diff options
Diffstat (limited to 'arch/arm/cpu/ixp/timer.c')
| -rw-r--r-- | arch/arm/cpu/ixp/timer.c | 124 |
1 files changed, 58 insertions, 66 deletions
diff --git a/arch/arm/cpu/ixp/timer.c b/arch/arm/cpu/ixp/timer.c index edf341ff9f..9f3ea42ece 100644 --- a/arch/arm/cpu/ixp/timer.c +++ b/arch/arm/cpu/ixp/timer.c @@ -1,4 +1,7 @@ /* + * (C) Copyright 2010 + * Michael Schwingen, michael@schwingen.org + * * (C) Copyright 2006 * Stefan Roese, DENX Software Engineering, sr@denx.de. * @@ -31,105 +34,94 @@ #include <common.h> #include <asm/arch/ixp425.h> +#include <asm/io.h> +#include <div64.h> -#ifdef CONFIG_TIMER_IRQ - -#define FREQ 66666666 -#define CLOCK_TICK_RATE (((FREQ / CONFIG_SYS_HZ & ~IXP425_OST_RELOAD_MASK) + 1) * CONFIG_SYS_HZ) -#define LATCH ((CLOCK_TICK_RATE + CONFIG_SYS_HZ/2) / CONFIG_SYS_HZ) /* For divider */ +DECLARE_GLOBAL_DATA_PTR; /* - * When interrupts are enabled, use timer 2 for time/delay generation... + * The IXP42x time-stamp timer runs at 2*OSC_IN (66.666MHz when using a + * 33.333MHz crystal). */ - -static volatile ulong timestamp; - -static void timer_isr(void *data) +static inline unsigned long long tick_to_time(unsigned long long tick) { - unsigned int *pTime = (unsigned int *)data; - - (*pTime)++; - - /* - * Reset IRQ source - */ - *IXP425_OSST = IXP425_OSST_TIMER_2_PEND; + tick *= CONFIG_SYS_HZ; + do_div(tick, CONFIG_IXP425_TIMER_CLK); + return tick; } -ulong get_timer (ulong base) +static inline unsigned long long time_to_tick(unsigned long long time) { - return timestamp - base; + time *= CONFIG_IXP425_TIMER_CLK; + do_div(time, CONFIG_SYS_HZ); + return time; } -void reset_timer (void) +static inline unsigned long long us_to_tick(unsigned long long us) { - timestamp = 0; + us = us * CONFIG_IXP425_TIMER_CLK + 999999; + do_div(us, 1000000); + return us; } -int timer_init (void) +unsigned long long get_ticks(void) { - /* install interrupt handler for timer */ - irq_install_handler(IXP425_TIMER_2_IRQ, timer_isr, (void *)×tamp); - - /* setup the Timer counter value */ - *IXP425_OSRT2 = (LATCH & ~IXP425_OST_RELOAD_MASK) | IXP425_OST_ENABLE; + ulong now = readl(IXP425_OSTS_B); + + if (readl(IXP425_OSST) & IXP425_OSST_TIMER_TS_PEND) { + /* rollover of timestamp timer register */ + gd->timestamp += (0xFFFFFFFF - gd->lastinc) + now + 1; + writel(IXP425_OSST_TIMER_TS_PEND, IXP425_OSST); + } else { + /* move stamp forward with absolut diff ticks */ + gd->timestamp += (now - gd->lastinc); + } + gd->lastinc = now; + return gd->timestamp; +} - /* enable timer irq */ - *IXP425_ICMR = (1 << IXP425_TIMER_2_IRQ); - return 0; -} -#else -ulong get_timer (ulong base) +void reset_timer_masked(void) { - return get_timer_masked () - base; + /* capture current timestamp counter */ + gd->lastinc = readl(IXP425_OSTS_B); + /* start "advancing" time stamp from 0 */ + gd->timestamp = 0; } -void ixp425_udelay(unsigned long usec) +void reset_timer(void) { - /* - * This function has a max usec, but since it is called from udelay - * we should not have to worry... be happy - */ - unsigned long usecs = CONFIG_SYS_HZ/1000000L & ~IXP425_OST_RELOAD_MASK; - - *IXP425_OSST = IXP425_OSST_TIMER_1_PEND; - usecs |= IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE; - *IXP425_OSRT1 = usecs; - while (!(*IXP425_OSST & IXP425_OSST_TIMER_1_PEND)); + reset_timer_masked(); } -void __udelay (unsigned long usec) +ulong get_timer_masked(void) { - while (usec--) ixp425_udelay(1); + return tick_to_time(get_ticks()); } -static ulong reload_constant = 0xfffffff0; - -void reset_timer_masked (void) +ulong get_timer(ulong base) { - ulong reload = reload_constant | IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE; + return get_timer_masked() - base; +} - *IXP425_OSST = IXP425_OSST_TIMER_1_PEND; - *IXP425_OSRT1 = reload; +void set_timer(ulong t) +{ + gd->timestamp = time_to_tick(t); } -ulong get_timer_masked (void) +/* delay x useconds AND preserve advance timestamp value */ +void __udelay(unsigned long usec) { - /* - * Note that it is possible for this to wrap! - * In this case we return max. - */ - ulong current = *IXP425_OST1; - if (*IXP425_OSST & IXP425_OSST_TIMER_1_PEND) - { - return reload_constant; - } - return (reload_constant - current); + unsigned long long tmp; + + tmp = get_ticks() + us_to_tick(usec); + + while (get_ticks() < tmp) + ; } int timer_init(void) { + writel(IXP425_OSST_TIMER_TS_PEND, IXP425_OSST); return 0; } -#endif |