On 03.11.2015 18:16, Pavel Fedin wrote:
> Add documentation for new subnode properties, allowing bank configuration.
> Based on u-boot implementation, but heavily reworked.
Please mention also fixing the size of mapped memory in <reg> in the
example.
>
> Signed-off-by: Pavel Fedin <p.fedin@xxxxxxxxxxx>
> ---
> .../bindings/arm/samsung/exynos-srom.txt | 68 +++++++++++++++++++++-
> 1 file changed, 66 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/arm/samsung/exynos-srom.txt b/Documentation/devicetree/bindings/arm/samsung/exynos-srom.txt
> index 33886d5..ee378ca 100644
> --- a/Documentation/devicetree/bindings/arm/samsung/exynos-srom.txt
> +++ b/Documentation/devicetree/bindings/arm/samsung/exynos-srom.txt
> @@ -5,8 +5,72 @@ Required properties:
>
> - reg: offset and length of the register set
>
> -Example:
> +- #address-cells: Must be set to 2 to allow memory address translation
> +
> +- #size-cells: Must be set to 1 to allow CS address passing
> +
> +- ranges: Must be set up to reflect the memory layout with four integer values
> + per bank:
> + <bank-number> 0 <physical address of bank> <size>
> +
These are mentioned as required but actually they shouldn't be, if there
are no peripherals.
By making them required you would be breaking ABI. I see that actually
the ABI is not broken by the driver so maybe just add a separate
optional section for subdevices.
In that section you would described required attributes and subnodes.
> +Sub-nodes:
> +The SROM controller can be used to attach external peripherials. In this case
s/peripherials/peripherals/
> +device nodes should be added as subnodes to the SROMc node. These subnodes,
> +except regular device specification, should contain the following properties,
> +describing configuration of the relevant SROM bank:
> +
> +Required properties:
> +- reg: bank number, base address (relative to start of the bank) and size of
> + the memory mapped for the device. Note that base address will be
> + typically 0 as this is the start of the bank.
> +
> +- samsung,srom-timing : array of 6 integers, specifying bank timings in the
> + following order: Tacp, Tcah, Tcoh, Tacc, Tcos, Tacs.
> + Each value is specified in cycles (0 - 15) and has the
> + following meaning:
> + Tacp : Page mode access cycle at Page mode
> + Tcah : Address holding time after CSn
> + Tcoh : Chip selection hold on OEn
> + Tacc : Access cycle
This one has values 1-32 clock cycles
> + Tcos : Chip selection set-up before OEn
> + Tacs : Address set-up before CSn
> +
> +Optional properties:
> +- reg-io-width : data width in bytes (1 or 2). If omitted, default of 1 is used.
> +
> +- samsung,srom-page-mode : page mode configuration for the bank:
> + 0 - normal (one data)
> + 1 - four data
> + If omitted, default of 0 is used.
> +
> +Example: basic definition, no banks are configured
> + sromc@12570000 {
> + compatible = "samsung,exynos-srom";
> + reg = <0x12570000 0x14>;
> + };
> +
> +Example: SROMc with smsc 911x ethernet chip on bank 3
Maybe:
s/smsc 911x ethernet/SMSC911x Ethernet/
Best regards,
Krzysztof
> sromc@12570000 {
> + #address-cells = <2>;
> + #size-cells = <1>;
> + ranges = <0 0 0x04000000 0x20000 // Bank0
> + 1 0 0x05000000 0x20000 // Bank1
> + 2 0 0x06000000 0x20000 // Bank2
> + 3 0 0x07000000 0x20000>; // Bank3
> +
> compatible = "samsung,exynos-srom";
> - reg = <0x12570000 0x10>;
> + reg = <0x12570000 0x14>;
> +
> + ethernet@3 {
> + compatible = "smsc,lan9115";
> + reg = <3 0 0x10000>; // Bank 3, offset = 0
> + phy-mode = "mii";
> + interrupt-parent = <&gpx0>;
> + interrupts = <5 8>;
> + reg-io-width = <2>;
> + smsc,irq-push-pull;
> + smsc,force-internal-phy;
> +
> + samsung,srom-config = <1 9 12 1 9 1 1>;
> + };
> };
>
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