// SPDX-License-Identifier: GPL-2.0+
/*
* u_audio.c -- interface to USB gadget "ALSA sound card" utilities
*
* Copyright (C) 2016
* Author: Ruslan Bilovol <ruslan.bilovol@gmail.com>
*
* Sound card implementation was cut-and-pasted with changes
* from f_uac2.c and has:
* Copyright (C) 2011
* Yadwinder Singh (yadi.brar01@gmail.com)
* Jaswinder Singh (jaswinder.singh@linaro.org)
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/control.h>
#include <sound/tlv.h>
#include <linux/usb/audio.h>
#include "u_audio.h"
#define BUFF_SIZE_MAX (PAGE_SIZE * 16)
#define PRD_SIZE_MAX PAGE_SIZE
#define MIN_PERIODS 4
enum {
UAC_FBACK_CTRL,
UAC_P_PITCH_CTRL,
UAC_MUTE_CTRL,
UAC_VOLUME_CTRL,
UAC_RATE_CTRL,
};
/* Runtime data params for one stream */
struct uac_rtd_params {
struct snd_uac_chip *uac; /* parent chip */
bool ep_enabled; /* if the ep is enabled */
struct snd_pcm_substream *ss;
/* Ring buffer */
ssize_t hw_ptr;
void *rbuf;
unsigned int pitch; /* Stream pitch ratio to 1000000 */
unsigned int max_psize; /* MaxPacketSize of endpoint */
struct usb_request **reqs;
struct usb_request *req_fback; /* Feedback endpoint request */
bool fb_ep_enabled; /* if the ep is enabled */
/* Volume/Mute controls and their state */
int fu_id; /* Feature Unit ID */
struct snd_ctl_elem_id snd_kctl_volume_id;
struct snd_ctl_elem_id snd_kctl_mute_id;
s16 volume_min, volume_max, volume_res;
s16 volume;
int mute;
struct snd_ctl_elem_id snd_kctl_rate_id; /* read-only current rate */
int srate; /* selected samplerate */
int active; /* playback/capture running */
spinlock_t lock; /* lock for control transfers */
};
struct snd_uac_chip {
struct g_audio *audio_dev;
struct uac_rtd_params 