Re: [PATCH v3 5/5] arm64: dts: qcom: sa8775p: Add ep pcie0 controller node

Mrinmay Sarkar
2023-10-26T05:33:59Z

On 10/25/2023 1:22 PM, Manivannan Sadhasivam wrote:
> On Thu, Oct 19, 2023 at 05:07:10PM +0530, Mrinmay Sarkar wrote:
>> Add ep pcie dtsi node for pcie0 controller found on sa8775p platform.
>> It supports gen4 and x2 link width. Due to some stability issue in
>> gen4 enabling gen3 as of now.
>>
>> Signed-off-by: Mrinmay Sarkar <quic_msarkar@quicinc.com>
>> ---
>> arch/arm64/boot/dts/qcom/sa8775p.dtsi | 48 +++++++++++++++++++++++++++++++++++
>> 1 file changed, 48 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/sa8775p.dtsi b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
>> index 13dd44d..2aa7383 100644
>> --- a/arch/arm64/boot/dts/qcom/sa8775p.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
>> @@ -3714,4 +3714,52 @@
>>
>> status = "disabled";
>> };
>> +
>> + pcie0_ep: pcie-ep@1c00000 {
>> + compatible = "qcom,sa8775p-pcie-ep";
>> + reg = <0x0 0x01c00000 0x0 0x3000>,
>> + <0x0 0x40000000 0x0 0xf20>,
>> + <0x0 0x40000f20 0x0 0xa8>,
>> + <0x0 0x40001000 0x0 0x4000>,
>> + <0x0 0x40200000 0x0 0x100000>,
>> + <0x0 0x01c03000 0x0 0x1000>,
>> + <0x0 0x40005000 0x0 0x2000>;
> Can we sort the reg entries?
>
>> + reg-names = "parf", "dbi", "elbi", "atu", "addr_space",
>> + "mmio", "dma";
>> +
>> + clocks = <&gcc GCC_PCIE_0_AUX_CLK>,
>> + <&gcc GCC_PCIE_0_CFG_AHB_CLK>,
>> + <&gcc GCC_PCIE_0_MSTR_AXI_CLK>,
>> + <&gcc GCC_PCIE_0_SLV_AXI_CLK>,
>> + <&gcc GCC_PCIE_0_SLV_Q2A_AXI_CLK>;
>> +
>> + clock-names = "aux",
>> + "cfg",
>> + "bus_master",
>> + "bus_slave",
>> + "slave_q2a";
>> +
>> + interrupts = <GIC_SPI 306 IRQ_TYPE_LEVEL_HIGH>,
>> + <GIC_SPI 147 IRQ_TYPE_LEVEL_HIGH>,
>> + <GIC_SPI 630 IRQ_TYPE_LEVEL_HIGH>;
>> +
>> + interrupt-names = "global", "doorbell", "dma";
>> +
>> + interconnects = <&pcie_anoc MASTER_PCIE_0 0 &mc_virt SLAVE_EBI1 0>,
>> + <&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_PCIE_0 0>;
>> + interconnect-names = "pcie-mem", "cpu-pcie";
>> +
>> + iommu-map = <0x0 &pcie_smmu 0x0000 0x1>,
>> + <0x100 &pcie_smmu 0x0001 0x1>;
> I think I recommended using "iommu-map" instead of "iommus" property. But
> looking at it again, I think it is fine to use just "iommus" property as the SID
> will be associated with the EP directly.
>
> Unless you want to have different SID for each function.
>
>> +
>> + resets = <&gcc GCC_PCIE_0_BCR>;
>> + reset-names = "core";
>> + power-domains = <&gcc PCIE_0_GDSC>;
>> + phys = <&pcie0_phy>;
>> + phy-names = "pciephy";
>> + max-link-speed = <3>;
> Please add a comment here that you are limiting the Gen speed due to stability
> issues. Like,
>
> max-link-speed = <3>; /* FIXME: Limiting the Gen speed due to stability issues */
>
>> + num-lanes = <2>;
> Can you check if the controller is cache coherent? If so, we should add
> "dma-coherent" property.
>
> - Mani

For cache coherency we need driver change as well. So will add this
property along with driver change.

--Mrinmay

>> +
>> + status = "disabled";
>> + };
>> };
>> --
>> 2.7.4
>>