On July 30, 2024 12:18:20 PM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
On 30/07/2024 11:52, Arend Van Spriel wrote:
On July 30, 2024 11:01:43 AM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
On 30/07/2024 08:37, Arend Van Spriel wrote:
+ Linus W
On July 30, 2024 5:31:15 AM Jacobe Zang <jacobe.zang@xxxxxxxxxx> wrote:
Not only AP6275P Wi-Fi device but also all Broadcom wireless devices allow
external low power clock input. In DTS the clock as an optional choice in
the absence of an internal clock.
Reviewed-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx>
Signed-off-by: Jacobe Zang <jacobe.zang@xxxxxxxxxx>
---
.../bindings/net/wireless/brcm,bcm4329-fmac.yaml | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git
a/Documentation/devicetree/bindings/net/wireless/brcm,bcm4329-fmac.yaml
b/Documentation/devicetree/bindings/net/wireless/brcm,bcm4329-fmac.yaml
index 2c2093c77ec9a..a3607d55ef367 100644
--- a/Documentation/devicetree/bindings/net/wireless/brcm,bcm4329-fmac.yaml
+++ b/Documentation/devicetree/bindings/net/wireless/brcm,bcm4329-fmac.yaml
@@ -122,6 +122,14 @@ properties:
NVRAM. This would normally be filled in by the bootloader from platform
configuration data.
+ clocks:
+ items:
+ - description: External Low Power Clock input (32.768KHz)
+
+ clock-names:
+ items:
+ - const: lpo
+
We still have an issue that this clock input is also present in the
bindings specification broadcom-bluetooth.yaml (not in bluetooth
subfolder). This clock is actually a chip resource. What happens if both
are defined and both wifi and bt drivers try to enable this clock? Can this
be expressed in yaml or can we only put a textual warning in the property
descriptions?
Just like all clocks, what would happen? It will be enabled.
Oh, wow! Cool stuff. But seriously is it not a problem to have two entities
controlling one and the same clock? Is this use-case taken into account by
the clock framework?
Yes, it is handled correctly. That's a basic use-case, handled by CCF
since some years (~12?). Anyway, whatever OS is doing (or not doing)
with the clocks is independent of the bindings here. The question is
Agree. Probably the bindings would not be the place to document this if it
would be an issue.
about hardware - does this node, which represents PCI interface of the
chip, has/uses the clocks.
The schematics I found for the wifi module and the khadas edge platform
show these are indeed wired to the chip.
Regards,
Arend
Best regards,
Krzysztof
