Register a dsp device
int register_sound_dsp(const struct file_operations * fops, int dev);
fops
File operations for the driver
dev
Unit number to allocate
Allocate a DSP device. Unit is the number of the DSP requested. Pass -1 to request the next free DSP unit.
This function allocates both the audio and dsp device entries together and will always allocate them as a matching pair - eg dsp3/audio3
On success, the allocated number is returned. On failure, a negative error code is returned.