Hi On Thu, Sep 07, 2023 at 03:39:57PM +0900, Chanho Park wrote: > Hi, > > > -----Original Message----- > > From: Heinrich Schuchardt <heinrich.schucha...@canonical.com> > > Sent: Thursday, September 7, 2023 2:27 AM > > To: Chanho Park <chanho61.p...@samsung.com>; Simon Glass > > <s...@chromium.org> > > Cc: u-boot@lists.denx.de; Rick Chen <r...@andestech.com>; Leo > > <ycli...@andestech.com> > > Subject: Re: [PATCH v3 3/3] timer: riscv_aclint_timer: add > > timer_get_boot_us for BOOTSTAGE > > > > 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 > Still typo 10000000 -> 1000000 > > > > Where is the old implementation that you refer to? > > I referred it from timer_get_boot_us function of lib/time.c > > lib/time.c > 55 else if (timer_rate > 1000000) > 56 return lldiv(count, timer_rate / 1000000); > 57 else > 58 return (unsigned long long)count * 1000000 / timer_rate; > > > > > > 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
Reviewed-by: Leo Yu-Chi Liang <ycli...@andestech.com> > > > > 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. > > 'rate' seems to be Hz not kHz. So, I think they need to be corrected. > > > > > 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? > > Actually, I tried to use lib/time.c's implementation or make a generic > function in timer-uclass.c as you mentioned. > However, there are different implementations in cadence-ttc.c, > rockchip_timer.c, tegra-timer.c, omap-timer.c and tsc_timer.c. > The basic codes seems to be almost identical if we can get a DM timer > successfully but fallback codes look different. > If timer_get_boot_us can be implement in the timer-uclass.c, we still need > per-driver callback function for supporting these different fallback codes. > I think we could merge this patch set first, and then think more thoroghly about how we are going to clean this up. Best regards, Leo > Best Regards, > Chanho Park >