Re: [PATCH] Enable wifi on the BeagleV-Ahead

[Thomas Gerner]

Am 12.05.26 um 20:39 schrieb Shengyu Qu:
> > +
> > +    brcmf_pwrseq: brcmf-pwrseq {
> > +        compatible = "mmc-pwrseq-simple";
> > +        reset-gpios = <&gpio2 31 GPIO_ACTIVE_LOW>; /* WL-REG-ON */
> > +    };
> >   };
>
> I think such pwrseq won't work? Need to set timing parameter, for 
> example:
> https://github.com/torvalds/linux/blob/1d5dcaa3bd65f2e8c9baa14a393d3a2dc5db7524/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts#L71 

I think this is not necessary. The WiFi chip gets powerd up with the 
board power and the power cannot be disabled. The only job for this 
pwrseq is to release gpio2 pin 31 when the kernel initialize the chip. 
According to the data sheet the release of the pin should happen not 
earlier than 2 cycles of the 32.768kHz clock after powered up. As the 
kernel start takes much longer than this 2 cycles and I think there is 
no extra timing necessary.

The broadcom driver has a also a property "reset-gpios", but this does 
not work. It does not configure the pin as output, it configure it as 
input. Then the driver does not initialize the chip. May be this is a 
bug in the broadcom driver, don't know.

Best regards
Thomas