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.p...@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,
};
