tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * otg.c -- USB OTG utility code
3 *
4 * Copyright (C) 2004 Texas Instruments
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12#include <linux/kernel.h>
13#include <linux/export.h>
14#include <linux/err.h>
15#include <linux/device.h>
16#include <linux/slab.h>
17
18#include <linux/usb/otg.h>
19
20static LIST_HEAD(phy_list);
21static DEFINE_SPINLOCK(phy_lock);
22
23static struct usb_phy *__usb_find_phy(struct list_head *list,
24 enum usb_phy_type type)
25{
26 struct usb_phy *phy = NULL;
27
28 list_for_each_entry(phy, list, head) {
29 if (phy->type != type)
30 continue;
31
32 return phy;
33 }
34
35 return ERR_PTR(-ENODEV);
36}
37
38static void devm_usb_phy_release(struct device *dev, void *res)
39{
40 struct usb_phy *phy = *(struct usb_phy **)res;
41
42 usb_put_phy(phy);
43}
44
45static int devm_usb_phy_match(struct device *dev, void *res, void *match_data)
46{
47 return res == match_data;
48}
49
50/**
51 * devm_usb_get_phy - find the USB PHY
52 * @dev - device that requests this phy
53 * @type - the type of the phy the controller requires
54 *
55 * Gets the phy using usb_get_phy(), and associates a device with it using
56 * devres. On driver detach, release function is invoked on the devres data,
57 * then, devres data is freed.
58 *
59 * For use by USB host and peripheral drivers.
60 */
61struct usb_phy *devm_usb_get_phy(struct device *dev, enum usb_phy_type type)
62{
63 struct usb_phy **ptr, *phy;
64
65 ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
66 if (!ptr)
67 return NULL;
68
69 phy = usb_get_phy(type);
70 if (!IS_ERR(phy)) {
71 *ptr = phy;
72 devres_add(dev, ptr);
73 } else
74 devres_free(ptr);
75
76 return phy;
77}
78EXPORT_SYMBOL(devm_usb_get_phy);
79
80/**
81 * usb_get_phy - find the USB PHY
82 * @type - the type of the phy the controller requires
83 *
84 * Returns the phy driver, after getting a refcount to it; or
85 * -ENODEV if there is no such phy. The caller is responsible for
86 * calling usb_put_phy() to release that count.
87 *
88 * For use by USB host and peripheral drivers.
89 */
90struct usb_phy *usb_get_phy(enum usb_phy_type type)
91{
92 struct usb_phy *phy = NULL;
93 unsigned long flags;
94
95 spin_lock_irqsave(&phy_lock, flags);
96
97 phy = __usb_find_phy(&phy_list, type);
98 if (IS_ERR(phy)) {
99 pr_err("unable to find transceiver of type %s\n",
100 usb_phy_type_string(type));
101 goto err0;
102 }
103
104 get_device(phy->dev);
105
106err0:
107 spin_unlock_irqrestore(&phy_lock, flags);
108
109 return phy;
110}
111EXPORT_SYMBOL(usb_get_phy);
112
113/**
114 * devm_usb_put_phy - release the USB PHY
115 * @dev - device that wants to release this phy
116 * @phy - the phy returned by devm_usb_get_phy()
117 *
118 * destroys the devres associated with this phy and invokes usb_put_phy
119 * to release the phy.
120 *
121 * For use by USB host and peripheral drivers.
122 */
123void devm_usb_put_phy(struct device *dev, struct usb_phy *phy)
124{
125 int r;
126
127 r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy);
128 dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
129}
130EXPORT_SYMBOL(devm_usb_put_phy);
131
132/**
133 * usb_put_phy - release the USB PHY
134 * @x: the phy returned by usb_get_phy()
135 *
136 * Releases a refcount the caller received from usb_get_phy().
137 *
138 * For use by USB host and peripheral drivers.
139 */
140void usb_put_phy(struct usb_phy *x)
141{
142 if (x)
143 put_device(x->dev);
144}
145EXPORT_SYMBOL(usb_put_phy);
146
147/**
148 * usb_add_phy - declare the USB PHY
149 * @x: the USB phy to be used; or NULL
150 * @type - the type of this PHY
151 *
152 * This call is exclusively for use by phy drivers, which
153 * coordinate the activities of drivers for host and peripheral
154 * controllers, and in some cases for VBUS current regulation.
155 */
156int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
157{
158 int ret = 0;
159 unsigned long flags;
160 struct usb_phy *phy;
161
162 if (x->type != USB_PHY_TYPE_UNDEFINED) {
163 dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
164 return -EINVAL;
165 }
166
167 spin_lock_irqsave(&phy_lock, flags);
168
169 list_for_each_entry(phy, &phy_list, head) {
170 if (phy->type == type) {
171 ret = -EBUSY;
172 dev_err(x->dev, "transceiver type %s already exists\n",
173 usb_phy_type_string(type));
174 goto out;
175 }
176 }
177
178 x->type = type;
179 list_add_tail(&x->head, &phy_list);
180
181out:
182 spin_unlock_irqrestore(&phy_lock, flags);
183 return ret;
184}
185EXPORT_SYMBOL(usb_add_phy);
186
187/**
188 * usb_remove_phy - remove the OTG PHY
189 * @x: the USB OTG PHY to be removed;
190 *
191 * This reverts the effects of usb_add_phy
192 */
193void usb_remove_phy(struct usb_phy *x)
194{
195 unsigned long flags;
196
197 spin_lock_irqsave(&phy_lock, flags);
198 if (x)
199 list_del(&x->head);
200 spin_unlock_irqrestore(&phy_lock, flags);
201}
202EXPORT_SYMBOL(usb_remove_phy);
203
204const char *otg_state_string(enum usb_otg_state state)
205{
206 switch (state) {
207 case OTG_STATE_A_IDLE:
208 return "a_idle";
209 case OTG_STATE_A_WAIT_VRISE:
210 return "a_wait_vrise";
211 case OTG_STATE_A_WAIT_BCON:
212 return "a_wait_bcon";
213 case OTG_STATE_A_HOST:
214 return "a_host";
215 case OTG_STATE_A_SUSPEND:
216 return "a_suspend";
217 case OTG_STATE_A_PERIPHERAL:
218 return "a_peripheral";
219 case OTG_STATE_A_WAIT_VFALL:
220 return "a_wait_vfall";
221 case OTG_STATE_A_VBUS_ERR:
222 return "a_vbus_err";
223 case OTG_STATE_B_IDLE:
224 return "b_idle";
225 case OTG_STATE_B_SRP_INIT:
226 return "b_srp_init";
227 case OTG_STATE_B_PERIPHERAL:
228 return "b_peripheral";
229 case OTG_STATE_B_WAIT_ACON:
230 return "b_wait_acon";
231 case OTG_STATE_B_HOST:
232 return "b_host";
233 default:
234 return "UNDEFINED";
235 }
236}
237EXPORT_SYMBOL(otg_state_string);