drm/bridge: ti-sn65dsi86: Use drm_bridge_connector

The ti-sn65dsi86 driver shouldn't hand-roll its own bridge
connector. It should use the normal drm_bridge_connector. Let's switch
to do that, removing all of the custom code.

NOTE: this still _doesn't_ implement DRM_BRIDGE_ATTACH_NO_CONNECTOR
support for ti-sn65dsi86 and that would still be a useful thing to do
in the future. It was attempted in the past [1] but put on the back
burner. However, unless we instantly change ti-sn65dsi86 fully from
not supporting DRM_BRIDGE_ATTACH_NO_CONNECTOR at all to _only_
supporting DRM_BRIDGE_ATTACH_NO_CONNECTOR then we'll still need a bit
of time when we support both. This is a better way to support the old
way where the driver hand rolls things itself.

A new notes about the implementation here:
* When using the drm_bridge_connector the connector should be created
  after all the bridges, so we change the ordering a bit.
* I'm reasonably certain that we don't need to do anything to "free"
  the new drm_bridge_connector. If drm_bridge_connector_init() returns
  success then we know drm_connector_init() was called with the
  `drm_bridge_connector_funcs`. The `drm_bridge_connector_funcs` has a
  .destroy() that does all the cleanup. drm_connector_init() calls
  __drm_mode_object_add() with a drm_connector_free() that will call
  the .destroy().
* I'm also reasonably certain that I don't need to "undo" the
  drm_bridge_attach() if drm_bridge_connector_init() fails. The
  "detach" function is private and other similar code doesn't try to
  undo the drm_bridge_attach() in error cases. There's also a comment
  indicating the lack of balance at the top of drm_bridge_attach().

[1] https://lore.kernel.org/r/20210920225801.227211-4-robdclark@gmail.com

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204161245.v2.1.I3ab26b7f197cc56c874246a43e57913e9c2c1028@changeid

diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index ba136a1..38616aa 100644 (file)
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -26,6 +26,7 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
+#include <drm/drm_bridge_connector.h>
 #include <drm/dp/drm_dp_aux_bus.h>
 #include <drm/dp/drm_dp_helper.h>
 #include <drm/drm_mipi_dsi.h>
@@ -174,7 +175,7 @@ struct ti_sn65dsi86 {
        struct regmap                   *regmap;
        struct drm_dp_aux               aux;
        struct drm_bridge               bridge;
-       struct drm_connector            connector;
+       struct drm_connector            *connector;
        struct device_node              *host_node;
        struct mipi_dsi_device          *dsi;
        struct clk                      *refclk;
@@ -646,54 +647,6 @@ static struct auxiliary_driver ti_sn_aux_driver = {
        .id_table = ti_sn_aux_id_table,
 };
 
-/* -----------------------------------------------------------------------------
- * DRM Connector Operations
- */
-
-static struct ti_sn65dsi86 *
-connector_to_ti_sn65dsi86(struct drm_connector *connector)
-{
-       return container_of(connector, struct ti_sn65dsi86, connector);
-}
-
-static int ti_sn_bridge_connector_get_modes(struct drm_connector *connector)
-{
-       struct ti_sn65dsi86 *pdata = connector_to_ti_sn65dsi86(connector);
-
-       return drm_bridge_get_modes(pdata->next_bridge, connector);
-}
-
-static struct drm_connector_helper_funcs ti_sn_bridge_connector_helper_funcs = {
-       .get_modes = ti_sn_bridge_connector_get_modes,
-};
-
-static const struct drm_connector_funcs ti_sn_bridge_connector_funcs = {
-       .fill_modes = drm_helper_probe_single_connector_modes,
-       .destroy = drm_connector_cleanup,
-       .reset = drm_atomic_helper_connector_reset,
-       .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
-       .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
-};
-
-static int ti_sn_bridge_connector_init(struct ti_sn65dsi86 *pdata)
-{
-       int ret;
-
-       ret = drm_connector_init(pdata->bridge.dev, &pdata->connector,
-                                &ti_sn_bridge_connector_funcs,
-                                DRM_MODE_CONNECTOR_eDP);
-       if (ret) {
-               DRM_ERROR("Failed to initialize connector with drm\n");
-               return ret;
-       }
-
-       drm_connector_helper_add(&pdata->connector,
-                                &ti_sn_bridge_connector_helper_funcs);
-       drm_connector_attach_encoder(&pdata->connector, pdata->bridge.encoder);
-
-       return 0;
-}
-
 /*------------------------------------------------------------------------------
  * DRM Bridge
  */
@@ -757,10 +710,6 @@ static int ti_sn_bridge_attach(struct drm_bridge *bridge,
                return ret;
        }
 
-       ret = ti_sn_bridge_connector_init(pdata);
-       if (ret < 0)
-               goto err_conn_init;
-
        /* We never want the next bridge to *also* create a connector: */
        flags |= DRM_BRIDGE_ATTACH_NO_CONNECTOR;
 
@@ -768,13 +717,20 @@ static int ti_sn_bridge_attach(struct drm_bridge *bridge,
        ret = drm_bridge_attach(bridge->encoder, pdata->next_bridge,
                                &pdata->bridge, flags);
        if (ret < 0)
-               goto err_dsi_host;
+               goto err_initted_aux;
+
+       pdata->connector = drm_bridge_connector_init(pdata->bridge.dev,
+                                                    pdata->bridge.encoder);
+       if (IS_ERR(pdata->connector)) {
+               ret = PTR_ERR(pdata->connector);
+               goto err_initted_aux;
+       }
+
+       drm_connector_attach_encoder(pdata->connector, pdata->bridge.encoder);
 
        return 0;
 
-err_dsi_host:
-       drm_connector_cleanup(&pdata->connector);
-err_conn_init:
+err_initted_aux:
        drm_dp_aux_unregister(&pdata->aux);
        return ret;
 }
@@ -824,7 +780,7 @@ static void ti_sn_bridge_set_dsi_rate(struct ti_sn65dsi86 *pdata)
 
 static unsigned int ti_sn_bridge_get_bpp(struct ti_sn65dsi86 *pdata)
 {
-       if (pdata->connector.display_info.bpc <= 6)
+       if (pdata->connector->display_info.bpc <= 6)
                return 18;
        else
                return 24;