Re: [PATCH 2/3] soc: renesas: Add support to read LSI DEVID register of RZ/G2{L,LC} SoC's

Hi Geert,

Thank you for the review.

On Wed, Jun 9, 2021 at 8:27 AM Geert Uytterhoeven [off-list ref] wrote:

Hi Prabhakar,

On Fri, Jun 4, 2021 at 8:09 PM Lad Prabhakar
[off-list ref] wrote:

quoted

Add support for reading the LSI DEVID register which is present in
SYSC block of RZ/G2{L,LC} SoC's.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>

Thanks for your patch!

quoted

--- a/drivers/soc/renesas/renesas-soc.c
+++ b/drivers/soc/renesas/renesas-soc.c

@@ -56,6 +56,11 @@ static const struct renesas_family fam_rzg2 __initconst __maybe_unused = {
        .reg    = 0xfff00044,           /* PRR (Product Register) */
 };

+static const struct renesas_family fam_rzg2l __initconst __maybe_unused = {
+       .name   = "RZ/G2L",
+       .reg    = 0x11020a04,

Please don't add hardcoded register addresses for new SoCs (i.e. drop
".reg").  The "renesas,r9a07g044-sysc" is always present.
And if it were missing, the hardcoded fallback would lead into the
classic CCCR/PRR scheme, which is not correct for RZ/G2L...

I wanted to avoid iomap for the entire sysc block for just a single register.

quoted

@@ -348,6 +361,25 @@ static int __init renesas_soc_init(void)
                goto done;
        }

+       np = of_find_compatible_node(NULL, NULL, "renesas,r9a07g044-sysc");
+       if (np) {
+               of_node_put(np);
+               chipid = ioremap(family->reg, 4);

Just use of_iomap(np, 0)...

will do.

quoted

+
+               if (chipid) {
+                       product = readl(chipid);

... and add the DEVID offset within the SYSC block here.

will do.

Cheers,
Prabhakar

quoted

+                       iounmap(chipid);
+
+                       if (soc->id && (product & 0xfffffff) != soc->id) {
+                               pr_warn("SoC mismatch (product = 0x%x)\n",
+                                       product);
+                               return -ENODEV;
+                       }
+               }
+
+               goto done;
+       }
+
        /* Try PRR first, then hardcoded fallback */
        np = of_find_compatible_node(NULL, NULL, "renesas,prr");
        if (np) {

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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