path: root/arch/arm/kernel/arch_timer.c
diff options
authorJonathan Austin <Jonathan.Austin@arm.com>2012-09-21 18:51:44 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-09-26 22:57:52 +0100
commit56942fec06efa0e17df0f4c3b438332c923b9014 (patch)
tree89b604c987b7f6a0eaaa16af7a9d8f45711349a7 /arch/arm/kernel/arch_timer.c
parenta1b2dde70419ae947fd7c9c8fcad7da005dc600e (diff)
ARM: 7538/1: delay: add registration mechanism for delay timer sources
The current timer-based delay loop relies on the architected timer to initiate the switch away from the polling-based implementation. This is unfortunate for platforms without the architected timers but with a suitable delay source (that is, constant frequency, always powered-up and ticking as long as the CPUs are online). This patch introduces a registration mechanism for the delay timer (which provides an unconditional read_current_timer implementation) and updates the architected timer code to use the new interface. Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/arch_timer.c')
1 files changed, 8 insertions, 9 deletions
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index c04c2a6da470..c8ef20747ee7 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -21,6 +21,7 @@
#include <linux/io.h>
#include <asm/cputype.h>
+#include <asm/delay.h>
#include <asm/localtimer.h>
#include <asm/arch_timer.h>
#include <asm/system_info.h>
@@ -39,8 +40,7 @@ enum ppi_nr {
static int arch_timer_ppi[MAX_TIMER_PPI];
static struct clock_event_device __percpu **arch_timer_evt;
-extern void init_current_timer_delay(unsigned long freq);
+static struct delay_timer arch_delay_timer;
static bool arch_timer_use_virtual = true;
@@ -325,12 +325,9 @@ static cycle_t arch_counter_read(struct clocksource *cs)
return arch_counter_get_cntpct();
-int read_current_timer(unsigned long *timer_val)
+static unsigned long arch_timer_read_current_timer(void)
- if (!arch_timer_rate)
- return -ENXIO;
- *timer_val = arch_counter_get_cntpct();
- return 0;
+ return arch_counter_get_cntpct();
static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
@@ -441,11 +438,13 @@ static int __init arch_timer_register(void)
arch_timer_global_evt.cpumask = cpumask_of(0);
err = arch_timer_setup(&arch_timer_global_evt);
if (err)
goto out_free_irq;
- init_current_timer_delay(arch_timer_rate);
+ /* Use the architected timer for the delay loop. */
+ arch_delay_timer.read_current_timer = &arch_timer_read_current_timer;
+ arch_delay_timer.freq = arch_timer_rate;
+ register_current_timer_delay(&arch_delay_timer);
return 0;