pwm: fsl-ftm: Clean up the code

This patch intends to prepare for converting to direct regmap API usage.
Signed-off-by: NXiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: NThierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-fsl-ftm.c

@@ -21,11 +21,10 @@
 #include <linux/slab.h>
 
 #define FTM_SC		0x00
-#define FTM_SC_CLK_MASK	0x3
-#define FTM_SC_CLK_SHIFT	3
-#define FTM_SC_CLK(c)	(((c) + 1) << FTM_SC_CLK_SHIFT)
+#define FTM_SC_CLK_MASK_SHIFT	3
+#define FTM_SC_CLK_MASK	(3 << FTM_SC_CLK_MASK_SHIFT)
+#define FTM_SC_CLK(c)	(((c) + 1) << FTM_SC_CLK_MASK_SHIFT)
 #define FTM_SC_PS_MASK	0x7
-#define FTM_SC_PS_SHIFT	0
 
 #define FTM_CNT		0x04
 #define FTM_MOD		0x08
@@ -258,7 +257,7 @@ static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		}
 
 		val = readl(fpc->base + FTM_SC);
-		val &= ~(FTM_SC_PS_MASK << FTM_SC_PS_SHIFT);
+		val &= ~FTM_SC_PS_MASK;
 		val |= fpc->clk_ps;
 		writel(val, fpc->base + FTM_SC);
 		writel(period - 1, fpc->base + FTM_MOD);
@@ -305,7 +304,7 @@ static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc)
 
 	/* select counter clock source */
 	val = readl(fpc->base + FTM_SC);
-	val &= ~(FTM_SC_CLK_MASK << FTM_SC_CLK_SHIFT);
+	val &= ~FTM_SC_CLK_MASK;
 	val |= FTM_SC_CLK(fpc->cnt_select);
 	writel(val, fpc->base + FTM_SC);
 
@@ -357,7 +356,7 @@ static void fsl_counter_clock_disable(struct fsl_pwm_chip *fpc)
 
 	/* no users left, disable PWM counter clock */
 	val = readl(fpc->base + FTM_SC);
-	val &= ~(FTM_SC_CLK_MASK << FTM_SC_CLK_SHIFT);
+	val &= ~FTM_SC_CLK_MASK;
 	writel(val, fpc->base + FTM_SC);
 
 	clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);