Messages in this thread | | | Subject | Re: [PATCH 1/3] usb: USB Type-C Connector Class | From | Oliver Neukum <> | Date | Thu, 18 Feb 2016 14:44:25 +0100 |
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On Thu, 2016-02-18 at 15:25 +0200, Heikki Krogerus wrote:
Hi,
> > We have port directories for port power switching. How is > > the connector directory linked to them? > > I'm sorry, I don't think I understand this point.
Like this:
oneukum@linux-dtbq:/sys/bus/usb/devices/3-0:1.0> ls -l total 0 -rw-r--r-- 1 root root 4096 Feb 18 14:34 authorized -r--r--r-- 1 root root 4096 Feb 18 14:34 bAlternateSetting -r--r--r-- 1 root root 4096 Feb 18 14:34 bInterfaceClass -r--r--r-- 1 root root 4096 Feb 18 14:34 bInterfaceNumber -r--r--r-- 1 root root 4096 Feb 18 14:34 bInterfaceProtocol -r--r--r-- 1 root root 4096 Feb 18 14:34 bInterfaceSubClass -r--r--r-- 1 root root 4096 Feb 18 14:34 bNumEndpoints lrwxrwxrwx 1 root root 0 Feb 17 15:59 driver -> ../../../../../bus/usb/drivers/hub drwxr-xr-x 3 root root 0 Feb 18 09:35 ep_81 -r--r--r-- 1 root root 4096 Feb 18 14:34 modalias drwxr-xr-x 2 root root 0 Feb 18 09:35 power lrwxrwxrwx 1 root root 0 Feb 17 15:59 subsystem -> ../../../../../bus/usb -r--r--r-- 1 root root 4096 Feb 18 14:34 supports_autosuspend -rw-r--r-- 1 root root 4096 Feb 18 14:34 uevent drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port1 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port10 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port11 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port12 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port13 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port14 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port15 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port2 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port3 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port4 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port5 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port6 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port7 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port8 drwxr-xr-x 3 root root 0 Feb 18 09:35 usb3-port9
usb*-port*
They correspond to the connectors a system has. It seems to me that we want a link connecting them if the correspondance is known.
> > Likewise, if we have USB PD, we have to know how that > > is linked to the connector directory. > > So you mean when we have USB PD PHY or controller, right? That > will be the parent of the connector device if we have one on the > platform.
So the parentage is different on whether a PD controller is present? That needs to be documented. And so we cannot deal with separate modules for a PD driver?
[..] > > Furthermore, do these files support poll?
At least the current role and mode can change, so in principle poll() makes sense.
> > And lastly we can get "Attention" as a message connected > > with a connector in an alternate mode. How does user space > > learn about that? > > The class should notify the userspace with uevent on > connection/disconnection regardless what is being connected, or what > mode the connector enters initially.
Yes, but "Attention" in the sense of 6.4.4.3.6 of the PD spec. Does this need to be handled in the kernel? Do we generate a uevent for that?
> So do you want to see that explained in the ABI document?
No.
Regards Oliver
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