msm: mdss: dp: parse all sink/link status fields on HPD IRQ

Parse all the sink/link status fields on HPD IRQ. These
fields contain update sink/link status and are needed in
order to determine whether link re-training will be
required. Furthermore, this action is mandatory as per
CTS compliance specification 1.2a.

CRs-Fixed: 1076516
Change-Id: I8c8fef768fa22c1a52f42596e3707e9b0e2c8e4d
Signed-off-by: Tatenda Chipeperekwa <tatendac@codeaurora.org>

3 files changed, 50 insertions, 12 deletions

diff --git a/drivers/video/fbdev/msm/mdss_dp.c b/drivers/video/fbdev/msm/mdss_dp.c
index bbd4642b34da..dbf6f16d735f 100644
--- a/drivers/video/fbdev/msm/mdss_dp.c
+++ b/drivers/video/fbdev/msm/mdss_dp.c
@@ -2297,11 +2297,11 @@ static void mdss_dp_process_hpd_irq_high(struct mdss_dp_drv_pdata *dp)
 
 	dp->hpd_irq_on = true;
 
-	mdss_dp_aux_parse_test_request(dp);
-
-	mdss_dp_send_test_response(dp);
+	mdss_dp_aux_parse_sink_status_field(dp);
 
 	if (mdss_dp_is_link_training_requested(dp)) {
+		mdss_dp_send_test_response(dp);
+
 		pr_info("%s requested: link rate = 0x%x, lane count = 0x%x\n",
 				mdss_dp_get_test_name(TEST_LINK_TRAINING),
 				dp->test_data.test_link_rate,
diff --git a/drivers/video/fbdev/msm/mdss_dp.h b/drivers/video/fbdev/msm/mdss_dp.h
index a4e8902d0bf3..f6af1f011f7b 100644
--- a/drivers/video/fbdev/msm/mdss_dp.h
+++ b/drivers/video/fbdev/msm/mdss_dp.h
@@ -261,6 +261,11 @@ struct dpcd_test_request {
 	u32 response;
 };
 
+struct dpcd_sink_count {
+	u32 count;
+	bool cp_ready;
+};
+
 struct display_timing_desc {
 	u32 pclk;
 	u32 h_addressable; /* addressable + boder = active */
@@ -463,6 +468,7 @@ struct mdss_dp_drv_pdata {
 	void *hdcp_data;
 	struct hdcp_ops *hdcp_ops;
 	struct dpcd_test_request test_data;
+	struct dpcd_sink_count sink_count;
 };
 
 enum dp_lane_count {
@@ -549,7 +555,7 @@ void mdss_dp_phy_initialize(struct mdss_dp_drv_pdata *dp);
 
 void mdss_dp_dpcd_cap_read(struct mdss_dp_drv_pdata *dp);
 int mdss_dp_dpcd_status_read(struct mdss_dp_drv_pdata *dp);
-void mdss_dp_aux_parse_test_request(struct mdss_dp_drv_pdata *dp);
+void mdss_dp_aux_parse_sink_status_field(struct mdss_dp_drv_pdata *dp);
 int mdss_dp_edid_read(struct mdss_dp_drv_pdata *dp);
 int mdss_dp_link_train(struct mdss_dp_drv_pdata *dp);
 void dp_aux_i2c_handler(struct mdss_dp_drv_pdata *dp, u32 isr);
diff --git a/drivers/video/fbdev/msm/mdss_dp_aux.c b/drivers/video/fbdev/msm/mdss_dp_aux.c
index 0ccd727dc5e8..a1668ea0d3f8 100644
--- a/drivers/video/fbdev/msm/mdss_dp_aux.c
+++ b/drivers/video/fbdev/msm/mdss_dp_aux.c
@@ -953,10 +953,10 @@ static int dp_link_status_read(struct mdss_dp_drv_pdata *ep, int len)
 }
 
 /**
- * dp_sink_send_test_response() - sends a test response to the sink
+ * mdss_dp_aux_send_test_response() - sends a test response to the sink
  * @dp: Display Port Driver data
  */
-static void dp_sink_send_test_response(struct mdss_dp_drv_pdata *dp)
+void mdss_dp_aux_send_test_response(struct mdss_dp_drv_pdata *dp)
 {
 	char test_response[4];
 
@@ -1059,6 +1059,41 @@ exit:
 }
 
 /**
+ * dp_sink_parse_sink_count() - parses the sink count
+ * @ep: Display Port Driver data
+ *
+ * Parses the DPCD to check if there is an update to the sink count
+ * (Byte 0x200), and whether all the sink devices connected have Content
+ * Protection enabled.
+ */
+static void dp_sink_parse_sink_count(struct mdss_dp_drv_pdata *ep)
+{
+	char *bp;
+	char data;
+	struct edp_buf *rp;
+	int rlen;
+	int const param_len = 0x1;
+	int const sink_count_addr = 0x200;
+
+	rlen = dp_aux_read_buf(ep, sink_count_addr, param_len, 0);
+	if (rlen < param_len) {
+		pr_err("failed to read sink count\n");
+		return;
+	}
+	rp = &ep->rxp;
+	bp = rp->data;
+	data = *bp++;
+
+	/* BIT 7, BIT 5:0 */
+	ep->sink_count.count = (data & BIT(7)) << 6 | (data & 0x63);
+	/* BIT 6*/
+	ep->sink_count.cp_ready = data & BIT(6);
+
+	pr_debug("sink_count = 0x%x, cp_ready = 0x%x\n",
+			ep->sink_count.count, ep->sink_count.cp_ready);
+}
+
+/**
  * dp_is_test_supported() - checks if test requested by sink is supported
  * @test_requested: test requested by the sink
  *
@@ -1611,14 +1646,11 @@ void mdss_dp_dpcd_cap_read(struct mdss_dp_drv_pdata *ep)
 	dp_sink_capability_read(ep, 16);
 }
 
-void mdss_dp_aux_parse_test_request(struct mdss_dp_drv_pdata *ep)
+void mdss_dp_aux_parse_sink_status_field(struct mdss_dp_drv_pdata *ep)
 {
+	dp_sink_parse_sink_count(ep);
 	dp_sink_parse_test_request(ep);
-}
-
-void mdss_dp_aux_send_test_response(struct mdss_dp_drv_pdata *ep)
-{
-	dp_sink_send_test_response(ep);
+	dp_link_status_read(ep, 6);
 }
 
 int mdss_dp_dpcd_status_read(struct mdss_dp_drv_pdata *ep)