linux/sound/usb/helper.c
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

121 lines
2.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
*/
#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;
int timeout;
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;
}