From: "Chanho Park" <chanho61.park@samsung.com>
To: "'Leo Liang'" <ycliang@andestech.com>
Cc: "'Rick Chen'" <rick@andestech.com>,
"'Simon Glass'" <sjg@chromium.org>, <u-boot@lists.denx.de>
Subject: RE: [PATCH v2 2/3] riscv: timer: add timer_get_boot_us for BOOTSTAGE
Date: Mon, 4 Sep 2023 16:41:06 +0900 [thread overview]
Message-ID: <003b01d9df03$2a01d780$7e058680$@samsung.com> (raw)
In-Reply-To: <ZPWAx5JcsZRizFxb@swlinux02>
Hi,
> -----Original Message-----
> From: Leo Liang <ycliang@andestech.com>
> Sent: Monday, September 4, 2023 4:01 PM
> To: Chanho Park <chanho61.park@samsung.com>
> Cc: Rick Chen <rick@andestech.com>; Simon Glass <sjg@chromium.org>; u-
> boot@lists.denx.de
> Subject: Re: [PATCH v2 2/3] riscv: timer: add timer_get_boot_us for
> BOOTSTAGE
>
> Hi Chanho,
>
> On Mon, Aug 28, 2023 at 06:49:37PM +0900, Chanho Park wrote:
> > timer_get_boot_us function is required to record the boot stages as
> > us-based timestamp.
> >
> > Signed-off-by: Chanho Park <chanho61.park@samsung.com>
> > ---
> > drivers/timer/riscv_timer.c | 21 +++++++++++++++++++++
> > 1 file changed, 21 insertions(+)
> >
> > diff --git a/drivers/timer/riscv_timer.c b/drivers/timer/riscv_timer.c
> > index 3627ed79b819..6cb589fcdc45 100644
> > --- a/drivers/timer/riscv_timer.c
> > +++ b/drivers/timer/riscv_timer.c
> > @@ -11,6 +11,7 @@
> > */
> >
> > #include <common.h>
> > +#include <div64.h>
> > #include <dm.h>
> > #include <errno.h>
> > #include <timer.h>
> > @@ -50,6 +51,26 @@ u64 notrace timer_early_get_count(void) } #endif
> >
> > +#if CONFIG_IS_ENABLED(RISCV_SMODE) && 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_SMODE_TIMER_FREQ;
> > + ticks = riscv_timer_get_count(NULL);
> > + }
> > +
> > + return lldiv(ticks * 1000, (rate / 1000));
>
> Could you elaborate a little how this formula is derived?
Sure. Below is the original formula. To avoid zero of (tick/rate), I split
the calculation to ticks and rate, respectively.
Time(us) = (ticks / rate) * 1000000
Or (ticks * 1000000) / rate
Or tick / (rate / 10000000)
Best Regards,
Chanho Park
next prev parent reply other threads:[~2023-09-04 7:41 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20230828094952epcas2p31c71a57ef3486cbd75f605057cc8085f@epcas2p3.samsung.com>
2023-08-28 9:49 ` [PATCH v2 0/3] bootstage support for risc-v Chanho Park
[not found] ` <CGME20230828094952epcas2p497990b22d236fdaf4239dc9df80e4c7a@epcas2p4.samsung.com>
2023-08-28 9:49 ` [PATCH v2 1/3] riscv: bootstage: correct bootstage_report guard Chanho Park
2023-09-04 6:41 ` Leo Liang
[not found] ` <CGME20230828094952epcas2p1826292dae2e93fb619cc5fa146bb0787@epcas2p1.samsung.com>
2023-08-28 9:49 ` [PATCH v2 2/3] riscv: timer: add timer_get_boot_us for BOOTSTAGE Chanho Park
2023-09-04 7:01 ` Leo Liang
2023-09-04 7:41 ` Chanho Park [this message]
[not found] ` <CGME20230828094953epcas2p3fc191dd7a0d387cfd987240b972c79b5@epcas2p3.samsung.com>
2023-08-28 9:49 ` [PATCH v2 3/3] timer: riscv_aclint_timer: " Chanho Park
2023-09-04 7:02 ` Leo Liang
2023-09-04 7:42 ` Chanho Park
2023-09-04 16:48 ` Simon Glass
2023-09-05 5:02 ` Chanho Park
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