On 06.09.23 07:18, Chanho Park wrote:
timer_get_boot_us function is required to record the boot stages as us-based timestamp. To get a micro-second time from a timer tick, this converts the formula like below to avoid zero result of (tick / rate) part.
From: time(us) = (tick / rate) * 10000000
Where is the old implementation that you refer to?
To : time(us) = (tick * 1000) / (rate / 1000)
Signed-off-by: Chanho Park chanho61.park@samsung.com
drivers/timer/riscv_aclint_timer.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)
diff --git a/drivers/timer/riscv_aclint_timer.c b/drivers/timer/riscv_aclint_timer.c index e29d527c8d77..73fb87912851 100644 --- a/drivers/timer/riscv_aclint_timer.c +++ b/drivers/timer/riscv_aclint_timer.c @@ -6,6 +6,7 @@
#include <common.h> #include <clk.h> +#include <div64.h> #include <dm.h> #include <timer.h> #include <asm/io.h> @@ -44,6 +45,28 @@ u64 notrace timer_early_get_count(void) } #endif
+#if CONFIG_IS_ENABLED(RISCV_MMODE) && CONFIG_IS_ENABLED(BOOTSTAGE) +ulong timer_get_boot_us(void) +{
- int ret;
- u64 ticks = 0;
- u32 rate;
- ret = dm_timer_init();
- if (!ret) {
rate = timer_get_rate(gd->timer);timer_get_count(gd->timer, &ticks);- } else {
rate = RISCV_MMODE_TIMER_FREQ;ticks = readq((void __iomem *)MTIME_REG(RISCV_MMODE_TIMERBASE,RISCV_MMODE_TIMEROFF));- }
- /* Below is converted from time(us) = (tick / rate) * 10000000 */
- return lldiv(ticks * 1000, (rate / 1000));
I found similar code in drivers/timer/cadence-ttc.c and drivers/timer/omap-timer.c with
us = (ticks * 1000) / rate; return us.
Either their code or yours must be wrong.
What I am missing in include/timer.h is a documentation that defines if timer_dev_priv.clock_rate and timer_get_rate() yield the frequency in Hz or kHz.
Once we have added the missing information in the include we can start reviewing this patch.
I really dislike that we have code per architecture and don't update and use a implementation in lib/time.c (where we also have an implementation) or drivers/timer/timer-uclass.c. Can't we have a single implementation which is driver model based and eliminate all others?
Best regards
Heinrich
+} +#endif
- static const struct timer_ops riscv_aclint_timer_ops = { .get_count = riscv_aclint_timer_get_count, };