PCF_CTRL_ACK       48 dev/ic/pcf8584.c     PCF_CTRL_STA | PCF_CTRL_ACK)
PCF_CTRL_ACK       50 dev/ic/pcf8584.c     PCF_CTRL_STO | PCF_CTRL_ACK)
PCF_CTRL_ACK       51 dev/ic/pcf8584.c #define PCF_CTRL_REPSTART	(PCF_CTRL_ESO | PCF_CTRL_STA | PCF_CTRL_ACK)
PCF_CTRL_ACK       52 dev/ic/pcf8584.c #define PCF_CTRL_IDLE		(PCF_CTRL_PIN | PCF_CTRL_ESO | PCF_CTRL_ACK)