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Diffstat (limited to 'Documentation/devicetree/bindings/mmc/sdhci-sprd.txt')
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diff --git a/Documentation/devicetree/bindings/mmc/sdhci-sprd.txt b/Documentation/devicetree/bindings/mmc/sdhci-sprd.txt new file mode 100644 index 000000000..eb7eb1b52 --- /dev/null +++ b/Documentation/devicetree/bindings/mmc/sdhci-sprd.txt @@ -0,0 +1,67 @@ +* Spreadtrum SDHCI controller (sdhci-sprd) + +The Secure Digital (SD) Host controller on Spreadtrum SoCs provides an interface +for MMC, SD and SDIO types of cards. + +This file documents differences between the core properties in mmc.txt +and the properties used by the sdhci-sprd driver. + +Required properties: +- compatible: Should contain "sprd,sdhci-r11". +- reg: physical base address of the controller and length. +- interrupts: Interrupts used by the SDHCI controller. +- clocks: Should contain phandle for the clock feeding the SDHCI controller +- clock-names: Should contain the following: + "sdio" - SDIO source clock (required) + "enable" - gate clock which used for enabling/disabling the device (required) + "2x_enable" - gate clock controlling the device for some special platforms (optional) + +Optional properties: +- assigned-clocks: the same with "sdio" clock +- assigned-clock-parents: the default parent of "sdio" clock +- pinctrl-names: should be "default", "state_uhs" +- pinctrl-0: should contain default/high speed pin control +- pinctrl-1: should contain uhs mode pin control + +PHY DLL delays are used to delay the data valid window, and align the window +to sampling clock. PHY DLL delays can be configured by following properties, +and each property contains 4 cells which are used to configure the clock data +write line delay value, clock read command line delay value, clock read data +positive edge delay value and clock read data negative edge delay value. +Each cell's delay value unit is cycle of the PHY clock. + +- sprd,phy-delay-legacy: Delay value for legacy timing. +- sprd,phy-delay-sd-highspeed: Delay value for SD high-speed timing. +- sprd,phy-delay-sd-uhs-sdr50: Delay value for SD UHS SDR50 timing. +- sprd,phy-delay-sd-uhs-sdr104: Delay value for SD UHS SDR50 timing. +- sprd,phy-delay-mmc-highspeed: Delay value for MMC high-speed timing. +- sprd,phy-delay-mmc-ddr52: Delay value for MMC DDR52 timing. +- sprd,phy-delay-mmc-hs200: Delay value for MMC HS200 timing. +- sprd,phy-delay-mmc-hs400: Delay value for MMC HS400 timing. +- sprd,phy-delay-mmc-hs400es: Delay value for MMC HS400 enhanced strobe timing. + +Examples: + +sdio0: sdio@20600000 { + compatible = "sprd,sdhci-r11"; + reg = <0 0x20600000 0 0x1000>; + interrupts = <GIC_SPI 60 IRQ_TYPE_LEVEL_HIGH>; + + clock-names = "sdio", "enable"; + clocks = <&ap_clk CLK_EMMC_2X>, + <&apahb_gate CLK_EMMC_EB>; + assigned-clocks = <&ap_clk CLK_EMMC_2X>; + assigned-clock-parents = <&rpll CLK_RPLL_390M>; + + pinctrl-names = "default", "state_uhs"; + pinctrl-0 = <&sd0_pins_default>; + pinctrl-1 = <&sd0_pins_uhs>; + + sprd,phy-delay-sd-uhs-sdr104 = <0x3f 0x7f 0x2e 0x2e>; + bus-width = <8>; + non-removable; + no-sdio; + no-sd; + cap-mmc-hw-reset; + status = "okay"; +}; |