Hi Simon, On Tue, Apr 17, 2018 at 11:10 PM, Simon Glass <[email protected]> wrote: > Hi Bin, > > On 15 April 2018 at 23:06, Bin Meng <[email protected]> wrote: >> Hi Simon, >> >> On Fri, Apr 13, 2018 at 12:42 AM, Simon Glass <[email protected]> wrote: >>> Hi, >>> >>> On 8 April 2018 at 19:22, Bin Meng <[email protected]> wrote: >>>> Hi Ivan, >>>> >>>> On Sat, Apr 7, 2018 at 3:18 AM, Ivan Gorinov <[email protected]> >>>> wrote: >>>>> Add HPET driver as an alternative timer for x86 (default is TSC). >>>>> HPET counter has constant frequency and does not need calibration. >>>>> This change also makes TSC timer driver optional on x86. >>>>> New HPET driver can also be selected as the early timer on x86. >>>>> >>>>> HPET can be selected as the tick timer in the Device Tree "chosen" node: >>>>> >>>>> /include/ "hpet.dtsi" >>>>> >>>>> ... >>>>> >>>>> chosen { >>>>> tick-timer = "/hpet"; >>>>> }; >>>>> >>>>> Signed-off-by: Ivan Gorinov <[email protected]> >>>>> --- >>>>> arch/Kconfig | 2 +- >>>>> arch/x86/Kconfig | 21 ++++++ >>>>> arch/x86/dts/hpet.dtsi | 7 ++ >>>>> drivers/timer/Kconfig | 9 +++ >>>>> drivers/timer/Makefile | 1 + >>>>> drivers/timer/hpet_timer.c | 179 >>>>> +++++++++++++++++++++++++++++++++++++++++++++ >>>>> drivers/timer/tsc_timer.c | 8 ++ >>>>> 7 files changed, 226 insertions(+), 1 deletion(-) >>>>> create mode 100644 arch/x86/dts/hpet.dtsi >>>>> create mode 100644 drivers/timer/hpet_timer.c >>>>> >>> >>> [..] >>>>> diff --git a/drivers/timer/tsc_timer.c b/drivers/timer/tsc_timer.c >>>>> index 9296de6..bd0e75c 100644 >>>>> --- a/drivers/timer/tsc_timer.c >>>>> +++ b/drivers/timer/tsc_timer.c >>>>> @@ -277,6 +277,8 @@ success: >>>>> return delta / 1000; >>>>> } >>>>> >>>>> +#ifdef CONFIG_X86_EARLY_TIMER_TSC >>>> >>>> Why do we surround the following APIs with CONFIG_X86_EARLY_TIMER_TSC? >>>> These APIs are generic U-Boot timer APIs. If we select >>>> CONFIG_X86_EARLY_TIMER_HPET, these APIs are not available and will >>>> cause build error. >>>> >>>> Simon, do you think we should fix such in the timer uclass driver? >>> >>> We should not have arch-specific code in the uclass, or in any generic >>> driver. >> >> What I meant is these APIs like get_timer(). Can such APIs be moved to >> timer uclass driver? To avoid conflicts with other timer drivers, in >> this patch it was solved by using the config option >> CONFIG_X86_EARLY_TIMER_TSC to hide this in the TSC driver, which does > > Well get_timer() just calls get_ticks() which uses DM, so what exactly > are you proposing here? >
The tsc_timer.c has the get_timer() implementation while lib/time.c provides a default one that calls into DM. When I saw this new HPET driver I got confused and thought we should move such from timer driver to the uclass driver. My original comments regarding to CONFIG_X86_EARLY_TIMER_TSC is to make sure we support mixed use of timers, eg: HPET as the early timer and TSC as the normal timer. I will have a look at the latest patch. Regards, Bin _______________________________________________ U-Boot mailing list [email protected] https://lists.denx.de/listinfo/u-boot
