clocksource/drivers/ingenic: Use bitfield macro helpers

Use "FIELD_GET()" and "FIELD_PREP()" to simplify the code.

[dlezcano] : Changed title
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1627638188-116163-1-git-send-email-zhouyanjie@wanyeetech.com

drivers/clocksource/ingenic-sysost.c

@@ -4,6 +4,7 @@
  * Copyright (c) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
@@ -34,8 +35,6 @@
 /* bits within the OSTCCR register */
 #define OSTCCR_PRESCALE1_MASK	0x3
 #define OSTCCR_PRESCALE2_MASK	0xc
-#define OSTCCR_PRESCALE1_LSB	0
-#define OSTCCR_PRESCALE2_LSB	2
 
 /* bits within the OSTCR register */
 #define OSTCR_OST1CLR			BIT(0)
@@ -98,7 +97,7 @@ static unsigned long ingenic_ost_percpu_timer_recalc_rate(struct clk_hw *hw,
 
 	prescale = readl(ost_clk->ost->base + info->ostccr_reg);
 
-	prescale = (prescale & OSTCCR_PRESCALE1_MASK) >> OSTCCR_PRESCALE1_LSB;
+	prescale = FIELD_GET(OSTCCR_PRESCALE1_MASK, prescale);
 
 	return parent_rate >> (prescale * 2);
 }
@@ -112,7 +111,7 @@ static unsigned long ingenic_ost_global_timer_recalc_rate(struct clk_hw *hw,
 
 	prescale = readl(ost_clk->ost->base + info->ostccr_reg);
 
-	prescale = (prescale & OSTCCR_PRESCALE2_MASK) >> OSTCCR_PRESCALE2_LSB;
+	prescale = FIELD_GET(OSTCCR_PRESCALE2_MASK, prescale);
 
 	return parent_rate >> (prescale * 2);
 }
@@ -151,7 +150,8 @@ static int ingenic_ost_percpu_timer_set_rate(struct clk_hw *hw, unsigned long re
 	int val;
 
 	val = readl(ost_clk->ost->base + info->ostccr_reg);
-	val = (val & ~OSTCCR_PRESCALE1_MASK) | (prescale << OSTCCR_PRESCALE1_LSB);
+	val &= ~OSTCCR_PRESCALE1_MASK;
+	val |= FIELD_PREP(OSTCCR_PRESCALE1_MASK, prescale);
 	writel(val, ost_clk->ost->base + info->ostccr_reg);
 
 	return 0;
@@ -166,7 +166,8 @@ static int ingenic_ost_global_timer_set_rate(struct clk_hw *hw, unsigned long re
 	int val;
 
 	val = readl(ost_clk->ost->base + info->ostccr_reg);
-	val = (val & ~OSTCCR_PRESCALE2_MASK) | (prescale << OSTCCR_PRESCALE2_LSB);
+	val &= ~OSTCCR_PRESCALE2_MASK;
+	val |= FIELD_PREP(OSTCCR_PRESCALE2_MASK, prescale);
 	writel(val, ost_clk->ost->base + info->ostccr_reg);
 
 	return 0;