xref: /third_party/FreeBSD/sys/dev/usb/usb_util.c (revision f9f848fa)
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2008-2022 Hans Petter Selasky
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include "implementation/global_implementation.h"
29
30/*------------------------------------------------------------------------*
31 *	device_set_usb_desc
32 *
33 * This function can be called at probe or attach to set the USB
34 * device supplied textual description for the given device.
35 *------------------------------------------------------------------------*/
36void
37device_set_usb_desc(device_t dev)
38{
39	struct usb_attach_arg *uaa;
40	struct usb_device *udev;
41	struct usb_interface *iface;
42	char *temp_p;
43	usb_error_t err;
44	uint8_t do_unlock;
45
46	if (dev == NULL) {
47		/* should not happen */
48		return;
49	}
50	uaa = device_get_ivars(dev);
51	if (uaa == NULL) {
52		/* can happen if called at the wrong time */
53		return;
54	}
55	udev = uaa->device;
56	iface = uaa->iface;
57
58	if ((iface == NULL) ||
59	    (iface->idesc == NULL) ||
60	    (iface->idesc->iInterface == 0)) {
61		err = USB_ERR_INVAL;
62	} else {
63		err = USB_ERR_NORMAL_COMPLETION;
64	}
65
66	/* Protect scratch area */
67	do_unlock = usbd_ctrl_lock(udev);
68
69	temp_p = (char *)udev->scratch.data;
70
71	if (err == 0) {
72		/* try to get the interface string ! */
73		err = usbd_req_get_string_any(udev, NULL, temp_p,
74		    sizeof(udev->scratch.data),
75		    iface->idesc->iInterface);
76	}
77	if (err != 0) {
78		/* use default description */
79		usb_devinfo(udev, temp_p,
80		    sizeof(udev->scratch.data));
81	}
82
83	if (do_unlock)
84		usbd_ctrl_unlock(udev);
85
86	device_set_desc_copy(dev, temp_p);
87	device_printf(dev, "<%s> on %s\n", temp_p,
88	    device_get_nameunit(udev->bus->bdev));
89}
90
91/*------------------------------------------------------------------------*
92 *	 usb_pause_mtx - factored out code
93 *
94 * This function will delay the code by the passed number of system
95 * ticks. The passed mutex "mtx" will be dropped while waiting, if
96 * "mtx" is different from NULL.
97 *------------------------------------------------------------------------*/
98void
99usb_pause_mtx(struct mtx *mtx, int timo)
100{
101	if (mtx != NULL)
102		mtx_unlock(mtx);
103
104	/*
105	 * Add one tick to the timeout so that we don't return too
106	 * early! Note that pause() will assert that the passed
107	 * timeout is positive and non-zero!
108	 */
109	pause("USBWAIT", (uint32_t)(timo + 1));
110
111	if (mtx != NULL)
112		mtx_lock(mtx);
113}
114
115/*------------------------------------------------------------------------*
116 *	usb_printbcd
117 *
118 * This function will print the version number "bcd" to the string
119 * pointed to by "p" having a maximum length of "p_len" bytes
120 * including the terminating zero.
121 *------------------------------------------------------------------------*/
122void
123usb_printbcd(char *p, uint16_t p_len, uint16_t bcd)
124{
125	if (snprintf_s(p, p_len, p_len - 1, "%x.%02x", bcd >> 8, bcd & 0xff)) {
126		/* ignore any errors */
127	}
128}
129
130/*------------------------------------------------------------------------*
131 *	usb_trim_spaces
132 *
133 * This function removes spaces at the beginning and the end of the string
134 * pointed to by the "p" argument.
135 *------------------------------------------------------------------------*/
136void
137usb_trim_spaces(char *p)
138{
139	char *q;
140	char *e;
141
142	if (p == NULL)
143		return;
144	q = e = p;
145	while (*q == ' ')		/* skip leading spaces */
146		q++;
147	while ((*p = *q++))		/* copy string */
148		if (*p++ != ' ')	/* remember last non-space */
149			e = p;
150	*e = 0;				/* kill trailing spaces */
151}
152
153/*------------------------------------------------------------------------*
154 *	usb_make_str_desc - convert an ASCII string into a UNICODE string
155 *------------------------------------------------------------------------*/
156uint8_t
157usb_make_str_desc(void *ptr, uint16_t max_len, const char *s)
158{
159	struct usb_string_descriptor *p = ptr;
160	uint8_t totlen;
161	int j;
162
163	if (max_len < 2) {
164		/* invalid length */
165		return (0);
166	}
167	max_len = ((max_len / 2) - 1);
168
169	j = strlen(s);
170
171	if (j < 0) {
172		j = 0;
173	}
174	if (j > 126) {
175		j = 126;
176	}
177	if (max_len > j) {
178		max_len = j;
179	}
180	totlen = (max_len + 1) * 2;
181
182	p->bLength = totlen;
183	p->bDescriptorType = UDESC_STRING;
184
185	while (max_len--) {
186		USETW2(p->bString[max_len], 0, s[max_len]);
187	}
188	return (totlen);
189}
190
191/*------------------------------------------------------------------------*
192 *	usb_check_request - prevent damaging USB requests
193 *
194 * Return values:
195 * 0: Access allowed
196 * Else: No access
197 *------------------------------------------------------------------------*/
198#if USB_HAVE_UGEN
199int
200usb_check_request(struct usb_device *udev, struct usb_device_request *req)
201{
202	struct usb_endpoint *ep;
203	int error;
204
205	/*
206	 * Avoid requests that would damage the bus integrity:
207	 */
208	if (((req->bmRequestType == UT_WRITE_DEVICE) &&
209	    (req->bRequest == UR_SET_ADDRESS)) ||
210	    ((req->bmRequestType == UT_WRITE_DEVICE) &&
211	    (req->bRequest == UR_SET_CONFIG)) ||
212	    ((req->bmRequestType == UT_WRITE_INTERFACE) &&
213	    (req->bRequest == UR_SET_INTERFACE))) {
214		/*
215		 * These requests can be useful for testing USB drivers.
216		 */
217		error = priv_check(curthread, PRIV_DRIVER);
218		if (error)
219			return (error);
220	}
221
222	/*
223	 * Special case - handle clearing of stall
224	 */
225	if (req->bmRequestType == UT_WRITE_ENDPOINT) {
226		ep = usbd_get_ep_by_addr(udev, req->wIndex[0]);
227		if (ep == NULL)
228			return (EINVAL);
229		if ((req->bRequest == UR_CLEAR_FEATURE) &&
230		    (UGETW(req->wValue) == UF_ENDPOINT_HALT))
231			usbd_clear_data_toggle(udev, ep);
232	}
233
234	/* TODO: add more checks to verify the interface index */
235
236	return (0);
237}
238#endif
239