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authorBastian Krause <bst@pengutronix.de>2020-09-17 20:32:39 +0200
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2020-09-24 09:56:03 +0200
commit965fe1ceea05de735f63d1c1f90f0310fc830a8d (patch)
tree92c748dd8eda99d758cf0e2ed23e8476039292df /Documentation
parent35425bafc772ee189e3c3790d7c672b80ba65909 (diff)
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dt-bindings: rtc: let aux-voltage-chargeable supersede trickle-diode-disable
Some RTCs can be equipped with a chargeable battery or supercap. Every RTC allowing this whose driver's implement it are charged by default. To disable this the trickle-diode-disable flag exists. If a driver did not support charging and some time later one wants to add that feature, there is currently no way to do it without breaking dt backwards compatibility. RTCs on boards without the trickle-diode-disable flag in their device tree would suddenly charge their battery/supercap which is a change in behavior. Change that by introducing aux-voltage-chargeable, not as a flag but as a uint32 enum allowing to set "do not charge" (0) or "charge" (1). This dt property is optional, so we can now distinguish these cases. Care must be taken to support the old behavior for device trees without aux-voltage-chargeable nonetheless to stay compatible. Signed-off-by: Bastian Krause <bst@pengutronix.de> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Reviewed-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20200917183246.19446-2-bst@pengutronix.de
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/rtc/rtc.yaml10
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/rtc/rtc.yaml b/Documentation/devicetree/bindings/rtc/rtc.yaml
index ee237b2ed66a..6b8a11325691 100644
--- a/Documentation/devicetree/bindings/rtc/rtc.yaml
+++ b/Documentation/devicetree/bindings/rtc/rtc.yaml
@@ -17,6 +17,15 @@ properties:
$nodename:
pattern: "^rtc(@.*|-[0-9a-f])*$"
+ aux-voltage-chargeable:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [0, 1]
+ description: |
+ Tells whether the battery/supercap of the RTC (if any) is
+ chargeable or not:
+ 0: not chargeable
+ 1: chargeable
+
quartz-load-femtofarads:
$ref: /schemas/types.yaml#/definitions/uint32
description:
@@ -35,6 +44,7 @@ properties:
description:
Do not use internal trickle charger diode. Should be given if
internal trickle charger diode should be disabled.
+ deprecated: true
trickle-resistor-ohms:
$ref: /schemas/types.yaml#/definitions/uint32