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.
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.
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
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/usb.h>
27 * combine bytes and get an integer value
29 unsigned int snd_usb_combine_bytes(unsigned char *bytes, int 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);
41 * parse descriptor buffer and return the pointer starting the given
44 void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype)
56 if (p[1] == dtype && (!after || (void *)p > after)) {
65 * find a class-specified interface descriptor with the given subtype.
67 void *snd_usb_find_csint_desc(void *buffer, int buflen, void *after, u8 dsubtype)
69 unsigned char *p = after;
71 while ((p = snd_usb_find_desc(buffer, buflen, p,
72 USB_DT_CS_INTERFACE)) != NULL) {
73 if (p[0] >= 3 && p[2] == dsubtype)
79 /* check the validity of pipe and EP types */
80 int snd_usb_pipe_sanity_check(struct usb_device *dev, unsigned int pipe)
82 static const int pipetypes[4] = {
83 PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT
85 struct usb_host_endpoint *ep;
87 ep = usb_pipe_endpoint(dev, pipe);
88 if (usb_pipetype(pipe) != pipetypes[usb_endpoint_type(&ep->desc)])
94 * Wrapper for usb_control_msg().
95 * Allocates a temp buffer to prevent dmaing from/to the stack.
97 int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
98 __u8 requesttype, __u16 value, __u16 index, void *data,
105 if (snd_usb_pipe_sanity_check(dev, pipe))
109 buf = kmemdup(data, size, GFP_KERNEL);
114 if (requesttype & USB_DIR_IN)
115 timeout = USB_CTRL_GET_TIMEOUT;
117 timeout = USB_CTRL_SET_TIMEOUT;
119 err = usb_control_msg(dev, pipe, request, requesttype,
120 value, index, buf, size, timeout);
123 memcpy(data, buf, size);
127 snd_usb_ctl_msg_quirk(dev, pipe, request, requesttype,
128 value, index, data, size);
133 unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
134 struct usb_host_interface *alts)
136 switch (snd_usb_get_speed(chip->dev)) {
138 case USB_SPEED_WIRELESS:
139 case USB_SPEED_SUPER:
140 case USB_SPEED_SUPER_PLUS:
141 if (get_endpoint(alts, 0)->bInterval >= 1 &&
142 get_endpoint(alts, 0)->bInterval <= 4)
143 return get_endpoint(alts, 0)->bInterval - 1;