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 */ 30 struct 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 41 struct 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 60 struct 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 84 static inline struct g_audio *func_to_g_audio(struct usb_function *f) 85 { 86 return container_of(f, struct g_audio, func); 87 } 88 89 static 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 */ 114 int g_audio_setup(struct g_audio *g_audio, const char *pcm_name, 115 const char *card_name); 116 void g_audio_cleanup(struct g_audio *g_audio); 117 118 int u_audio_start_capture(struct g_audio *g_audio); 119 void u_audio_stop_capture(struct g_audio *g_audio); 120 int u_audio_start_playback(struct g_audio *g_audio); 121 void u_audio_stop_playback(struct g_audio *g_audio); 122 123 int u_audio_get_capture_srate(struct g_audio *audio_dev, u32 *val); 124 int u_audio_set_capture_srate(struct g_audio *audio_dev, int srate); 125 int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val); 126 int u_audio_set_playback_srate(struct g_audio *audio_dev, int srate); 127 128 int u_audio_get_volume(struct g_audio *g_audio, int playback, s16 *val); 129 int u_audio_set_volume(struct g_audio *g_audio, int playback, s16 val); 130 int u_audio_get_mute(struct g_audio *g_audio, int playback, int *val); 131 int u_audio_set_mute(struct g_audio *g_audio, int playback, int val); 132 133 void u_audio_suspend(struct g_audio *g_audio); 134 135 #endif /* __U_AUDIO_H */ 136