[PATCH v3 2/3] drm/vc4: Move reset_pipe() to an atomic helper

[Herve Codina <herve.codina@bootlin.com>]

reset_pipe() allows to reset the CRTC active outputs.

In order to use it from other drivers without code duplication, move it
to an atomic helper without any functional changes.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 drivers/gpu/drm/drm_atomic_helper.c | 41 +++++++++++++++++++++++++++++
 drivers/gpu/drm/vc4/vc4_hdmi.c      | 30 +--------------------
 include/drm/drm_atomic_helper.h     |  2 ++
 3 files changed, 44 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 8ed186ddaeaf..4225b814ea35 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -3363,6 +3363,47 @@ int drm_atomic_helper_disable_all(struct drm_device *dev,
 }
 EXPORT_SYMBOL(drm_atomic_helper_disable_all);
 
+/**
+ * drm_atomic_helper_reset_pipe - 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_pipe(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_pipe);
+
 /**
  * drm_atomic_helper_shutdown - shutdown all CRTC
  * @dev: DRM device
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index e3818c48c9b8..19f6592a8cc5 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -269,34 +269,6 @@ static void vc4_hdmi_cec_update_clk_div(struct vc4_hdmi *vc4_hdmi)
 static void vc4_hdmi_cec_update_clk_div(struct vc4_hdmi *vc4_hdmi) {}
 #endif
 
-static int reset_pipe(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;
-}
-
 static int vc4_hdmi_reset_link(struct drm_connector *connector,
 			       struct drm_modeset_acquire_ctx *ctx)
 {
@@ -375,7 +347,7 @@ static int vc4_hdmi_reset_link(struct drm_connector *connector,
 	 * would be perfectly happy if were to just reconfigure
 	 * the SCDC settings on the fly.
 	 */
-	return reset_pipe(crtc, ctx);
+	return drm_atomic_helper_reset_pipe(crtc, ctx);
 }
 
 static void vc4_hdmi_handle_hotplug(struct vc4_hdmi *vc4_hdmi,
diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
index 9aa0a05aa072..56eb6881cfb2 100644
--- a/include/drm/drm_atomic_helper.h
+++ b/include/drm/drm_atomic_helper.h
@@ -139,6 +139,8 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set,
 
 int drm_atomic_helper_disable_all(struct drm_device *dev,
 				  struct drm_modeset_acquire_ctx *ctx);
+int drm_atomic_helper_reset_pipe(struct drm_crtc *crtc,
+				 struct drm_modeset_acquire_ctx *ctx);
 void drm_atomic_helper_shutdown(struct drm_device *dev);
 struct drm_atomic_state *
 drm_atomic_helper_duplicate_state(struct drm_device *dev,
-- 
2.47.1