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5fd54ace | 1 | // SPDX-License-Identifier: GPL-2.0 |
69bec725 PC |
2 | /* |
3 | * of.c The helpers for hcd device tree support | |
4 | * | |
5 | * Copyright (C) 2016 Freescale Semiconductor, Inc. | |
1a7e3948 JH |
6 | * Author: Peter Chen <peter.chen@freescale.com> |
7 | * Copyright (C) 2017 Johan Hovold <johan@kernel.org> | |
69bec725 PC |
8 | */ |
9 | ||
10 | #include <linux/of.h> | |
82e82130 | 11 | #include <linux/of_graph.h> |
0573f2c5 | 12 | #include <linux/usb/of.h> |
69bec725 PC |
13 | |
14 | /** | |
7739376e JH |
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 | |
69bec725 | 18 | * |
7739376e JH |
19 | * Look up the node of a USB device given its parent hub device and one-based |
20 | * port number. | |
69bec725 | 21 | * |
60a93cff JH |
22 | * Return: A pointer to the node with incremented refcount if found, or |
23 | * %NULL otherwise. | |
69bec725 | 24 | */ |
7739376e | 25 | struct device_node *usb_of_get_device_node(struct usb_device *hub, int port1) |
69bec725 PC |
26 | { |
27 | struct device_node *node; | |
7739376e | 28 | u32 reg; |
69bec725 | 29 | |
7739376e JH |
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; | |
69bec725 PC |
36 | } |
37 | ||
38 | return NULL; | |
39 | } | |
7739376e | 40 | EXPORT_SYMBOL_GPL(usb_of_get_device_node); |
69bec725 | 41 | |
1a7e3948 JH |
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 | |
9f3aedbe | 48 | * has a node and its descriptors report the following: |
1a7e3948 JH |
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 | */ | |
57 | bool 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 | } | |
77 | EXPORT_SYMBOL_GPL(usb_of_has_combined_node); | |
78 | ||
82e82130 SB |
79 | static 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 | ||
c7a5403e JC |
87 | for_each_child_of_node(np, child) { |
88 | if (of_property_present(child, "reg")) { | |
89 | of_node_put(child); | |
82e82130 | 90 | return true; |
c7a5403e JC |
91 | } |
92 | } | |
82e82130 SB |
93 | |
94 | return false; | |
95 | } | |
96 | ||
97 | /** | |
98 | * usb_of_get_connect_type() - get a USB hub's port connect_type | |
99 | * @hub: hub to which port is for @port1 | |
100 | * @port1: one-based index of port | |
101 | * | |
102 | * Get the connect_type of @port1 based on the device node for @hub. If the | |
103 | * port is described in the OF graph, the connect_type is "hotplug". If the | |
104 | * @hub has a child device has with a 'reg' property equal to @port1 the | |
105 | * connect_type is "hard-wired". If there isn't an OF graph or child node at | |
106 | * all then the connect_type is "unknown". Otherwise, the port is considered | |
107 | * "unused" because it isn't described at all. | |
108 | * | |
109 | * Return: A connect_type for @port1 based on the device node for @hub. | |
110 | */ | |
111 | enum usb_port_connect_type usb_of_get_connect_type(struct usb_device *hub, int port1) | |
112 | { | |
113 | struct device_node *np, *child, *ep, *remote_np; | |
114 | enum usb_port_connect_type connect_type; | |
115 | ||
116 | /* Only set connect_type if binding has ports/hardwired devices. */ | |
117 | if (!usb_of_has_devices_or_graph(hub)) | |
118 | return USB_PORT_CONNECT_TYPE_UNKNOWN; | |
119 | ||
120 | /* Assume port is unused if there's a graph or a child node. */ | |
121 | connect_type = USB_PORT_NOT_USED; | |
122 | ||
123 | np = hub->dev.of_node; | |
124 | /* | |
125 | * Hotplug ports are connected to an available remote node, e.g. | |
126 | * usb-a-connector compatible node, in the OF graph. | |
127 | */ | |
128 | if (of_graph_is_present(np)) { | |
129 | ep = of_graph_get_endpoint_by_regs(np, port1, -1); | |
130 | if (ep) { | |
131 | remote_np = of_graph_get_remote_port_parent(ep); | |
132 | of_node_put(ep); | |
133 | if (of_device_is_available(remote_np)) | |
134 | connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG; | |
135 | of_node_put(remote_np); | |
136 | } | |
137 | } | |
138 | ||
139 | /* | |
140 | * Hard-wired ports are child nodes with a reg property corresponding | |
141 | * to the port number, i.e. a usb device. | |
142 | */ | |
143 | child = usb_of_get_device_node(hub, port1); | |
144 | if (of_device_is_available(child)) | |
145 | connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED; | |
146 | of_node_put(child); | |
147 | ||
148 | return connect_type; | |
149 | } | |
150 | EXPORT_SYMBOL_GPL(usb_of_get_connect_type); | |
151 | ||
1a7e3948 JH |
152 | /** |
153 | * usb_of_get_interface_node() - get a USB interface node | |
154 | * @udev: USB device of interface | |
155 | * @config: configuration value | |
156 | * @ifnum: interface number | |
157 | * | |
158 | * Look up the node of a USB interface given its USB device, configuration | |
159 | * value and interface number. | |
160 | * | |
161 | * Return: A pointer to the node with incremented refcount if found, or | |
162 | * %NULL otherwise. | |
163 | */ | |
164 | struct device_node * | |
165 | usb_of_get_interface_node(struct usb_device *udev, u8 config, u8 ifnum) | |
166 | { | |
167 | struct device_node *node; | |
168 | u32 reg[2]; | |
169 | ||
170 | for_each_child_of_node(udev->dev.of_node, node) { | |
171 | if (of_property_read_u32_array(node, "reg", reg, 2)) | |
172 | continue; | |
173 | ||
174 | if (reg[0] == ifnum && reg[1] == config) | |
175 | return node; | |
176 | } | |
177 | ||
178 | return NULL; | |
179 | } | |
180 | EXPORT_SYMBOL_GPL(usb_of_get_interface_node); |