Re: [PATCH 0/3] arm64: mx93: etherrnet: set TX_CLK in RMII mode

From: Steffen Trumtrar <s.trumtrar@pengutronix.de>
To: "Sébastien Szymanski" <sebastien.szymanski@armadeus.com>
Cc: "David S. Miller" <davem@davemloft.net>,
	 Eric Dumazet <edumazet@google.com>,
	 Jakub Kicinski <kuba@kernel.org>,
	 Paolo Abeni <pabeni@redhat.com>,  Rob Herring <robh@kernel.org>,
	 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	 Conor Dooley <conor+dt@kernel.org>,
	Shawn Guo <shawnguo@kernel.org>,
	 Sascha Hauer <s.hauer@pengutronix.de>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	 Fabio Estevam <festevam@gmail.com>,
	 Clark Wang <xiaoning.wang@nxp.com>,
	 Linux Team <linux-imx@nxp.com>,
	 Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Jose Abreu <joabreu@synopsys.com>,
	 Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	 netdev@vger.kernel.org, devicetree@vger.kernel.org,
	 imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
	 linux-kernel@vger.kernel.org,
	linux-stm32@st-md-mailman.stormreply.com
Subject: Re: [PATCH 0/3] arm64: mx93: etherrnet: set TX_CLK in RMII mode
Date: Tue, 23 Apr 2024 08:43:58 +0200	[thread overview]
Message-ID: <87mspkk28h.fsf@pengutronix.de> (raw)
In-Reply-To: <f01d49cf-5955-405c-9c2b-05b0c7bb982c@armadeus.com> ("Sébastien Szymanski"'s message of "Mon, 22 Apr 2024 11:28:08 +0200")

Hi,

On 2024-04-22 at 11:28 +02, Sébastien Szymanski <sebastien.szymanski@armadeus.com> wrote: 

> Hello,  On 4/22/24 10:46, Steffen Trumtrar wrote: 
> > This series adds support for setting the TX_CLK direction in the eQOS ethernet core on the i.MX93 when RMII mode is used.  According to AN14149, when the i.MX93 ethernet controller is used in RMII mode, the TX_CLK *must* be set to output mode. 
>  Must ? I don't think that is true. Downstream NXP kernel has an option to set TX_CLK as an input: 
>

re-reading that passage again, it only says "other registers that must be configured" and that the ENET_QOS_CLK_TX_CLK_SEL bit "is 0b1" for RMII. So, maybe you are right. 

Thanks,
Steffen

> https://github.com/nxp-imx/linux-imx/blob/lf-6.6.y/Documentation/devicetree/bindings/net/nxp%2Cdwmac-imx.yaml#L69
> 
> https://github.com/nxp-imx/linux-imx/commit/fbc17f6f7919d03c275fc48b0400c212475b60ec
> 

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