Re: [PATCH v10 01/12] exynos5-fimc-is: Add Exynos5 FIMC-IS device tree bindings documentation

[Mark Rutland <mark.rutland@arm.com>]

Hi,

Apologies for the late reply. I have a few comments, but nothing major.

On Fri, Oct 18, 2013 at 06:37:28AM +0100, Arun Kumar K wrote:
> The patch adds the DT binding documentation for Samsung
> Exynos5 SoC series imaging subsystem (FIMC-IS).
> 
> Signed-off-by: Arun Kumar K <arun.kk@samsung.com>
> Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
> ---
>  .../devicetree/bindings/media/exynos5-fimc-is.txt  |   84 ++++++++++++++++++++
>  1 file changed, 84 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/exynos5-fimc-is.txt
> 
> diff --git a/Documentation/devicetree/bindings/media/exynos5-fimc-is.txt b/Documentation/devicetree/bindings/media/exynos5-fimc-is.txt
> new file mode 100644
> index 0000000..0525417
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/exynos5-fimc-is.txt
> @@ -0,0 +1,84 @@
> +Samsung EXYNOS5 SoC series Imaging Subsystem (FIMC-IS)
> +------------------------------------------------------
> +
> +The camera subsystem on Samsung Exynos5 SoC has some changes relative
> +to previous SoC versions. Exynos5 has almost similar MIPI-CSIS and
> +FIMC-LITE IPs but has a much improved version of FIMC-IS which can
> +handle sensor controls and camera post-processing operations. The
> +Exynos5 FIMC-IS has a dedicated ARM Cortex A5 processor, many
> +post-processing blocks (ISP, DRC, FD, ODC, DIS, 3DNR) and two
> +dedicated scalers (SCC and SCP).
> +
> +fimc-is node
> +------------
> +
> +Required properties:
> +
> +- compatible        : must be "samsung,exynos5250-fimc-is"

s/must be/should contain/

> +- reg               : physical base address and size of the memory mapped
> +                      registers
> +- interrupt-parent  : parent interrupt controller

I don't think this is actually required in all cases. It's a standard property
that people can add if it happens to be required in a particular instance.

> +- interrupts        : fimc-is interrupt to the parent interrupt controller

Is this the only interrupt the device generates? If so:

- interrupts: interrupt-specifier for the fimc-is interrupt.

> +- clocks            : list of clock specifiers, corresponding to entries in
> +                      clock-names property
> +- clock-names       : must contain "isp", "mcu_isp", "isp_div0", "isp_div1",
> +                      "isp_divmpwm", "mcu_isp_div0", "mcu_isp_div1" entries,
> +                      matching entries in the clocks property
> +- samsung,pmu       : phandle to the Power Management Unit (PMU) node
> +
> +i2c-isp (ISP I2C bus controller) nodes
> +--------------------------------------
> +The i2c-isp node is defined as the child node of fimc-is.

There are multiple of these, so how about the following instead:

The i2c-isp nodes should be children of the fimc-is node.

It might be worth pointing out that ranges, #address-cells, and #size-cells
should be present as appropriate.

> +
> +Required properties:
> +
> +- compatible	: should be "samsung,exynos4212-i2c-isp" for Exynos4212,
> +		  Exynos4412 and Exynos5250 SoCs

Similarly, s/should be/must contain/

> +- reg		: physical base address and length of the registers set
> +- clocks	: must contain gate clock specifier for this controller
> +- clock-names	: must contain "i2c_isp" entry

I'd prefer clocks to be described as for the simc-is, with clock names being
something like:

- clock-names: should contain "i2c_isp" for the gate clock.

> +
> +For the i2c-isp node, it is required to specify a pinctrl state named "default",
> +according to the pinctrl bindings defined in ../pinctrl/pinctrl-bindings.txt.

I'd prefer a mention of pinctrl-0 and pinctrl-names, as that's what most other
bindings do.

Also, as this is described as required it should be in the example.

> +
> +Device tree nodes of the image sensors controlled directly by the FIMC-IS
> +firmware must be child nodes of their corresponding ISP I2C bus controller node.
> +The data link of these image sensors must be specified using the common video
> +interfaces bindings, defined in video-interfaces.txt.

These don't seem to be in the example and probably should be.

Otherwise, this looks fine. With those points fixed up:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Thanks,
Mark.