diff options
| -rwxr-xr-x | arch/arm/cpu/armv7/imx-common/timer.c | 75 |
1 files changed, 57 insertions, 18 deletions
diff --git a/arch/arm/cpu/armv7/imx-common/timer.c b/arch/arm/cpu/armv7/imx-common/timer.c index 98e9f4a..1645ff8 100755 --- a/arch/arm/cpu/armv7/imx-common/timer.c +++ b/arch/arm/cpu/armv7/imx-common/timer.c @@ -25,6 +25,7 @@ #include <common.h> #include <asm/io.h> +#include <div64.h> #include <asm/arch/imx-regs.h> /* General purpose timers registers */ @@ -50,6 +51,22 @@ DECLARE_GLOBAL_DATA_PTR; #define timestamp (gd->tbl) #define lastinc (gd->lastinc) +static inline unsigned long long tick_to_time(unsigned long long tick) +{ + tick *= CONFIG_SYS_HZ; + do_div(tick, CLK_32KHZ); + + return tick; +} + +static inline unsigned long long us_to_tick(unsigned long long usec) +{ + usec *= CLK_32KHZ; + do_div(usec, 1000000); + + return usec; +} + int timer_init(void) { int i; @@ -75,36 +92,58 @@ int timer_init(void) return 0; } -ulong get_timer_masked(void) +unsigned long long get_ticks(void) { - ulong val = __raw_readl(&cur_gpt->counter); - val /= (CLK_32KHZ / CONFIG_SYS_HZ); - if (val >= lastinc) - timestamp += (val - lastinc); - else - timestamp += ((0xFFFFFFFF / (CLK_32KHZ / CONFIG_SYS_HZ)) - - lastinc) + val; - lastinc = val; + ulong now = __raw_readl(&cur_gpt->counter); /* current tick value */ + + if (now >= lastinc) { + /* + * normal mode (non roll) + * move stamp forward with absolut diff ticks + */ + timestamp += (now - lastinc); + } else { + /* we have rollover of incrementer */ + timestamp += (0xFFFFFFFF - lastinc) + now; + } + lastinc = now; return timestamp; } +ulong get_timer_masked(void) +{ + /* + * get_ticks() returns a long long (64 bit), it wraps in + * 2^64 / CONFIG_MX25_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~ + * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in + * 5 * 10^6 days - long enough. + */ + return tick_to_time(get_ticks()); +} + ulong get_timer(ulong base) { return get_timer_masked() - base; } -/* delay x useconds AND preserve advance timestamp value */ +/* delay x useconds AND preserve advance timstamp value */ void __udelay(unsigned long usec) { - unsigned long now, start, tmo; - tmo = usec * (CLK_32KHZ / 1000) / 1000; - - if (!tmo) - tmo = 1; + unsigned long long tmp; + ulong tmo; - now = start = readl(&cur_gpt->counter); + tmo = us_to_tick(usec); + tmp = get_ticks() + tmo; /* get current timestamp */ - while ((now - start) < tmo) - now = readl(&cur_gpt->counter); + while (get_ticks() < tmp) /* loop till event */ + /*NOP*/; +} +/* + * This function is derived from PowerPC code (timebase clock frequency). + * On ARM it returns the number of timer ticks per second. + */ +ulong get_tbclk(void) +{ + return CLK_32KHZ; } |