1 files changed, 40 insertions, 0 deletions
diff --git a/sound/usb/helper.h b/sound/usb/helper.h
new file mode 100644
index 000000000..e2b51ec96
--- /dev/null
+++ b/sound/usb/helper.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __USBAUDIO_HELPER_H
+#define __USBAUDIO_HELPER_H
+
+unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size);
+
+void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype);
+void *snd_usb_find_csint_desc(void *descstart, int desclen, void *after, u8 dsubtype);
+
+int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe,
+		    __u8 request, __u8 requesttype, __u16 value, __u16 index,
+		    void *data, __u16 size);
+
+unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
+					 struct usb_host_interface *alts);
+
+struct usb_host_interface *
+snd_usb_get_host_interface(struct snd_usb_audio *chip, int ifnum, int altsetting);
+
+/*
+ * retrieve usb_interface descriptor from the host interface
+ * (conditional for compatibility with the older API)
+ */
+#define get_iface_desc(iface)	(&(iface)->desc)
+#define get_endpoint(alt,ep)	(&(alt)->endpoint[ep].desc)
+#define get_ep_desc(ep)		(&(ep)->desc)
+#define get_cfg_desc(cfg)	(&(cfg)->desc)
+
+#define snd_usb_get_speed(dev) ((dev)->speed)
+
+static inline int snd_usb_ctrl_intf(struct snd_usb_audio *chip)
+{
+	return get_iface_desc(chip->ctrl_intf)->bInterfaceNumber;
+}
+
+/* in validate.c */
+bool snd_usb_validate_audio_desc(void *p, int protocol);
+bool snd_usb_validate_midi_desc(void *p);
+
+#endif /* __USBAUDIO_HELPER_H */