On Tuesday 14 June 2016 04:34 AM, Douglas Anderson wrote:
> As of an earlier change in this series ("Documentation: mmc:
> sdhci-of-arasan: Add ability to export card clock") the SDHCI driver
> used on Rockchip SoCs can now expose its clock. Let's now specify that
> the PHY can use it.
>
> Letting the PHY get access to this clock means it can adjust
> phyctrl_frqsel field appropriately. Although the Rockchip PHY appears
> slightly different than the reference Arasan one, you can see that the
> Arasan datasheet [1] had it defined as:
> Select the frequency range of DLL operation:
> 3b'000 => 200MHz to 170 MHz
> 3b'001 => 170MHz to 140 MHz
> 3b'010 => 140MHz to 110 MHz
> 3b'011 => 110MHz to 80MHz
> 3b'100 => 80MHz to 50 MHz
> 3b'101 => 275Mhz to 250MHz
> 3b'110 => 250MHz to 225MHz
> 3b'111 => 225MHz to 200MHz
>
> On the Rockchip version of the PHY we have less granularity but the idea
> is the same.
>
> [1]: https://arasan.com/wp-content/media/eMMC-5-1-Total-Solution_Rev-1-3.pdf
>
> Signed-off-by: Douglas Anderson <diand...@chromium.org>
Acked-by: Kishon Vijay Abraham I <kis...@ti.com>
> ---
> Changes in v2:
> - List out clocks and clock names (Rob)
>
> Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
> b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
> index 555cb0f40690..e3ea55763b0a 100644
> --- a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
> +++ b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
> @@ -7,6 +7,13 @@ Required properties:
> - reg: PHY register address offset and length in "general
> register files"
>
> +Optional clocks using the clock bindings (see ../clock/clock-bindings.txt),
> +specified by name:
> + - clock-names: Should contain "emmcclk". Although this is listed as
> optional
> + (because most boards can get basic functionality without having
> + access to it), it is strongly suggested.
> + - clocks: Should have a phandle to the card clock exported by the SDHCI
> driver.
> +
> Example:
>
>
> @@ -20,6 +27,8 @@ grf: syscon@ff770000 {
> emmcphy: phy@f780 {
> compatible = "rockchip,rk3399-emmc-phy";
> reg = <0xf780 0x20>;
> + clocks = <&sdhci>;
> + clock-names = "emmcclk";
> #phy-cells = <0>;
> };
> };
>
