Re: [PATCH 2/3] arm64: dts: qcom: sc7280: Add Camera Control Interface busses
From: Konrad Dybcio
Date: Fri Sep 29 2023 - 10:19:09 EST
On 29.09.2023 16:15, Bryan O'Donoghue wrote:
> On 29/09/2023 14:35, Konrad Dybcio wrote:
>>
>>
>> On 9/29/23 10:01, Luca Weiss wrote:
>>> Add the CCI busses found on sc7280 and their pinctrl states.
>>>
>>> Signed-off-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx>
>>> ---
>>> arch/arm64/boot/dts/qcom/sc7280.dtsi | 136 +++++++++++++++++++++++++++++++++++
>>> 1 file changed, 136 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/qcom/sc7280.dtsi b/arch/arm64/boot/dts/qcom/sc7280.dtsi
>>> index 66f1eb83cca7..65550de2e4ff 100644
>>> --- a/arch/arm64/boot/dts/qcom/sc7280.dtsi
>>> +++ b/arch/arm64/boot/dts/qcom/sc7280.dtsi
>>> @@ -3793,6 +3793,86 @@ videocc: clock-controller@aaf0000 {
>>> #power-domain-cells = <1>;
>>> };
>>> + cci0: cci@ac4a000 {
>>> + compatible = "qcom,sc7280-cci", "qcom,msm8996-cci";
>>> + reg = <0 0x0ac4a000 0 0x1000>;
>>> + interrupts = <GIC_SPI 460 IRQ_TYPE_EDGE_RISING>;
>>> + power-domains = <&camcc CAM_CC_TITAN_TOP_GDSC>;
>>> +
>>> + clocks = <&camcc CAM_CC_CAMNOC_AXI_CLK>,
>>> + <&camcc CAM_CC_SLOW_AHB_CLK_SRC>,
>>> + <&camcc CAM_CC_CPAS_AHB_CLK>,
>>> + <&camcc CAM_CC_CCI_0_CLK>,
>>> + <&camcc CAM_CC_CCI_0_CLK_SRC>;
>>> + clock-names = "camnoc_axi",
>>> + "slow_ahb_src",
>>> + "cpas_ahb",
>>> + "cci",
>>> + "cci_src";
>> I guess this is more of a question to e.g. Bryan, but are all of these clocks actually necessary?
>>
>> Konrad
> Hmm its a good question, we generally take the approach of adopting all of the downstream clocks for these camera interfaces verbatim.
>
> The clock plan for this part only calls out cci_X_clk and cci_x_clk_src for the CCI however we know that to be incomplete since we *absolutely* need to have the AXI for the block clocked to access those registers, same deal with the AHB bus.
>
> AXI: registers
> AHB: data
>
> In the above list the only clock you might conceivably not need is CPAS_AHB_CLK.
>
> Let me zap that clock from sdm845 since I have an rb3 right in front of me and see what happens.
>
> Crash and reset
>
> --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> @@ -4402,13 +4402,11 @@ cci: cci@ac4a000 {
> clocks = <&clock_camcc CAM_CC_CAMNOC_AXI_CLK>,
> <&clock_camcc CAM_CC_SOC_AHB_CLK>,
> <&clock_camcc CAM_CC_SLOW_AHB_CLK_SRC>,
> - <&clock_camcc CAM_CC_CPAS_AHB_CLK>,
> <&clock_camcc CAM_CC_CCI_CLK>,
> <&clock_camcc CAM_CC_CCI_CLK_SRC>;
> clock-names = "camnoc_axi",
> "soc_ahb",
> "slow_ahb_src",
> - "cpas_ahb",
> "cci",
> "cci_src";
>
>
> I think the list is good tbh
WDYT about camcc consuming ahb, like dispcc does?
AXI, hmm.. not quite sure what to do with it
Konrad