diff options
Diffstat (limited to 'arch/arm/plat-iop/time.c')
| -rw-r--r-- | arch/arm/plat-iop/time.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm/plat-iop/time.c b/arch/arm/plat-iop/time.c index 8da95d57c21f..5506c9b45612 100644 --- a/arch/arm/plat-iop/time.c +++ b/arch/arm/plat-iop/time.c @@ -19,6 +19,7 @@ #include <linux/init.h> #include <linux/timex.h> #include <linux/io.h> +#include <linux/clocksource.h> #include <mach/hardware.h> #include <asm/irq.h> #include <asm/uaccess.h> @@ -26,6 +27,43 @@ #include <asm/mach/time.h> #include <mach/time.h> +/* + * IOP clocksource (free-running timer 1). + */ +static cycle_t iop_clocksource_read(struct clocksource *unused) +{ + return 0xffffffffu - read_tcr1(); +} + +static struct clocksource iop_clocksource = { + .name = "iop_timer1", + .rating = 300, + .read = iop_clocksource_read, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static void __init iop_clocksource_set_hz(struct clocksource *cs, unsigned int hz) +{ + u64 temp; + u32 shift; + + /* Find shift and mult values for hz. */ + shift = 32; + do { + temp = (u64) NSEC_PER_SEC << shift; + do_div(temp, hz); + if ((temp >> 32) == 0) + break; + } while (--shift != 0); + + cs->shift = shift; + cs->mult = (u32) temp; + + printk(KERN_INFO "clocksource: %s uses shift %u mult %#x\n", + cs->name, cs->shift, cs->mult); +} + static unsigned long ticks_per_jiffy; static unsigned long ticks_per_usec; static unsigned long next_jiffy_time; @@ -99,8 +137,15 @@ void __init iop_init_time(unsigned long tick_rate) */ write_trr0(ticks_per_jiffy - 1); write_tmr0(timer_ctl); + + /* + * Set up free-running clocksource timer 1. + */ write_trr1(0xffffffff); + write_tcr1(0xffffffff); write_tmr1(timer_ctl); + iop_clocksource_set_hz(&iop_clocksource, tick_rate); + clocksource_register(&iop_clocksource); setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq); } |