---

Notes:
    v1->v2:
    Split "val = (val & ~OSTCCR_PRESCALEx_MASK) | 
FIELD_PREP(OSTCCR_PRESCALEx_MASK, prescale)"
    into "val &= ~OSTCCR_PRESCALEx_MASK" and "val |= 
FIELD_PREP(OSTCCR_PRESCALEx_MASK, prescale)"
    as Paul Cercueil's suggestion.

 drivers/clocksource/ingenic-sysost.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/clocksource/ingenic-sysost.c 

b/drivers/clocksource/ingenic-sysost.c
index a129840..cb6fc2f 100644

--- a/drivers/clocksource/ingenic-sysost.c
+++ b/drivers/clocksource/ingenic-sysost.c

@@ -4,6 +4,7 @@
  * Copyright (c) 2020 周琰杰 (Zhou Yanjie) 

[off-list ref]
  */

+#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;
--
2.7.4