/* SPDX-License-Identifier: GPL-2.0+ */ /* * u_audio.h -- interface to USB gadget "ALSA sound card" utilities * * Copyright (C) 2016 * Author: Ruslan Bilovol <ruslan.bilovol@gmail.com> */ #ifndef __U_AUDIO_H #define __U_AUDIO_H #include <linux/usb/composite.h> struct uac_params { /* playback */ int p_chmask; /* channel mask */ int p_srate; /* rate in Hz */ int p_ssize; /* sample size */ /* capture */ int c_chmask; /* channel mask */ int c_srate; /* rate in Hz */ int c_ssize; /* sample size */ int req_number; /* number of preallocated requests */ }; struct g_audio { struct usb_function func; struct usb_gadget *gadget; struct usb_ep *in_ep; struct usb_ep *out_ep; /* Max packet size for all in_ep possible speeds */ unsigned int in_ep_maxpsize; /* Max packet size for all out_ep possible speeds */ unsigned int out_ep_maxpsize; /* The ALSA Sound Card it represents on the USB-Client side */ struct snd_uac_chip *uac; struct uac_params params; }; static inline struct g_audio *func_to_g_audio(struct usb_function *f) { return container_of(f, struct g_audio, func); } static inline uint num_channels(uint chanmask) { uint num = 0; while (chanmask) { num += (chanmask & 1); chanmask >>= 1; } return num; } /* * g_audio_setup - initialize one virtual ALSA sound card * @g_audio: struct with filled params, in_ep_maxpsize, out_ep_maxpsize * @pcm_name: the id string for a PCM instance of this sound card * @card_name: name of this soundcard * * This sets up the single virtual ALSA sound card that may be exported by a * gadget driver using this framework. * * Context: may sleep * * Returns zero on success, or a negative error on failure. */ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name, const char *card_name); void g_audio_cleanup(struct g_audio *g_audio); int u_audio_start_capture(struct g_audio *g_audio); void u_audio_stop_capture(struct g_audio *g_audio); int u_audio_start_playback(struct g_audio *g_audio); void u_audio_stop_playback(struct g_audio *g_audio); #endif /* __U_AUDIO_H */