xref: /linux/drivers/gpu/drm/drm_bridge_helper.c (revision 8c7c767a5efb69f26f62a728eadec3fee4fa372e)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 #include <linux/export.h>
4 
5 #include <drm/drm_atomic.h>
6 #include <drm/drm_atomic_helper.h>
7 #include <drm/drm_bridge.h>
8 #include <drm/drm_bridge_helper.h>
9 #include <drm/drm_modeset_lock.h>
10 
11 /**
12  * drm_bridge_helper_reset_crtc - Reset the pipeline feeding a bridge
13  * @bridge: DRM bridge to reset
14  * @ctx: lock acquisition context
15  *
16  * Reset a @bridge pipeline. It will power-cycle all active components
17  * between the CRTC and connector that bridge is connected to.
18  *
19  * As it relies on drm_atomic_helper_reset_crtc(), the same limitations
20  * apply.
21  *
22  * Returns:
23  *
24  * 0 on success or a negative error code on failure. If the error
25  * returned is EDEADLK, the whole atomic sequence must be restarted.
26  */
27 int drm_bridge_helper_reset_crtc(struct drm_bridge *bridge,
28 				 struct drm_modeset_acquire_ctx *ctx)
29 {
30 	struct drm_connector *connector;
31 	struct drm_encoder *encoder = bridge->encoder;
32 	struct drm_device *dev = encoder->dev;
33 	struct drm_crtc *crtc;
34 	int ret;
35 
36 	ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
37 	if (ret)
38 		return ret;
39 
40 	connector = drm_atomic_get_connector_for_encoder(encoder, ctx);
41 	if (IS_ERR(connector)) {
42 		ret = PTR_ERR(connector);
43 		goto out;
44 	}
45 
46 	if (!connector->state) {
47 		ret = -EINVAL;
48 		goto out;
49 	}
50 
51 	crtc = connector->state->crtc;
52 	ret = drm_atomic_helper_reset_crtc(crtc, ctx);
53 	if (ret)
54 		goto out;
55 
56 out:
57 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
58 	return ret;
59 }
60 EXPORT_SYMBOL(drm_bridge_helper_reset_crtc);
61