ocmem_write
ocmem_write(ocmem, OCMEM_REG_REGION_MODE_CTL, region_mode_ctrl);
ocmem_write(ocmem, OCMEM_REG_PSGSC_CTL(i), data);
ocmem_write(ocmem, OCMEM_REG_GFX_MPU_START, buf->offset);
ocmem_write(ocmem, OCMEM_REG_GFX_MPU_END,
ocmem_write(ocmem, OCMEM_REG_GFX_MPU_START, 0x0);
ocmem_write(ocmem, OCMEM_REG_GFX_MPU_END, 0x0);