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1/*
2 * of.c The helpers for hcd device tree support
3 *
4 * Copyright (C) 2016 Freescale Semiconductor, Inc.
5 * Author: Peter Chen <peter.chen@freescale.com>
6 *
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 of
9 * the License as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/of.h>
21
22/**
23 * usb_of_get_child_node - Find the device node match port number
24 * @parent: the parent device node
25 * @portnum: the port number which device is connecting
26 *
27 * Find the node from device tree according to its port number.
28 *
29 * Return: On success, a pointer to the device node, %NULL on failure.
30 */
31struct device_node *usb_of_get_child_node(struct device_node *parent,
32 int portnum)
33{
34 struct device_node *node;
35 u32 port;
36
37 for_each_child_of_node(parent, node) {
38 if (!of_property_read_u32(node, "reg", &port)) {
39 if (port == portnum)
40 return node;
41 }
42 }
43
44 return NULL;
45}
46EXPORT_SYMBOL_GPL(usb_of_get_child_node);
47
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * of.c The helpers for hcd device tree support
4 *
5 * Copyright (C) 2016 Freescale Semiconductor, Inc.
6 * Author: Peter Chen <peter.chen@freescale.com>
7 * Copyright (C) 2017 Johan Hovold <johan@kernel.org>
8 */
9
10#include <linux/of.h>
11#include <linux/of_graph.h>
12#include <linux/usb/of.h>
13
14/**
15 * usb_of_get_device_node() - get a USB device node
16 * @hub: hub to which device is connected
17 * @port1: one-based index of port
18 *
19 * Look up the node of a USB device given its parent hub device and one-based
20 * port number.
21 *
22 * Return: A pointer to the node with incremented refcount if found, or
23 * %NULL otherwise.
24 */
25struct device_node *usb_of_get_device_node(struct usb_device *hub, int port1)
26{
27 struct device_node *node;
28 u32 reg;
29
30 for_each_child_of_node(hub->dev.of_node, node) {
31 if (of_property_read_u32(node, "reg", ®))
32 continue;
33
34 if (reg == port1)
35 return node;
36 }
37
38 return NULL;
39}
40EXPORT_SYMBOL_GPL(usb_of_get_device_node);
41
42/**
43 * usb_of_has_combined_node() - determine whether a device has a combined node
44 * @udev: USB device
45 *
46 * Determine whether a USB device has a so called combined node which is
47 * shared with its sole interface. This is the case if and only if the device
48 * has a node and its descriptors report the following:
49 *
50 * 1) bDeviceClass is 0 or 9, and
51 * 2) bNumConfigurations is 1, and
52 * 3) bNumInterfaces is 1.
53 *
54 * Return: True iff the device has a device node and its descriptors match the
55 * criteria for a combined node.
56 */
57bool usb_of_has_combined_node(struct usb_device *udev)
58{
59 struct usb_device_descriptor *ddesc = &udev->descriptor;
60 struct usb_config_descriptor *cdesc;
61
62 if (!udev->dev.of_node)
63 return false;
64
65 switch (ddesc->bDeviceClass) {
66 case USB_CLASS_PER_INTERFACE:
67 case USB_CLASS_HUB:
68 if (ddesc->bNumConfigurations == 1) {
69 cdesc = &udev->config->desc;
70 if (cdesc->bNumInterfaces == 1)
71 return true;
72 }
73 }
74
75 return false;
76}
77EXPORT_SYMBOL_GPL(usb_of_has_combined_node);
78
79static bool usb_of_has_devices_or_graph(const struct usb_device *hub)
80{
81 const struct device_node *np = hub->dev.of_node;
82 struct device_node *child;
83
84 if (of_graph_is_present(np))
85 return true;
86
87 for_each_child_of_node(np, child)
88 if (of_property_present(child, "reg"))
89 return true;
90
91 return false;
92}
93
94/**
95 * usb_of_get_connect_type() - get a USB hub's port connect_type
96 * @hub: hub to which port is for @port1
97 * @port1: one-based index of port
98 *
99 * Get the connect_type of @port1 based on the device node for @hub. If the
100 * port is described in the OF graph, the connect_type is "hotplug". If the
101 * @hub has a child device has with a 'reg' property equal to @port1 the
102 * connect_type is "hard-wired". If there isn't an OF graph or child node at
103 * all then the connect_type is "unknown". Otherwise, the port is considered
104 * "unused" because it isn't described at all.
105 *
106 * Return: A connect_type for @port1 based on the device node for @hub.
107 */
108enum usb_port_connect_type usb_of_get_connect_type(struct usb_device *hub, int port1)
109{
110 struct device_node *np, *child, *ep, *remote_np;
111 enum usb_port_connect_type connect_type;
112
113 /* Only set connect_type if binding has ports/hardwired devices. */
114 if (!usb_of_has_devices_or_graph(hub))
115 return USB_PORT_CONNECT_TYPE_UNKNOWN;
116
117 /* Assume port is unused if there's a graph or a child node. */
118 connect_type = USB_PORT_NOT_USED;
119
120 np = hub->dev.of_node;
121 /*
122 * Hotplug ports are connected to an available remote node, e.g.
123 * usb-a-connector compatible node, in the OF graph.
124 */
125 if (of_graph_is_present(np)) {
126 ep = of_graph_get_endpoint_by_regs(np, port1, -1);
127 if (ep) {
128 remote_np = of_graph_get_remote_port_parent(ep);
129 of_node_put(ep);
130 if (of_device_is_available(remote_np))
131 connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
132 of_node_put(remote_np);
133 }
134 }
135
136 /*
137 * Hard-wired ports are child nodes with a reg property corresponding
138 * to the port number, i.e. a usb device.
139 */
140 child = usb_of_get_device_node(hub, port1);
141 if (of_device_is_available(child))
142 connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
143 of_node_put(child);
144
145 return connect_type;
146}
147EXPORT_SYMBOL_GPL(usb_of_get_connect_type);
148
149/**
150 * usb_of_get_interface_node() - get a USB interface node
151 * @udev: USB device of interface
152 * @config: configuration value
153 * @ifnum: interface number
154 *
155 * Look up the node of a USB interface given its USB device, configuration
156 * value and interface number.
157 *
158 * Return: A pointer to the node with incremented refcount if found, or
159 * %NULL otherwise.
160 */
161struct device_node *
162usb_of_get_interface_node(struct usb_device *udev, u8 config, u8 ifnum)
163{
164 struct device_node *node;
165 u32 reg[2];
166
167 for_each_child_of_node(udev->dev.of_node, node) {
168 if (of_property_read_u32_array(node, "reg", reg, 2))
169 continue;
170
171 if (reg[0] == ifnum && reg[1] == config)
172 return node;
173 }
174
175 return NULL;
176}
177EXPORT_SYMBOL_GPL(usb_of_get_interface_node);