Re: Question about SC16IS752 device tree.

[Zhou Yanjie]

Hi Nikolaus,

On 2022/5/10 上午4:19, H. Nikolaus Schaller wrote:
> Hi,
>
> > Am 09.05.2022 um 20:41 schrieb Zhou Yanjie <zhouyanjie@xxxxxxxxxxxxxx>:
> >
> > Hi Paul,
> >
> > On 2022/5/10 上午2:13, Paul Cercueil wrote:
> > > I can't say for sure that it's your problem, but your bluetooth nodes are missing "reg" properties.
> >
> > Unfortunately it doesn't seem to be the problem here, I added "reg" and
> > the problem persists, and I've looked at other device trees that contain
> > "brcm,bcm43438-bt", none of them use "reg", and "reg" is not mentioned in
> > neither "Documentation/devicetree/bindings/serial/nxp,sc16is7xx.txt" nor
> > "Documentation/devicetree/bindings/net/broadcom-bluetooth.yaml".
> what happens if you remove the serdev children from DTS? Does the driver create two separate /dev/tty ports? And do they work?


Yes, there will be two separate /dev/tty ports (ttySC0 and ttySC1), and
both ports can work normally, but at this time the two bluetooth modules
are not working.

I guess it is because the driver does not detect bluetooth module nodes,
so the inability to operate "reset-gpios" and "device-wakeup-gpios" causes
the bluetooth module to work incorrectly.


> Maybe the sc16is752 driver does not separate them for child nodes, i.e. while "reg" should be added it may not be handled?


I'm not too sure, I'm not very familiar with serial port systems.
If the truth is what you think, how should I improve it?


Best regards!


> BR,
> Nikolaus