linux-kernel - [PATCH v5 7/9] drm/msm/dp: Support only IRQ

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Message-ID: <1647452154-16361-8-git-send-email-quic_sbillaka@quicinc.com>
Date:   Wed, 16 Mar 2022 23:05:52 +0530
From:   Sankeerth Billakanti <quic_sbillaka@...cinc.com>
To:     <dri-devel@...ts.freedesktop.org>, <linux-arm-msm@...r.kernel.org>,
        <freedreno@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>,
        <devicetree@...r.kernel.org>
CC:     Sankeerth Billakanti <quic_sbillaka@...cinc.com>,
        <robdclark@...il.com>, <seanpaul@...omium.org>,
        <swboyd@...omium.org>, <quic_kalyant@...cinc.com>,
        <quic_abhinavk@...cinc.com>, <dianders@...omium.org>,
        <quic_khsieh@...cinc.com>, <agross@...nel.org>,
        <bjorn.andersson@...aro.org>, <robh+dt@...nel.org>,
        <krzk+dt@...nel.org>, <sean@...rly.run>, <airlied@...ux.ie>,
        <daniel@...ll.ch>, <thierry.reding@...il.com>, <sam@...nborg.org>,
        <dmitry.baryshkov@...aro.org>, <quic_vproddut@...cinc.com>
Subject: [PATCH v5 7/9] drm/msm/dp: Support only IRQ_HPD and REPLUG interrupts for eDP

	The panel-edp enables the eDP panel power during probe, get_modes
and enable. The eDP connect and disconnect interrupts for the eDP/DP
controller are directly dependent on panel power. As eDP display can be
assumed as always connected, the controller driver can skip the eDP
connect and disconnect interrupts. Any disruption in the link status
will be indicated via the IRQ_HPD interrupts.

	So, the eDP controller driver can just enable the IRQ_HPD and
replug interrupts. The DP controller driver still needs to enable all
the interrupts.

	The interrupt register will still reflect the connect and
disconnect interrupt status without generating an actual HW interrupt.
The controller driver should not handle those masked interrupts.

Signed-off-by: Sankeerth Billakanti <quic_sbillaka@...cinc.com>
---
 drivers/gpu/drm/msm/dp/dp_catalog.c |  9 +++------
 drivers/gpu/drm/msm/dp/dp_display.c | 24 ++++++++++++++++++++++--
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
index 2c3b0f7..f15316b 100644
--- a/drivers/gpu/drm/msm/dp/dp_catalog.c
+++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
@@ -592,10 +592,6 @@ void dp_catalog_ctrl_hpd_config(struct dp_catalog *dp_catalog)
 
 	u32 reftimer = dp_read_aux(catalog, REG_DP_DP_HPD_REFTIMER);
 
-	/* enable HPD plug and unplug interrupts */
-	dp_catalog_hpd_config_intr(dp_catalog,
-		DP_DP_HPD_PLUG_INT_MASK | DP_DP_HPD_UNPLUG_INT_MASK, true);
-
 	/* Configure REFTIMER and enable it */
 	reftimer |= DP_DP_HPD_REFTIMER_ENABLE;
 	dp_write_aux(catalog, REG_DP_DP_HPD_REFTIMER, reftimer);
@@ -622,13 +618,14 @@ u32 dp_catalog_hpd_get_intr_status(struct dp_catalog *dp_catalog)
 {
 	struct dp_catalog_private *catalog = container_of(dp_catalog,
 				struct dp_catalog_private, dp_catalog);
-	int isr = 0;
+	int isr, mask;
 
 	isr = dp_read_aux(catalog, REG_DP_DP_HPD_INT_STATUS);
 	dp_write_aux(catalog, REG_DP_DP_HPD_INT_ACK,
 				 (isr & DP_DP_HPD_INT_MASK));
+	mask = dp_read_aux(catalog, REG_DP_DP_HPD_INT_MASK);
 
-	return isr;
+	return isr & (DP_DP_HPD_STATE_STATUS_MASK | mask);
 }
 
 int dp_catalog_ctrl_get_interrupt(struct dp_catalog *dp_catalog)
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 688bbed..5775db8 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -687,7 +687,8 @@ 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 */
-	dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_PLUG_INT_MASK, true);
+	if (dp->dp_display.connector_type == DRM_MODE_CONNECTOR_DisplayPort)
+		dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_PLUG_INT_MASK, true);
 
 	DRM_DEBUG_DP("After, type=%d hpd_state=%d\n",
 			dp->dp_display.connector_type, state);
@@ -1096,10 +1097,17 @@ void msm_dp_snapshot(struct msm_disp_state *disp_state, struct msm_dp *dp)
 
 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.connector_type == DRM_MODE_CONNECTOR_DisplayPort)
+		dp_catalog_hpd_config_intr(dp->catalog,
+				DP_DP_HPD_PLUG_INT_MASK |
+				DP_DP_HPD_UNPLUG_INT_MASK,
+				true);
+
 	/* Enable interrupt first time
 	 * we are leaving dp clocks on during disconnect
 	 * and never disable interrupt
@@ -1383,6 +1391,12 @@ static int dp_pm_resume(struct device *dev)
 	dp_catalog_ctrl_hpd_config(dp->catalog);
 
 
+	if (dp->dp_display.connector_type == DRM_MODE_CONNECTOR_DisplayPort)
+		dp_catalog_hpd_config_intr(dp->catalog,
+				DP_DP_HPD_PLUG_INT_MASK |
+				DP_DP_HPD_UNPLUG_INT_MASK,
+				true);
+
 	if (dp_catalog_link_is_connected(dp->catalog)) {
 		/*
 		 * set sink to normal operation mode -- D0
@@ -1647,6 +1661,9 @@ void dp_bridge_enable(struct drm_bridge *drm_bridge)
 		return;
 	}
 
+	if (dp->connector_type == DRM_MODE_CONNECTOR_eDP)
+		dp_hpd_plug_handle(dp_display, 0);
+
 	mutex_lock(&dp_display->event_mutex);
 
 	/* stop sentinel checking */
@@ -1711,6 +1728,9 @@ void dp_bridge_post_disable(struct drm_bridge *drm_bridge)
 
 	dp_display = container_of(dp, struct dp_display_private, dp_display);
 
+	if (dp->connector_type == DRM_MODE_CONNECTOR_eDP)
+		dp_hpd_unplug_handle(dp_display, 0);
+
 	mutex_lock(&dp_display->event_mutex);
 
 	/* stop sentinel checking */
-- 
2.7.4