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

From: Geert Uytterhoeven <geert+renesas@glider.be>
To: tf-a@lists.trustedfirmware.org
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>,
	linux-renesas-soc@vger.kernel.org,
	Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH TF-A] fix(plat/rcar3): Fix RPC-IF device node name
Date: Tue, 29 Mar 2022 14:17:20 +0200	[thread overview]
Message-ID: <3685623bed84674039adb61e723288d359ab0a50.1648544199.git.geert+renesas@glider.be> (raw)

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].

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;
 	}
-- 
2.25.1

