Re: [PATCH 2/5] arm64: dts: qcom: lemans: Add SDHC controller and SDC pin configuration

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 9/5/25 3:44 PM, Dmitry Baryshkov wrote:
> On Fri, Sep 05, 2025 at 02:04:47PM +0200, Konrad Dybcio wrote:
>> On 9/5/25 1:45 PM, Dmitry Baryshkov wrote:
>>> On Fri, Sep 05, 2025 at 01:14:29PM +0200, Konrad Dybcio wrote:
>>>> On 9/4/25 7:32 PM, Dmitry Baryshkov wrote:
>>>>> On Thu, Sep 04, 2025 at 04:34:05PM +0200, Konrad Dybcio wrote:
>>>>>> On 9/4/25 3:35 PM, Dmitry Baryshkov wrote:
>>>>>>> On Wed, Sep 03, 2025 at 09:58:33PM +0530, Wasim Nazir wrote:
>>>>>>>> On Wed, Sep 03, 2025 at 06:12:59PM +0200, Konrad Dybcio wrote:
>>>>>>>>> On 8/27/25 3:20 AM, Dmitry Baryshkov wrote:
>>>>>>>>>> On Tue, Aug 26, 2025 at 11:51:01PM +0530, Wasim Nazir wrote:
>>>>>>>>>>> From: Monish Chunara <quic_mchunara@xxxxxxxxxxx>
>>>>>>>>>>>
>>>>>>>>>>> Introduce the SDHC v5 controller node for the Lemans platform.
>>>>>>>>>>> This controller supports either eMMC or SD-card, but only one
>>>>>>>>>>> can be active at a time. SD-card is the preferred configuration
>>>>>>>>>>> on Lemans targets, so describe this controller.
>>>>>>>>>>>
>>>>>>>>>>> Define the SDC interface pins including clk, cmd, and data lines
>>>>>>>>>>> to enable proper communication with the SDHC controller.
>>>>>>>>>>>
>>>>>>>>>>> Signed-off-by: Monish Chunara <quic_mchunara@xxxxxxxxxxx>
>>>>>>>>>>> Co-developed-by: Wasim Nazir <wasim.nazir@xxxxxxxxxxxxxxxx>
>>>>>>>>>>> Signed-off-by: Wasim Nazir <wasim.nazir@xxxxxxxxxxxxxxxx>
>>>>>>>>>>> ---
>>>>>>>>>>>  arch/arm64/boot/dts/qcom/lemans.dtsi | 70 ++++++++++++++++++++++++++++++++++++
>>>>>>>>>>>  1 file changed, 70 insertions(+)
>>>>>>>>>>>
>>>>>>>>>>> diff --git a/arch/arm64/boot/dts/qcom/lemans.dtsi b/arch/arm64/boot/dts/qcom/lemans.dtsi
>>>>>>>>>>> index 99a566b42ef2..a5a3cdba47f3 100644
>>>>>>>>>>> --- a/arch/arm64/boot/dts/qcom/lemans.dtsi
>>>>>>>>>>> +++ b/arch/arm64/boot/dts/qcom/lemans.dtsi
>>>>>>>>>>> @@ -3834,6 +3834,36 @@ apss_tpdm2_out: endpoint {
>>>>>>>>>>>  			};
>>>>>>>>>>>  		};
>>>>>>>>>>>  
>>>>>>>>>>> +		sdhc: mmc@87c4000 {
>>>>>>>>>>> +			compatible = "qcom,sa8775p-sdhci", "qcom,sdhci-msm-v5";
>>>>>>>>>>> +			reg = <0x0 0x087c4000 0x0 0x1000>;
>>>>>>>>>>> +
>>>>>>>>>>> +			interrupts = <GIC_SPI 383 IRQ_TYPE_LEVEL_HIGH>,
>>>>>>>>>>> +				     <GIC_SPI 521 IRQ_TYPE_LEVEL_HIGH>;
>>>>>>>>>>> +			interrupt-names = "hc_irq", "pwr_irq";
>>>>>>>>>>> +
>>>>>>>>>>> +			clocks = <&gcc GCC_SDCC1_AHB_CLK>,
>>>>>>>>>>> +				 <&gcc GCC_SDCC1_APPS_CLK>;
>>>>>>>>>>> +			clock-names = "iface", "core";
>>>>>>>>>>> +
>>>>>>>>>>> +			interconnects = <&aggre1_noc MASTER_SDC 0 &mc_virt SLAVE_EBI1 0>,
>>>>>>>>>>> +					<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_SDC1 0>;
>>>>>>>>>>> +			interconnect-names = "sdhc-ddr", "cpu-sdhc";
>>>>>>>>>>> +
>>>>>>>>>>> +			iommus = <&apps_smmu 0x0 0x0>;
>>>>>>>>>>> +			dma-coherent;
>>>>>>>>>>> +
>>>>>>>>>>> +			resets = <&gcc GCC_SDCC1_BCR>;
>>>>>>>>>>> +
>>>>>>>>>>> +			no-sdio;
>>>>>>>>>>> +			no-mmc;
>>>>>>>>>>> +			bus-width = <4>;
>>>>>>>>>>
>>>>>>>>>> This is the board configuration, it should be defined in the EVK DTS.
>>>>>>>>>
>>>>>>>>> Unless the controller is actually incapable of doing non-SDCards
>>>>>>>>>
>>>>>>>>> But from the limited information I can find, this one should be able
>>>>>>>>> to do both
>>>>>>>>>
>>>>>>>>
>>>>>>>> It’s doable, but the bus width differs when this controller is used for
>>>>>>>> eMMC, which is supported on the Mezz board. So, it’s cleaner to define
>>>>>>>> only what’s needed for each specific usecase on the board.
>>>>>>>
>>>>>>> `git grep no-sdio arch/arm64/boot/dts/qcom/` shows that we have those
>>>>>>> properties inside the board DT. I don't see a reason to deviate.
>>>>>>
>>>>>> Just to make sure we're clear
>>>>>>
>>>>>> I want the author to keep bus-width in SoC dt and move the other
>>>>>> properties to the board dt
>>>>>
>>>>> I think bus-width is also a property of the board. In the end, it's a
>>>>> question of schematics whether we route 1 wire or all 4 wires. git-log
>>>>> shows that bus-width is being sent in both files (and probalby we should
>>>>> sort that out).
>>>>
>>>> Actually this is the controller capability, so if it can do 8, it should
>>>> be 8 and the MMC core will do whatever it pleases (the not-super-sure
>>>> docs that I have say 8 for this platform)
>>>
>>> Isn't it a physical width of the bus between the controller and the slot
>>> or eMMC chip?
>>
>> No, that's matched against reported (sd/mmc) card capabilities IIUC
> 
> What if both host and the card support 4 bits bus (normal SD card), but
> board has only one data wire?

Ohhh, touche.. I assumed it's "smart" like PCIe, but it's (probably)
not.

Sorry for the trouble, Wasim. Let's keep 4 for now and get this patch
merged.

Konrad> 




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [Linux for Sparc]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux