cras/src/server/cras_system_state.h

/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 *
 * Handles various system-level settings.
 *
 * Volume:  The system volume is represented as a value from 0 to 100.  This
 * number will be interpreted by the output device and applied to the hardware.
 * The value will be mapped to dB by the active device as it will know its curve
 * the best.
 */

#ifndef CRAS_SYSTEM_STATE_H_
#define CRAS_SYSTEM_STATE_H_

#include <stddef.h>

#include "cras_types.h"

#define CRAS_MAX_SYSTEM_VOLUME 100
#define DEFAULT_CAPTURE_GAIN 2000 /* 20dB of gain. */
/* Default to 1--dB of range for palyback and capture. */
#define DEFAULT_MIN_VOLUME_DBFS -10000
#define DEFAULT_MAX_VOLUME_DBFS 0
#define DEFAULT_MIN_CAPTURE_GAIN -5000
#define DEFAULT_MAX_CAPTURE_GAIN 5000

struct cras_tm;

/* Initialize system settings.
 *
 * Args:
 *    device_config_dir - Directory for device configs where volume curves live.
 */
void cras_system_state_init(const char *device_config_dir);
void cras_system_state_deinit();

/* Sets the suffix string to control which UCM config fo load. */
void cras_system_state_set_internal_ucm_suffix(const char *internal_ucm_suffix);

/* Sets the system volume.  Will be applied by the active device. */
void cras_system_set_volume(size_t volume);
/* Gets the current system volume. */
size_t cras_system_get_volume();

/* Sets the system capture volume.  Will be applied by the active device. */
void cras_system_set_capture_gain(long gain);
/* Gets the current system capture volume. */
long cras_system_get_capture_gain();

/* Sets if the system is muted by the user. */
void cras_system_set_user_mute(int muted);
/* Sets if the system is muted for . */
void cras_system_set_mute(int muted);
/* Sets if the system muting is locked or not. */
void cras_system_set_mute_locked(int locked);
/* Gets the current mute state of the system. */
int cras_system_get_mute();
/* Gets the current user mute state. */
int cras_system_get_user_mute();
/* Gets the current system mute state. */
int cras_system_get_system_mute();
/* Gets if the system muting is locked or not. */
int cras_system_get_mute_locked();

/* Gets the suspend state of audio. */
int cras_system_get_suspended();

/* Sets the suspend state of audio.
 * Args:
 *    suspend - True for suspend, false for resume.
 */
void cras_system_set_suspended(int suspend);

/* Sets if the system capture path is muted or not. */
void cras_system_set_capture_mute(int muted);
/* Sets if the system capture path muting is locked or not. */
void cras_system_set_capture_mute_locked(int locked);
/* Gets the current mute state of the system capture path. */
int cras_system_get_capture_mute();
/* Gets if the system capture path muting is locked or not. */
int cras_system_get_capture_mute_locked();

/* Sets the value in dB of the MAX and MIN volume settings.  This will allow
 * clients to query what range of control is available.  Both arguments are
 * specified as dB * 100.
 * Args:
 *     min - dB value when volume = 1 (0 mutes).
 *     max - dB value when volume = CRAS_MAX_SYSTEM_VOLUME
 */
void cras_system_set_volume_limits(long min, long max);
/* Returns the dB value when volume = 1, in dB * 100. */
long cras_system_get_min_volume();
/* Returns the dB value when volume = CRAS_MAX_SYSTEM_VOLUME, in dB * 100. */
long cras_system_get_max_volume();

/* Sets the limits in dB * 100 of the MAX and MIN capture gain.  This will allow
 * clients to query what range of control is available.  Both arguments are
 * specified as dB * 100.
 * Args:
 *     min - minimum allowed capture gain.
 *     max - maximum allowed capture gaax.
 */
void cras_system_set_capture_gain_limits(long min, long max);
/* Returns the max value allowed for capture gain in dB * 100. */
long cras_system_get_min_capture_gain();
/* Returns the min value allowed for capture gain in dB * 100. */
long cras_system_get_max_capture_gain();

/* Adds a card at the given index to the system.  When a new card is found
 * (through a udev event notification) this will add the card to the system,
 * causing its devices to become available for playback/capture.
 * Args:
 *    alsa_card_info - Info about the alsa card (Index, type, etc.).
 * Returns:
 *    0 on success, negative error on failure (Can't create or card already
 *    exists).
 */
int cras_system_add_alsa_card(struct cras_alsa_card_info *alsa_card_info);

/* Removes a card.  When a device is removed this will do the cleanup.  Device
 * at index must have been added using cras_system_add_alsa_card().
 * Args:
 *    alsa_card_index - Index ALSA uses to refer to the card.  The X in "hw:X".
 * Returns:
 *    0 on success, negative error on failure (Can't destroy or card doesn't
 *    exist).
 */
int cras_system_remove_alsa_card(size_t alsa_card_index);

/* Checks if an alsa card has been added to the system.
 * Args:
 *    alsa_card_index - Index ALSA uses to refer to the card.  The X in "hw:X".
 * Returns:
 *    1 if the card has already been added, 0 if not.
 */
int cras_system_alsa_card_exists(unsigned alsa_card_index);

/* Poll interface provides a way of getting a callback when 'select'
 * returns for a given file descriptor.
 */

/* Register the function to use to inform the select loop about new
 * file descriptors and callbacks.
 * Args:
 *    add - The function to call when a new fd is added.
 *    rm - The function to call when a new fd is removed.
 *    select_data - Additional value passed back to add and remove.
 * Returns:
 *    0 on success, or -EBUSY if there is already a registered handler.
 */
int cras_system_set_select_handler(int (*add)(int fd,
					      void (*callback)(void *data),
					      void *callback_data,
					      void *select_data),
				  void (*rm)(int fd, void *select_data),
				  void *select_data);

/* Adds the fd and callback pair.  When select indicates that fd is readable,
 * the callback will be called.
 * Args:
 *    fd - The file descriptor to pass to select(2).
 *    callback - The callback to call when fd is ready.
 *    callback_data - Value passed back to the callback.
 * Returns:
 *    0 on success or a negative error code on failure.
 */
int cras_system_add_select_fd(int fd,
			      void (*callback)(void *data),
			      void *callback_data);

/* Removes the fd from the list of fds that are passed to select.
 * Args:
 *    fd - The file descriptor to remove from the list.
 */
void cras_system_rm_select_fd(int fd);

/* Signals that an audio input or output stream has been added to the system.
 * This allows the count of active streams can be used to notice when the audio
 * subsystem is idle.
 * Args:
 *   direction - Directions of audio streams.
 */
void cras_system_state_stream_added(enum CRAS_STREAM_DIRECTION direction);

/* Signals that an audio input or output stream has been removed from the
 * system.  This allows the count of active streams can be used to notice when
 * the audio subsystem is idle.
 * Args:
 *   direction - Directions of audio stream.
 */
void cras_system_state_stream_removed(enum CRAS_STREAM_DIRECTION direction);

/* Returns the number of active playback and capture streams. */
unsigned cras_system_state_get_active_streams();

/* Returns the number of active streams with given direction.
 * Args:
 *   direction - Directions of audio stream.
 */
unsigned cras_system_state_get_active_streams_by_direction(
	enum CRAS_STREAM_DIRECTION direction);

/* Fills ts with the time the last stream was removed from the system, the time
 * the stream count went to zero.
 */
void cras_system_state_get_last_stream_active_time(struct cras_timespec *ts);

/* Returns output devices information.
 * Args:
 *    devs - returns the array of output devices information.
 * Returns:
 *    number of output devices.
 */
int cras_system_state_get_output_devs(const struct cras_iodev_info **devs);

/* Returns input devices information.
 * Args:
 *    devs - returns the array of input devices information.
 * Returns:
 *    number of input devices.
 */
int cras_system_state_get_input_devs(const struct cras_iodev_info **devs);

/* Returns output nodes information.
 * Args:
 *    nodes - returns the array of output nodes information.
 * Returns:
 *    number of output nodes.
 */
int cras_system_state_get_output_nodes(const struct cras_ionode_info **nodes);

/* Returns input nodes information.
 * Args:
 *    nodes - returns the array of input nodes information.
 * Returns:
 *    number of input nodes.
 */
int cras_system_state_get_input_nodes(const struct cras_ionode_info **nodes);

/* Returns a pointer to the current system state that is shared with clients.
 * This also 'locks' the structure by incrementing the update count to an odd
 * value.
 */
struct cras_server_state *cras_system_state_update_begin();

/* Unlocks the system state structure that was updated after calling
 * cras_system_state_update_begin by again incrementing the update count.
 */
void cras_system_state_update_complete();

/* Gets a pointer to the system state without locking it.  Only used for debug
 * log.  Don't add calls to this function. */
struct cras_server_state *cras_system_state_get_no_lock();

/* Returns the shm fd for the server_state structure. */
key_t cras_sys_state_shm_fd();

/* Returns the timer manager. */
struct cras_tm *cras_system_state_get_tm();

#endif /* CRAS_SYSTEM_STATE_H_ */