[PATCH/RFC v3 01/22] reset: Add renesas,rst DT bindings

Add DT bindings for the Renesas R-Car Reset Controller (R-Car Gen1
RESET/WDT and R-Car Gen2/Gen3 RST).

As the features provided by the hardware module differ a lot across the
various SoC families and members, only SoC-specific compatible values
are defined.

For now we use the RST only for providing access to the state of the
mode pins.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Magnus Damm <redacted>
---
v3:
  - Clarify current usage,
  - Use "renesas,<soctype>-rst" instead of "renesas,rst-<soctype>",
  - Drop "syscon" compatible value,
  - Add R-Car M3-W,
  - Add R-Car Gen1,

v2:
  - Add Acked-by.
---
 .../devicetree/bindings/reset/renesas,rst.txt      | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/renesas,rst.txt

diff --git a/Documentation/devicetree/bindings/reset/renesas,rst.txt b/Documentation/devicetree/bindings/reset/renesas,rst.txt
new file mode 100644
index 0000000000000000..488c72e1ee849cd3
--- /dev/null
+++ b/Documentation/devicetree/bindings/reset/renesas,rst.txt

@@ -0,0 +1,35 @@
+DT bindings for the Renesas R-Car Reset Controller
+
+The R-Car Reset Controller provides reset control, and implements the following
+functions:
+  - Latching of the levels on mode pins when PRESET# is negated,
+  - Mode monitoring register,
+  - Reset control of peripheral devices (on R-Car Gen1),
+  - Watchdog timer (on R-Car Gen1).