On Thu, Jul 02, 2026 at 11:27:04AM +0100, Simon Glass wrote: > Hi Yao, > > On 2026-07-01T11:17:53, Yao Zi <[email protected]> wrote: > > timer: Add loongarch_timer driver > > > > Implement a timer driver for LoongArch architecture driver. > > > > It's synced in hardware for every core in a system, and frequency > > information can be gathered from CPUCFG instruction. > > > > It is not described in fdt, thus I have to declare a DRVINFO > > for it. > > > > Signed-off-by: Jiaxun Yang <[email protected]> > > Signed-off-by: Yao Zi <[email protected]> > > > > drivers/timer/Kconfig | 8 +++ > > drivers/timer/Makefile | 1 + > > drivers/timer/loongarch_timer.c | 112 > > ++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 121 insertions(+) > > > diff --git a/drivers/timer/loongarch_timer.c > > b/drivers/timer/loongarch_timer.c > > @@ -0,0 +1,112 @@ > > +#include <dm.h> > > +#include <errno.h> > > +#include <timer.h> > > +#include <asm/loongarch.h> > > lldiv() is used below but div64.h is not included. Please add it > (see riscv_timer.c). > > > diff --git a/drivers/timer/loongarch_timer.c > > b/drivers/timer/loongarch_timer.c > > @@ -0,0 +1,112 @@ > > +static int loongarch_timer_bind(struct udevice *dev) > > +{ > > + struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev); > > + u32 rate; > > + > > + rate = loongarch_timer_get_freq_cpucfg(); > > + uc_priv->clock_rate = rate; > > + > > + return 0; > > +} > > This is wired up as .probe below, so please rename to > loongarch_timer_probe(). Also, if loongarch_timer_get_freq_cpucfg() > returns 0 (LLFTP not present, or CPUCFG5 reads back zero) the driver > still probes with clock_rate=0, which then trips a divide-by-zero > in timer_get_boot_us(). Perhaps return -EINVAL in that case?
In case of missing LLFTP, I think bailing out would be correct. I'd prefer to return -ENODEV since LLFTP represents support for constant frequency counter and timer, when it's missing we don't even have a stable timer to poke at all. And CPUCFG5 represents "the corresponding multiplication factor of the clock used by the timer", thus I don't think CPUCFG5 = 0 is a reasonable hardware implementation, and prefer to ignore this case. ... > Regards, > Simon Regards, Yao Zi
