2025-05-10 21:49:39 +08:00

139 lines
3.6 KiB
C

// 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>
#define UAC_VOLUME_CUR 0x0000
#define UAC_VOLUME_RES 0x0080 /* 0.5 dB */
#define UAC_VOLUME_MAX 0x1900 /* 25 dB */
#define UAC_VOLUME_MIN 0xE700 /* -25 dB */
#define UAC_VOLUME_NEGATIVE_INFINITY 0x8000
#define UAC_MAX_RATES 10
struct uac_params {
/* playback */
int p_volume;
int p_mute;
int p_chmask; /* channel mask */
int p_srate[UAC_MAX_RATES]; /* rate in Hz */
int p_srate_active; /* selected rate in Hz */
int p_ssize; /* sample size */
/* capture */
int c_volume;
int c_mute;
int c_chmask; /* channel mask */
int c_srate[UAC_MAX_RATES]; /* rate in Hz */
int c_srate_active; /* selected rate in Hz */
int c_ssize; /* sample size */
int ppm; /* difference between audio clk and usb clk */
int req_number; /* number of preallocated requests */
};
enum usb_state_index {
SET_INTERFACE_OUT,
SET_INTERFACE_IN,
SET_SAMPLE_RATE_OUT,
SET_SAMPLE_RATE_IN,
SET_VOLUME_OUT,
SET_VOLUME_IN,
SET_MUTE_OUT,
SET_MUTE_IN,
SET_AUDIO_CLK,
SET_USB_STATE_MAX,
};
enum stream_state_index {
STATE_OUT,
STATE_IN,
};
struct frame_number_data {
uint32_t fn_begin; /* frame number when starting statistics */
uint32_t fn_last; /* frame number in the latest statistics */
uint32_t fn_overflow; /* the time of frame number overflow */
uint32_t second; /* total seconds counted */
ktime_t time_begin; /* system time when starting statistics */
ktime_t time_last; /* system time in the latest statistics */
};
struct g_audio {
struct device *device;
bool usb_state[SET_USB_STATE_MAX];
bool stream_state[2];
struct work_struct work;
struct frame_number_data *fn;
struct delayed_work ppm_work;
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);
int u_audio_set_capture_srate(struct g_audio *audio_dev, int srate);
int u_audio_set_playback_srate(struct g_audio *audio_dev, int srate);
int u_audio_fu_set_cmd(struct usb_audio_control *con, u8 cmd, int value);
int u_audio_fu_get_cmd(struct usb_audio_control *con, u8 cmd);
#endif /* __U_AUDIO_H */