[tip:timers/core] clocksource/drivers/stm32: Add the timer delay callback

From: tip-bot for Daniel Lezcano
Date: Mon Jan 08 2018 - 12:38:21 EST


Commit-ID: 81abdbbffd69fecdac37fe1d2b44a21227ee23d4
Gitweb: https://git.kernel.org/tip/81abdbbffd69fecdac37fe1d2b44a21227ee23d4
Author: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
AuthorDate: Mon, 8 Jan 2018 14:28:58 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 8 Jan 2018 17:57:26 +0100

clocksource/drivers/stm32: Add the timer delay callback

Add the timer delay callback, that saves us ~90ms of boot time.

Tested-by: Benjamin Gaignard <benjamin.gaignard@xxxxxx>
Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Acked-by: Benjamin Gaignard <benjamin.gaignard@xxxxxx>
Cc: Alexandre Torgue <alexandre.torgue@xxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1515418139-23276-19-git-send-email-daniel.lezcano@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
drivers/clocksource/timer-stm32.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c
index 21b7492..c7d1dae 100644
--- a/drivers/clocksource/timer-stm32.c
+++ b/drivers/clocksource/timer-stm32.c
@@ -9,6 +9,7 @@
#include <linux/kernel.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
+#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/of.h>
@@ -88,6 +89,13 @@ static u64 notrace stm32_read_sched_clock(void)
return readl_relaxed(stm32_timer_cnt);
}

+static struct delay_timer stm32_timer_delay;
+
+static unsigned long stm32_read_delay(void)
+{
+ return readl_relaxed(stm32_timer_cnt);
+}
+
static void stm32_clock_event_disable(struct timer_of *to)
{
writel_relaxed(0, timer_of_base(to) + TIM_DIER);
@@ -230,6 +238,11 @@ static int __init stm32_clocksource_init(struct timer_of *to)
stm32_timer_cnt = timer_of_base(to) + TIM_CNT;
sched_clock_register(stm32_read_sched_clock, bits, timer_of_rate(to));
pr_info("%s: STM32 sched_clock registered\n", name);
+
+ stm32_timer_delay.read_current_timer = stm32_read_delay;
+ stm32_timer_delay.freq = timer_of_rate(to);
+ register_current_timer_delay(&stm32_timer_delay);
+ pr_info("%s: STM32 delay timer registered\n", name);
}

return clocksource_mmio_init(timer_of_base(to) + TIM_CNT, name,