priv = crtc->dev->dev_private;
442 const u32 flags_mask = DISPLAY_FLAGS_DE_HIGH | DISPLAY_FLAGS_DE_LOW |
443 DISPLAY_FLAGS_PIXDATA_POSEDGE | DISPLAY_FLAGS_PIXDATA_NEGEDGE |
444 DISPLAY_FLAGS_SYNC_POSEDGE | DISPLAY_FLAGS_SYNC_NEGEDGE;
445 unsigned int i;
447 DBG("%s: set mode: %d:\"%s\" %d %d %d %d %d %d %d %d %d %d 0x%x 0x%x",
448 omap_crtc->name, mode->base.id, mode->name,
449 mode->vrefresh, mode->clock,
450 mode->hdisplay, mode->hsync_start, mode->hsync_end, mode->htotal,
451 mode->vdisplay, mode->vsync_start, mode->vsync_end, mode->vtotal,
452 mode->type, mode->flags);
454 drm_display_mode_to_videomode(mode, &omap_crtc->vm);
457 * HACK: This fixes the vm flags.
458 * struct drm_display_mode does not contain the VSYNC/HSYNC/DE flags
459 * and they get lost when converting back and forth between
460 * struct drm_display_mode and struct videomode. The hack below
461 * goes and fetches the missing flags from the panel drivers.
463 * Correct solution would be to use DRM's bus-flags, but that's not
464 * easily possible before the omapdrm's panel/encoder driver model
465 * has been changed to the DRM model.
468 for (i = 0; i < priv->num_encoders; ++i) {
469 struct drm_encoder *encoder = priv->encoders[i];
471 if (encoder->crtc == crtc) {
472 struct omap_dss_device *dssdev;
474 dssdev = omap_encoder_get_dssdev(encoder);
476 if (dssdev) {
477 struct videomode vm = {0};
479 dssdev->driver->get_timings(dssdev, &vm);
481 omap_crtc->vm.flags |= vm.flags & flags_mask;
484 break;
489 static int omap_crtc_atomic_check(struct drm_crtc *crtc,
490 struct drm_crtc_state *state)
492 struct drm_plane_state *pri_state;
494 if (state->color_mgmt_changed && state->gamma_lut) {
495 uint length = state->gamma_lut->length /
496 sizeof(struct drm_color_lut);
498 if (length < 2)
499 return -EINVAL;
502 pri_state = drm_atomic_get_new_plane_state(state->state, crtc->primary);
503 if (pri_state) {
504 struct omap_crtc_state *omap_crtc_state =
505 to_omap_crtc_state(state);
507 /* Mirror new values for zpos and rotation in omap_crtc_state */
508 omap_crtc_state->zpos = pri_state->zpos;
509 omap_crtc_state->rotation = pri_state->rotation;
512 return 0;
515 static void omap_crtc_atomic_begin(struct drm_crtc *crtc,
516 struct drm_crtc_state *old_crtc_state)
520 static void omap_crtc_atomic_flush(struct drm_crtc *crtc,
521 struct drm_crtc_state *old_crtc_state)
523 struct omap_drm_private *priv = crtc->dev->dev_private;
524 struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
525 int ret;
527 if (crtc->state->color_mgmt_changed) {
528 struct drm_color_lut *lut = NULL;
529 uint length = 0;
531 if (crtc->state->gamma_lut) {
532 lut = (struct drm_color_lut *)
533 crtc->state->gamma_lut->data;
534 length = crtc->state->gamma_lut->length /
535 sizeof(*lut);
537 priv->dispc_ops->mgr_set_gamma(omap_crtc->channel, lut, length);
540 omap_crtc_write_crtc_properties(crtc);
542 /* Only flush the CRTC if it is currently enabled. */
543 if (!omap_crtc->enabled)
544 return;
546 DBG("%s: GO", omap_crtc->name);
548 ret = drm_crtc_vblank_get(crtc);
549 WARN_ON(ret != 0);
551 spin_lock_irq(&crtc->dev->event_lock);
552 priv->dispc_ops->mgr_go(omap_crtc->channel);
553 omap_crtc_arm_event(crtc);
554 spin_unlock_irq(&crtc->dev->event_lock);
557 static int omap_crtc_atomic_set_property(struct drm_crtc *crtc,
558 struct drm_crtc_state *state,
559 struct drm_property *property,
560 uint64_t val)
562 struct omap_drm_private *priv = crtc->dev->dev_private;
563 struct drm_plane_state *plane_state;
566 * Delegate property set to the primary plane. Get the plane state and
567 * set the property directly, the shadow copy will be assigned in the
568 * omap_crtc_atomic_check callback. This way updates to plane state will
569 * always be mirrored in the crtc state correctly.
571 plane_state = drm_atomic_get_plane_state(state->state, crtc->primary);
572 if (IS_ERR(plane_state))
573 return PTR_ERR(plane_state);
575 if (property == crtc->primary->rotation_property)
576 plane_state->rotation = val;
577 else if (property == priv->zorder_prop)
578 plane_state->zpos = val;
579 else
580 return -EINVAL;
582 return 0;
585 static int omap_crtc_atomic_get_property(struct drm_crtc *crtc,
586 const struct drm_crtc_state *state,
587 struct drm_property *property,
588 uint64_t *val)
590 struct omap_drm_private *priv = crtc->dev->dev_private;
591 struct omap_crtc_state *omap_state = to_omap_crtc_state(state);
593 if (property == crtc->primary->rotation_property)
594 *val = omap_state->rotation;
595 else if (property == priv->zorder_prop)
596 *val = omap_state->zpos;
597 else
598 return -EINVAL;
600 return 0;
603 static void omap_crtc_reset(struct drm_crtc *crtc)
605 if (crtc->state)
606 __drm_atomic_helper_crtc_destroy_state(crtc->state);
608 kfree(crtc->state);
609 crtc->state = kzalloc(sizeof(struct omap_crtc_state), GFP_KERNEL);
611 if (crtc->state)
612 crtc->state->crtc = crtc;
615 static struct drm_crtc_state *
616 omap_crtc_duplicate_state(struct drm_crtc *crtc)
618 struct omap_crtc_state *state, *current_state;
620 if (WARN_ON(!crtc->state))
621 return NULL;
623 current_state = to_omap_crtc_state(crtc->state);
625 state = kmalloc(sizeof(*state), GFP_KERNEL);
626 if (!state)
627 return NULL;
629 __drm_atomic_helper_crtc_duplicate_state(crtc, &state->base);
631 state->zpos = current_state->zpos;
632 state->rotation = current_state->rotation;
634 return &state->base;
637 static const struct drm_crtc_funcs omap_crtc_funcs = {
638 .reset = omap_crtc_reset,
639 .set_config = drm_atomic_helper_set_config,
640 .destroy = omap_crtc_destroy,
641 .page_flip = drm_atomic_helper_page_flip,
642 .gamma_set = drm_atomic_helper_legacy_gamma_set,
643 .atomic_duplicate_state = omap_crtc_duplicate_state,
644 .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
645 .atomic_set_property = omap_crtc_atomic_set_property,
646 .atomic_get_property = omap_crtc_atomic_get_property,
647 .enable_vblank = omap_irq_enable_vblank,
648 .disable_vblank = omap_irq_disable_vblank,
651 static const struct drm_crtc_helper_funcs omap_crtc_helper_funcs = {
652 .mode_set_nofb = omap_crtc_mode_set_nofb,
653 .atomic_check = omap_crtc_atomic_check,
654 .atomic_begin = omap_crtc_atomic_begin,
655 .atomic_flush = omap_crtc_atomic_flush,
656 .atomic_enable = omap_crtc_atomic_enable,
657 .atomic_disable = omap_crtc_atomic_disable,
658 .mode_valid = omap_crtc_mode_valid,
661 /* -----------------------------------------------------------------------------
662 * Init and Cleanup
665 static const char *channel_names[] = {
666 [OMAP_DSS_CHANNEL_LCD] = "lcd",
667 [OMAP_DSS_CHANNEL_DIGIT] = "tv",
668 [OMAP_DSS_CHANNEL_LCD2] = "lcd2",
669 [OMAP_DSS_CHANNEL_LCD3] = "lcd3",
672 void omap_crtc_pre_init(void)
674 memset(omap_crtcs, 0, sizeof(omap_crtcs));
676 dss_install_mgr_ops(&mgr_ops);
679 void omap_crtc_pre_uninit(void)
681 dss_uninstall_mgr_ops();
684 /* initialize crtc */
685 struct drm_crtc *omap_crtc_init(struct drm_device *dev,
686 struct drm_plane *plane, struct omap_dss_device *dssdev)
688 struct omap_drm_private *priv = dev->dev_private;
689 struct drm_crtc *crtc = NULL;
690 struct omap_crtc *omap_crtc;
691 enum omap_channel channel;
692 struct omap_dss_device *out;
693 int ret;
695 out = omapdss_find_output_from_display(dssdev);
696 channel = out->dispc_channel;
697 omap_dss_put_device(out);
699 DBG("%s", channel_names[channel]);
701 /* Multiple displays on same channel is not allowed */
702 if (WARN_ON(omap_crtcs[channel] != NULL))
703 return ERR_PTR(-EINVAL);
705 omap_crtc = kzalloc(sizeof(*omap_crtc), GFP_KERNEL);
706 if (!omap_crtc)
707 return ERR_PTR(-ENOMEM);
709 crtc = &omap_crtc->base;
711 init_waitqueue_head(&omap_crtc->pending_wait);
713 omap_crtc->channel = channel;
714 omap_crtc->name = channel_names[channel];
716 ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
717 &omap_crtc_funcs, NULL);
718 if (ret < 0) {
719 dev_err(dev->dev, "%s(): could not init crtc for: %s\n",
720 __func__, dssdev->name);
721 kfree(omap_crtc);
722 return ERR_PTR(ret);
725 drm_crtc_helper_add(crtc, &omap_crtc_helper_funcs);
727 /* The dispc API adapts to what ever size, but the HW supports
728 * 256 element gamma table for LCDs and 1024 element table for
729 * OMAP_DSS_CHANNEL_DIGIT. X server assumes 256 element gamma
730 * tables so lets use that. Size of HW gamma table can be
731 * extracted with dispc_mgr_gamma_size(). If it returns 0
732 * gamma table is not supprted.
734 if (priv->dispc_ops->mgr_gamma_size(channel)) {
735 uint gamma_lut_size = 256;
737 drm_crtc_enable_color_mgmt(crtc, 0, false, gamma_lut_size);
738 drm_mode_crtc_set_gamma_size(crtc, gamma_lut_size);
741 omap_plane_install_properties(crtc->primary, &crtc->base);
743 omap_crtcs[channel] = omap_crtc;
745 return crtc;