From: rmk+kernel@arm•linux.org.uk (Russell King)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH CFT] ARM: orion: implement ARM delay timer
Date: Mon, 19 Oct 2015 17:13:07 +0100 [thread overview]
Message-ID: <E1ZoD3b-0006UD-Rp@rmk-PC.arm.linux.org.uk> (raw)
Implement an ARM delay timer to be used for udelay() on orion legacy
platforms. This allows us to skip the delay loop calibration at boot.
It also means that udelay() will be unaffected by CPU frequency changes
when cpufreq is enabled on these platforms.
Signed-off-by: Russell King <rmk+kernel@arm•linux.org.uk>
---
This needs to be tested beyond build testing...
arch/arm/plat-orion/time.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/arm/plat-orion/time.c b/arch/arm/plat-orion/time.c
index 8085a8aac812..ffb93db68e9c 100644
--- a/arch/arm/plat-orion/time.c
+++ b/arch/arm/plat-orion/time.c
@@ -18,6 +18,7 @@
#include <linux/irq.h>
#include <linux/sched_clock.h>
#include <plat/time.h>
+#include <asm/delay.h>
/*
* MBus bridge block registers.
@@ -188,6 +189,15 @@ orion_time_set_base(void __iomem *_timer_base)
timer_base = _timer_base;
}
+static unsigned long orion_delay_timer_read(void)
+{
+ return ~readl(timer_base + TIMER0_VAL_OFF);
+}
+
+static struct delay_timer orion_delay_timer = {
+ .read_current_timer = orion_delay_timer_read,
+};
+
void __init
orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask,
unsigned int irq, unsigned int tclk)
@@ -202,6 +212,9 @@ orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask,
ticks_per_jiffy = (tclk + HZ/2) / HZ;
+ orion_delay_timer.freq = tclk;
+ register_current_timer_delay(&orion_delay_timer);
+
/*
* Set scale and timer for sched_clock.
*/
--
2.1.0
next reply other threads:[~2015-10-19 16:13 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-19 16:13 Russell King [this message]
2015-12-07 10:19 ` [PATCH CFT] ARM: orion: implement ARM delay timer Russell King - ARM Linux
2015-12-07 14:03 ` Andrew Lunn
2015-12-07 15:00 ` Russell King - ARM Linux
2015-12-07 15:09 ` Andrew Lunn
2016-01-27 7:58 ` Gregory CLEMENT
2016-01-27 9:45 ` Russell King - ARM Linux
2016-01-27 9:52 ` Gregory CLEMENT
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=E1ZoD3b-0006UD-Rp@rmk-PC.arm.linux.org.uk \
--to=rmk+kernel@arm$(echo .)linux.org.uk \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox