Hi Conor,

On Fri, Aug 19, 2022 at 8:40 PM [off-list ref] wrote:

On 15/08/2022 16:14, Lad Prabhakar wrote:

quoted

Add initial device tree for Renesas RZ/Five RISC-V CPU Core (AX45MP
Single).

Below is the list of IP blocks added in the initial SoC DTSI which can be
used to boot via initramfs on RZ/Five SMARC EVK:
- AX45MP CPU
- CPG
- PINCTRL
- PLIC
- SCIF0
- SYSC

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
v1->v2
* Dropped including makefile change
* Updated ndev count
---
 arch/riscv/boot/dts/renesas/r9a07g043.dtsi | 121 +++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 arch/riscv/boot/dts/renesas/r9a07g043.dtsi

diff --git a/arch/riscv/boot/dts/renesas/r9a07g043.dtsi b/arch/riscv/boot/dts/renesas/r9a07g043.dtsi
new file mode 100644
index 000000000000..b288d2607796
--- /dev/null
+++ b/arch/riscv/boot/dts/renesas/r9a07g043.dtsi

@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/*
+ * Device Tree Source for the RZ/Five SoC
+ *
+ * Copyright (C) 2022 Renesas Electronics Corp.
+ */
+
+#include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/clock/r9a07g043-cpg.h>
+
+/ {
+     compatible = "renesas,r9a07g043";
+     #address-cells = <2>;
+     #size-cells = <2>;
+
+     /* clock can be either from exclk or crystal oscillator (XIN/XOUT) */
+     extal_clk: extal-clk {
+             compatible = "fixed-clock";
+             #clock-cells = <0>;
+             /* This value must be overridden by the board */
+             clock-frequency = <0>;

What's the value in having the clock-frequency here if the board .dtsi
overwrites it? dtbs_check will complain if someone forgets to fill it
IIUC & what the missing frequency means is also kinda obvious, no?

Some external clocks may be optional. Hence "dtbs_check" will complain
if no "clock-frequency" is missing.

That aside, by convention so far we have put things like extals or
reference clocks below the /cpus node. Could you do the same here too
please?

Really? We've been putting them at the root node for a long time,
since the separate "clocks" grouping subnode was deprecated.
The extal-clk is not even part of the SoC, so it should definitely
not be under the /cpus node.

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