On 21/10/2024 08:41, Marco Felsch wrote: > On 24-10-07, Krzysztof Kozlowski wrote: >> On 07/10/2024 14:58, POPESCU Catalin wrote: >>>>>> >>>>>> + vcc-supply: >>>>>> + description: >>>>>> + phandle of the regulator that provides the supply voltage. >>>>>> + >>>>>> + reset-gpios: >>>>>> + description: >>>>>> + Chip powerdown/reset signal (PDn). >>>>>> + >>>>> Hi Catalin, >>>>> >>>>> For NXP WIFI/BT chip, WIFI and BT share the one PDn pin, which means that both wifi and BT controller will be powered on and off at the same time. >>>>> Taking the M.2 NXP WIFI/BT module as an example, pin56(W_DISABLE1) is connected to the WIFI/BT chip PDn pin, we has already controlled this pin in the corresponding PCIe/SDIO controller dts nodes. >>>>> It is not clear to me what exactly pins for vcc-supply and reset-gpios you describing here. Can you help understand the corresponding pins on M.2 interface as an example? Thanks. >>> >>> Hi Sherry, >>> >>> Regulators and reset controls being refcounted, we can then implement >>> powerup sequence in both bluetooth/wlan drivers and have the drivers >>> operate independently. This way bluetooth driver would has no dependance >>> on the wlan driver for : >>> >>> - its power supply >>> >>> - its reset pin (PDn) >>> >>> - its firmware (being downloaded as part of the combo firmware) >>> >>> For the wlan driver we use mmc power sequence to drive the chip reset >>> pin and there's another patchset that adds support for reset control >>> into the mmc pwrseq simple driver. >>> >>>> Please wrap your replies. >>>> >>>> It seems you need power sequencing just like Bartosz did for Qualcomm WCN. >>> >>> Hi Krzysztof, >>> >>> I'm not familiar with power sequencing, but looks like way more >>> complicated than reset controls. So, why power sequencing is recommended >>> here ? Is it b/c a supply is involved ? >> >> Based on earlier message: >> >> "For NXP WIFI/BT chip, WIFI and BT share the one PDn pin, which means >> that both wifi and BT controller will be powered on and off at the same >> time." >> >> but maybe that's not needed. No clue, I don't know the hardware. But be >> carefully what you write in the bindings, because then it will be ABI. > > We noticed the new power-sequencing infrastructure which is part of 6.11 > too but I don't think that this patch is wrong. The DT ABI won't break > if we switch to the power-sequencing later on since the "reset-gpios" > are not marked as required. So it is up to the driver to handle it > either via a separate power-sequence driver or via "power-supply" and > "reset-gpios" directly. That's not the point. We expect correct hardware description. If you say now it has "reset-gpios" but later say "actually no, because it has PMU", I respond: no. Describe the hardware, not current Linux. Best regards, Krzysztof
