struct i915_audio_component_ops — callbacks defined in gfx driver
struct i915_audio_component_ops { struct module * owner; void (* get_power) (struct device *); void (* put_power) (struct device *); void (* codec_wake_override) (struct device *, bool enable); int (* get_cdclk_freq) (struct device *); int (* sync_audio_rate) (struct device *, int port, int rate); };