diff options
Diffstat (limited to 'drivers/usb/gadget/function/u_audio.h')
| -rw-r--r-- | drivers/usb/gadget/function/u_audio.h | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/u_audio.h b/drivers/usb/gadget/function/u_audio.h new file mode 100644 index 000000000..9512b8fcc --- /dev/null +++ b/drivers/usb/gadget/function/u_audio.h @@ -0,0 +1,135 @@ +/* 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> +#include "uac_common.h" + +/* + * Same maximum frequency deviation on the slower side as in + * sound/usb/endpoint.c. Value is expressed in per-mil deviation. + */ +#define FBACK_SLOW_MAX 250 + +/* + * Maximum frequency deviation on the faster side, default value for UAC1/2. + * Value is expressed in per-mil deviation. + * UAC2 provides the value as a parameter as it impacts the endpoint required + * bandwidth. + */ +#define FBACK_FAST_MAX 5 + +/* Feature Unit parameters */ +struct uac_fu_params { + int id; /* Feature Unit ID */ + + bool mute_present; /* mute control enable */ + + bool volume_present; /* volume control enable */ + s16 volume_min; /* min volume in 1/256 dB */ + s16 volume_max; /* max volume in 1/256 dB */ + s16 volume_res; /* volume resolution in 1/256 dB */ +}; + +struct uac_params { + /* playback */ + int p_chmask; /* channel mask */ + int p_srates[UAC_MAX_RATES]; /* available rates in Hz (0 terminated list) */ + int p_ssize; /* sample size */ + struct uac_fu_params p_fu; /* Feature Unit parameters */ + + /* capture */ + int c_chmask; /* channel mask */ + int c_srates[UAC_MAX_RATES]; /* available rates in Hz (0 terminated list) */ + int c_ssize; /* sample size */ + struct uac_fu_params c_fu; /* Feature Unit parameters */ + + /* rates are dynamic, in uac_rtd_params */ + + int req_number; /* number of preallocated requests */ + int fb_max; /* upper frequency drift feedback limit per-mil */ +}; + +struct g_audio { + struct usb_function func; + struct usb_gadget *gadget; + + struct usb_ep *in_ep; + + struct usb_ep *out_ep; + /* feedback IN endpoint corresponding to out_ep */ + struct usb_ep *in_ep_fback; + + /* 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; + + /* Notify UAC driver about control change */ + int (*notify)(struct g_audio *g_audio, int unit_id, int cs); + + /* 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_get_capture_srate(struct g_audio *audio_dev, u32 *val); +int u_audio_set_capture_srate(struct g_audio *audio_dev, int srate); +int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val); +int u_audio_set_playback_srate(struct g_audio *audio_dev, int srate); + +int u_audio_get_volume(struct g_audio *g_audio, int playback, s16 *val); +int u_audio_set_volume(struct g_audio *g_audio, int playback, s16 val); +int u_audio_get_mute(struct g_audio *g_audio, int playback, int *val); +int u_audio_set_mute(struct g_audio *g_audio, int playback, int val); + +void u_audio_suspend(struct g_audio *g_audio); + +#endif /* __U_AUDIO_H */ |