1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun */
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun #include <linux/init.h>
6*4882a593Smuzhiyun #include <linux/slab.h>
7*4882a593Smuzhiyun #include <linux/usb.h>
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include "usbaudio.h"
10*4882a593Smuzhiyun #include "helper.h"
11*4882a593Smuzhiyun #include "quirks.h"
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun /*
14*4882a593Smuzhiyun * combine bytes and get an integer value
15*4882a593Smuzhiyun */
snd_usb_combine_bytes(unsigned char * bytes,int size)16*4882a593Smuzhiyun unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size)
17*4882a593Smuzhiyun {
18*4882a593Smuzhiyun switch (size) {
19*4882a593Smuzhiyun case 1: return *bytes;
20*4882a593Smuzhiyun case 2: return combine_word(bytes);
21*4882a593Smuzhiyun case 3: return combine_triple(bytes);
22*4882a593Smuzhiyun case 4: return combine_quad(bytes);
23*4882a593Smuzhiyun default: return 0;
24*4882a593Smuzhiyun }
25*4882a593Smuzhiyun }
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun /*
28*4882a593Smuzhiyun * parse descriptor buffer and return the pointer starting the given
29*4882a593Smuzhiyun * descriptor type.
30*4882a593Smuzhiyun */
snd_usb_find_desc(void * descstart,int desclen,void * after,u8 dtype)31*4882a593Smuzhiyun void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype)
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun u8 *p, *end, *next;
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun p = descstart;
36*4882a593Smuzhiyun end = p + desclen;
37*4882a593Smuzhiyun for (; p < end;) {
38*4882a593Smuzhiyun if (p[0] < 2)
39*4882a593Smuzhiyun return NULL;
40*4882a593Smuzhiyun next = p + p[0];
41*4882a593Smuzhiyun if (next > end)
42*4882a593Smuzhiyun return NULL;
43*4882a593Smuzhiyun if (p[1] == dtype && (!after || (void *)p > after)) {
44*4882a593Smuzhiyun return p;
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun p = next;
47*4882a593Smuzhiyun }
48*4882a593Smuzhiyun return NULL;
49*4882a593Smuzhiyun }
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun /*
52*4882a593Smuzhiyun * find a class-specified interface descriptor with the given subtype.
53*4882a593Smuzhiyun */
snd_usb_find_csint_desc(void * buffer,int buflen,void * after,u8 dsubtype)54*4882a593Smuzhiyun void *snd_usb_find_csint_desc(void *buffer, int buflen, void *after, u8 dsubtype)
55*4882a593Smuzhiyun {
56*4882a593Smuzhiyun unsigned char *p = after;
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun while ((p = snd_usb_find_desc(buffer, buflen, p,
59*4882a593Smuzhiyun USB_DT_CS_INTERFACE)) != NULL) {
60*4882a593Smuzhiyun if (p[0] >= 3 && p[2] == dsubtype)
61*4882a593Smuzhiyun return p;
62*4882a593Smuzhiyun }
63*4882a593Smuzhiyun return NULL;
64*4882a593Smuzhiyun }
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun /*
67*4882a593Smuzhiyun * Wrapper for usb_control_msg().
68*4882a593Smuzhiyun * Allocates a temp buffer to prevent dmaing from/to the stack.
69*4882a593Smuzhiyun */
snd_usb_ctl_msg(struct usb_device * dev,unsigned int pipe,__u8 request,__u8 requesttype,__u16 value,__u16 index,void * data,__u16 size)70*4882a593Smuzhiyun int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
71*4882a593Smuzhiyun __u8 requesttype, __u16 value, __u16 index, void *data,
72*4882a593Smuzhiyun __u16 size)
73*4882a593Smuzhiyun {
74*4882a593Smuzhiyun int err;
75*4882a593Smuzhiyun void *buf = NULL;
76*4882a593Smuzhiyun int timeout;
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun if (usb_pipe_type_check(dev, pipe))
79*4882a593Smuzhiyun return -EINVAL;
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun if (size > 0) {
82*4882a593Smuzhiyun buf = kmemdup(data, size, GFP_KERNEL);
83*4882a593Smuzhiyun if (!buf)
84*4882a593Smuzhiyun return -ENOMEM;
85*4882a593Smuzhiyun }
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun if (requesttype & USB_DIR_IN)
88*4882a593Smuzhiyun timeout = USB_CTRL_GET_TIMEOUT;
89*4882a593Smuzhiyun else
90*4882a593Smuzhiyun timeout = USB_CTRL_SET_TIMEOUT;
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun err = usb_control_msg(dev, pipe, request, requesttype,
93*4882a593Smuzhiyun value, index, buf, size, timeout);
94*4882a593Smuzhiyun
95*4882a593Smuzhiyun if (size > 0) {
96*4882a593Smuzhiyun memcpy(data, buf, size);
97*4882a593Smuzhiyun kfree(buf);
98*4882a593Smuzhiyun }
99*4882a593Smuzhiyun
100*4882a593Smuzhiyun snd_usb_ctl_msg_quirk(dev, pipe, request, requesttype,
101*4882a593Smuzhiyun value, index, data, size);
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun return err;
104*4882a593Smuzhiyun }
105*4882a593Smuzhiyun
snd_usb_parse_datainterval(struct snd_usb_audio * chip,struct usb_host_interface * alts)106*4882a593Smuzhiyun unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
107*4882a593Smuzhiyun struct usb_host_interface *alts)
108*4882a593Smuzhiyun {
109*4882a593Smuzhiyun switch (snd_usb_get_speed(chip->dev)) {
110*4882a593Smuzhiyun case USB_SPEED_HIGH:
111*4882a593Smuzhiyun case USB_SPEED_WIRELESS:
112*4882a593Smuzhiyun case USB_SPEED_SUPER:
113*4882a593Smuzhiyun case USB_SPEED_SUPER_PLUS:
114*4882a593Smuzhiyun if (get_endpoint(alts, 0)->bInterval >= 1 &&
115*4882a593Smuzhiyun get_endpoint(alts, 0)->bInterval <= 4)
116*4882a593Smuzhiyun return get_endpoint(alts, 0)->bInterval - 1;
117*4882a593Smuzhiyun break;
118*4882a593Smuzhiyun default:
119*4882a593Smuzhiyun break;
120*4882a593Smuzhiyun }
121*4882a593Smuzhiyun return 0;
122*4882a593Smuzhiyun }
123*4882a593Smuzhiyun
124