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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 | // 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 (usb_pipe_type_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_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; } struct usb_host_interface * snd_usb_get_host_interface(struct snd_usb_audio *chip, int ifnum, int altsetting) { struct usb_interface *iface; iface = usb_ifnum_to_if(chip->dev, ifnum); if (!iface) return NULL; return usb_altnum_to_altsetting(iface, altsetting); } |