* [PATCH] arm64: dts: imx8mp: use correct clock for eqos timestamping counter
@ 2023-07-19 13:59 Johannes Zink
2023-07-19 14:03 ` Fabio Estevam
0 siblings, 1 reply; 3+ messages in thread
From: Johannes Zink @ 2023-07-19 13:59 UTC (permalink / raw)
To: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam,
NXP Linux Team
Cc: patchwork-jzi, devicetree, linux-arm-kernel, linux-kernel,
Johannes Zink
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 <j.zink@pengutronix.de>
---
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 = <ð_mac2>;
---
base-commit: ba345b77fae7054d0cbd033283c47033e45db6d8
change-id: 20230719-imx8mp_enet_qos_use_125mhz_clock-1c4611c979ba
Best regards,
--
Johannes Zink <j.zink@pengutronix.de>
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] arm64: dts: imx8mp: use correct clock for eqos timestamping counter
2023-07-19 13:59 [PATCH] arm64: dts: imx8mp: use correct clock for eqos timestamping counter Johannes Zink
@ 2023-07-19 14:03 ` Fabio Estevam
2023-07-19 14:12 ` Johannes Zink
0 siblings, 1 reply; 3+ messages in thread
From: Fabio Estevam @ 2023-07-19 14:03 UTC (permalink / raw)
To: Johannes Zink
Cc: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, NXP Linux Team,
patchwork-jzi, devicetree, linux-arm-kernel, linux-kernel
Hi Johannes,
On Wed, Jul 19, 2023 at 10:59 AM Johannes Zink <j.zink@pengutronix.de> wrote:
>
> 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 <j.zink@pengutronix.de>
> ---
> 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>;
Shouldn't this also be changed to:
assigned-clock-rates = <0>, <125000000>, <125000000>;
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] arm64: dts: imx8mp: use correct clock for eqos timestamping counter
2023-07-19 14:03 ` Fabio Estevam
@ 2023-07-19 14:12 ` Johannes Zink
0 siblings, 0 replies; 3+ messages in thread
From: Johannes Zink @ 2023-07-19 14:12 UTC (permalink / raw)
To: Fabio Estevam
Cc: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, NXP Linux Team,
patchwork-jzi, devicetree, linux-arm-kernel, linux-kernel
Hi Fabio,
On 7/19/23 16:03, Fabio Estevam wrote:
> Hi Johannes,
>
> On Wed, Jul 19, 2023 at 10:59 AM Johannes Zink <j.zink@pengutronix.de> wrote:
>>
>> 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 <j.zink@pengutronix.de>
>> ---
>> 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>;
>
> Shouldn't this also be changed to:
>
> assigned-clock-rates = <0>, <125000000>, <125000000>;
>
good catch, thanks! Gonna fix it in v2.
Best regards
Johannes
--
Pengutronix e.K. | Johannes Zink |
Steuerwalder Str. 21 | https://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686| Fax: +49-5121-206917-5555 |
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2023-07-19 13:59 [PATCH] arm64: dts: imx8mp: use correct clock for eqos timestamping counter Johannes Zink
2023-07-19 14:03 ` Fabio Estevam
2023-07-19 14:12 ` Johannes Zink
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