[PATCH v5 1/2] usb: provide a device tree node to USB devices

[Bin Meng]

On Thu, May 21, 2020 at 12:40 AM Michael Walle <michael at walle.cc> wrote:
>
> It is possible to specify a device tree node for an USB device. This is
> useful if you have a static USB setup and want to use aliases which
> point to these nodes, like on the Raspberry Pi.
> The nodes are matched against their hub port number, the compatible
> strings are not matched for now.
>
> Signed-off-by: Michael Walle <michael at walle.cc>
> ---
> This is a new patch in v5:
>   Fixes the ethernet0 alias on Raspberry Pis. This has never been
>   working, but wasn't a problem until recently. Patch 2/2 changes
>   the allocation of the numbers and reserves possible aliases.
>
>  drivers/usb/host/usb-uclass.c | 41 ++++++++++++++++++++++++++++++-----
>  1 file changed, 36 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/host/usb-uclass.c b/drivers/usb/host/usb-uclass.c
> index cb79dfbbd5..f42c0625cb 100644
> --- a/drivers/usb/host/usb-uclass.c
> +++ b/drivers/usb/host/usb-uclass.c
> @@ -494,6 +494,35 @@ static int usb_match_one_id(struct usb_device_descriptor *desc,
>         return usb_match_one_id_intf(desc, int_desc, id);
>  }
>
> +static ofnode usb_get_ofnode(struct udevice *hub, int port)
> +{
> +       ofnode node;
> +       u32 reg;
> +
> +       if (!dev_has_of_node(hub))
> +               return ofnode_null();
> +
> +       /*
> +        * The USB controller and its USB hub are two different udevices,
> +        * but the device tree has only one node for both. Thus we are
> +        * assigning this node to both udevices.
> +        * If port is zero, the controller scans its root hub, thus we
> +        * are using the same ofnode as the controller here.
> +        */
> +       if (!port)
> +               return dev_ofnode(hub);
> +
> +       ofnode_for_each_subnode(node, dev_ofnode(hub)) {
> +               if (ofnode_read_u32(node, "reg", &reg))
> +                       continue;
> +
> +               if (reg == port)
> +                       return node;
> +       }
> +
> +       return ofnode_null();
> +}
> +
>  /**
>   * usb_find_and_bind_driver() - Find and bind the right USB driver
>   *
> @@ -502,13 +531,14 @@ static int usb_match_one_id(struct usb_device_descriptor *desc,
>  static int usb_find_and_bind_driver(struct udevice *parent,
>                                     struct usb_device_descriptor *desc,
>                                     struct usb_interface_descriptor *iface,
> -                                   int bus_seq, int devnum,
> +                                   int bus_seq, int devnum, int port,
>                                     struct udevice **devp)
>  {
>         struct usb_driver_entry *start, *entry;
>         int n_ents;
>         int ret;
>         char name[30], *str;
> +       ofnode node = usb_get_ofnode(parent, port);
>
>         *devp = NULL;
>         debug("%s: Searching for driver\n", __func__);
> @@ -533,8 +563,8 @@ static int usb_find_and_bind_driver(struct udevice *parent,
>                          * find another driver. For now this doesn't seem
>                          * necesssary, so just bind the first match.
>                          */
> -                       ret = device_bind(parent, drv, drv->name, NULL, -1,
> -                                         &dev);
> +                       ret = device_bind_ofnode(parent, drv, drv->name, NULL,
> +                                                node, &dev);
>                         if (ret)
>                                 goto error;
>                         debug("%s: Match found: %s\n", __func__, drv->name);
> @@ -651,9 +681,10 @@ int usb_scan_device(struct udevice *parent, int port,
>         if (ret) {
>                 if (ret != -ENOENT)
>                         return ret;
> -               ret = usb_find_and_bind_driver(parent, &udev->descriptor, iface,
> +               ret = usb_find_and_bind_driver(parent, &udev->descriptor,
> +                                              iface,
>                                                udev->controller_dev->seq,
> -                                              udev->devnum, &dev);
> +                                              udev->devnum, port, &dev);
>                 if (ret)
>                         return ret;
>                 created = true;
> --

Do we have tests added ?

Regards,
Bin