Sean Anderson <sean.anderson@xxxxxxxx> 于2022年1月15日周六 10:11写道： > > This is a rework of patches 3-5 of [1]. It attempts to correctly program > REFCLKPER and REFCLK_FLADJ based on the reference clock frequency. Since > we no longer need a special property duplicating this configuration, > snps,ref-clock-period-ns is deprecated. > > Please test this! Patches 3/4 in this series have the effect of > programming REFCLKPER and REFCLK_FLADJ on boards which already configure > the "ref" clock. I have build tested, but not much else. DWC3 databook states a *condition* for program those settings: This field must be programmed to a non-zero value only if GFLADJ_REFCLK_LPM_SEL is set to '1' or GCTL.SOFITPSYNC is set to '1'. The value is derived as follows: FLADJ_REF_CLK_FLADJ=((125000/ref_clk_period_integer)-(125000/ref_clk_period)) * ref_clk_period where ■ the ref_clk_period_integer is the integer value of the ref_clk period got by truncating the decimal (fractional) value that is programmed in the GUCTL.REF_CLK_PERIOD field. ■ the ref_clk_period is the ref_clk period including the fractional value. So you may need a condition check, with that, only required users are effected even with "ref" clock specified. Li Jun > > [1] https://lore.kernel.org/linux-usb/20220114044230.2677283-1-robert.hancock@xxxxxxxxxx/ > > > Sean Anderson (6): > dt-bindings: usb: dwc3: Deprecate snps,ref-clock-period-ns > usb: dwc3: Get clocks individually > usb: dwc3: Calculate REFCLKPER based on reference clock > usb: dwc3: Handle fractional reference clocks > arm64: dts: zynqmp: Move USB clocks to dwc3 node > arm64: dts: ipq6018: Use reference clock to set dwc3 period > > .../devicetree/bindings/usb/snps,dwc3.yaml | 7 +- > arch/arm64/boot/dts/qcom/ipq6018.dtsi | 3 +- > .../arm64/boot/dts/xilinx/zynqmp-clk-ccf.dtsi | 4 +- > arch/arm64/boot/dts/xilinx/zynqmp.dtsi | 4 +- > drivers/usb/dwc3/core.c | 98 ++++++++++++++++--- > drivers/usb/dwc3/core.h | 6 +- > 6 files changed, 98 insertions(+), 24 deletions(-) > > -- > 2.25.1 >
