linux/sound/usb/power.h
Jorge Sanjuan 11785ef532 ALSA: usb-audio: Initial Power Domain support
Thee USB Audio Class 3 (UAC3) introduces Power Domains as a new
feature to let a host turn individual parts of an audio function
to different power states via USB requests. This lets the device
get to know a bit amore about what the host is up to in order to
optimize power consumption efficiently.

The Power Domains are optional for UAC3 configuration but all
UAC3 devices shall include at least one BADD configuration where
the support for Power Domains is compulsory.

This patch adds a set of features/helpers to parse these power
domains and change their status.

Signed-off-by: Jorge Sanjuan <jorge.sanjuan@codethink.co.uk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-31 15:01:22 +02:00

38 lines
924 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __USBAUDIO_POWER_H
#define __USBAUDIO_POWER_H
struct snd_usb_power_domain {
int pd_id; /* UAC3 Power Domain ID */
int pd_d1d0_rec; /* D1 to D0 recovery time */
int pd_d2d0_rec; /* D2 to D0 recovery time */
};
enum {
UAC3_PD_STATE_D0,
UAC3_PD_STATE_D1,
UAC3_PD_STATE_D2,
};
int snd_usb_power_domain_set(struct snd_usb_audio *chip,
struct snd_usb_power_domain *pd,
unsigned char state);
struct snd_usb_power_domain *
snd_usb_find_power_domain(struct usb_host_interface *ctrl_iface,
unsigned char id);
#ifdef CONFIG_PM
int snd_usb_autoresume(struct snd_usb_audio *chip);
void snd_usb_autosuspend(struct snd_usb_audio *chip);
#else
static inline int snd_usb_autoresume(struct snd_usb_audio *chip)
{
return 0;
}
static inline void snd_usb_autosuspend(struct snd_usb_audio *chip)
{
}
#endif
#endif /* __USBAUDIO_POWER_H */