diff options
Diffstat (limited to 'cpu')
| -rw-r--r-- | cpu/arm_cortexa8/mx53/timer.c | 71 |
1 files changed, 33 insertions, 38 deletions
diff --git a/cpu/arm_cortexa8/mx53/timer.c b/cpu/arm_cortexa8/mx53/timer.c index e6b7846..1f959b8 100644 --- a/cpu/arm_cortexa8/mx53/timer.c +++ b/cpu/arm_cortexa8/mx53/timer.c @@ -25,6 +25,7 @@ #include <common.h> #include <asm/arch/mx53.h> +#include <div64.h> /* General purpose timers registers */ #define GPTCR __REG(GPT1_BASE_ADDR) /* Control register */ @@ -35,10 +36,11 @@ /* General purpose timers bitfields */ #define GPTCR_SWR (1<<15) /* Software reset */ #define GPTCR_FRR (1<<9) /* Freerun / restart */ -#define GPTCR_CLKSOURCE_32 (0x100<<6) /* Clock source */ -#define GPTCR_CLKSOURCE_IPG (0x001<<6) /* Clock source */ +#define GPTCR_CLKSOURCE_32 (4<<6) /* Clock source */ #define GPTCR_TEN (1) /* Timer enable */ -#define GPTPR_VAL (50) + +static ulong timestamp; +static ulong lastinc; static inline void setup_gpt(void) { @@ -54,9 +56,10 @@ static inline void setup_gpt(void) GPTCR = GPTCR_SWR; for (i = 0; i < 100; i++) GPTCR = 0; /* We have no udelay by now */ - GPTPR = GPTPR_VAL; /* 50Mhz / 50 */ - /* Freerun Mode, PERCLK1 input */ - GPTCR |= GPTCR_CLKSOURCE_IPG | GPTCR_TEN; + GPTPR = 0; /* 32KHz */ + /* Freerun Mode, CLK32 input */ + GPTCR = GPTCR | GPTCR_CLKSOURCE_32 | GPTCR_TEN; + reset_timer_masked(); } int timer_init(void) @@ -68,60 +71,52 @@ int timer_init(void) void reset_timer_masked(void) { - GPTCR = 0; - /* Freerun Mode, PERCLK1 input */ - GPTCR = GPTCR_CLKSOURCE_IPG | GPTCR_TEN; + /* capture current incrementer value time */ + lastinc = GPTCNT / (CONFIG_MX53_CLK32 / CONFIG_SYS_HZ); + timestamp = 0; /* start "advancing" time stamp from 0 */ } -inline ulong get_timer_masked(void) +void reset_timer(void) { - ulong val = GPTCNT; - - return val; + reset_timer_masked(); } -void reset_timer(void) +inline ulong get_timer_masked(void) { - reset_timer_masked(); + ulong val = GPTCNT; + val /= (CONFIG_MX53_CLK32 / CONFIG_SYS_HZ); + if (val >= lastinc) + timestamp += (val - lastinc); + else + timestamp += ((0xFFFFFFFF / (CONFIG_MX53_CLK32 / CONFIG_SYS_HZ)) + - lastinc) + val; + lastinc = val; + return timestamp; } ulong get_timer(ulong base) { - ulong tmp; - - tmp = get_timer_masked(); - - if (tmp <= (base * 1000)) { - /* Overflow */ - tmp += (0xffffffff - base); - } - - return (tmp / 1000) - base; + return get_timer_masked() - base; } void set_timer(ulong t) { + timestamp = t; } /* delay x useconds AND perserve advance timstamp value */ /* GPTCNT is now supposed to tick 1 by 1 us. */ void udelay(unsigned long usec) { - ulong tmp; - + unsigned long now, start, tmo; setup_gpt(); - tmp = get_timer_masked(); /* get current timestamp */ + tmo = usec * (CONFIG_MX53_CLK32 / 1000) / 1000; + if (!tmo) + tmo = 1; - /* if setting this forward will roll time stamp */ - if ((usec + tmp + 1) < tmp) { - /* reset "advancing" timestamp to 0, set lastinc value */ - reset_timer_masked(); - } else { - /* else, set advancing stamp wake up time */ - tmp += usec; - } + now = start = GPTCNT; - while (get_timer_masked() < tmp) /* loop till event */ - /*NOP*/; + while ((now - start) < tmo) + now = GPTCNT; } |