On Thu, 10 Oct 2024 14:19:43 +0800, Wei Fang wrote: > Per the RMII specification, the REF_CLK is sourced from MAC to PHY > or from an external source. But for TJA11xx PHYs, they support to > output a 50MHz RMII reference clock on REF_CLK pin. Previously the > "nxp,rmii-refclk-in" was added to indicate that in RMII mode, if > this property present, REF_CLK is input to the PHY, otherwise it > is output. This seems inappropriate now. Because according to the > RMII specification, the REF_CLK is originally input, so there is > no need to add an additional "nxp,rmii-refclk-in" property to > declare that REF_CLK is input. > Unfortunately, because the "nxp,rmii-refclk-in" property has been > added for a while, and we cannot confirm which DTS use the TJA1100 > and TJA1101 PHYs, changing it to switch polarity will cause an ABI > break. But fortunately, this property is only valid for TJA1100 and > TJA1101. For TJA1103/TJA1104/TJA1120/TJA1121 PHYs, this property is > invalid because they use the nxp-c45-tja11xx driver, which is a > different driver from TJA1100/TJA1101. Therefore, for PHYs using > nxp-c45-tja11xx driver, add "nxp,rmii-refclk-out" property to > support outputting RMII reference clock on REF_CLK pin. > > Signed-off-by: Wei Fang <wei.fang@xxxxxxx> > --- > V2 changes: > 1. Change the property name from "nxp,reverse-mode" to > "nxp,phy-output-refclk". > 2. Simplify the description of the property. > 3. Modify the subject and commit message. > V3 changes: > 1. Keep the "nxp,rmii-refclk-in" property for TJA1100 and TJA1101. > 2. Rephrase the commit message and subject. > V4 changes: > 1. Change the property name from "nxp,phy-output-refclk" to > "nxp,rmii-refclk-out", which means the opposite of "nxp,rmii-refclk-in". > 2. Refactor the patch after fixing the original issue with this YAML. > V5 changes: > 1. Reword the description of "nxp,rmii-refclk-out" property. > --- > .../devicetree/bindings/net/nxp,tja11xx.yaml | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > Reviewed-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
