Linux Manuals

snd_ctl_unregister_ioctl – de-register the device-specific control-ioctls Synopsis int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn); Arguments fcn ioctl callback function to unregister Copyright

snd_ctl_sync_vmaster – Sync the vmaster slaves and hook Synopsis void snd_ctl_sync_vmaster(struct snd_kcontrol *kcontrol, bool hook_only); Arguments kcontrol vmaster kctl element hook_only sync only the hook Description Forcibly call the put callback of each slave and call the hook function to synchronize with the current value of the given vmaster element. NOP when NULL is passed…

snd_ctl_replace – replace the control instance of the card Synopsis int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, bool add_on_replace); Arguments card the card instance kcontrol the control instance to replace add_on_replace add the control if not already added Description Replaces the given control. If the given control does not exist and the add_on_replace flag is…

snd_ctl_rename_id – replace the id of a control on the card Synopsis int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id); Arguments card the card instance src_id the old id dst_id the new id Description Finds the control with the old id from the card, and replaces the id with the new one. Return…

snd_ctl_remove_id – remove the control of the given id and release it Synopsis int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id); Arguments card the card instance id the control id to remove Description Finds the control instance with the given id, removes it from the card list and releases it. Return 0 if successful, or a…

snd_ctl_remove – remove the control from the card and release it Synopsis int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol); Arguments card the card instance kcontrol the control instance to remove Description Removes the control from the card and then releases the instance. You don’t need to call snd_ctl_free_one. You must be in the write lock…

snd_ctl_register_ioctl_compat – register the device-specific 32bit compat control-ioctls Synopsis int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn); Arguments fcn ioctl callback function Copyright

snd_ctl_register_ioctl – register the device-specific control-ioctls Synopsis int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn); Arguments fcn ioctl callback function Description called from each device manager like pcm.c, hwdep.c, etc. Copyright

snd_ctl_notify – Send notification to user-space for a control change Synopsis void snd_ctl_notify(struct snd_card *card, unsigned int mask, struct snd_ctl_elem_id *id); Arguments card the card to send notification mask the event mask, SNDRV_CTL_EVENT_* id the ctl element id to send notification Description This function adds an event record with the given id and mask, appends…

snd_ctl_new1 – create a control instance from the template Synopsis struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol, void *private_data); Arguments ncontrol the initialization record private_data the private data to set Description Allocates a new struct snd_kcontrol instance and initialize from the given template. When the access field of ncontrol is 0, it’s assumed as READWRITE access….

snd_ctl_make_virtual_master – Create a virtual master control Synopsis struct snd_kcontrol *snd_ctl_make_virtual_master(char *name, const unsigned int *tlv); Arguments name name string of the control element to create tlv optional TLV int array for dB information Description Creates a virtual master control with the given name string. After creating a vmaster element, you can add the slave…

snd_ctl_free_one – release the control instance Synopsis void snd_ctl_free_one(struct snd_kcontrol *kcontrol); Arguments kcontrol the control instance Description Releases the control instance created via snd_ctl_new or snd_ctl_new1. Don’t call this after the control was added to the card. Copyright

snd_ctl_find_numid – find the control instance with the given number-id Synopsis struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid); Arguments card the card instance numid the number-id to search Description Finds the control instance with the given number-id from the card. The caller must down card->controls_rwsem before calling this function (if the race condition can…

snd_ctl_find_id – find the control instance with the given id Synopsis struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card, struct snd_ctl_elem_id *id); Arguments card the card instance id the id to search Description Finds the control instance with the given id from the card. The caller must down card->controls_rwsem before calling this function (if the race condition can…

snd_ctl_enum_info – fills the info structure for an enumerated control Synopsis int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels, unsigned int items, const char *const names[]); Arguments info the structure to be filled channels the number of the control’s channels; often one items the number of control values; also the size of names names[] an array…

snd_ctl_boolean_stereo_info – Helper function for a standard boolean info callback with stereo two channels Synopsis int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo); Arguments kcontrol the kcontrol instance uinfo info to store Description This is a function that can be used as info callback for a standard boolean control with stereo two channels. Copyright

snd_ctl_boolean_mono_info – Helper function for a standard boolean info callback with a mono channel Synopsis int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo); Arguments kcontrol the kcontrol instance uinfo info to store Description This is a function that can be used as info callback for a standard boolean control with a single mono channel. Copyright

snd_ctl_add_vmaster_hook – Add a hook to a vmaster control Synopsis int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kcontrol, void (*hook)(void *private_data, int), void *private_data); Arguments kcontrol vmaster kctl element hook the hook function private_data the private_data pointer to be saved Description Adds the given hook to the vmaster control element so that it’s called at each time when the…

snd_ctl_add_slave_uncached – Add a virtual slave control Synopsis int snd_ctl_add_slave_uncached(struct snd_kcontrol *master, struct snd_kcontrol *slave); Arguments master vmaster element slave slave element to add Description Add a virtual slave control to the given master. Unlike snd_ctl_add_slave, the element added via this function is supposed to have volatile values, and get callback is called at each…

snd_ctl_add_slave – Add a virtual slave control Synopsis int snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave); Arguments master vmaster element slave slave element to add Description Add a virtual slave control to the given master element created via snd_ctl_create_virtual_master beforehand. All slaves must be the same type (returning the same information via info callback). The function…