[PATCH RFC 01/13] drm/connector: Introduce an HDMI connector

[Maxime Ripard]

A lot of the various HDMI drivers duplicate some logic that depends on
the HDMI spec itself and not really a particular hardware
implementation.

Output BPC or format selection, infoframe generation are good examples
of such areas.

This creates a lot of boilerplate, with a lot of variations, which makes
it hard for userspace to rely on, and makes it difficult to get it right
for drivers.

Let's create a new connector variant specifically dedicated to HDMI
controllers that will allow to abstract away the duplicated logic.

Hopefully, this will make drivers simpler to handle, and their behaviour
more consistent.

Signed-off-by: Maxime Ripard <mripard@xxxxxxxxxx>
---
 drivers/gpu/drm/Makefile             |  1 +
 drivers/gpu/drm/drm_hdmi_connector.c | 45 ++++++++++++++++++++++++++++++++++++
 include/drm/drm_connector.h          | 16 +++++++++++++
 3 files changed, 62 insertions(+)

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 7a09a89b493b..1520d4ccd3d7 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -27,6 +27,7 @@ drm-y := \
 	drm_fourcc.o \
 	drm_framebuffer.o \
 	drm_gem.o \
+	drm_hdmi_connector.o \
 	drm_ioctl.o \
 	drm_lease.o \
 	drm_managed.o \
diff --git a/drivers/gpu/drm/drm_hdmi_connector.c b/drivers/gpu/drm/drm_hdmi_connector.c
new file mode 100644
index 000000000000..62f01dd2e6df
--- /dev/null
+++ b/drivers/gpu/drm/drm_hdmi_connector.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <drm/drm_connector.h>
+#include <drm/drm_mode.h>
+
+#include <linux/export.h>
+
+/**
+ * drmm_hdmi_connector_init - Init a preallocated HDMI connector
+ * @dev: DRM device
+ * @hdmi_connector: A pointer to the HDMI connector to init
+ * @connector_type: user visible type of the connector
+ * @ddc: optional pointer to the associated ddc adapter
+ *
+ * Initialises a preallocated HDMI connector. Connectors can be
+ * subclassed as part of driver connector objects.
+ *
+ * Cleanup is automatically handled with a call to
+ * drm_connector_cleanup() in a DRM-managed action.
+ *
+ * The connector structure should be allocated with drmm_kzalloc().
+ *
+ * Returns:
+ * Zero on success, error code on failure.
+ */
+int drmm_hdmi_connector_init(struct drm_device *dev,
+			     struct drm_hdmi_connector *hdmi_connector,
+			     const struct drm_connector_funcs *funcs,
+			     int connector_type,
+			     struct i2c_adapter *ddc)
+{
+	struct drm_connector *connector = &hdmi_connector->base;
+	int ret;
+
+	if (connector_type != DRM_MODE_CONNECTOR_HDMIA ||
+	    connector_type != DRM_MODE_CONNECTOR_HDMIB)
+		return -EINVAL;
+
+	ret = drmm_connector_init(dev, connector, funcs, connector_type, ddc);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+EXPORT_SYMBOL(drmm_hdmi_connector_init);
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index d300fde6c1a4..1859b74083f5 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -2042,6 +2042,22 @@ void drm_connector_attach_privacy_screen_provider(
 	struct drm_connector *connector, struct drm_privacy_screen *priv);
 void drm_connector_update_privacy_screen(const struct drm_connector_state *connector_state);
 
+struct drm_hdmi_connector {
+	/**
+	 * @base: Base Connector
+	 */
+	struct drm_connector base;
+};
+
+#define connector_to_hdmi_connector(connector) \
+	container_of_const(connector, struct drm_hdmi_connector, base)
+
+int drmm_hdmi_connector_init(struct drm_device *dev,
+			     struct drm_hdmi_connector *hdmi_connector,
+			     const struct drm_connector_funcs *funcs,
+			     int connector_type,
+			     struct i2c_adapter *ddc);
+
 /**
  * struct drm_tile_group - Tile group metadata
  * @refcount: reference count

-- 
2.41.0