FreeBSD/Linux Kernel Cross Reference
sys/dev/usb/usb_fdt_support.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause
      *
      * Copyright (c) 2019 Ian Lepore <ian@FreeBSD.org>
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/types.h>
    #include <sys/condvar.h>
    
    #include <dev/fdt/fdt_common.h>
    #include <dev/ofw/ofw_bus_subr.h>
    #include <dev/ofw/openfirm.h>
    
    #include <dev/usb/usb.h>
    #include <dev/usb/usbdi.h>
    #include <dev/usb/usb_process.h>
    #include <dev/usb/usb_busdma.h>
    #include <dev/usb/usb_controller.h>
    #include <dev/usb/usb_bus.h>
    #include <dev/usb/usb_device.h>
    #include <dev/usb/usb_freebsd.h>
    #include <dev/usb/usb_fdt_support.h>
    #include <dev/usb/net/usb_ethernet.h>
    
    /*
     * Define a constant for allocating an array pointers to serve as a stack of
     * devices between the controller and any arbitrary device on the bus.  The
     * stack ends with the device itself, so add 1 to the max hub nesting depth.
     */
    #define MAX_UDEV_NEST   (MAX(USB_HUB_MAX_DEPTH, USB_SS_HUB_DEPTH_MAX) + 1)
    
    static phandle_t
    find_udev_in_children(phandle_t parent, struct usb_device *udev)
    {
            phandle_t child;
            ssize_t proplen;
            uint32_t port;
            char compat[16]; /* big enough for "usb1234,abcd" */
    
            /*
             * USB device nodes in FDT have a compatible string of "usb" followed by
             * the vendorId,productId rendered in hex.  The port number is encoded
             * in the standard 'reg' property; it is one-based in the FDT data, but
             * usb_device.port_index is zero-based.  To uniquely identify a device,
             * both the compatible string and the port number must match.
             */
            snprintf(compat, sizeof(compat), "usb%x,%x",
                UGETW(udev->ddesc.idVendor), UGETW(udev->ddesc.idProduct));
            for (child = OF_child(parent); child != 0; child = OF_peer(child)) {
                    if (!ofw_bus_node_is_compatible(child, compat))
                            continue;
                    proplen = OF_getencprop(child, "reg", &port, sizeof(port));
                    if (proplen != sizeof(port))
                            continue;
                    if (port == (udev->port_index + 1))
                            return (child);
            }
            return (-1);
    }
    
    static bool
    is_valid_mac_addr(uint8_t *addr)
    {
    
            /*
             * All-bits-zero and all-bits-one are a couple common cases of what
             * might get read from unprogrammed eeprom or OTP data, weed them out.
             */
            if ((addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]) == 0x00)
                    return (false);
            if ((addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff)
                    return (false);
            return (true);
    }
    
   int
   usb_fdt_get_mac_addr(device_t dev, struct usb_ether* ue)
   {
           phandle_t node;
           ssize_t i, proplen;
           uint8_t mac[sizeof(ue->ue_eaddr)];
           static const char *properties[] = {
               "mac-address",
               "local-mac-address"
           };
   
           if ((node = usb_fdt_get_node(ue->ue_dev, ue->ue_udev)) == -1)
                   return (ENXIO);
           for (i = 0; i < nitems(properties); ++i) {
                   proplen = OF_getprop(node, properties[i], mac, sizeof(mac));
                   if (proplen == sizeof(mac) && is_valid_mac_addr(mac)) {
                           memcpy(ue->ue_eaddr, mac, sizeof(ue->ue_eaddr));
                           return (0);
                   }
           }
           return (ENXIO);
   }
   
   phandle_t
   usb_fdt_get_node(device_t dev, struct usb_device *udev)
   {
           struct usb_device *ud;
           struct usb_device *udev_stack[MAX_UDEV_NEST];
           phandle_t controller_node, node;
           int idx;
   
           /*
            * Start searching at the controller node.  The usb_device links to the
            * bus, and its parent is the controller.  If we can't get the
            * controller node, the requesting device cannot be in the fdt data.
            */
           if ((controller_node = ofw_bus_get_node(udev->bus->parent)) == -1)
                   return (-1);
   
           /*
            * Walk up the usb hub ancestor hierarchy, building a stack of devices
            * that begins with the requesting device and includes all the hubs
            * between it and the controller, NOT including the root hub (the FDT
            * bindings treat the controller and root hub as the same thing).
            */
           for (ud = udev, idx = 0; ud->parent_hub != NULL; ud = ud->parent_hub) {
                   KASSERT(idx < nitems(udev_stack), ("Too many hubs"));
                   udev_stack[idx++] = ud;
           }
   
           /*
            * Now walk down the stack of udevs from the controller to the
            * requesting device, and also down the hierarchy of nested children of
            * the controller node in the fdt data.  At each nesting level of fdt
            * data look for a child node whose properties match the vID,pID,portIdx
            * tuple for the udev at the corresponding layer of the udev stack.  As
            * long as we keep matching up child nodes with udevs, loop and search
            * within the children of the just-found child for the next-deepest hub.
            * If at any level we fail to find a matching node, stop searching and
            * return.  When we hit the end of the stack (the requesting device) we
            * return whatever the result was for the search at that nesting level.
            */
           for (node = controller_node;;) {
                   node = find_udev_in_children(node, udev_stack[--idx]);
                   if (idx == 0 || node == -1)
                           break;
           }
           return (node);
   }

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