SDHCI_FSL_TBPTR_WND_MASK
reg &= ~SDHCI_FSL_TBPTR_WND_MASK;
reg &= ~(SDHCI_FSL_TBPTR_WND_MASK << SDHCI_FSL_TBPTR_WND_START_SHIFT);
wnd_start &= SDHCI_FSL_TBPTR_WND_MASK;
wnd_end = reg & SDHCI_FSL_TBPTR_WND_MASK;