Hi Geert,
Thank you for the review.
On Mon, Nov 8, 2021 at 4:40 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>
> Hi Prabhakar,
>
> On Wed, Nov 3, 2021 at 6:31 PM Lad Prabhakar
> <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> wrote:
> > On RZ/G2L devices should be explicitly pulled out of reset for it
> > to work. This patch adds support to read the "resets" property and
> > performs deassert/assert when required.
> >
> > Also, propagate the error to the caller of sci_parse_dt() instead of
> > returning NULL in case of failure.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
>
> Thanks for your patch!
>
> > ---
> > Hi Geert,
> > For handling the resets I was in dual mind whether to perform
> > reset based on compatible strings or soc-id, let me know your
> > thoughts. Currently no SoC's use "renesas,sci" so using the same
> > for performing the reset operation for SCI.
>
> We do, on H8/300.
>
Missed that.
> > --- a/drivers/tty/serial/sh-sci.c
> > +++ b/drivers/tty/serial/sh-sci.c
> > @@ -3203,23 +3204,58 @@ static const struct of_device_id of_sci_match[] = {
> > };
> > MODULE_DEVICE_TABLE(of, of_sci_match);
> >
> > +static void sci_reset_control_assert(void *data)
> > +{
> > + reset_control_assert(data);
> > +}
> > +
> > static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
> > unsigned int *dev_id)
> > {
> > struct device_node *np = pdev->dev.of_node;
> > + const struct of_device_id *of_id;
> > struct plat_sci_port *p;
> > struct sci_port *sp;
> > const void *data;
> > int id;
> >
> > if (!IS_ENABLED(CONFIG_OF) || !np)
> > - return NULL;
> > + return ERR_PTR(-EINVAL);
> > +
> > + of_id = of_match_device(of_sci_match, &pdev->dev);
> > + if (!of_id)
> > + return ERR_PTR(-EINVAL);
> >
> > - data = of_device_get_match_data(&pdev->dev);
> > + if (!strcmp(of_id->compatible, "renesas,scif-r9a07g044") ||
> > + !strcmp(of_id->compatible, "renesas,sci")) {
>
> This will match on H8/300, too, which doesn't have resets.
> Please match against "renesas,sci-r9a07g044" instead.
>
> Please don't use explicit strcmp() calls here, but add a flag to
> of_sci_match[].data.
>
Agreed, does the below hunk look good for handling the reset?
-#define SCI_OF_DATA(type, regtype) (void *)((type) << 16 | (regtype))
+#define SCIx_RESET BIT(31)
+#define SCI_OF_DATA(type, regtype, reset) (void *)(reset |
(type) << 16 | (regtype))
#define SCI_OF_TYPE(data) ((unsigned long)(data) >> 16)
#define SCI_OF_REGTYPE(data) ((unsigned long)(data) & 0xffff)
@@ -3169,7 +3170,11 @@ static const struct of_device_id of_sci_match[] = {
},
{
.compatible = "renesas,scif-r9a07g044",
- .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
+ .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE,
SCIx_RESET),
+ },
+ {
+ .compatible = "renesas,sci-r9a07g044",
+ .data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE, SCIx_RESET),
},
Cheers,
Prabhakar
> > + struct reset_control *rstc;
> > + int ret;
> > +
> > + rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> > + if (IS_ERR(rstc)) {
> > + dev_err(&pdev->dev, "Error: missing reset ctrl\n");
> > + return ERR_PTR(PTR_ERR(rstc));
> > + }
> > +
> > + ret = reset_control_deassert(rstc);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to deassert %d\n", ret);
> > + return ERR_PTR(ret);
> > + }
> > +
> > + ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
> > + ret);
> > + return ERR_PTR(ret);
> > + }
> > + }
> > +
> > + data = of_id->data;
> >
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
