DMA_RB_WPTR
reg = DMA_RB_WPTR + DMA0_REGISTER_OFFSET;
reg = DMA_RB_WPTR + DMA1_REGISTER_OFFSET;
WREG32(DMA_RB_WPTR + reg_offset, 0);
WREG32(DMA_RB_WPTR + reg_offset, ring->wptr << 2);
reg = DMA_RB_WPTR + DMA0_REGISTER_OFFSET;
reg = DMA_RB_WPTR + DMA1_REGISTER_OFFSET;
WREG32(DMA_RB_WPTR, 0);
WREG32(DMA_RB_WPTR, ring->wptr << 2);
return (RREG32(DMA_RB_WPTR) & 0x3fffc) >> 2;
WREG32(DMA_RB_WPTR, (ring->wptr << 2) & 0x3fffc);