PLL1_CLOCK = 0,
        PLL2_CLOCK,
        PLL3_CLOCK,
+#ifdef CONFIG_MX53
        PLL4_CLOCK,
+#endif
        PLL_CLOCKS,
 };
 
        u32 ret_val = 0;
        u32 ccsr = readl(&mxc_ccm->ccsr);
 
-       if (((ccsr >> 9) & 1) == 0)
-               ret_val = MXC_HCLK;
-       else
+       if (ccsr & MXC_CCM_CCSR_LP_APM)
                ret_val = MXC_CLK32 * 1024;
+       else
+               ret_val = MXC_HCLK;
 
        return ret_val;
 }
        switch (index) {
        case PLL1_CLOCK:
                /* Switch ARM to PLL2 clock */
-               writel(ccsr | 0x4, &mxc_ccm->ccsr);
+               writel(ccsr | MXC_CCM_CCSR_PLL1_SW_CLK_SEL,
+                               &mxc_ccm->ccsr);
                CHANGE_PLL_SETTINGS(pll, pll_param->pd,
                                        pll_param->mfi, pll_param->mfn,
                                        pll_param->mfd);
                /* Switch back */
-               writel(ccsr & ~0x4, &mxc_ccm->ccsr);
+               writel(ccsr & ~MXC_CCM_CCSR_PLL1_SW_CLK_SEL,
+                               &mxc_ccm->ccsr);
                break;
        case PLL2_CLOCK:
                /* Switch to pll2 bypass clock */
-               writel(ccsr | 0x2, &mxc_ccm->ccsr);
+               writel(ccsr | MXC_CCM_CCSR_PLL2_SW_CLK_SEL,
+                               &mxc_ccm->ccsr);
                CHANGE_PLL_SETTINGS(pll, pll_param->pd,
                                        pll_param->mfi, pll_param->mfn,
                                        pll_param->mfd);
                /* Switch back */
-               writel(ccsr & ~0x2, &mxc_ccm->ccsr);
+               writel(ccsr & ~MXC_CCM_CCSR_PLL2_SW_CLK_SEL,
+                               &mxc_ccm->ccsr);
                break;
        case PLL3_CLOCK:
                /* Switch to pll3 bypass clock */
-               writel(ccsr | 0x1, &mxc_ccm->ccsr);
+               writel(ccsr | MXC_CCM_CCSR_PLL3_SW_CLK_SEL,
+                               &mxc_ccm->ccsr);
                CHANGE_PLL_SETTINGS(pll, pll_param->pd,
                                        pll_param->mfi, pll_param->mfn,
                                        pll_param->mfd);
                /* Switch back */
-               writel(ccsr & ~0x1, &mxc_ccm->ccsr);
+               writel(ccsr & ~MXC_CCM_CCSR_PLL3_SW_CLK_SEL,
+                               &mxc_ccm->ccsr);
                break;
+#ifdef CONFIG_MX53
        case PLL4_CLOCK:
                /* Switch to pll4 bypass clock */
-               writel(ccsr | 0x20, &mxc_ccm->ccsr);
+               writel(ccsr | MXC_CCM_CCSR_PLL4_SW_CLK_SEL,
+                               &mxc_ccm->ccsr);
                CHANGE_PLL_SETTINGS(pll, pll_param->pd,
                                        pll_param->mfi, pll_param->mfn,
                                        pll_param->mfd);
                /* Switch back */
-               writel(ccsr & ~0x20, &mxc_ccm->ccsr);
+               writel(ccsr & ~MXC_CCM_CCSR_PLL4_SW_CLK_SEL,
+                               &mxc_ccm->ccsr);
                break;
+#endif
        default:
                return -EINVAL;
        }
 
        u32 cmeor;
 };
 
+/* Define the bits in register CCSR */
+#if defined(CONFIG_MX51)
+#define MXC_CCM_CCSR_LP_APM                    (0x1 << 9)
+#elif defined(CONFIG_MX53)
+#define MXC_CCM_CCSR_LP_APM                    (0x1 << 10)
+#define MXC_CCM_CCSR_PLL4_SW_CLK_SEL           (0x1 << 9)
+#endif
+#define MXC_CCM_CCSR_STEP_SEL_OFFSET           7
+#define MXC_CCM_CCSR_STEP_SEL_MASK             (0x3 << 7)
+#define MXC_CCM_CCSR_STEP_SEL(v)               (((v) & 0x3) << 7)
+#define MXC_CCM_CCSR_STEP_SEL_RD(r)            (((r) >> 7) & 0x3)
+#define MXC_CCM_CCSR_PLL2_DIV_PODF_OFFSET      5
+#define MXC_CCM_CCSR_PLL2_DIV_PODF_MASK                (0x3 << 5)
+#define MXC_CCM_CCSR_PLL2_DIV_PODF(v)          (((v) & 0x3) << 5)
+#define MXC_CCM_CCSR_PLL2_DIV_PODF_RD(r)       (((r) >> 5) & 0x3)
+#define MXC_CCM_CCSR_PLL3_DIV_PODF_OFFSET      3
+#define MXC_CCM_CCSR_PLL3_DIV_PODF_MASK                (0x3 << 3)
+#define MXC_CCM_CCSR_PLL3_DIV_PODF(v)          (((v) & 0x3) << 3)
+#define MXC_CCM_CCSR_PLL3_DIV_PODF_RD(r)       (((r) >> 3) & 0x3)
+#define MXC_CCM_CCSR_PLL1_SW_CLK_SEL           (0x1 << 2)
+#define MXC_CCM_CCSR_PLL2_SW_CLK_SEL           (0x1 << 1)
+#define MXC_CCM_CCSR_PLL3_SW_CLK_SEL           0x1
+
 /* Define the bits in register CACRR */
 #define MXC_CCM_CACRR_ARM_PODF_OFFSET          0
 #define MXC_CCM_CACRR_ARM_PODF_MASK            0x7