MTK_NOR_REG_CFG2
val = readl(sp->base + MTK_NOR_REG_CFG2);
writel(val | MTK_NOR_WR_BUF_EN, sp->base + MTK_NOR_REG_CFG2);
ret = readl_poll_timeout(sp->base + MTK_NOR_REG_CFG2, val,
writel(val & ~MTK_NOR_WR_BUF_EN, sp->base + MTK_NOR_REG_CFG2);
ret = readl_poll_timeout(sp->base + MTK_NOR_REG_CFG2, val,
mtk_nor_rmw(sp, MTK_NOR_REG_CFG2, MTK_NOR_WR_CUSTOM_OP_EN, 0);