[PATCH v3 01/12] dt-bindings: clock: renesas,r9a08g045-vbattb: Document VBATTB

Claudiu
2024-08-30T13:02:34Z

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

The VBATTB IP of the Renesas RZ/G3S SoC controls the clock for RTC,
the tamper detector and a small general usage memory of 128B. Add
documentation for it.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v3:
- moved the file to clock dt bindings directory as it is the
only functionality supported at the moment; the other functionalities
(tamper detector, SRAM) are offered though register spreaded
though the address space of the VBATTB IP and not actually
individual devices; the other functionalities are not
planned to be supported soon and if they will be I think they
fit better on auxiliary bus than MFD
- dropped interrupt names as requested in the review process
- dropped the inner node for clock controller
- added #clock-cells
- added rtx clock
- updated description for renesas,vbattb-load-nanofarads
- included dt-bindings/interrupt-controller/irq.h in examples section

Changes in v2:
- changed file name and compatible
- updated title, description sections
- added clock controller part documentation and drop dedicated file
for it included in v1
- used items to describe interrupts, interrupt-names, clocks, clock-names,
resets
- dropped node labels and status
- updated clock-names for clock controller to cope with the new
logic on detecting the necessity to setup bypass

.../clock/renesas,r9a08g045-vbattb.yaml | 81 +++++++++++++++++++
1 file changed, 81 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/renesas,r9a08g045-vbattb.yaml

diff --git a/Documentation/devicetree/bindings/clock/renesas,r9a08g045-vbattb.yaml b/Documentation/devicetree/bindings/clock/renesas,r9a08g045-vbattb.yaml
new file mode 100644
index 000000000000..29df0e01fae5
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/renesas,r9a08g045-vbattb.yaml
@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/renesas,r9a08g045-vbattb.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas Battery Backup Function (VBATTB)
+
+description:
+ Renesas VBATTB is an always on powered module (backed by battery) which
+ controls the RTC clock (VBATTCLK), tamper detection logic and a small
+ general usage memory (128B).
+
+maintainers:
+ - Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
+
+properties:
+ compatible:
+ const: renesas,r9a08g045-vbattb
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ items:
+ - description: tamper detector interrupt
+
+ clocks:
+ items:
+ - description: VBATTB module clock
+ - description: RTC input clock (crystal oscillator or external clock device)
+
+ clock-names:
+ items:
+ - const: bclk
+ - const: rtx
+
+ '#clock-cells':
+ const: 1
+
+ power-domains:
+ maxItems: 1
+
+ resets:
+ items:
+ - description: VBATTB module reset
+
+ renesas,vbattb-load-nanofarads:
+ description: load capacitance of the on board crystal oscillator
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [ 4000, 7000, 9000, 12500 ]
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - clocks
+ - clock-names
+ - '#clock-cells'
+ - power-domains
+ - resets
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/clock/r9a08g045-cpg.h>
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/interrupt-controller/irq.h>
+
+ vbattb@1005c000 {
+ compatible = "renesas,r9a08g045-vbattb";
+ reg = <0x1005c000 0x1000>;
+ interrupts = <GIC_SPI 43 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&cpg CPG_MOD R9A08G045_VBAT_BCLK>, <&vbattb_xtal>;
+ clock-names = "bclk", "rtx";
+ #clock-cells = <1>;
+ power-domains = <&cpg>;
+ resets = <&cpg R9A08G045_VBAT_BRESETN>;
+ renesas,vbattb-load-nanofarads = <12500>;
+ };
--
2.39.2