From 923df96b9f31b7d08d8438ff9677326d9537accf Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 6 Jul 2012 15:46:45 +0100 Subject: 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 Reviewed-by: Stephen Boyd Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/kernel/arch_timer.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index dd58035..dbbeec4 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -223,6 +223,14 @@ static cycle_t arch_counter_read(struct clocksource *cs) return arch_counter_get_cntpct(); } +int read_current_timer(unsigned long *timer_val) +{ + if (!arch_timer_rate) + return -ENXIO; + *timer_val = arch_counter_get_cntpct(); + return 0; +} + static struct clocksource clocksource_counter = { .name = "arch_sys_counter", .rating = 400, -- cgit v1.1