1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include "usbaudio.h"
#include "helper.h"
#include "quirks.h"
/*
* combine bytes and get an integer value
*/
unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size)
{
switch (size) {
case 1: return *bytes;
case 2: return combine_word(bytes);
case 3: return combine_triple(bytes);
case 4: return combine_quad(bytes);
default: return 0;
}
}
/*
* parse descriptor buffer and return the pointer starting the given
* descriptor type.
*/
void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype)
{
u8 *p, *end, *next;
p = descstart;
end = p + desclen;
for (; p < end;) {
if (p[0] < 2)
return NULL;
next = p + p[0];
if (next > end)
return NULL;
if (p[1] == dtype && (!after || (void *)p > after)) {
return p;
}
p = next;
}
return NULL;
}
/*
* find a class-specified interface descriptor with the given subtype.
*/
void *snd_usb_find_csint_desc(void *buffer, int buflen, void *after, u8 dsubtype)
{
unsigned char *p = after;
while ((p = snd_usb_find_desc(buffer, buflen, p,
USB_DT_CS_INTERFACE)) != NULL) {
if (p[0] >= 3 && p[2] == dsubtype)
return p;
}
return NULL;
}
/* check the validity of pipe and EP types */
int snd_usb_pipe_sanity_check(struct usb_device *dev, unsigned int pipe)
{
static const int pipetypes[4] = {
PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT
};
struct usb_host_endpoint *ep;
ep = usb_pipe_endpoint(dev, pipe);
if (usb_pipetype(pipe) != pipetypes[usb_endpoint_type(&ep->desc)])
return -EINVAL;
return 0;
}
/*
* Wrapper for usb_control_msg().
* Allocates a temp buffer to prevent dmaing from/to the stack.
*/
int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
__u8 requesttype, __u16 value, __u16 index, void *data,
__u16 size)
{
int err;
void *buf = NULL;
int timeout;
if (snd_usb_pipe_sanity_check(dev, pipe))
return -EINVAL;
if (size > 0) {
buf = kmemdup(data, size, GFP_KERNEL);
if (!buf)
return -ENOMEM;
}
if (requesttype & USB_DIR_IN)
timeout = USB_CTRL_GET_TIMEOUT;
else
timeout = USB_CTRL_SET_TIMEOUT;
err = usb_control_msg(dev, pipe, request, requesttype,
value, index, buf, size, timeout);
if (size > 0) {
memcpy(data, buf, size);
kfree(buf);
}
snd_usb_ctl_msg_quirk(dev, pipe, request, requesttype,
value, index, data, size);
return err;
}
unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
struct usb_host_interface *alts)
{
switch (snd_usb_get_speed(chip->dev)) {
case USB_SPEED_HIGH:
case USB_SPEED_WIRELESS:
case USB_SPEED_SUPER:
case USB_SPEED_SUPER_PLUS:
if (get_endpoint(alts, 0)->bInterval >= 1 &&
get_endpoint(alts, 0)->bInterval <= 4)
return get_endpoint(alts, 0)->bInterval - 1;
break;
default:
break;
}
return 0;
}
|
