[PATCH v3 2/3] drm: introduce drm_writeback_connector_init_with_encoder API

[Abhinav Kumar]

For vendors drivers which pass an already allocated and
initialized encoder especially for cases where the encoder
hardware is shared OR the writeback encoder shares the resources
with the rest of the display pipeline introduce a new API,
drm_writeback_connector_init_with_encoder() which expects
an initialized encoder as a parameter and only sets up the
writeback connector.

Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
---
 drivers/gpu/drm/drm_writeback.c | 42 +++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_writeback.h     |  5 +++++
 2 files changed, 47 insertions(+)

diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
index 17c1471..373b7e9 100644
--- a/drivers/gpu/drm/drm_writeback.c
+++ b/drivers/gpu/drm/drm_writeback.c
@@ -265,6 +265,48 @@ int drm_writeback_connector_init(struct drm_device *dev,
 }
 EXPORT_SYMBOL(drm_writeback_connector_init);
 
+/**
+ * drm_writeback_connector_init_with_encoder - Initialize a writeback connector and its properties
+ * using the encoder which already assigned and initialized
+ *
+ * @dev: DRM device
+ * @wb_connector: Writeback connector to initialize
+ * @con_funcs: Connector funcs vtable
+ * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder
+ * @formats: Array of supported pixel formats for the writeback engine
+ * @n_formats: Length of the formats array
+ *
+ * This function creates the writeback-connector-specific properties if they
+ * have not been already created, initializes the connector as
+ * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property
+ * values.
+ *
+ * This function assumes that the drm_writebac_connector's encoder has already been
+ * created and initialized before invoking this function.
+ *
+ * In addition, this function also assumes that callers of this API will manage
+ * assigning the encoder helper functions, possible_crtcs and any other encoder
+ * specific operation which is otherwise handled by drm_writeback_connector_init().
+ *
+ * Drivers should always use this function instead of drm_connector_init() to
+ * set up writeback connectors.
+ *
+ * Returns: 0 on success, or a negative error code
+ */
+int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
+		struct drm_writeback_connector *wb_connector,
+		const struct drm_connector_funcs *con_funcs, const u32 *formats,
+		int n_formats)
+{
+	int ret = 0;
+
+	ret = drm_writeback_connector_setup(dev, wb_connector, con_funcs, formats,
+			n_formats);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_writeback_connector_init_with_encoder);
+
 int drm_writeback_set_fb(struct drm_connector_state *conn_state,
 			 struct drm_framebuffer *fb)
 {
diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h
index 5e002bc..5e752c8 100644
--- a/include/drm/drm_writeback.h
+++ b/include/drm/drm_writeback.h
@@ -168,6 +168,11 @@ int drm_writeback_connector_init(struct drm_device *dev,
 				 const struct drm_encoder_helper_funcs *enc_helper_funcs,
 				 const u32 *formats, int n_formats, uint32_t possible_crtcs);
 
+int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
+		struct drm_writeback_connector *wb_connector,
+		const struct drm_connector_funcs *con_funcs, const u32 *formats,
+		int n_formats);
+
 int drm_writeback_set_fb(struct drm_connector_state *conn_state,
 			 struct drm_framebuffer *fb);
 
-- 
2.7.4