The Linux Manuals (man pages) document is an important part of Linux documents. Linux Manuals are organized as several sections. Each section has a group of commands for a specific area in Linux usage, administration or development.
snd_ctl_add – add the control instance to the card Synopsis int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol); Arguments card the card instance kcontrol the control instance to add Description Adds the control instance created via snd_ctl_new or snd_ctl_new1 to the given card. Assigns also an unique numid used for fast search. It frees automatically the…
snd_ctl_activate_id – activate/inactivate the control of the given id Synopsis int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id, int active); Arguments card the card instance id the control id to activate/inactivate active non-zero to activate Description Finds the control instance with the given id, and activate or inactivate the control together with notification, if changed. The…
snd_compress_register – register compressed device Synopsis int snd_compress_register(struct snd_compr *device); Arguments device compressed device to register Copyright
snd_component_add – add a component string Synopsis int snd_component_add(struct snd_card *card, const char *component); Arguments card soundcard structure component the component id string Description This function adds the component id string to the supported list. The component can be referred from the alsa-lib. Return Zero otherwise a negative error code. Copyright
snd_card_set_id – set card identification name Synopsis void snd_card_set_id(struct snd_card *card, const char *nid); Arguments card soundcard structure nid new identification string Description This function sets the card identification and checks for name collisions. Copyright
snd_card_register – register the soundcard Synopsis int snd_card_register(struct snd_card *card); Arguments card soundcard structure Description This function registers all the devices assigned to the soundcard. Until calling this, the ALSA control interface is blocked from the external accesses. Thus, you should call this function at the end of the initialization of the card. Return Zero…
snd_card_new – create and initialize a soundcard structure Synopsis int snd_card_new(struct device *parent, int idx, const char *xid, struct module *module, int extra_size, struct snd_card **card_ret); Arguments parent the parent device object idx card index (address) [0 … (SNDRV_CARDS-1)] xid card identification (ASCII string) module top level module for locking extra_size allocate this extra size…
snd_card_free_when_closed – Disconnect the card, free it later eventually Synopsis int snd_card_free_when_closed(struct snd_card *card); Arguments card soundcard structure Description Unlike snd_card_free, this function doesn’t try to release the card resource immediately, but tries to disconnect at first. When the card is still in use, the function returns before freeing the resources. The card resources will…
snd_card_free – frees given soundcard structure Synopsis int snd_card_free(struct snd_card *card); Arguments card soundcard structure Description This function releases the soundcard structure and the all assigned devices automatically. That is, you don’t have to release the devices by yourself. This function waits until the all resources are properly released. Return Zero. Frees all associated devices…
snd_card_file_remove – remove the file from the file list Synopsis int snd_card_file_remove(struct snd_card *card, struct file *file); Arguments card soundcard structure file file pointer Description This function removes the file formerly added to the card via snd_card_file_add function. If all files are removed and snd_card_free_when_closed was called beforehand, it processes the pending release of resources….
snd_card_file_add – add the file to the file list of the card Synopsis int snd_card_file_add(struct snd_card *card, struct file *file); Arguments card soundcard structure file file pointer Description This function adds the file to the file linked-list of the card. This linked-list is used to keep tracking the connection state, and to avoid the release…
snd_card_disconnect – disconnect all APIs from the file-operations (user space) Synopsis int snd_card_disconnect(struct snd_card *card); Arguments card soundcard structure Description Disconnects all APIs from the file-operations (user space). Return Zero, otherwise a negative error code. Note The current implementation replaces all active file->f_op with special dummy file operations (they do nothing except release). Copyright
snd_card_add_dev_attr – Append a new sysfs attribute group to card Synopsis int snd_card_add_dev_attr(struct snd_card *card, const struct attribute_group *group); Arguments card card instance group attribute group to append Copyright
snd_ac97_write_cache – write a value on the given register and update the cache Synopsis void snd_ac97_write_cache(struct snd_ac97 *ac97, unsigned short reg, unsigned short value); Arguments ac97 the ac97 instance reg the register to change value the value to set Description Writes a value on the given register and updates the register cache. The cached values…
snd_ac97_write – write a value on the given register Synopsis void snd_ac97_write(struct snd_ac97 *ac97, unsigned short reg, unsigned short value); Arguments ac97 the ac97 instance reg the register to change value the value to set Description Writes a value on the given register. This will invoke the write callback directly after the register check. This…
snd_ac97_update_power – update the powerdown register Synopsis int snd_ac97_update_power(struct snd_ac97 *ac97, int reg, int powerup); Arguments ac97 the codec instance reg the rate register, e.g. AC97_PCM_FRONT_DAC_RATE powerup non-zero when power up the part Description Update the AC97 powerdown register bits of the given part. Return Zero. Copyright
snd_ac97_update_bits – update the bits on the given register Synopsis int snd_ac97_update_bits(struct snd_ac97 *ac97, unsigned short reg, unsigned short mask, unsigned short value); Arguments ac97 the ac97 instance reg the register to change mask the bit-mask to change value the value to set Description Updates the masked-bits on the given register only when the value…
snd_ac97_update – update the value on the given register Synopsis int snd_ac97_update(struct snd_ac97 *ac97, unsigned short reg, unsigned short value); Arguments ac97 the ac97 instance reg the register to change value the value to set Description Compares the value with the register cache and updates the value only when the value is changed. Return 1…
snd_ac97_tune_hardware – tune up the hardware Synopsis int snd_ac97_tune_hardware(struct snd_ac97 *ac97, const struct ac97_quirk *quirk, const char *override); Arguments ac97 the ac97 instance quirk quirk list override explicit quirk value (overrides the list if non-NULL) Description Do some workaround for each pci device, such as renaming of the headphone (true line-out) control as “Master”. The…
snd_ac97_suspend – General suspend function for AC97 codec Synopsis void snd_ac97_suspend(struct snd_ac97 *ac97); Arguments ac97 the ac97 instance Description Suspends the codec, power down the chip. Copyright