Re: [PATCH 7/8] arm64: dts: qcom: ipq9574: Add USB related nodes

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On 06/03/2023 13:26, Varadarajan Narayanan wrote:
> Dmitry,
> 
> On 3/2/2023 9:52 PM, Dmitry Baryshkov wrote:
>> On Thu, 2 Mar 2023 at 11:57, Varadarajan Narayanan
>> <quic_varada@quicinc.com> wrote:
>>> Add USB phy and controller related nodes
>>>
>>> Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
>>> ---
>>>   arch/arm64/boot/dts/qcom/ipq9574.dtsi | 92 
>>> +++++++++++++++++++++++++++++++++++
>>>   1 file changed, 92 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/qcom/ipq9574.dtsi 
>>> b/arch/arm64/boot/dts/qcom/ipq9574.dtsi
>>> index 2bb4053..319b5bd 100644
>>> --- a/arch/arm64/boot/dts/qcom/ipq9574.dtsi
>>> +++ b/arch/arm64/boot/dts/qcom/ipq9574.dtsi

[skipped]


>>> +               usb3: usb3@8A00000 {
>> You know the drill. This node is in the wrong place.
>>
>>> +                       compatible = "qcom,dwc3";
>>> +                       reg = <0x8AF8800 0x400>;
>>> +                       #address-cells = <1>;
>>> +                       #size-cells = <1>;
>>> +                       ranges;
>>> +
>>> +                       clocks = <&gcc GCC_SNOC_USB_CLK>,
>>> +                               <&gcc GCC_ANOC_USB_AXI_CLK>,
>>> +                               <&gcc GCC_USB0_MASTER_CLK>,
>>> +                               <&gcc GCC_USB0_SLEEP_CLK>,
>>> +                               <&gcc GCC_USB0_MOCK_UTMI_CLK>;
>>> +
>>> +                       clock-names = "sys_noc_axi",
>>> +                               "anoc_axi",
>>> +                               "master",
>>> +                               "sleep",
>>> +                               "mock_utmi";
>> Please fix the indentation of the lists.
>>
>>> +
>>> +                       assigned-clocks = <&gcc GCC_SNOC_USB_CLK>,
>>> +                                         <&gcc GCC_ANOC_USB_AXI_CLK>,
>> Why do you assign clock rates to the NOC clocks? Should they be set
>> using the interconnect instead?
> 
> The SNOC and ANOC run at a fixed speed of 350MHz and 342MHz respectively 
> and are not scaled. These clocks are for the interface between the USB 
> block and the SNOC/ANOC. Do we still need to use interconnect?

Maybe I misunderstand something here. If the snoc and anoc speeds are at 
350 MHz and 342 MHz, why do you assign clock-rates of 200 MHz?

Is it enough to call clk_prepare_enable() for these clocks or the rate 
really needs to be set?


> 
>>> +                                         <&gcc GCC_USB0_MASTER_CLK>,
>>> +                                         <&gcc GCC_USB0_MOCK_UTMI_CLK>;
>>> +                       assigned-clock-rates = <200000000>,
>>> +                                              <200000000>,
>>> +                                              <200000000>,
>>> +                                              <24000000>;
>>> +
>>> +                       resets = <&gcc GCC_USB_BCR>;
>>> +                       status = "disabled";
>>> +
>>> +                       dwc_0: dwc3@8A00000 {
>>> +                               compatible = "snps,dwc3";
>>> +                               reg = <0x8A00000 0xcd00>;
>>> +                               clock-names = "ref";
>>> +                               clocks = <&gcc GCC_USB0_MOCK_UTMI_CLK>;
>> clocks before clock-names
>>
>>> +                               interrupts = <GIC_SPI 140 
>>> IRQ_TYPE_LEVEL_HIGH>;
>>> +                               phys = <&qusb_phy_0>, <&usb0_ssphy>;
>>> +                               phy-names = "usb2-phy", "usb3-phy";
>>> +                               tx-fifo-resize;
>>> +                               snps,dis_ep_cache_eviction;
>>> +                               snps,is-utmi-l1-suspend;
>>> +                               snps,hird-threshold = /bits/ 8 <0x0>;
>>> +                               snps,dis_u2_susphy_quirk;
>>> +                               snps,dis_u3_susphy_quirk;
>>> +                               snps,quirk-frame-length-adjustment = 
>>> <0x0A87F0A0>;
>>> +                               dr_mode = "host";
>>> +                       };
>>> +               };
>>> +
>>>                  pcie0_phy: phy@84000 {
>>>                          compatible = 
>>> "qcom,ipq9574-qmp-gen3x1-pcie-phy";
>>>                          reg = <0x00084000 0x1bc>; /* Serdes PLL */
>>> -- 
>>> 2.7.4
> 
> Will address these and post a new revision.
> 
> Thanks
> 
> Varada
> 

-- 
With best wishes
Dmitry