[RFC PATCH v3 1/8] dt-bindings: battry: add new battery parameters

From: Matti Vaittinen
Date: Thu Feb 20 2020 - 02:34:36 EST


- trickle-charge-current-microamp:

Some chargers have 3 charging stages. First one when battery is almost
empty is often called as trickle-charge. Last state when battery has been
"woken up" is usually called as fast-charge. In addition to this some
chargers have a 'middle state' which ROHM BD99954 data-sheet describes as
pre-charge. Some batteries can benefit from this 3-phase charging
[citation needed].

Introduce trickle-charge-current-microamp so that batteries can give
charging current limit for all three states.

- precharge-upper-limit-microvolt:

When battery voltage has reached certain limit we change from
trickle-charge to next charging state (pre-charge for BD99954). Allow
battery to specify this limit.

- re-charge-voltage-microvolt:

Allow giving a battery specific voltage limit for chargers which can
automatically re-start charging when battery has discharghed down to
this limit.

- over-voltage-threshold-microvolt

Allow specifying voltage threshold after which the battery is assumed to
be faulty.

Signed-off-by: Matti Vaittinen <matti.vaittinen@xxxxxxxxxxxxxxxxx>
Documentation/devicetree/bindings/power/supply/battery.txt | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/power/supply/battery.txt b/Documentation/devicetree/bindings/power/supply/battery.txt
index 5c913d4cf36c..1ad05dd59213 100644
--- a/Documentation/devicetree/bindings/power/supply/battery.txt
+++ b/Documentation/devicetree/bindings/power/supply/battery.txt
@@ -11,15 +11,21 @@ different type. This prevents unpredictable, potentially harmful,
behavior should a replacement that changes the battery type occur
without a corresponding update to the dtb.

+Please note that not all charger drivers respect all of the properties.
Required Properties:
- compatible: Must be "simple-battery"

Optional Properties:
+ - over-voltage-threshold-microvolt: battery over-voltage limit
+ - re-charge-voltage-microvolt: limit to automatically start charging again
- voltage-min-design-microvolt: drained battery voltage
- voltage-max-design-microvolt: fully charged battery voltage
- energy-full-design-microwatt-hours: battery design energy
- charge-full-design-microamp-hours: battery design capacity
+ - trickle-charge-current-microamp: current for trickle-charge phase
- precharge-current-microamp: current for pre-charge phase
+ - precharge-upper-limit-microvolt: limit when to change to constant charging
- charge-term-current-microamp: current for charge termination phase
- constant-charge-current-max-microamp: maximum constant input current
- constant-charge-voltage-max-microvolt: maximum constant input voltage

Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]