Hi Bin,
On 15 April 2018 at 23:06, Bin Meng <bmeng...@gmail.com> wrote:
> Hi Simon,
>
> On Fri, Apr 13, 2018 at 12:42 AM, Simon Glass <s...@chromium.org> wrote:
>> Hi,
>>
>> On 8 April 2018 at 19:22, Bin Meng <bmeng...@gmail.com> wrote:
>>> Hi Ivan,
>>>
>>> On Sat, Apr 7, 2018 at 3:18 AM, Ivan Gorinov <ivan.gori...@intel.com> 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 <ivan.gori...@intel.com>
>>>> ---
>>>> 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?
> not make sense.
>
> Regards,
> Bin
Regards,
Simon
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