Re: [PATCH v2 0/7] usb: dwc3: Calculate REFCLKPER et. al. from reference clock

From: Baruch Siach
Date: Wed Jan 19 2022 - 13:20:11 EST


Hi Sean,

On Tue, Jan 18 2022, Sean Anderson wrote:
> 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.

Tested here on IPQ6010 based system. USB still works. But the with "ref"
clock at 24MHz, period is calculated as 0x29. Previous
snps,ref-clock-period-ns value used to be 0x32.

Is that expected?

Thanks,
baruch

>
> [1] https://lore.kernel.org/linux-usb/20220114044230.2677283-1-robert.hancock@xxxxxxxxxx/
>
> Changes in v2:
> - Document clock members
> - Also program GFLADJ.240MHZDECR
> - Don't program GFLADJ if the version is < 2.50a
> - Add snps,ref-clock-frequency-hz property for ACPI
>
> Sean Anderson (7):
> 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: Program GFLADJ
> usb: dwc3: Add snps,ref-clock-frequency-hz property for ACPI
> 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 | 112 +++++++++++++++---
> drivers/usb/dwc3/core.h | 17 ++-
> 6 files changed, 120 insertions(+), 27 deletions(-)


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