[PATCH 03/13] arm64: dts: ti: k3-am642-sk: fix USB clocking for compliance

[Siddharth Vadapalli]

From: Luis Parga <luis.parga at ti.com>

According to section "6.5.3 Normative Spread Spectrum Clocking (SSC)" of
the USB 3.2 Specification, SSC should be enabled by default. This protects
against EMI violations. Hence, enable internal SSC for USB SuperSpeed.

Fixes: 4e8aa4e3559a ("arm64: dts: ti: k3-am642-sk: Enable USB Super-Speed HOST port")
Cc: <stable at vger.kernel.org>
Signed-off-by: Luis Parga <luis.parga at ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli at ti.com>
---
 arch/arm64/boot/dts/ti/k3-am642-sk.dts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/boot/dts/ti/k3-am642-sk.dts b/arch/arm64/boot/dts/ti/k3-am642-sk.dts
index d28a38c87f32..9f63fea5e6a4 100644
--- a/arch/arm64/boot/dts/ti/k3-am642-sk.dts
+++ b/arch/arm64/boot/dts/ti/k3-am642-sk.dts
@@ -463,6 +463,11 @@ &serdes_refclk {
 
 &serdes_wiz0 {
 	bootph-all;
+	ti,core-clk-sel = <1>;  /* Select internal reference clock */
+	ti,ssc-enable; /* Enable SSC */
+	ti,ssc-type = <1>; /* 1 for Downspread */
+	ti,ssc-frequency-hz = <33000>; /* 33 KHz */
+	ti,ssc-depth-per-mil = <5>; /* 0.5% depth */
 };
 
 &serdes0 {
@@ -473,6 +478,7 @@ serdes0_usb_link: phy at 0 {
 		cdns,num-lanes = <1>;
 		#phy-cells = <0>;
 		cdns,phy-type = <PHY_TYPE_USB3>;
+		cdns,ssc-mode = <2>; /* 2 for internal SSC */
 		resets = <&serdes_wiz0 1>;
 	};
 };
-- 
2.51.1