diff options
| author | Will Deacon <will.deacon@arm.com> | 2012-07-06 18:46:45 +0400 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-07-09 20:42:23 +0400 |
| commit | 923df96b9f31b7d08d8438ff9677326d9537accf (patch) | |
| tree | 3df937a0431a2ae0500ae011f5742a28611490fa /arch/arm/include/asm/timex.h | |
| parent | f8f5701bdaf9134b1f90e5044a82c66324d2073f (diff) | |
| download | linux-923df96b9f31b7d08d8438ff9677326d9537accf.tar.xz | |
ARM: 7451/1: arch timer: implement read_current_timer and get_cycles
This patch implements read_current_timer using the architected timers
when they are selected via CONFIG_ARM_ARCH_TIMER. If they are detected
not to be usable at runtime, we return -ENXIO to the caller.
Furthermore, if read_current_timer is exported then we can implement
get_cycles in terms of it for use as both an entropy source and for
implementing __udelay and friends.
Tested-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
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/include/asm/timex.h')
| -rw-r--r-- | arch/arm/include/asm/timex.h | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/arm/include/asm/timex.h b/arch/arm/include/asm/timex.h index 3be8de3adaba..ce119442277c 100644 --- a/arch/arm/include/asm/timex.h +++ b/arch/arm/include/asm/timex.h @@ -12,13 +12,15 @@ #ifndef _ASMARM_TIMEX_H #define _ASMARM_TIMEX_H +#include <asm/arch_timer.h> #include <mach/timex.h> typedef unsigned long cycles_t; -static inline cycles_t get_cycles (void) -{ - return 0; -} +#ifdef ARCH_HAS_READ_CURRENT_TIMER +#define get_cycles() ({ cycles_t c; read_current_timer(&c) ? 0 : c; }) +#else +#define get_cycles() (0) +#endif #endif |