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-rw-r--r-- | Documentation/devicetree/bindings/mmc/sdhci-cadence.txt | 80 |
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diff --git a/Documentation/devicetree/bindings/mmc/sdhci-cadence.txt b/Documentation/devicetree/bindings/mmc/sdhci-cadence.txt new file mode 100644 index 000000000..fa423c277 --- /dev/null +++ b/Documentation/devicetree/bindings/mmc/sdhci-cadence.txt @@ -0,0 +1,80 @@ +* Cadence SD/SDIO/eMMC Host Controller + +Required properties: +- compatible: should be one of the following: + "cdns,sd4hc" - default of the IP + "socionext,uniphier-sd4hc" - for Socionext UniPhier SoCs +- reg: offset and length of the register set for the device. +- interrupts: a single interrupt specifier. +- clocks: phandle to the input clock. + +Optional properties: +For eMMC configuration, supported speed modes are not indicated by the SDHCI +Capabilities Register. Instead, the following properties should be specified +if supported. See mmc.txt for details. +- mmc-ddr-1_8v +- mmc-ddr-1_2v +- mmc-hs200-1_8v +- mmc-hs200-1_2v +- mmc-hs400-1_8v +- mmc-hs400-1_2v + +Some PHY delays can be configured by following properties. +PHY DLL input delays: +They are used to delay the data valid window, and align the window +to sampling clock. The delay starts from 5ns (for delay parameter equal to 0) +and it is increased by 2.5ns in each step. +- cdns,phy-input-delay-sd-highspeed: + Value of the delay in the input path for SD high-speed timing + Valid range = [0:0x1F]. +- cdns,phy-input-delay-legacy: + Value of the delay in the input path for legacy timing + Valid range = [0:0x1F]. +- cdns,phy-input-delay-sd-uhs-sdr12: + Value of the delay in the input path for SD UHS SDR12 timing + Valid range = [0:0x1F]. +- cdns,phy-input-delay-sd-uhs-sdr25: + Value of the delay in the input path for SD UHS SDR25 timing + Valid range = [0:0x1F]. +- cdns,phy-input-delay-sd-uhs-sdr50: + Value of the delay in the input path for SD UHS SDR50 timing + Valid range = [0:0x1F]. +- cdns,phy-input-delay-sd-uhs-ddr50: + Value of the delay in the input path for SD UHS DDR50 timing + Valid range = [0:0x1F]. +- cdns,phy-input-delay-mmc-highspeed: + Value of the delay in the input path for MMC high-speed timing + Valid range = [0:0x1F]. +- cdns,phy-input-delay-mmc-ddr: + Value of the delay in the input path for eMMC high-speed DDR timing + Valid range = [0:0x1F]. + +PHY DLL clock delays: +Each delay property represents the fraction of the clock period. +The approximate delay value will be +(<delay property value>/128)*sdmclk_clock_period. +- cdns,phy-dll-delay-sdclk: + Value of the delay introduced on the sdclk output + for all modes except HS200, HS400 and HS400_ES. + Valid range = [0:0x7F]. +- cdns,phy-dll-delay-sdclk-hsmmc: + Value of the delay introduced on the sdclk output + for HS200, HS400 and HS400_ES speed modes. + Valid range = [0:0x7F]. +- cdns,phy-dll-delay-strobe: + Value of the delay introduced on the dat_strobe input + used in HS400 / HS400_ES speed modes. + Valid range = [0:0x7F]. + +Example: + emmc: sdhci@5a000000 { + compatible = "socionext,uniphier-sd4hc", "cdns,sd4hc"; + reg = <0x5a000000 0x400>; + interrupts = <0 78 4>; + clocks = <&clk 4>; + bus-width = <8>; + mmc-ddr-1_8v; + mmc-hs200-1_8v; + mmc-hs400-1_8v; + cdns,phy-dll-delay-sdclk = <0>; + }; |