1/* SPDX-License-Identifier: GPL-2.0+ */
  2/*
  3 * u_audio.h -- interface to USB gadget "ALSA sound card" utilities
  4 *
  5 * Copyright (C) 2016
  6 * Author: Ruslan Bilovol <ruslan.bilovol@gmail.com>
  7 */
  8
  9#ifndef __U_AUDIO_H
 10#define __U_AUDIO_H
 11
 12#include <linux/usb/composite.h>
 13#include "uac_common.h"
 14
 15/*
 16 * Same maximum frequency deviation on the slower side as in
 17 * sound/usb/endpoint.c. Value is expressed in per-mil deviation.
 18 */
 19#define FBACK_SLOW_MAX	250
 20
 21/*
 22 * Maximum frequency deviation on the faster side, default value for UAC1/2.
 23 * Value is expressed in per-mil deviation.
 24 * UAC2 provides the value as a parameter as it impacts the endpoint required
 25 * bandwidth.
 26 */
 27#define FBACK_FAST_MAX 5
 28
 29/* Feature Unit parameters */
 30struct uac_fu_params {
 31	int id;			/* Feature Unit ID */
 32
 33	bool mute_present;	/* mute control enable */
 34
 35	bool volume_present;	/* volume control enable */
 36	s16 volume_min;		/* min volume in 1/256 dB */
 37	s16 volume_max;		/* max volume in 1/256 dB */
 38	s16 volume_res;		/* volume resolution in 1/256 dB */
 39};
 40
 41struct uac_params {
 42	/* playback */
 43	int p_chmask;	/* channel mask */
 44	int p_srates[UAC_MAX_RATES];	/* available rates in Hz (0 terminated list) */
 45	int p_ssize;	/* sample size */
 46	struct uac_fu_params p_fu;	/* Feature Unit parameters */
 47
 48	/* capture */
 49	int c_chmask;	/* channel mask */
 50	int c_srates[UAC_MAX_RATES];	/* available rates in Hz (0 terminated list) */
 51	int c_ssize;	/* sample size */
 52	struct uac_fu_params c_fu;	/* Feature Unit parameters */
 53
 54	/* rates are dynamic, in uac_rtd_params */
 55
 56	int req_number; /* number of preallocated requests */
 57	int fb_max;	/* upper frequency drift feedback limit per-mil */
 58};
 59
 60struct g_audio {
 61	struct usb_function func;
 62	struct usb_gadget *gadget;
 63
 64	struct usb_ep *in_ep;
 65
 66	struct usb_ep *out_ep;
 67	/* feedback IN endpoint corresponding to out_ep */
 68	struct usb_ep *in_ep_fback;
 69
 70	/* Max packet size for all in_ep possible speeds */
 71	unsigned int in_ep_maxpsize;
 72	/* Max packet size for all out_ep possible speeds */
 73	unsigned int out_ep_maxpsize;
 74
 75	/* Notify UAC driver about control change */
 76	int (*notify)(struct g_audio *g_audio, int unit_id, int cs);
 77
 78	/* The ALSA Sound Card it represents on the USB-Client side */
 79	struct snd_uac_chip *uac;
 80
 81	struct uac_params params;
 82};
 83
 84static inline struct g_audio *func_to_g_audio(struct usb_function *f)
 85{
 86	return container_of(f, struct g_audio, func);
 87}
 88
 89static inline uint num_channels(uint chanmask)
 90{
 91	uint num = 0;
 92
 93	while (chanmask) {
 94		num += (chanmask & 1);
 95		chanmask >>= 1;
 96	}
 97
 98	return num;
 99}
100
101/*
102 * g_audio_setup - initialize one virtual ALSA sound card
103 * @g_audio: struct with filled params, in_ep_maxpsize, out_ep_maxpsize
104 * @pcm_name: the id string for a PCM instance of this sound card
105 * @card_name: name of this soundcard
106 *
107 * This sets up the single virtual ALSA sound card that may be exported by a
108 * gadget driver using this framework.
109 *
110 * Context: may sleep
111 *
112 * Returns zero on success, or a negative error on failure.
113 */
114int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
115					const char *card_name);
116void g_audio_cleanup(struct g_audio *g_audio);
117
118int u_audio_start_capture(struct g_audio *g_audio);
119void u_audio_stop_capture(struct g_audio *g_audio);
120int u_audio_start_playback(struct g_audio *g_audio);
121void u_audio_stop_playback(struct g_audio *g_audio);
122
123int u_audio_get_capture_srate(struct g_audio *audio_dev, u32 *val);
124int u_audio_set_capture_srate(struct g_audio *audio_dev, int srate);
125int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val);
126int u_audio_set_playback_srate(struct g_audio *audio_dev, int srate);
127
128int u_audio_get_volume(struct g_audio *g_audio, int playback, s16 *val);
129int u_audio_set_volume(struct g_audio *g_audio, int playback, s16 val);
130int u_audio_get_mute(struct g_audio *g_audio, int playback, int *val);
131int u_audio_set_mute(struct g_audio *g_audio, int playback, int val);
132
133void u_audio_suspend(struct g_audio *g_audio);
134
135#endif /* __U_AUDIO_H */