Hi, On Wed, Jul 31, 2024 at 02:57:37PM GMT, Arend van Spriel wrote: > On 7/30/2024 7:38 PM, Sebastian Reichel wrote: > > Hi, > > > > On Tue, Jul 30, 2024 at 01:16:57PM GMT, Arend Van Spriel wrote: > > > 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. > > > > I have a Rockchip RK3588 Evaluation Board on my desk, which uses the > > same WLAN AP6275P module. I think I already commented on a prior > > version of this series: The LPO clock is needed to make the PCIe > > device visible on the bus. That means this series only works if the > > clock has already been running. Otherwise the PCIe driver will never > > be probed. To become visible the devices requires: > > > > 1. The LPO clock to be enabled > > 2. Power to be applied > > 3. The WL_EN gpio to be configured correctly > > > > If one of the above is not met, the device will not even appear in > > 'lspci'. I believe the binding needs to take into consideration, that > > pwrseq is needed for the PCIe side. Fortuantely the heavy lifting of > > creating the proper infrastructure for this has already been done by > > Bartosz Golaszewski for Qualcomm WLAN chips. What is missing is a > > pwrseq driver for the Broadcom chip (or this specific module?). > > That does not really make sense. There is no relation between the LPO clock > and the PCIe clocks so 1) being a requirement for probing the device looks > odd. It also does not match past experience when I assisted Andy Green in > getting this module up and running almost two years ago. Well, first of all I can easily reproduce this on my RK3588 EVB1. I intentionally ignore any bluetooth bits to avoid cross-effects from bluetooth enabling any clocks / regulators / GPIOs and make sure the RTC output clock is disabled at boot time (i.e. boot once without any reference to the RTC clock and without 'clk_ignore_unused' kernel argument). When booting up like this the WLAN device is not visible in 'lspci' despite the WL_REG_ON GPIO being hogged. If I additionally hack the RTC output clock to be enabled the WLAN device becomes visible in 'lspci'. The datasheet fully explains this: https://www.lcsc.com/datasheet/lcsc_datasheet_2203281730_AMPAK-Tech-AP6275P_C2984107.pdf PDF Page 23/24 (20/21 in the footer) has the Host Interface Timing Diagram. WL_REG_ON should only be enabled after 2 cycles from LPO. That means with LPO being disabled WL_REG_ON cannot be enabled. I'm pretty sure WL_REG_ON means WLAN_REGULATOR_ON, so the logic is not powered. On page 27 (24 in the footer) there is also a PCIe Power-On Timing diagram, which shows that WL_REG_ON must be enabled before the PCIe refclk is enabled. So there is a specific power up sequence, which must be followed. Greetings, -- Sebastian
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