[v4,10/13] drm/msm/dp: Rely on hpd_enable/disable callbacks

  From: Bjorn Andersson <bjorn.andersson@linaro.org>

The DisplayPort controller's internal HPD interrupt handling is used for
cases where the HPD signal is connected to a GPIO which is pinmuxed into
the DisplayPort controller. In other configurations the HPD notification
might be delivered by the DRM framework from an associated bridge.

This difference is not appropriately represented by the "is_edp"
boolean, but is properly represented by the frameworks invocation of the
hpd_enable() and hpd_disable() callbacks. Switch the current condition
to rely on these callbacks instead.

This ensures appropriate handling of the three cases; no bridge
connected, a bridge without DRM_BRIDGE_OP_HPD and a bridge with
DRM_BRIDGE_OP_HPD.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
---

Worth mentioning, I did look into moving the HPD enablement/disablement
completely into these new callbacks, but that affect the entire power
management model of the driver, so I think it's worth to tackle that in
subsequent changes. It seems also reasonable to expect that we by such
modifications could leave the block unclocked until the external HPD
notification arrives...

Changes since v3:
- Introduced reliance on hpd_enable/disable callbacks instead of next_bridge

 drivers/gpu/drm/msm/dp/dp_display.c | 35 ++++++++++++++++++++---------
 drivers/gpu/drm/msm/dp/dp_display.h |  1 +
 drivers/gpu/drm/msm/dp/dp_drm.c     |  2 ++
 drivers/gpu/drm/msm/dp/dp_drm.h     |  2 ++
 4 files changed, 30 insertions(+), 10 deletions(-)
  

On 5 December 2022 20:44:30 GMT+03:00, Bjorn Andersson <quic_bjorande@quicinc.com> wrote:
>From: Bjorn Andersson <bjorn.andersson@linaro.org>
>
>The DisplayPort controller's internal HPD interrupt handling is used for
>cases where the HPD signal is connected to a GPIO which is pinmuxed into
>the DisplayPort controller. In other configurations the HPD notification
>might be delivered by the DRM framework from an associated bridge.
>
>This difference is not appropriately represented by the "is_edp"
>boolean, but is properly represented by the frameworks invocation of the
>hpd_enable() and hpd_disable() callbacks. Switch the current condition
>to rely on these callbacks instead.
>
>This ensures appropriate handling of the three cases; no bridge
>connected, a bridge without DRM_BRIDGE_OP_HPD and a bridge with
>DRM_BRIDGE_OP_HPD.
>
>Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
>Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
>---
>
>Worth mentioning, I did look into moving the HPD enablement/disablement
>completely into these new callbacks, but that affect the entire power
>management model of the driver, so I think it's worth to tackle that in
>subsequent changes. It seems also reasonable to expect that we by such
>modifications could leave the block unclocked until the external HPD
>notification arrives...

I see... I still suppose this is the way to go in the long term.

For now:

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

>
>Changes since v3:
>- Introduced reliance on hpd_enable/disable callbacks instead of next_bridge
>
> drivers/gpu/drm/msm/dp/dp_display.c | 35 ++++++++++++++++++++---------
> drivers/gpu/drm/msm/dp/dp_display.h |  1 +
> drivers/gpu/drm/msm/dp/dp_drm.c     |  2 ++
> drivers/gpu/drm/msm/dp/dp_drm.h     |  2 ++
> 4 files changed, 30 insertions(+), 10 deletions(-)
>
>diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
>index bb92c33beff8..3e464c33ff11 100644
>--- a/drivers/gpu/drm/msm/dp/dp_display.c
>+++ b/drivers/gpu/drm/msm/dp/dp_display.c
>@@ -610,7 +610,7 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
> 	}
> 
> 	/* enable HDP irq_hpd/replug interrupt */
>-	if (!dp->dp_display.is_edp)
>+	if (dp->dp_display.internal_hpd)
> 		dp_catalog_hpd_config_intr(dp->catalog,
> 					   DP_DP_IRQ_HPD_INT_MASK | DP_DP_HPD_REPLUG_INT_MASK,
> 					   true);
>@@ -653,7 +653,7 @@ static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
> 			dp->dp_display.connector_type, state);
> 
> 	/* disable irq_hpd/replug interrupts */
>-	if (!dp->dp_display.is_edp)
>+	if (dp->dp_display.internal_hpd)
> 		dp_catalog_hpd_config_intr(dp->catalog,
> 					   DP_DP_IRQ_HPD_INT_MASK | DP_DP_HPD_REPLUG_INT_MASK,
> 					   false);
>@@ -682,7 +682,7 @@ static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
> 	}
> 
> 	/* disable HPD plug interrupts */
>-	if (!dp->dp_display.is_edp)
>+	if (dp->dp_display.internal_hpd)
> 		dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_PLUG_INT_MASK, false);
> 
> 	/*
>@@ -701,7 +701,7 @@ static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
> 	dp_display_handle_plugged_change(&dp->dp_display, false);
> 
> 	/* enable HDP plug interrupt to prepare for next plugin */
>-	if (!dp->dp_display.is_edp)
>+	if (dp->dp_display.internal_hpd)
> 		dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_PLUG_INT_MASK, true);
> 
> 	drm_dbg_dp(dp->drm_dev, "After, type=%d hpd_state=%d\n",
>@@ -1086,8 +1086,8 @@ static void dp_display_config_hpd(struct dp_display_private *dp)
> 	dp_display_host_init(dp);
> 	dp_catalog_ctrl_hpd_config(dp->catalog);
> 
>-	/* Enable plug and unplug interrupts only for external DisplayPort */
>-	if (!dp->dp_display.is_edp)
>+	/* Enable plug and unplug interrupts only if requested */
>+	if (dp->dp_display.internal_hpd)
> 		dp_catalog_hpd_config_intr(dp->catalog,
> 				DP_DP_HPD_PLUG_INT_MASK |
> 				DP_DP_HPD_UNPLUG_INT_MASK,
>@@ -1379,8 +1379,7 @@ static int dp_pm_resume(struct device *dev)
> 
> 	dp_catalog_ctrl_hpd_config(dp->catalog);
> 
>-
>-	if (!dp->dp_display.is_edp)
>+	if (dp->dp_display.internal_hpd)
> 		dp_catalog_hpd_config_intr(dp->catalog,
> 				DP_DP_HPD_PLUG_INT_MASK |
> 				DP_DP_HPD_UNPLUG_INT_MASK,
>@@ -1778,6 +1777,22 @@ void dp_bridge_mode_set(struct drm_bridge *drm_bridge,
> 		!!(dp_display->dp_mode.drm_mode.flags & DRM_MODE_FLAG_NHSYNC);
> }
> 
>+void dp_bridge_hpd_enable(struct drm_bridge *bridge)
>+{
>+	struct msm_dp_bridge *dp_bridge = to_dp_bridge(bridge);
>+	struct msm_dp *dp_display = dp_bridge->dp_display;
>+
>+	dp_display->internal_hpd = true;
>+}
>+
>+void dp_bridge_hpd_disable(struct drm_bridge *bridge)
>+{
>+	struct msm_dp_bridge *dp_bridge = to_dp_bridge(bridge);
>+	struct msm_dp *dp_display = dp_bridge->dp_display;
>+
>+	dp_display->internal_hpd = false;
>+}
>+
> void dp_bridge_hpd_notify(struct drm_bridge *bridge,
> 			  enum drm_connector_status status)
> {
>@@ -1785,8 +1800,8 @@ void dp_bridge_hpd_notify(struct drm_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)
>+	/* Plug events are generated by the dp_display_irq_handler() */
>+	if (dp_display->internal_hpd)
> 		return;
> 
> 	if (!dp->core_initialized) {
>diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
>index dcedf021f7fe..371337d0fae2 100644
>--- a/drivers/gpu/drm/msm/dp/dp_display.h
>+++ b/drivers/gpu/drm/msm/dp/dp_display.h
>@@ -21,6 +21,7 @@ struct msm_dp {
> 	bool power_on;
> 	unsigned int connector_type;
> 	bool is_edp;
>+	bool internal_hpd;
> 
> 	hdmi_codec_plugged_cb plugged_cb;
> 
>diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
>index 3898366ebd5e..275370f21115 100644
>--- a/drivers/gpu/drm/msm/dp/dp_drm.c
>+++ b/drivers/gpu/drm/msm/dp/dp_drm.c
>@@ -102,6 +102,8 @@ 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_enable   = dp_bridge_hpd_enable,
>+	.hpd_disable  = dp_bridge_hpd_disable,
> 	.hpd_notify   = dp_bridge_hpd_notify,
> };
> 
>diff --git a/drivers/gpu/drm/msm/dp/dp_drm.h b/drivers/gpu/drm/msm/dp/dp_drm.h
>index 79e6b2cf2d25..250f7c66201f 100644
>--- a/drivers/gpu/drm/msm/dp/dp_drm.h
>+++ b/drivers/gpu/drm/msm/dp/dp_drm.h
>@@ -32,6 +32,8 @@ 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_enable(struct drm_bridge *bridge);
>+void dp_bridge_hpd_disable(struct drm_bridge *bridge);
> void dp_bridge_hpd_notify(struct drm_bridge *bridge,
> 			  enum drm_connector_status status);
>