[PATCH v5 1/1] dt-bindings: net: dwmac: Document STM32 property st,ext-phyclk
Krzysztof Kozlowski
krzysztof.kozlowski at linaro.org
Sat Mar 30 11:40:20 PDT 2024
On 28/03/2024 15:08, Christophe Roullier wrote:
> The Linux kernel dwmac-stm32 driver currently supports three DT
> properties used to configure whether PHY clock are generated by
> the MAC or supplied to the MAC from the PHY.
>
> Originally there were two properties, st,eth-clk-sel and
> st,eth-ref-clk-sel, each used to configure MAC clocking in
> different bus mode and for different MAC clock frequency.
> Since it is possible to determine the MAC 'eth-ck' clock
> frequency from the clock subsystem and PHY bus mode from
> the 'phy-mode' property, two disparate DT properties are
> no longer required to configure MAC clocking.
>
> Linux kernel commit 1bb694e20839 ("net: ethernet: stmmac: simplify phy modes management for stm32")
> introduced a third, unified, property st,ext-phyclk. This property
> covers both use cases of st,eth-clk-sel and st,eth-ref-clk-sel DT
> properties, as well as a new use case for 25 MHz clock generated
> by the MAC.
>
> The third property st,ext-phyclk is so far undocumented,
> document it.
>
> Below table summarizes the clock requirement and clock sources for
> supported PHY interface modes.
> __________________________________________________________________________
> |PHY_MODE | Normal | PHY wo crystal| PHY wo crystal |No 125Mhz from PHY|
> | | | 25MHz | 50MHz | |
>
> ---------------------------------------------------------------------------
> | MII | - | eth-ck | n/a | n/a |
> | | | st,ext-phyclk | | |
>
> ---------------------------------------------------------------------------
> | GMII | - | eth-ck | n/a | n/a |
> | | | st,ext-phyclk | | |
>
> ---------------------------------------------------------------------------
> | RGMII | - | eth-ck | n/a | eth-ck |
> | | | st,ext-phyclk | | st,eth-clk-sel or|
> | | | | | st,ext-phyclk |
>
> ---------------------------------------------------------------------------
> | RMII | - | eth-ck | eth-ck | n/a |
> | | | st,ext-phyclk | st,eth-ref-clk-sel | |
> | | | | or st,ext-phyclk | |
>
> ---------------------------------------------------------------------------
>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski at linaro.org>
> Signed-off-by: Christophe Roullier <christophe.roullier at foss.st.com>
Can you please start testing patches *before* sending them?
Best regards,
Krzysztof
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