drm/atomic-helper: Introduce drm_atomic_helper_reset_crtc()

drm_atomic_helper_reset_crtc() allows to reset the CRTC active outputs.

This resets all active components available between the CRTC and
connectors.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250210132620.42263-3-herve.codina@bootlin.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>

1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 26bf2465cee7..d6a206fc9ddd 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -3401,6 +3401,47 @@ free:
 EXPORT_SYMBOL(drm_atomic_helper_disable_all);
 
 /**
+ * drm_atomic_helper_reset_crtc - reset the active outputs of a CRTC
+ * @crtc: DRM CRTC
+ * @ctx: lock acquisition context
+ *
+ * Reset the active outputs by indicating that connectors have changed.
+ * This implies a reset of all active components available between the CRTC and
+ * connectors.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_atomic_helper_reset_crtc(struct drm_crtc *crtc,
+				 struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_atomic_state *state;
+	struct drm_crtc_state *crtc_state;
+	int ret;
+
+	state = drm_atomic_state_alloc(crtc->dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = ctx;
+
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state)) {
+		ret = PTR_ERR(crtc_state);
+		goto out;
+	}
+
+	crtc_state->connectors_changed = true;
+
+	ret = drm_atomic_commit(state);
+out:
+	drm_atomic_state_put(state);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_reset_crtc);
+
+/**
  * drm_atomic_helper_shutdown - shutdown all CRTC
  * @dev: DRM device
  *