diff options
| author | Sander Speetjens <sander.speetjens@gmail.com> | 2026-10-18 17:10:55 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2026-10-19 22:24:02 +0200 |
| commit | 58db0fbeef2a2cceef452a874e9983ccd66f3e78 (patch) | |
| tree | a4cbdefbca9d5a1016be22d8642ff0d4b0ccf151 | |
| parent | 09399a7cd93222cf72bdb35e873c11cb0fbf5317 (diff) | |
dt-bindings: rtc: Add property for Raspberry Pi 5 RTC
The Raspberry Pi 5 has a built-in RTC that can be battery-backed
via the VBAT pin. When a rechargeable coin cell is used, the
hardware requires a trickle-charge voltage to keep the battery
topped up.
Expose the trickle-voltage-millivolt DT property so the driver can
program the correct charge voltage for board specific configurations with
the attached battery.
The property is added to the existing raspberrypi,bcm2835-firmware
binding (rather than creating a new RTC node) because the RTC is
accessed exclusively through the firmware mailbox interface.
We only $ref the individual property from rtc.yaml and do not
reference the full schema, because the firmware node name does not
match the $nodename pattern required by rtc.yaml.
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Sander Speetjens <sander.speetjens@gmail.com>
Link: https://patch.msgid.link/20261018151056.1051330-3-sander.speetjens@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
| -rw-r--r-- | Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml index 983ea80eaec9..dc71fd57834e 100644 --- a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml +++ b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml @@ -133,6 +133,11 @@ properties: required: - compatible + trickle-voltage-millivolt: + $ref: /schemas/rtc/rtc.yaml#/properties/trickle-voltage-millivolt + minimum: 1300 + maximum: 5000 + required: - compatible - mboxes @@ -144,6 +149,7 @@ examples: firmware { compatible = "raspberrypi,bcm2835-firmware", "simple-mfd"; mboxes = <&mailbox>; + trickle-voltage-millivolt = <3300>; firmware_clocks: clocks { compatible = "raspberrypi,firmware-clocks"; |