drm/msm/hdmi: support attaching the "next" bridge

There might be a chain of bridges attached to the HDMI node
(including but not limited to the display-connector bridge). Add support
for attaching them right to the HDMI bridge chain.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/489709/
Link: https://lore.kernel.org/r/20220616085057.432353-1-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.c b/drivers/gpu/drm/msm/hdmi/hdmi.c
index 6acc17e..93fe61b 100644 (file)
--- a/drivers/gpu/drm/msm/hdmi/hdmi.c
+++ b/drivers/gpu/drm/msm/hdmi/hdmi.c
@@ -9,6 +9,7 @@
 #include <linux/of_gpio.h>
 
 #include <drm/drm_bridge_connector.h>
+#include <drm/drm_of.h>
 
 #include <sound/hdmi-codec.h>
 #include "hdmi.h"
@@ -133,6 +134,10 @@ static struct hdmi *msm_hdmi_init(struct platform_device *pdev)
        hdmi->config = config;
        spin_lock_init(&hdmi->reg_lock);
 
+       ret = drm_of_find_panel_or_bridge(pdev->dev.of_node, 1, 0, NULL, &hdmi->next_bridge);
+       if (ret && ret != -ENODEV)
+               goto fail;
+
        hdmi->mmio = msm_ioremap(pdev, config->mmio_name);
        if (IS_ERR(hdmi->mmio)) {
                ret = PTR_ERR(hdmi->mmio);
@@ -308,6 +313,15 @@ int msm_hdmi_modeset_init(struct hdmi *hdmi,
                goto fail;
        }
 
+       if (hdmi->next_bridge) {
+               ret = drm_bridge_attach(hdmi->encoder, hdmi->next_bridge, hdmi->bridge,
+                                       DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+               if (ret) {
+                       DRM_DEV_ERROR(dev->dev, "failed to attach next HDMI bridge: %d\n", ret);
+                       goto fail;
+               }
+       }
+
        hdmi->connector = drm_bridge_connector_init(hdmi->dev, encoder);
        if (IS_ERR(hdmi->connector)) {
                ret = PTR_ERR(hdmi->connector);

diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.h b/drivers/gpu/drm/msm/hdmi/hdmi.h
index a6c88d1..04a7438 100644 (file)
--- a/drivers/gpu/drm/msm/hdmi/hdmi.h
+++ b/drivers/gpu/drm/msm/hdmi/hdmi.h
@@ -62,6 +62,8 @@ struct hdmi {
        struct drm_connector *connector;
        struct drm_bridge *bridge;
 
+       struct drm_bridge *next_bridge;
+
        /* the encoder we are hooked to (outside of hdmi block) */
        struct drm_encoder *encoder;