[PATCH 0/3] Raspberry Pi 5 RTC driver

[Sander Speetjens]

The Raspberry Pi 5 has a battery-backed RTC located on the DA9091 PMIC.
Access to the RTC is provided exclusively through the VideoCore firmware
mailbox interface (not via a direct I2C/SPI register interface).

This series adds:
  - a DT binding for the "raspberrypi,rpi-rtc" compatible
  - the RTC driver that talks to the firmware
  - the corresponding DT node for the Raspberry Pi 5 B

The driver and binding are based on (and largely taken from) the
downstream Raspberry Pi kernel. The main changes for upstream are
the addition of a formal DT binding and moving the RTC node out of
the /soc node (it is not an MMIO device).

The driver supports time read/write, alarm, and optional trickle
charging voltage configuration via device-tree.

Testing
-------
- Hardware: Raspberry Pi 5 Model B revC
- Kernel: v7.2
- dt_binding_check: passed
- Basic RTC operations (read/write time, alarm) verified

Jonathan Bell (1):
  rtc: Add Raspberry Pi 5 RTC driver

Sander Speetjens (2):
  dt-bindings: rtc: Add Raspberry Pi 5 RTC binding
  arm64: dts: broadcom: Add RTC to Raspberry Pi 5 B

 .../bindings/rtc/raspberrypi,rtc-rpi.yaml     |  48 +++
 .../dts/broadcom/bcm2712-rpi-5-b-base.dtsi    |   7 +
 drivers/rtc/Kconfig                           |  11 +
 drivers/rtc/Makefile                          |   1 +
 drivers/rtc/rtc-rpi.c                         | 277 ++++++++++++++++++
 5 files changed, 344 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/raspberrypi,rtc-rpi.yaml
 create mode 100644 drivers/rtc/rtc-rpi.c

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2.55.0