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clocksource/drivers/arm_global_timer: Simplify prescaler register access

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Use GENMASK() to define the prescaler mask and make the whole driver use
the mask (together with helpers such as FIELD_{GET,PREP,FIT}) instead of
needing an additional shift and max value constant.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20240225151336.2728533-4-martin.blumenstingl@googlemail.com
This commit is contained in:
Martin Blumenstingl 2024-02-25 16:13:36 +01:00 • committed by Daniel Lezcano
parent e651f2fae3
commit 755350bcfb
1 changed files with 8 additions and 11 deletions
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19
drivers/clocksource/arm_global_timer.c
View file

@ -9,6 +9,7 @@
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/bitfield.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/cpu.h>
@ -31,10 +32,7 @@
#define GT_CONTROL_COMP_ENABLE BIT(1) /* banked */
#define GT_CONTROL_IRQ_ENABLE BIT(2) /* banked */
#define GT_CONTROL_AUTO_INC BIT(3) /* banked */
#define GT_CONTROL_PRESCALER_SHIFT 8
#define GT_CONTROL_PRESCALER_MAX 0xFF
#define GT_CONTROL_PRESCALER_MASK (GT_CONTROL_PRESCALER_MAX << \
GT_CONTROL_PRESCALER_SHIFT)
#define GT_CONTROL_PRESCALER_MASK GENMASK(15, 8)
#define GT_INT_STATUS 0x0c
#define GT_INT_STATUS_EVENT_FLAG BIT(0)
@ -248,7 +246,7 @@ static void gt_write_presc(u32 psv)
reg = readl(gt_base + GT_CONTROL);
reg &= ~GT_CONTROL_PRESCALER_MASK;
reg |= psv << GT_CONTROL_PRESCALER_SHIFT;
reg |= FIELD_PREP(GT_CONTROL_PRESCALER_MASK, psv);
writel(reg, gt_base + GT_CONTROL);
}
@ -257,8 +255,7 @@ static u32 gt_read_presc(void)
u32 reg;
reg = readl(gt_base + GT_CONTROL);
reg &= GT_CONTROL_PRESCALER_MASK;
return reg >> GT_CONTROL_PRESCALER_SHIFT;
return FIELD_GET(GT_CONTROL_PRESCALER_MASK, reg);
}
static void __init gt_delay_timer_init(void)
@ -273,9 +270,9 @@ static int __init gt_clocksource_init(void)
writel(0, gt_base + GT_COUNTER0);
writel(0, gt_base + GT_COUNTER1);
/* set prescaler and enable timer on all the cores */
writel(((CONFIG_ARM_GT_INITIAL_PRESCALER_VAL - 1) <<
GT_CONTROL_PRESCALER_SHIFT)
| GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL);
writel(FIELD_PREP(GT_CONTROL_PRESCALER_MASK,
CONFIG_ARM_GT_INITIAL_PRESCALER_VAL - 1) |
GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL);
#ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
sched_clock_register(gt_sched_clock_read, 64, gt_target_rate);
@ -301,7 +298,7 @@ static int gt_clk_rate_change_cb(struct notifier_block *nb,
psv--;
/* prescaler within legal range? */
if (psv > GT_CONTROL_PRESCALER_MAX)
if (!FIELD_FIT(GT_CONTROL_PRESCALER_MASK, psv))
return NOTIFY_BAD;
/*