Re: [PATCH] usb: role: rcar-usb3-role-switch: add support for R-Car SoCs

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, Apr 11, 2018 at 03:15:23AM +0000, Yoshihiro Shimoda wrote:
> > > +       host_node = of_parse_phandle(pdev->dev.of_node, "renesas,host", 0);
> > > +       if (!host_node)
> > > +               return -ENODEV;
> > > +
> > > +       pdev_host = of_find_device_by_node(host_node);
> > > +       if (!pdev_host)
> > > +               return -ENODEV;
> > > +
> > > +       of_node_put(host_node);
> > 
> > Isn't what Heikki tried to solve with graphs and stuff like that?
> 
> Heikki prepared "device connection" framework (devcon) [1] to get a device pointer.
> However, IIUC, we need to improve the framework for device tree environment because:
>  - The devcon needs each dev_name() through the endpoint array of struct device_connection.
>  - Each dev_name() on device tree environment will be <base address register>.<device name>,
>    f.e. "ee020000.usb". So, I don???t think adding such strings to a driver is a good way.

That is how the build-in connection descriptions are handled, but in
this case you want to describe them in your bindings, and to do that you
should use remote-endpoints, ie. OF graph bindings: bindings/graph.txt

> So, I wrote such a code by using existing APIs.
> Should I improve the framework first somehow? Or, is my understanding incorrect?

You don't necessarily need to propose any changes to the device
connection framework at this point, but you do need to use graph for
describing that connection. Once we add device graph handling to the
device connection framework, it is no problem to update this driver.

Of course, if you have time and interest in preparing a proposal for
graph handling to the device connection framework, I would appreciate
it.


Thanks,

-- 
heikki
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux