Re: [PATCH 1/2] edac: sifive: Add DT documentation for SiFive L2 cache Controller

Rob Herring
2019-03-28T13:16:57Z

On Tue, Mar 12, 2019 at 02:51:00PM +0530, Yash Shah wrote:
> DT documentation for L2 cache controller added.
>
> Signed-off-by: Yash Shah <yash.shah@sifive.com>
> ---
> .../devicetree/bindings/edac/sifive-edac-l2.txt | 31 ++++++++++++++++++++++
> 1 file changed, 31 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/edac/sifive-edac-l2.txt
>
> diff --git a/Documentation/devicetree/bindings/edac/sifive-edac-l2.txt b/Documentation/devicetree/bindings/edac/sifive-edac-l2.txt
> new file mode 100644
> index 0000000..abce09f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/edac/sifive-edac-l2.txt
> @@ -0,0 +1,31 @@
> +SiFive L2 Cache EDAC driver device tree bindings
> +-------------------------------------------------
> +This driver uses the EDAC framework to report L2 cache controller ECC errors.

Bindings are for h/w blocks, not drivers. (And Boris may want a single
driver, but bindings should reflect the h/w, not what Linux (currently)
wants.

Are the only controls for ECC? Are all the cache attributes discoverable
(size, ways, line size, level, etc.)?

> +
> +- compatible: Should be "sifive,<chip>-ccache" and "sifive,ccache<version>".
> + Supported compatible strings are:
> + "sifive,fu540-c000-ccache" for the SiFive cache controller v0 as integrated
> + onto the SiFive FU540 chip, and "sifive,ccache0" for the SiFive
> + cache controller v0 IP block with no chip integration tweaks.
> + Please refer to sifive-blocks-ip-versioning.txt for details
> +
> +- interrupts: Must contain 3 entries for FU540 (DirError, DataError, and
> + DataFail signals) or 4 entries for other chips (DirError, DirFail, DataError,
> + and DataFail signals)

3 or 4, but you only have 1 chip compatible defined?

> +
> +- interrupt-parent: Must be core interrupt controller

This is implied and could be in a parent node.

> +
> +- reg: Physical base address and size of L2 cache controller registers map
> + A second range can indicate L2 Loosely Integrated Memory
> +
> +- reg-names: Names for the cells of reg, must contain "control" and "sideband"
> +
> +Example:
> +
> +cache-controller@2010000 {
> + compatible = "sifive,fu540-c000-ccache", "sifive,ccache0";
> + interrupt-parent = <&plic>;
> + interrupts = <1 2 3>;
> + reg = <0x0 0x2010000 0x0 0x1000 0x0 0x8000000 0x0 0x2000000>;
> + reg-names = "control", "sideband";
> +};
> --
> 1.9.1
>