blob: c1db28f874c285d12f2ee310a57ce34daa54e301 [file] [log] [blame]
Daniel Macke5779992010-03-04 19:46:13 +01001/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
15 *
16 */
17
18#include <linux/init.h>
Stephen Rothwell36db0452010-03-29 16:02:50 +110019#include <linux/slab.h>
Daniel Macke5779992010-03-04 19:46:13 +010020#include <linux/usb.h>
21
22#include "usbaudio.h"
23#include "helper.h"
Daniel Mack2b58fd52012-09-04 10:23:07 +020024#include "quirks.h"
Daniel Macke5779992010-03-04 19:46:13 +010025
26/*
27 * combine bytes and get an integer value
28 */
29unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size)
30{
31 switch (size) {
32 case 1: return *bytes;
33 case 2: return combine_word(bytes);
34 case 3: return combine_triple(bytes);
35 case 4: return combine_quad(bytes);
36 default: return 0;
37 }
38}
39
40/*
41 * parse descriptor buffer and return the pointer starting the given
42 * descriptor type.
43 */
44void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype)
45{
46 u8 *p, *end, *next;
47
48 p = descstart;
49 end = p + desclen;
50 for (; p < end;) {
51 if (p[0] < 2)
52 return NULL;
53 next = p + p[0];
54 if (next > end)
55 return NULL;
56 if (p[1] == dtype && (!after || (void *)p > after)) {
57 return p;
58 }
59 p = next;
60 }
61 return NULL;
62}
63
64/*
65 * find a class-specified interface descriptor with the given subtype.
66 */
67void *snd_usb_find_csint_desc(void *buffer, int buflen, void *after, u8 dsubtype)
68{
69 unsigned char *p = after;
70
71 while ((p = snd_usb_find_desc(buffer, buflen, p,
72 USB_DT_CS_INTERFACE)) != NULL) {
73 if (p[0] >= 3 && p[2] == dsubtype)
74 return p;
75 }
76 return NULL;
77}
78
79/*
80 * Wrapper for usb_control_msg().
81 * Allocates a temp buffer to prevent dmaing from/to the stack.
82 */
83int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
84 __u8 requesttype, __u16 value, __u16 index, void *data,
Clemens Ladisch17d900c2011-09-26 21:15:27 +020085 __u16 size)
Daniel Macke5779992010-03-04 19:46:13 +010086{
87 int err;
88 void *buf = NULL;
89
90 if (size > 0) {
91 buf = kmemdup(data, size, GFP_KERNEL);
92 if (!buf)
93 return -ENOMEM;
94 }
95 err = usb_control_msg(dev, pipe, request, requesttype,
Clemens Ladisch17d900c2011-09-26 21:15:27 +020096 value, index, buf, size, 1000);
Daniel Macke5779992010-03-04 19:46:13 +010097 if (size > 0) {
98 memcpy(data, buf, size);
99 kfree(buf);
100 }
Daniel Mack2b58fd52012-09-04 10:23:07 +0200101
102 snd_usb_ctl_msg_quirk(dev, pipe, request, requesttype,
103 value, index, data, size);
104
Daniel Macke5779992010-03-04 19:46:13 +0100105 return err;
106}
107
108unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
109 struct usb_host_interface *alts)
110{
Paul Zimmerman4f4e8f62010-08-13 12:42:07 -0700111 switch (snd_usb_get_speed(chip->dev)) {
112 case USB_SPEED_HIGH:
113 case USB_SPEED_SUPER:
114 if (get_endpoint(alts, 0)->bInterval >= 1 &&
115 get_endpoint(alts, 0)->bInterval <= 4)
116 return get_endpoint(alts, 0)->bInterval - 1;
117 break;
118 default:
119 break;
120 }
121 return 0;
Daniel Macke5779992010-03-04 19:46:13 +0100122}
123