From: Matti Vaittinen <mazziesaccount@gmail.com>

Some of the chargers for lithium-ion batteries use a trickle-charging as
a first charging phase for very empty batteries, to "wake-up" the battery.
Trickle-charging is a low current, constant current phase. After the
voltage of the very empty battery has reached an upper limit for
trickle charging, the pre-charge phase is started with a higher current.

Allow defining the upper limit for trickle charging voltage, after which
the charging should be changed to the pre-charging.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

---
Revision history:
 v2 => v3:
 - Clarify the 'trickle-charging' the property refers to is the
   "pre-pre" -phase charging.
 RFCv1 => v2:
 - No changes
---
 Documentation/devicetree/bindings/power/supply/battery.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/power/supply/battery.yaml b/Documentation/devicetree/bindings/power/supply/battery.yaml
index bfb7b716ae13..d1a2080557a0 100644
--- a/Documentation/devicetree/bindings/power/supply/battery.yaml
+++ b/Documentation/devicetree/bindings/power/supply/battery.yaml
@@ -71,6 +71,10 @@ properties:
       NiMh bq24400) - that is different and not controlled by this
       property.
 
+  tricklecharge-upper-limit-microvolt:
+    description: limit when to change to precharge from trickle charge
+      Trickle-charging here refers "wake-up" or "pre-pre" -charging.
+
   precharge-current-microamp:
     description: current for pre-charge phase
 
-- 
2.51.0

On Wed, Nov 05, 2025 at 09:36:31AM +0200, Matti Vaittinen wrote:
> From: Matti Vaittinen <mazziesaccount@gmail.com>
> 
> Some of the chargers for lithium-ion batteries use a trickle-charging as
> a first charging phase for very empty batteries, to "wake-up" the battery.
> Trickle-charging is a low current, constant current phase. After the
> voltage of the very empty battery has reached an upper limit for
> trickle charging, the pre-charge phase is started with a higher current.
> 
> Allow defining the upper limit for trickle charging voltage, after which
> the charging should be changed to the pre-charging.
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> 

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof