diff mbox series

[v2,2/2] dt-bindings: mfd: cros-ec: add properties for thermal cooling cells

Message ID 20241125-extend_power_limit-v2-2-c3266a86e9b1@chromium.org (mailing list archive)
State Handled Elsewhere, archived
Headers show
Series Extend the cros_usbpd-charger to make it a passive thermal cooling device | expand

Commit Message

Sung-Chi, Li Nov. 25, 2024, 8:31 a.m. UTC
A charger chip is connect to the ChromeOS Embedded Controller (EC).
When external power input into the system, current would go through the
charger chip, generating heat in the system. The EC supports limiting
the input current, thus reducing the generated heat. As a result, EC is
a simulated passive cooling device.

We cannot reuse the existing charge managing mechanism in the power
framework due to:

- The power framework requires the charger to expose its thermal status,
  which is not a supported functionality on EC.
- We need to use different thermal sensors to run thermal control,
  rather than using thermal sensor on the charger.

Add the property '#cooling-cells' bindings, such that thermal framework
can recognize cros_ec as a valid thermal cooling device.

Signed-off-by: Sung-Chi Li <lschyi@chromium.org>
---
 Documentation/devicetree/bindings/mfd/google,cros-ec.yaml | 3 +++
 1 file changed, 3 insertions(+)

Comments

Krzysztof Kozlowski Nov. 25, 2024, 8:45 a.m. UTC | #1
On 25/11/2024 09:31, Sung-Chi Li wrote:
> A charger chip is connect to the ChromeOS Embedded Controller (EC).
> When external power input into the system, current would go through the
> charger chip, generating heat in the system. The EC supports limiting
> the input current, thus reducing the generated heat. As a result, EC is
> a simulated passive cooling device.

EC is not part of the SoC, therefore this is not a cooling device. It is
not thermal sensor either, but this you pushed before I could object.

> 
> We cannot reuse the existing charge managing mechanism in the power
> framework due to:
> 
> - The power framework requires the charger to expose its thermal status,
>   which is not a supported functionality on EC.

Fix power framework then.

> - We need to use different thermal sensors to run thermal control,
>   rather than using thermal sensor on the charger.

Nothing stops you from using thermal sensors or thermal control. Still,
this is not part of SoC, this is not thermal zone and this is not a SoC
cooling device.

NAK

Best regards,
Krzysztof
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
index aac8819bd00b..2b6f098057af 100644
--- a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
+++ b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
@@ -96,6 +96,9 @@  properties:
   '#gpio-cells':
     const: 2
 
+  '#cooling-cells':
+    const: 2
+
   gpio-controller: true
 
   typec: