v1->v2: 1.Use two fields (pll_reg & bypass_reg) instead of the 2-values array (reg[2]). 2.Remove the "pll_info->version" and add a "pll_info->rate_multiplier". 3.Fix the coding style and add more detailed commit message. 4.Remove [4/5] and [5/5] in v1, because some problems were found in subsequent tests. 5.Remove unnecessary spinlock as Paul Burton and Paul Cercueil's suggestion. 6.Change my Signed-off-by from "Zhou Yanjie <zhouyanjie@xxxxxxxx>" to "周琰杰 (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>" because the old mailbox is in an unstable state.