2023-07-19 14:17:27

by Johannes Zink

Subject: [PATCH] arm64: dts: imx8mp: use correct clock for eqos timestamping counter

The i.MX8MP Reference Manual rev 1 06/2021, section 11.7.2.5 "Timestamp
Support" indicates the PTP timestamp clock expects a typical frequency
of 125MHz.

As this also improves the precision of the measured timestamps: assign
appropriate 125MHz Clock parent. As no one except the timestamping
counter uses this clock, there are no side-effects of this change in
other peripherals.

Signed-off-by: Johannes Zink <[email protected]>
---
arch/arm64/boot/dts/freescale/imx8mp.dtsi | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
index 6f2f50e1639c..7f80dff914c2 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
@@ -1334,7 +1334,7 @@ eqos: ethernet@30bf0000 {
<&clk IMX8MP_CLK_ENET_QOS_TIMER>,
<&clk IMX8MP_CLK_ENET_QOS>;
assigned-clock-parents = <&clk IMX8MP_SYS_PLL1_266M>,
- <&clk IMX8MP_SYS_PLL2_100M>,
+ <&clk IMX8MP_SYS_PLL2_125M>,
<&clk IMX8MP_SYS_PLL2_125M>;
assigned-clock-rates = <0>, <100000000>, <125000000>;
nvmem-cells = <&eth_mac2>;

---
base-commit: ba345b77fae7054d0cbd033283c47033e45db6d8
change-id: 20230719-imx8mp_enet_qos_use_125mhz_clock-1c4611c979ba

Best regards,
--
Johannes Zink <[email protected]>