Messages in this thread |  | | Date | Mon, 17 Jan 2022 15:03:47 +0800 | | Subject | Re: [PATCH v9 3/4] clk: meson: add DT documentation for emmc clock controller | | From | Liang Yang <> |
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Hi Martin,
On 2022/1/15 8:09, Martin Blumenstingl wrote: > [ EXTERNAL EMAIL ] > > Hi Liang, > > On Fri, Jan 14, 2022 at 4:06 AM Liang Yang <liang.yang@amlogic.com> wrote: > [...] >>>> +properties: >>>> + compatible: >>>> + enum: >>>> + - "amlogic,axg-mmc-clkc", "syscon" >>> >>> Why is it a syscon? >> >> The register documented by reg is shared with SD/eMMC controller port C, >> and it need to be ops on NFC driver. > Can you please share an example how the .dts would look like in the > end for two example cases: > 1) using the sd_emmc_c MMC interface > 2) not using the MMC interface of sd_emmc_c but only using it's clocks > for the NFC I think both EMMC(although it is not implemented by 'axg-mmc-clkc' yet) and NAND clock have the same way in dts: ...... clocks = <&clkc CLKID_SD_EMMC_C>, <&sd_emmc_c_clkc CLKID_MMC_DIV>, <&sd_emmc_c_clkc CLKID_MMC_PHASE_RX>, <&sd_emmc_c_clkc CLKID_MMC_PHASE_TX>; clock-names = "core", "device", "rx", "tx"; amlogic,mmc-syscon = <&sd_emmc_c_clkc>; ......
> > Initially I wanted to suggest the usage of a sub-node with compatible > = "mmc-slot" (see > Documentation/devicetree/bindings/mmc/amlogic,meson-mx-sdio.txt for an > example) to decide whether the MMC controller is registered or whether > just the clock controller is registered. > However, the mmc-slot compatible string is not documented in > Documentation/devicetree/bindings/mmc/mmc-controller.yaml currently. > Maybe the MMC maintainers have any suggestions if other IPs have > similar requirements (for IPs with shared parts). > > > Best regards, > Martin > > .
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