On 5 December 2022 20:44:28 GMT+03:00, Bjorn Andersson <quic_bjorande@xxxxxxxxxxx> wrote:
>From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
>
>The DisplayPort controller's hot-plug mechanism is based on pinmuxing a
>physical signal on a GPIO pin into the controller. This is not always
>possible, either because there aren't dedicated GPIOs available or
>because the hot-plug signal is a virtual notification, in cases such as
>USB Type-C.
>
>For these cases, by implementing the hpd_notify() callback for the
>DisplayPort controller's drm_bridge, a downstream drm_bridge
>(next_bridge) can be used to track and signal the connection status
>changes.
>
>This makes it possible to use downstream drm_bridges such as
>display-connector or any virtual mechanism, as long as they are
>implemented as a drm_bridge.
>
>Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
>[bjorn: Drop connector->fwnode assignment and dev from struct msm_dp]
>Signed-off-by: Bjorn Andersson <quic_bjorande@xxxxxxxxxxx>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Minor nit: if for the next revision you reorder the patches to have hpd_enable first, then missing conditions, then this patch, it will look more logical.
>---
>
>Changes since v3:
>- None
>
> drivers/gpu/drm/msm/dp/dp_display.c | 22 ++++++++++++++++++++++
> drivers/gpu/drm/msm/dp/dp_drm.c | 1 +
> drivers/gpu/drm/msm/dp/dp_drm.h | 2 ++
> 3 files changed, 25 insertions(+)
>
>diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
>index 666b45c8ab80..17fcf8cd84cd 100644
>--- a/drivers/gpu/drm/msm/dp/dp_display.c
>+++ b/drivers/gpu/drm/msm/dp/dp_display.c
>@@ -1772,3 +1772,25 @@ void dp_bridge_mode_set(struct drm_bridge *drm_bridge,
> dp_display->dp_mode.h_active_low =
> !!(dp_display->dp_mode.drm_mode.flags & DRM_MODE_FLAG_NHSYNC);
> }
>+
>+void dp_bridge_hpd_notify(struct drm_bridge *bridge,
>+ enum drm_connector_status status)
>+{
>+ struct msm_dp_bridge *dp_bridge = to_dp_bridge(bridge);
>+ struct msm_dp *dp_display = dp_bridge->dp_display;
>+ struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
>+
>+ /* Without next_bridge interrupts are handled by the DP core directly */
>+ if (!dp_display->next_bridge)
>+ return;
>+
>+ if (!dp->core_initialized) {
>+ drm_dbg_dp(dp->drm_dev, "not initialized\n");
>+ return;
>+ }
>+
>+ if (!dp_display->is_connected && status == connector_status_connected)
>+ dp_add_event(dp, EV_HPD_PLUG_INT, 0, 0);
>+ else if (dp_display->is_connected && status == connector_status_disconnected)
>+ dp_add_event(dp, EV_HPD_UNPLUG_INT, 0, 0);
>+}
>diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
>index 6db82f9b03af..3898366ebd5e 100644
>--- a/drivers/gpu/drm/msm/dp/dp_drm.c
>+++ b/drivers/gpu/drm/msm/dp/dp_drm.c
>@@ -102,6 +102,7 @@ static const struct drm_bridge_funcs dp_bridge_ops = {
> .get_modes = dp_bridge_get_modes,
> .detect = dp_bridge_detect,
> .atomic_check = dp_bridge_atomic_check,
>+ .hpd_notify = dp_bridge_hpd_notify,
> };
>
> struct drm_bridge *dp_bridge_init(struct msm_dp *dp_display, struct drm_device *dev,
>diff --git a/drivers/gpu/drm/msm/dp/dp_drm.h b/drivers/gpu/drm/msm/dp/dp_drm.h
>index 82035dbb0578..79e6b2cf2d25 100644
>--- a/drivers/gpu/drm/msm/dp/dp_drm.h
>+++ b/drivers/gpu/drm/msm/dp/dp_drm.h
>@@ -32,5 +32,7 @@ enum drm_mode_status dp_bridge_mode_valid(struct drm_bridge *bridge,
> void dp_bridge_mode_set(struct drm_bridge *drm_bridge,
> const struct drm_display_mode *mode,
> const struct drm_display_mode *adjusted_mode);
>+void dp_bridge_hpd_notify(struct drm_bridge *bridge,
>+ enum drm_connector_status status);
>
> #endif /* _DP_DRM_H_ */
--
With best wishes
Dmitry
