mirror of https://gitee.com/openkylin/linux.git
124 lines
2.9 KiB
C
124 lines
2.9 KiB
C
/*
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
if (size > 0) {
|
|
buf = kmemdup(data, size, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
}
|
|
err = usb_control_msg(dev, pipe, request, requesttype,
|
|
value, index, buf, size, 1000);
|
|
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_SUPER:
|
|
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;
|
|
}
|
|
|