Re: [PATCH] ndfc driver

Anton Vorontsov
2008-12-09T02:11:18Z

Hi Sean,

On Mon, Dec 08, 2008 at 07:34:46PM -0500, Sean MacLennan wrote:
> On Thu, 4 Dec 2008 09:01:07 -0500
> "Josh Boyer" <jwboyer@linux.vnet.ibm.com> wrote:
>
> > In addition to an example DTS patch (probably to warp itself), could
> > you briefly write up a binding and put it in
> > Documentation/powerpc/dts-bindings/amcc (or similar)? Also please CC
> > the devicetree-discuss list on that part.
>
> Here is a start at the doc. I have sent it as a patch, but could just
> as easily send raw text.
>
> The example comes from the warp dts, just with less partitions, so I
> have not included a warp dts patch here.
>
> Cheers,
> Sean
>
> diff --git a/Documentation/powerpc/dts-bindings/amcc/ndfc.txt
> b/Documentation/powerpc/dts-bindings/amcc/ndfc.txt new file mode 100644
> index 0000000..668f4a9
> --- /dev/null
> +++ b/Documentation/powerpc/dts-bindings/amcc/ndfc.txt
> @@ -0,0 +1,31 @@
> +AMCC NDFC (NanD Flash Controller)
> +
> +Required properties:
> +- compatible : "amcc,ndfc".
> +- reg : should specify chip select and size used for the chip (0x2000).
> +
> +Optional properties:
> +- ccr : NDFC config and control register value (default 0).
> +- bank-settings : NDFC bank configuration register value (default 0).
> +- partition(s) - follows the OF MTD standard for partitions
> +
> +Example:
> +
> +nand@1,0 {
> + compatible = "amcc,ndfc";

The first line in this file says that this is a controller...

> + reg = <0x00000001 0x00000000 0x00002000>;
> + ccr = <0x00001000>;
> + bank-settings = <0x80002222>;
> + #address-cells = <1>;
> + #size-cells = <1>;
> + partition@0 {

So this is a controller with partitions? ;-)

Recalling my own mistakes with the FSL UPM NAND controller bindings,
and Josh's comment:

http://www.mail-archive.com/linuxppc-dev@ozlabs.org/msg16572.html

I think the bindings should look like this:

nand-controller@.. {
...controller's properties...

nand-chip@... {
...chip's properties...

partition@... {
...partition's properties...
};
};

nand-chip@... {
...
};
};

Sure, I understand that there are plenty of boards with the "old"
scheme flashed into the firmware... Just something you might
want to consider for the future updates for the driver/bindings.

Thanks,

--
Anton Vorontsov
email: cbouatmailru@gmail.com
irc://irc.freenode.net/bd2