// SPDX-License-Identifier: GPL-2.0
/*
* of.c The helpers for hcd device tree support
*
* Copyright (C) 2016 Freescale Semiconductor, Inc.
* Author: Peter Chen <[email protected]>
* Copyright (C) 2017 Johan Hovold <[email protected]>
*/
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/usb/of.h>
/**
* usb_of_get_device_node() - get a USB device node
* @hub: hub to which device is connected
* @port1: one-based index of port
*
* Look up the node of a USB device given its parent hub device and one-based
* port number.
*
* Return: A pointer to the node with incremented refcount if found, or
* %NULL otherwise.
*/
struct device_node *usb_of_get_device_node(struct usb_device *hub, int port1)
{
struct device_node *node;
u32 reg;
for_each_child_of_node(hub->dev.of_node, node) {
if (of_property_read_u32(node, "reg", ®))
continue;
if (reg == port1)
return node;
}
return NULL;
}
EXPORT_SYMBOL_GPL(usb_of_get_device_node);
/**
* usb_of_has_combined_node() - determine whether a device has a combined node
* @udev: USB device
*
* Determine whether a USB device has a so called combined node which is
* shared with its sole interface. This is the case if and only if the device
* has a node and its descriptors report the following:
*
* 1) bDeviceClass is 0 or 9, and
* 2) bNumConfigurations is 1, and
* 3) bNumInterfaces is 1.
*
* Return: True iff the device has a device node and its descriptors match the
* criteria for a combined node.
*/
bool usb_of_has_combined_node(struct usb_device *udev)
{
struct usb_device_descriptor *ddesc = &udev->descriptor;
struct usb_config_descriptor *cdesc;
if (!udev->dev.of_node)
return false;
switch (ddesc->bDeviceClass) {
case USB_CLASS_PER_INTERFACE:
case USB_CLASS_HUB:
if (ddesc->bNumConfigurations == 1) {
cdesc = &udev->config->desc;
if (cdesc->bNumInterfaces == 1)
return true;
}
}
return false;
}
EXPORT_SYMBOL_GPL(usb_of_has_combined_node);
static bool usb_of_has_devices_or_graph(const struct usb_device *hub)
{
const struct device_node *np = hub->dev.of_node;
struct device_node *child;
if (of_graph_is_present(np))
return true;
for_each_child_of_node(np, child) {
if (of_property_present(child, "reg")) {
of_node_put(child);
return true;
}
}
return false;
}
/**
* usb_of_get_connect_type() - get a USB hub's port connect_type
* @hub: hub to which port is for @port1
* @port1: one-based index of port
*
* Get the connect_type of @port1 based on the device node for @hub. If the
* port is described in the OF graph, the connect_type is "hotplug". If the
* @hub has a child device has with a 'reg' property equal to @port1 the
* connect_type is "hard-wired". If there isn't an OF graph or child node at
* all then the connect_type is "unknown". Otherwise, the port is considered
* "unused" because it isn't described at all.
*
* Return: A connect_type for @port1 based on the device node for @hub.
*/
enum usb_port_connect_type usb_of_get_connect_type(struct usb_device *hub, int port1)
{
struct device_node *np, *child, *ep, *remote_np;
enum usb_port_connect_type connect_type;
/* Only set connect_type if binding has ports/hardwired devices. */
if (!usb_of_has_devices_or_graph(hub))
return USB_PORT_CONNECT_TYPE_UNKNOWN;
/* Assume port is unused if there's a graph or a child node. */
connect_type = USB_PORT_NOT_USED;
np = hub->dev.of_node;
/*
* Hotplug ports are connected to an available remote node, e.g.
* usb-a-connector compatible node, in the OF graph.
*/
if (of_graph_is_present(np)) {
ep = of_graph_get_endpoint_by_regs(np, port1, -1);
if (ep) {
remote_np = of_graph_get_remote_port_parent(ep);
of_node_put(ep);
if (of_device_is_available(remote_np))
connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
of_node_put(remote_np);
}
}
/*
* Hard-wired ports are child nodes with a reg property corresponding
* to the port number, i.e. a usb device.
*/
child = usb_of_get_device_node(hub, port1);
if (of_device_is_available(child))
connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
of_node_put(child);
return connect_type;
}
EXPORT_SYMBOL_GPL(usb_of_get_connect_type);
/**
* usb_of_get_interface_node() - get a USB interface node
* @udev: USB device of interface
* @config: configuration value
* @ifnum: interface number
*
* Look up the node of a USB interface given its USB device, configuration
* value and interface number.
*
* Return: A pointer to the node with incremented refcount if found, or
* %NULL otherwise.
*/
struct device_node *
usb_of_get_interface_node(struct usb_device *udev, u8 config, u8 ifnum)
{
struct device_node *node;
u32 reg[2];
for_each_child_of_node(udev->dev.of_node, node) {
if (of_property_read_u32_array(node, "reg", reg, 2))
continue;
if (reg[0] == ifnum && reg[1] == config)
return node;
}
return NULL;
}
EXPORT_SYMBOL_GPL(usb_of_get_interface_node);
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