[PATCH 5/8] mmc: dw_mmc: dt-binding: Add tuning related things

[jh80.chung@samsung.com (Jaehoon Chung)]

Hi, Heiko.

On 09/01/2015 03:24 AM, Heiko Stuebner wrote:
> From: Alexandru M Stan <amstan@chromium.org>
> 
> Add ciu_drv, ciu_sample clocks and default-sample-phase. This will later
> be used by tuning code.

As i know, ciu_drv and ciu_sample clocks are generated with "ciu" clock.
But in these patch-set, ciu_drv and ciu_sample are controlled by clock framework.
It's a little strange.
Are there ciu_drv and ciu_sample clock on Rockchip?

Best Regards,
Jaehoon Chung

> 
> We do not touch ciu_drive (and by extension define default-drive-phase).
> Drive phase is mostly used to define minimum hold times, while one could
> write some code to determine what phase meets the minimum hold time
> (ex 10 degrees) this will not work with the current clock phase framework
> (which floors angles, so we'll get 0 deg, and there's no way to know what
> resolution the floors happen at). We assume that the default drive angles
> set by the hardware are good enough.
> 
> Signed-off-by: Alexandru M Stan <amstan@chromium.org>
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> ---
>  Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt
> index 346c609..5edadc2 100644
> --- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt
> +++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt
> @@ -42,11 +42,13 @@ Optional properties:
>  * clocks: from common clock binding: handle to biu and ciu clocks for the
>    bus interface unit clock and the card interface unit clock.
>  
> -* clock-names: from common clock binding: Shall be "biu" and "ciu".
> -  If the biu clock is missing we'll simply skip enabling it.  If the
> -  ciu clock is missing we'll just assume that the clock is running at
> +* clock-names: from common clock binding: Shall be "biu", "ciu", "ciu_drv" and
> +  "ciu_sample".  If the biu clock is missing we'll simply skip enabling it.
> +  If the ciu clock is missing we'll just assume that the clock is running at
>    clock-frequency.  It is an error to omit both the ciu clock and the
> -  clock-frequency.
> +  clock-frequency.  "ciu_drv" and "ciu_sample" are used to control the clock
> +  phases, "ciu_sample" is required for tuning high speed modes (if no other
> +  custom tuning method is defined).
>  
>  * clock-frequency: should be the frequency (in Hz) of the ciu clock.  If this
>    is specified and the ciu clock is specified then we'll try to set the ciu
> @@ -75,6 +77,10 @@ Optional properties:
>  * vmmc-supply: The phandle to the regulator to use for vmmc.  If this is
>    specified we'll defer probe until we can find this regulator.
>  
> +* default-sample-phase: The default phase to set ciu_sample at probing, low
> +  speeds or in case where all phases work at tuning time. If not specified
> +  0 deg will be used.
> +
>  Aliases:
>  
>  - All the MSHC controller nodes should be represented in the aliases node using
>