Re: [PATCH v5 05/12] dt: bindings: Add bindings for Marvell Xenon SD Host Controller

[Rob Herring <robh@kernel.org>]

On Wed, Jan 11, 2017 at 06:19:08PM +0100, Gregory CLEMENT wrote:
> From: Hu Ziji <huziji@marvell.com>
> 
> Marvell Xenon SDHC can support eMMC/SD/SDIO.
> Add Xenon-specific properties.
> Also add properties for Xenon PHY setting.
> 
> Signed-off-by: Hu Ziji <huziji@marvell.com>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
>  Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt | 197 +++++++-
>  1 file changed, 197 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
> 
> diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
> new file mode 100644
> index 000000000000..a3876d2cc616
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
> @@ -0,0 +1,197 @@
> +Marvell Xenon SDHCI Controller device tree bindings
> +This file documents differences between the core mmc properties
> +described by mmc.txt and the properties used by the Xenon implementation.
> +
> +Multiple SDHCs might be put into a single Xenon IP, to save size and cost.
> +Each SDHC is independent and owns independent resources, such as register sets,
> +clock and PHY.
> +Each SDHC should have an independent device tree node.
> +
> +Required Properties:
> +- compatible: should be one of the following
> +  - "marvell,armada-3700-sdhci": For controllers on Armada-3700 SoC.
> +  Must provide a second register area and marvell,pad-type.
> +  - "marvell,armada-8k-sdhci": For controllers on Armada 7K/8K SoC
> +
> +- clocks:
> +  Array of clocks required for SDHC.
> +  Require at least input clock for Xenon IP core.
> +
> +- clock-names:
> +  Array of names corresponding to clocks property.
> +  The input clock for Xenon IP core should be named as "core".
> +
> +- reg:
> +  * For "marvell,armada-3700-sdhci", two register areas.
> +    The first one for Xenon IP register. The second one for the Armada 3700 SoC
> +    PHY PAD Voltage Control register.
> +    Please follow the examples with compatible "marvell,armada-3700-sdhci"
> +    in below.
> +    Please also check property marvell,pad-type in below.
> +
> +  * For other compatible strings, one register area for Xenon IP.
> +
> +Optional Properties:
> +- mmccard:
> +  mmccard child node must be provided when current SDHC is for eMMC.
> +  Xenon SDHC often can support both SD and eMMC. This child node indicates that
> +  current SDHC is for eMMC card. Thus Xenon eMMC specific configuration and
> +  operations can be enabled prior to eMMC init sequence.
> +  Please refer to Documentation/devicetree/bindings/mmc/mmc-card.txt.
> +  This child node should not be set if current Xenon SDHC is for SD/SDIO.
> +
> +- bus-width:
> +  When 8-bit data bus width is in use for eMMC, this property should be
> +  explicitly provided and set as 8.
> +  It is optional when data bus width is 4-bit or 1-bit.
> +
> +- mmc-ddr-1_8v:
> +  Select this property when eMMC HS DDR is supported on SDHC side.
> +
> +- mmc-hs400-1_8v:
> +  Select this property when eMMC HS400 is supported on SDHC side.
> +
> +- no-1-8-v:
> +  Select this property when 1.8V signaling voltage supply is unavailable.
> +  When this property is enabled, both mmc-ddr-1_8v and mmc-hs400-1_8v should be
> +  cleared.
> +
> +- marvell,xenon-sdhc-id:
> +  Indicate the corresponding bit index of current SDHC in
> +  SDHC System Operation Control Register Bit[7:0].
> +  Set/clear the corresponding bit to enable/disable current SDHC.
> +  If Xenon IP contains only one SDHC, this property is optional.
> +
> +- marvell,xenon-phy-type:
> +  Xenon support mutilple types of PHYs.
> +  To select eMMC 5.1 PHY, set:
> +  marvell,xenon-phy-type = "emmc 5.1 phy"
> +  eMMC 5.1 PHY is the default choice if this property is not provided.
> +  To select eMMC 5.0 PHY, set:
> +  marvell,xenon-phy-type = "emmc 5.0 phy"
> +
> +  All those types of PHYs can support eMMC, SD and SDIO.
> +  Please note that this property only presents the type of PHY.
> +  It doesn't stand for the entire SDHC type or property.
> +  For example, "emmc 5.1 phy" doesn't mean that this Xenon SDHC only supports
> +  eMMC 5.1.
> +
> +- marvell,xenon-phy-znr:
> +  Set PHY ZNR value.
> +  Only available for eMMC PHY 5.1 and eMMC PHY 5.0.
> +  Valid range = [0:0x1F].
> +  ZNR is set as 0xF by default if this property is not provided.
> +
> +- marvell,xenon-phy-zpr:
> +  Set PHY ZPR value.
> +  Only available for eMMC PHY 5.1 and eMMC PHY 5.0.
> +  Valid range = [0:0x1F].
> +  ZPR is set as 0xF by default if this property is not provided.
> +
> +- marvell,xenon-phy-nr-success-tun:
> +  Set the number of required consecutive successful sampling points used to
> +  identify a valid sampling window, in tuning process.
> +  Valid range = [1:7].
> +  Set as 0x4 by default if this property is not provided.
> +
> +- marvell,xenon-phy-tun-step-divider:
> +  Set the divider for calculating TUN_STEP.
> +  Set as 64 by default if this property is not provided.
> +
> +- marvell,xenon-phy-slow-mode:
> +  If this property is selected, transfers will bypass PHY.
> +  Only available when bus frequency lower than 55MHz in SDR mde.
> +  Disabled by default. Please only try this property if timing issues always
> +  occur with PHY enabled in eMMC HS SDR, SD SDR12, SD SDR25, SD SDR50 mode.
> +
> +- marvell,xenon-tun-count:
> +  Xenon SDHC SoC usually doesn't provide re-tuning counter in
> +  Capabilities Register 3 Bit[11:8].
> +  This property provides the re-tuning counter.
> +  If this property is not set, default re-tuning counter will
> +  be set as 0x9 in driver.
> +
> +- marvell,pad-type:
> +  Type of Armada 3700 SoC PHY PAD Voltage Controller register.
> +  Only valid when "marvell,armada-3700-sdhci" is selected.
> +  Two types: "sd" and "fixed-1-8v".
> +  If "sd" is slected, SoC PHY PAD is set as 3.3V at the beginning and is
> +  switched to 1.8V when SD in UHS-I.
> +  If "fixed-1-8v" is slected, SoC PHY PAD is fixed 1.8V, such as for eMMC.
> +  Please follow the examples with compatible "marvell,armada-3700-sdhci"
> +  in below.
> +
> +Example:
> +- For eMMC:
> +
> +	sdhci@aa0000 {
> +		compatible = "marvell,armada-8k-sdhci";
> +		reg = <0xaa0000 0x1000>;
> +		interrupts = <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>
> +		clocks = <&emmc_clk>;
> +		clock-names = "core";
> +		bus-width = <8>;
> +		mmc-ddr-1_8v;
> +		mmc-hs400-1_8v;
> +		marvell,xenon-sdhc-id = <0>;

Should be dropped? With that,

Acked-by: Rob Herring <robh@kernel.org>