Re: [PATCHv4 3/4] iio: devicetree: Add DT binding documentation for Exynos3250 ADC

[Tomasz Figa <tomasz.figa@gmail.com>]

Hi Chanwoo,

On 18.06.2014 04:21, Chanwoo Choi wrote:
> This patch add DT binding documentation for Exynos3250 ADC IP. Exynos3250 has
> special clock ('sclk_tsadc') for ADC which provide clock to internal ADC.
> 
> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
> Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
>  .../devicetree/bindings/arm/samsung/exynos-adc.txt   | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt
> index 5d49f2b..3a5af82 100644
> --- a/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt
> +++ b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt
> @@ -14,6 +14,8 @@ Required properties:
>  				for exynos4412/5250 controllers.
>  			Must be "samsung,exynos-adc-v2" for
>  				future controllers.
> +			Must be "samsung,exynos3250-adc-v2" for
> +				for exynos3250 controllers.

You might change the last line for:

for controllers compatible with ADC of Exynos3250.

This is to make it also account for possible future SoCs which need
exactly the same handling.


>  - reg:			Contains ADC register address range (base address and
>  			length) and the address of the phy enable register.
>  - interrupts: 		Contains the interrupt information for the timer. The
> @@ -21,7 +23,11 @@ Required properties:
>  			the Samsung device uses.
>  - #io-channel-cells = <1>; As ADC has multiple outputs
>  - clocks		From common clock binding: handle to adc clock.
> +			From common clock binding: handle to sclk_tsadc clock
> +			if using Exynos3250.

This is not clear. It might sound like the "sclk_tsadc" clock is used on
Exynos3250 and "adc" on remaining SoCs. I'd write this simply as:

>From common clock bindings: handles to clocks specified in "clock-names"
property, in the same order.

>  - clock-names		From common clock binding: Shall be "adc".
> +			From common clock binding: Shall be "sclk_tsadc"
> +			if using Exynos3250.

This is also not clear. I'd recommend something like:

>From common clock bindings: list of clock input names used by ADC block:
    - "adc" : ADC bus clock,
    - "sclk_tsadc" : ADC special clock (only for Exynos3250 and
compatible ADC blocks).

Best regards,
Tomasz