void analog_volume_init(void)
{
snd_ctl_elem_info_t *info;
int i;
snd_ctl_elem_info_alloca(&info);
snd_ctl_elem_info_set_interface(info, SND_CTL_ELEM_IFACE_MIXER);
for (i = 0; i < 10; i++) {
snd_ctl_elem_info_set_name(info, DAC_VOLUME_NAME);
snd_ctl_elem_info_set_numid(info, 0);
snd_ctl_elem_info_set_index(info, i);
if (snd_ctl_elem_info(ctl, info) < 0)
break;
dac_max = snd_ctl_elem_info_get_max(info);
}
if (i < output_channels - 1)
dac_volumes = i;
else
dac_volumes = output_channels;
snd_ctl_elem_info_set_name(info, DAC_SENSE_NAME);
for (i = 0; i < dac_volumes; i++) {
snd_ctl_elem_info_set_numid(info, 0);
snd_ctl_elem_info_set_index(info, i);
if (snd_ctl_elem_info(ctl, info) < 0)
break;
}
dac_senses = i;
if (dac_senses > 0) {
snd_ctl_elem_info_set_numid(info, 0);
snd_ctl_elem_info_set_index(info, 0);
snd_ctl_elem_info(ctl, info);
dac_sense_items = snd_ctl_elem_info_get_items(info);
for (i = 0; i < dac_sense_items; i++) {
snd_ctl_elem_info_set_item(info, i);
snd_ctl_elem_info(ctl, info);
dac_sense_name[i] = strdup(snd_ctl_elem_info_get_item_name(info));
}
}
for (i = 0; i < 10; i++) {
snd_ctl_elem_info_set_name(info, ADC_VOLUME_NAME);
snd_ctl_elem_info_set_numid(info, 0);
snd_ctl_elem_info_set_index(info, i);
if (snd_ctl_elem_info(ctl, info) < 0)
break;
adc_max = snd_ctl_elem_info_get_max(info);
}
if (i < input_channels - 1)
adc_volumes = i;
else
adc_volumes = input_channels;
snd_ctl_elem_info_set_name(info, ADC_SENSE_NAME);
for (i = 0; i < adc_volumes; i++) {
snd_ctl_elem_info_set_numid(info, 0);
snd_ctl_elem_info_set_index(info, i);
if (snd_ctl_elem_info(ctl, info) < 0)
break;
}
adc_senses = i;
if (adc_senses > 0) {
snd_ctl_elem_info_set_numid(info, 0);
snd_ctl_elem_info_set_index(info, 0);
snd_ctl_elem_info(ctl, info);
adc_sense_items = snd_ctl_elem_info_get_items(info);
for (i = 0; i < adc_sense_items; i++) {
snd_ctl_elem_info_set_item(info, i);
snd_ctl_elem_info(ctl, info);
adc_sense_name[i] = strdup(snd_ctl_elem_info_get_item_name(info));
}
}
for (i = 0; i < 10; i++) {
snd_ctl_elem_info_set_name(info, IPGA_VOLUME_NAME);
snd_ctl_elem_info_set_numid(info, 0);
snd_ctl_elem_info_set_index(info, i);
if (snd_ctl_elem_info(ctl, info) < 0)
break;
}
if (i < input_channels - 1)
ipga_volumes = i;
else
ipga_volumes = input_channels;
}
void main( int argc, char *argv[] )
{
struct structArgs cmdArgs;
int errNum;
// ************************************************************************
// ALSA control elements.
// ************************************************************************
snd_ctl_t *ctl; // Simple control handle.
snd_ctl_elem_id_t *id; // Simple control element id.
snd_ctl_elem_value_t *control; // Simple control element value.
snd_ctl_elem_type_t type; // Simple control element type.
snd_ctl_elem_info_t *info; // Simple control info container.
// ************************************************************************
// Get command line parameters.
// ************************************************************************
argp_parse( &argp, argc, argv, 0, 0, &cmdArgs );
printf( "Card = %i\n", cmdArgs.card );
printf( "Control = %i\n", cmdArgs.control );
printf( "Value 1 = %i\n", cmdArgs.value1 );
printf( "Value 2 = %i\n", cmdArgs.value2 );
// ************************************************************************
// Set up ALSA control.
// ************************************************************************
sprintf( cmdArgs.deviceID, "hw:%i", cmdArgs.card );
printf( "Device ID = %s.\n", cmdArgs.deviceID );
if ( snd_ctl_open( &ctl, cmdArgs.deviceID, 1 ) < 0 )
{
printf( "Error opening control.\n" );
return;
}
// Initialise a simple control element id structure.
snd_ctl_elem_id_alloca( &id );
snd_ctl_elem_id_set_numid( id, cmdArgs.control );
// Initialise info element.
snd_ctl_elem_info_alloca( &info );
snd_ctl_elem_info_set_numid( info, cmdArgs.control );
// Is the control valid?
if ( snd_ctl_elem_info( ctl, info ) < 0 )
{
printf( "Error getting control element info.\n" );
return;
}
// Find type of control.
// either:
// SND_CTL_ELEM_TYPE_INTEGER,
// SND_CTL_ELEM_TYPE_INTEGER64,
// SND_CTL_ELEM_TYPE_ENUMERATED, etc.
// Only interested in INTEGER.
type = snd_ctl_elem_info_get_type( info );
if ( type != SND_CTL_ELEM_TYPE_INTEGER )
{
printf( "Control type is not integer.\n" );
printf( "Type = %s\n", type );
return;
}
// ************************************************************************
// Get some information for selected control.
// ************************************************************************
printf( "Min value for control = %d\n", snd_ctl_elem_info_get_min( info ));
printf( "Max value for control = %d\n", snd_ctl_elem_info_get_max( info ));
printf( "Step value for control = %d\n", snd_ctl_elem_info_get_step( info ));
// Initialise the control element value container.
snd_ctl_elem_value_alloca( &control );
snd_ctl_elem_value_set_id( control, id );
// ************************************************************************
// Set values for selected control.
// ************************************************************************
snd_ctl_elem_value_set_integer( control, 0, cmdArgs.value1 );
if ( snd_ctl_elem_write( ctl, control ) < 0 )
printf( "Error setting L volume" );
else
printf( "Set L volume to %d.\n", cmdArgs.value1 );
snd_ctl_elem_value_set_integer( control, 1, cmdArgs.value2 );
if ( snd_ctl_elem_write( ctl, control ) < 0 )
printf( "Error setting R volume" );
else
printf( "Set R volume to %d.\n", cmdArgs.value2 );
// ************************************************************************
// Clean up.
// ************************************************************************
snd_ctl_close( ctl );
return;
}
static int check_elem_set_props(struct elem_set_trial *trial)
{
snd_ctl_elem_id_t *id;
snd_ctl_elem_info_t *info;
unsigned int numid;
unsigned int index;
unsigned int i;
unsigned int j;
int err;
snd_ctl_elem_id_alloca(&id);
snd_ctl_elem_info_alloca(&info);
snd_ctl_elem_info_set_id(info, trial->id);
numid = snd_ctl_elem_id_get_numid(trial->id);
index = snd_ctl_elem_id_get_index(trial->id);
for (i = 0; i < trial->element_count; ++i) {
snd_ctl_elem_info_set_index(info, index + i);
/*
* In Linux 4.0 or former, ioctl(SNDRV_CTL_IOCTL_ELEM_ADD)
* doesn't fill all of fields for identification.
*/
if (numid > 0)
snd_ctl_elem_info_set_numid(info, numid + i);
err = snd_ctl_elem_info(trial->handle, info);
if (err < 0)
return err;
/* Check some common properties. */
if (snd_ctl_elem_info_get_type(info) != trial->type)
return -EIO;
if (snd_ctl_elem_info_get_count(info) != trial->member_count)
return -EIO;
for (j = 0; j < 4; ++j) {
if (snd_ctl_elem_info_get_dimension(info, j) !=
trial->dimension[j])
return -EIO;
}
/*
* In a case of IPC, this is the others. But in this case,
* it's myself.
*/
if (snd_ctl_elem_info_get_owner(info) != getpid())
return -EIO;
/*
* Just adding an element set by userspace applications,
* included elements are initially locked.
*/
if (!snd_ctl_elem_info_is_locked(info))
return -EIO;
/* Check type-specific properties. */
if (trial->check_elem_props != NULL) {
err = trial->check_elem_props(trial, info);
if (err < 0)
return err;
}
snd_ctl_elem_info_get_id(info, id);
err = snd_ctl_elem_unlock(trial->handle, id);
if (err < 0)
return err;
}
return 0;
}
