[PATCH v3 3/3] drm: simple_kms_helper: add support for bridges

[Andrea Merello]

Introduce drm_simple_display_pipe_attach_bridge() and
drm_simple_display_pipe_detach_bridge() in order to make it possible to use
drm encoders with the simple display pipes managed by simple_kms_helpers

Suggested-by: Daniel Vetter <daniel at ffwll.ch>
Signed-off-by: Andrea Merello <andrea.merello at gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Noralf Trønnes <noralf at tronnes.org>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: David Airlie <airlied at linux.ie>
---
 drivers/gpu/drm/drm_simple_kms_helper.c | 40 +++++++++++++++++++++++++++++++++
 include/drm/drm_simple_kms_helper.h     |  5 +++++
 2 files changed, 45 insertions(+)

diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c
index 3301e4a..8e9858b 100644
--- a/drivers/gpu/drm/drm_simple_kms_helper.c
+++ b/drivers/gpu/drm/drm_simple_kms_helper.c
@@ -140,6 +140,46 @@ static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 };
 
 /**
+ * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
+ * @pipe: simple display pipe object
+ * @bridge: bridge to attach
+ *
+ * Makes it possible to still use the drm_simple_display_pipe helpers when
+ * a DRM bridge has to be used.
+ *
+ * Note that you probably want to initialize the pipe by passing a NULL
+ * connector to drm_simple_display_pipe_init().
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
+					struct drm_bridge *bridge)
+{
+	bridge->encoder = &pipe->encoder;
+	pipe->encoder.bridge = bridge;
+	return drm_bridge_attach(pipe->encoder.dev, bridge);
+}
+EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
+
+/**
+ * drm_simple_display_pipe_detach_bridge - Detach the bridge from the display pipe
+ * @pipe: simple display pipe object
+ *
+ * Detaches the drm bridge previously attached with
+ * drm_simple_display_pipe_attach_bridge()
+ */
+void drm_simple_display_pipe_detach_bridge(struct drm_simple_display_pipe *pipe)
+{
+	if (WARN_ON(!pipe->encoder.bridge))
+		return;
+
+	drm_bridge_detach(pipe->encoder.bridge);
+	pipe->encoder.bridge = NULL;
+}
+EXPORT_SYMBOL(drm_simple_display_pipe_detach_bridge);
+
+/**
  * drm_simple_display_pipe_init - Initialize a simple display pipeline
  * @dev: DRM device
  * @pipe: simple display pipe object to initialize
diff --git a/include/drm/drm_simple_kms_helper.h b/include/drm/drm_simple_kms_helper.h
index 2690397..5245d1f 100644
--- a/include/drm/drm_simple_kms_helper.h
+++ b/include/drm/drm_simple_kms_helper.h
@@ -85,6 +85,11 @@ struct drm_simple_display_pipe {
 	const struct drm_simple_display_pipe_funcs *funcs;
 };
 
+int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
+					struct drm_bridge *bridge);
+
+void drm_simple_display_pipe_detach_bridge(struct drm_simple_display_pipe *pipe);
+
 int drm_simple_display_pipe_init(struct drm_device *dev,
 			struct drm_simple_display_pipe *pipe,
 			const struct drm_simple_display_pipe_funcs *funcs,
-- 
2.7.4