Re: [PATCH TF-A] fix(plat/rcar3): Fix RPC-IF device node name

[Geert Uytterhoeven <geert@linux-m68k.org>]

On Tue, Mar 29, 2022 at 2:17 PM Geert Uytterhoeven
<geert+renesas@glider.be> wrote:
> According to the Generic Names Recommendation in the Devicetree
> Specification Release v0.3, and the DT Bindings for the Renesas Reduced
> Pin Count Interface, the node name for a Renesas RPC-IF device should be
> "spi".  The node name matters, as the node is enabled by passing a DT
> fragment from TF-A to subsequent software.
>
> Fix this by renaming the device nodes from "rpc" to "spi".
>
> Fixes: 12c75c8886a0ee69 ("feat(plat/rcar3): emit RPC status to DT fragment if RPC unlocked")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> Background:
>
> On Renesas R-Car Gen3 platforms, the SPI Multi I/O Bus Controllers
> (RPC-IF) provide access to HyperFlash or QSPI storage.  On production
> systems, they are typically locked by the TF-A firmware, unless TF-A is
> built with RCAR_RPC_HYPERFLASH_LOCKED=0.  When unlocked, TF-A
> communicates this to subsequent software by passing a DT fragment that
> sets the "status" property of the RPC-IF device node to "okay".
>
> Unfortunately there are several issues preventing this from working all
> the way to Linux:
>   1. TF-A (and U-Boot on the receiving side) uses a device node name
>      that does not conform to the DT specification nor the DT bindings
>      for RPC-IF,
>   2. While U-Boot receives the RPC-IF enablement from TF-A, it does not
>      propagate it to Linux yet,
>   3. The DTS files that are part of Linux do not have RPC HyperFlash
>      support yet.
>
> This patch takes care of the first issue in TF-A.
>
> The related patches for U-Boot are [1].
> Patches to enable RPC-IF support in Linux are available at [2].

The patches to enable RPC HyperFlash support in Linux are now in
v5.19-rc1.  What needs to be done to accept the TF-A counterpart?

Thanks!

>
> Thanks for your comments!
>
> [1] "[PATCH u-boot 0/3] renesas: Fix RPC-IF enablement"
>     https://lore.kernel.org/r/cover.1648544792.git.geert+renesas@glider.be
> [2] "[PATCH 0/5] arm64: dts: renesas: rcar-gen3: Enable HyperFlash support"
>     https://lore.kernel.org/r/cover.1648548339.git.geert+renesas@glider.be
>
> ---
>  plat/renesas/rcar/bl2_plat_setup.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/plat/renesas/rcar/bl2_plat_setup.c b/plat/renesas/rcar/bl2_plat_setup.c
> index bbfa16927d6c2384..f85db8d650c6b1a5 100644
> --- a/plat/renesas/rcar/bl2_plat_setup.c
> +++ b/plat/renesas/rcar/bl2_plat_setup.c
> @@ -574,7 +574,7 @@ static void bl2_add_rpc_node(void)
>                 goto err;
>         }
>
> -       node = ret = fdt_add_subnode(fdt, node, "rpc@ee200000");
> +       node = ret = fdt_add_subnode(fdt, node, "spi@ee200000");
>         if (ret < 0) {
>                 goto err;
>         }

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