Need help - what is following line of code doing

#define PINMUX_MCASP_REG_0       (0)  //what is PINMUX_MCASP_REG_0
#define PINMUX_MCASP_MASK_0      (0x00FFFFFF)//what is PINMUX_MCASP_MASK_0
#define PINMUX_MCASP_VAL_0       (0x00111111)//what is PINMUX_MCASP_VAL_0
#define PINMUX_MCASP_REG_1       (1)
#define PINMUX_MCASP_MASK_1      (0x000FF000)
#define PINMUX_MCASP_VAL_1       (0x00011000)



   // enable the psc and config pinmux for mcasp.
   EVMC6748_lpscTransition(PSC1, DOMAIN0, LPSC_MCASP0, PSC_ENABLE); //what is the use of function EVMC6748_lpscTransition
   EVMC6748_pinmuxConfig(PINMUX_MCASP_REG_0, PINMUX_MCASP_MASK_0, PINMUX_MCASP_VAL_0); //EVMC6748_pinmuxConfig
   EVMC6748_pinmuxConfig(PINMUX_MCASP_REG_1, PINMUX_MCASP_MASK_1, PINMUX_MCASP_VAL_1);