From: Rob Herring rob.herring@calxeda.com
Many platforms duplicate pretty much the same timer code yet they all have a 32-bit freerunning counter register. Create a common implementation that minimally requires 2 or 3 defines to add timer support:
CONFIG_SYS_TIMER_RATE - Clock rate of the timer counter CONFIG_SYS_TIMER_COUNTER - Address of 32-bit counter CONFIG_SYS_TIMER_COUNTS_DOWN - Define if counter counts down
All functions are weak or ifdef'ed so they can still be overriden by any platform.
Signed-off-by: Rob Herring rob.herring@calxeda.com --- v2: - Move to common location for all arches - Add extern timer_read_counter declaration - Add new global data timebase_h and timebase_l
include/asm-generic/global_data.h | 2 ++ lib/time.c | 73 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 75 insertions(+)
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h index 77e06fb..0de0bea 100644 --- a/include/asm-generic/global_data.h +++ b/include/asm-generic/global_data.h @@ -72,6 +72,8 @@ typedef struct global_data { #if defined(CONFIG_SYS_I2C) int cur_i2c_bus; /* current used i2c bus */ #endif + unsigned long timebase_h; + unsigned long timebase_l; struct arch_global_data arch; /* architecture-specific data */ } gd_t; #endif diff --git a/lib/time.c b/lib/time.c index 68b8ff4..761272a 100644 --- a/lib/time.c +++ b/lib/time.c @@ -7,11 +7,84 @@
#include <common.h> #include <watchdog.h> +#include <div64.h> +#include <asm/io.h>
#ifndef CONFIG_WD_PERIOD # define CONFIG_WD_PERIOD (10 * 1000 * 1000) /* 10 seconds default*/ #endif
+DECLARE_GLOBAL_DATA_PTR; + +#ifdef CONFIG_SYS_TIMER_RATE +ulong notrace get_tbclk(void) +{ + return CONFIG_SYS_TIMER_RATE; +} +#endif + +#ifdef CONFIG_SYS_TIMER_COUNTER +unsigned long notrace timer_read_counter(void) +{ +#ifdef CONFIG_SYS_TIMER_COUNTS_DOWN + return ~readl(CONFIG_SYS_TIMER_COUNTER); +#else + return readl(CONFIG_SYS_TIMER_COUNTER); +#endif +} +#else +extern unsigned long timer_read_counter(void); +#endif + +unsigned long long __weak notrace get_ticks(void) +{ + unsigned long now = timer_read_counter(); + + /* increment tbu if tbl has rolled over */ + if (now < gd->timebase_l) + gd->timebase_h++; + gd->timebase_l = now; + return ((unsigned long long)gd->timebase_h << 32) | gd->timebase_l; +} + +static unsigned long long notrace tick_to_time(unsigned long long tick) +{ + unsigned int div = get_tbclk(); + + tick *= CONFIG_SYS_HZ; + do_div(tick, div); + return tick; +} + +ulong __weak get_timer(ulong base) +{ + return tick_to_time(get_ticks()) - base; +} + +unsigned long __weak notrace timer_get_us(void) +{ + return tick_to_time(get_ticks() * 1000); +} +static unsigned long long usec_to_tick(unsigned long usec) +{ + unsigned long long tick = usec * get_tbclk(); + usec *= get_tbclk(); + do_div(tick, 1000000); + return tick; +} + +void __weak __udelay(unsigned long usec) +{ + unsigned long long tmp; + ulong tmo; + + tmo = usec_to_tick(usec); + tmp = get_ticks() + tmo; /* get current timestamp */ + + while (get_ticks() < tmp) /* loop till event */ + /*NOP*/; +} + /* ------------------------------------------------------------------------- */
void udelay(unsigned long usec)