[PATCH v2 30/38] drm/msm/dp: add HPD callback for dp MST

[Yongxing Mou <quic_yongmou@quicinc.com>]

From: Abhinav Kumar <quic_abhinavk@quicinc.com>

Add HPD callback for the MST module which shall be invoked from the
dp_display's HPD handler to perform MST specific operations in case
of HPD. In MST case, route the HPD messages to MST module.

Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
---
 drivers/gpu/drm/msm/dp/dp_display.c | 20 ++++++++++++++------
 drivers/gpu/drm/msm/dp/dp_mst_drm.c | 34 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/msm/dp/dp_mst_drm.h |  2 ++
 3 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 8ac1215d8a635bc5477e79e08264c344ed1b27ac..323d1c0a9efa4fa30ce97317e873607c54409a11 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -599,9 +599,10 @@ static int msm_dp_display_handle_irq_hpd(struct msm_dp_display_private *dp)
 
 static int msm_dp_display_usbpd_attention_cb(struct device *dev)
 {
-	int rc = 0;
-	u32 sink_request;
 	struct msm_dp_display_private *dp = dev_get_dp_display_private(dev);
+	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
+	u32 sink_request;
+	int rc = 0;
 
 	/* check for any test request issued by sink */
 	rc = msm_dp_link_process_request(dp->link);
@@ -609,12 +610,18 @@ static int msm_dp_display_usbpd_attention_cb(struct device *dev)
 		sink_request = dp->link->sink_request;
 		drm_dbg_dp(dp->drm_dev, "hpd_state=%d sink_request=%d\n",
 					dp->hpd_state, sink_request);
-		if (sink_request & DS_PORT_STATUS_CHANGED)
-			rc = msm_dp_display_handle_port_status_changed(dp);
-		else
+		if (sink_request & DS_PORT_STATUS_CHANGED) {
+			if (!msm_dp_display->mst_active)
+				rc = msm_dp_display_handle_port_status_changed(dp);
+		} else {
 			rc = msm_dp_display_handle_irq_hpd(dp);
+		}
 	}
 
+	/* let MST specific IRQ events be handled by its callback */
+	if (msm_dp_display->mst_active)
+		msm_dp_mst_display_hpd_irq(&dp->msm_dp_display);
+
 	return rc;
 }
 
@@ -754,7 +761,8 @@ static int msm_dp_irq_hpd_handle(struct msm_dp_display_private *dp, u32 data)
 	drm_dbg_dp(dp->drm_dev, "Before, type=%d hpd_state=%d\n",
 			dp->msm_dp_display.connector_type, state);
 
-	if (state == ST_MAINLINK_READY || state == ST_DISCONNECT_PENDING) {
+	if ((state == ST_MAINLINK_READY || state == ST_DISCONNECT_PENDING) &&
+	    !dp->msm_dp_display.mst_active) {
 		/* wait until ST_CONNECTED */
 		msm_dp_add_event(dp, EV_IRQ_HPD_INT, 0, 1); /* delay = 1 */
 		mutex_unlock(&dp->event_mutex);
diff --git a/drivers/gpu/drm/msm/dp/dp_mst_drm.c b/drivers/gpu/drm/msm/dp/dp_mst_drm.c
index 489fa46aa518ff1cc5f4769b2153fc5153c4cb41..5f00ec2f83ad09b94fd6b602fc37f91cb55acf71 100644
--- a/drivers/gpu/drm/msm/dp/dp_mst_drm.c
+++ b/drivers/gpu/drm/msm/dp/dp_mst_drm.c
@@ -570,6 +570,40 @@ static struct msm_dp_mst_bridge_state *msm_dp_mst_br_priv_state(struct drm_atomi
 										&bridge->obj));
 }
 
+/* DP MST HPD IRQ callback */
+void msm_dp_mst_display_hpd_irq(struct msm_dp *dp_display)
+{
+	int rc;
+	struct msm_dp_mst *mst = dp_display->msm_dp_mst;
+	u8 ack[8] = {};
+	u8 esi[4];
+	unsigned int esi_res = DP_SINK_COUNT_ESI + 1;
+	bool handled;
+
+	rc = drm_dp_dpcd_read(mst->dp_aux, DP_SINK_COUNT_ESI,
+			      esi, 4);
+	if (rc != 4) {
+		DRM_ERROR("dpcd sink status read failed, rlen=%d\n", rc);
+		return;
+	}
+
+	drm_dbg_dp(dp_display->drm_dev, "mst irq: esi1[0x%x] esi2[0x%x] esi3[%x]\n",
+		   esi[1], esi[2], esi[3]);
+
+	rc = drm_dp_mst_hpd_irq_handle_event(&mst->mst_mgr, esi, ack, &handled);
+
+	/* ack the request */
+	if (handled) {
+		rc = drm_dp_dpcd_writeb(mst->dp_aux, esi_res, ack[1]);
+
+		if (rc != 1)
+			DRM_ERROR("dpcd esi_res failed. rc=%d\n", rc);
+
+		drm_dp_mst_hpd_irq_send_new_request(&mst->mst_mgr);
+	}
+	drm_dbg_dp(dp_display->drm_dev, "mst display hpd_irq handled:%d rc:%d\n", handled, rc);
+}
+
 /* DP MST Connector OPs */
 static int
 msm_dp_mst_connector_detect(struct drm_connector *connector,
diff --git a/drivers/gpu/drm/msm/dp/dp_mst_drm.h b/drivers/gpu/drm/msm/dp/dp_mst_drm.h
index 7b08346e0bb9189009c02745c243722c01d79493..d40cb8483f971b1331172b4e5da2c8f67e55e119 100644
--- a/drivers/gpu/drm/msm/dp/dp_mst_drm.h
+++ b/drivers/gpu/drm/msm/dp/dp_mst_drm.h
@@ -100,4 +100,6 @@ int msm_dp_mst_drm_bridge_init(struct msm_dp *dp, struct drm_encoder *encoder);
 
 int msm_dp_mst_init(struct msm_dp *dp_display, u32 max_streams, struct drm_dp_aux *drm_aux);
 
+void msm_dp_mst_display_hpd_irq(struct msm_dp *dp_display);
+
 #endif /* _DP_MST_DRM_H_ */

-- 
2.34.1