GPIO 151 sound/pci/ca0106/ca0106.h #define GPIO 0x18 /* Defaults: 005f03a3-Analog, 005f02a2-SPDIF. */ GPIO 99 sound/pci/emu10k1/emu10k1x.c #define GPIO 0x18 /* Defaults: 00001080-Analog, 00001000-SPDIF. */