On Mon, Feb 25, 2013 at 01:06:53PM -0600, Bastian Hecht wrote:
> We add the capabilty to probe Renesas SCI devices using Device Tree setup.
>
> Signed-off-by: Bastian Hecht <hechtb+renesas@xxxxxxxxx>
> ---
> Based on the topic/all+next branch from the 17th Feb. I couldn't rebase it on the current HEAD as the armadillo-reference code currently isn't in.
>
> changelog v2:
> - Renamed title to "Add OF support"
> - Removed fixed configurations from driver and added the following binding props:
> - renesas,scscr
> - renesas,scbrr-algo-id
> - renesas,autoconf
> - renesas,regtype
> See patch for descriptions
>
This looks much better, only a few minor nits.
> +Optional properties:
> +- renesas,autoconf : Set if device is capable of auto configuration
> +- renesas,regtype : Overwrite the register layout. Some legacy hardware versions
> + use a non-default register layout. Possible layouts are
> + 0 = SCIx_SH2_SCIF_FIFODATA_REGTYPE
> + 1 = SCIx_SH3_SCIF_REGTYPE
> + 2 = SCIx_SH4_SCIF_REGTYPE
> + 3 = SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE
> + 4 = SCIx_SH4_SCIF_FIFODATA_REGTYPE
> + 5 = SCIx_SH7705_SCIF_REGTYPE
> +
Here I would still opt to provide the full regtype set, even for the
"standard" layouts, as it's quite possible that newer port-types will use
older layouts.
In this case you could keep 0 as the probe type (which would be the
default anyways, so effectively a no-op), and then do the upper bounding
via SCIx_NR_REGTYPES.
> +/* This array belongs to the DT binding definition "renesas,regtype" */
> +static const char sci_regtype_modes[] = {
> + SCIx_SH2_SCIF_FIFODATA_REGTYPE,
> + SCIx_SH3_SCIF_REGTYPE,
> + SCIx_SH4_SCIF_REGTYPE,
> + SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE,
> + SCIx_SH4_SCIF_FIFODATA_REGTYPE,
> + SCIx_SH7705_SCIF_REGTYPE
> +};
> +
At which point all of this can go away.
> +static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
> + int *dev_id)
> +{
..
> + prop = of_get_property(np, "renesas,regtype", NULL);
> + if (prop) {
> + val = be32_to_cpup(prop);
> + if (val <= 0 || val >= ARRAY_SIZE(sci_regtype_modes)) {
> + dev_err(&pdev->dev, "invalid DT prop regtype\n");
> + return NULL;
> + }
> + p->regtype = sci_regtype_modes[be32_to_cpup(prop)];
> + }
> +
You can then compare against SCIx_PROBE_REGTYPE and SCIx_NR_REGTYPES, and
assign p->regtype the be32_to_cpup() value directly. Which will also make
it trivial to add new regtypes in the future, we would only need to
update the binding documentation.
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