[U-Boot] [PATCH v5 3/9] arm: add support for arch timer

Murali Karicheri m-karicheri2 at ti.com
Fri Apr 4 19:20:03 CEST 2014


On 4/4/2014 6:12 AM, FengHua wrote:
>
>
>> -----Original Messages-----
>> From: "Andrianov, Vitaly" <vitalya at ti.com>
>> Sent Time: 2014-04-03 19:22:34 (Thursday)
>> To: "Masahiro Yamada" <yamada.m at jp.panasonic.com>, "Karicheri, Muralidharan" <m-karicheri2 at ti.com>
>> Cc: "Rini, Tom" <trini at ti.com>, "u-boot at lists.denx.de" <u-boot at lists.denx.de>
>> Subject: Re: [U-Boot] [PATCH v5 3/9] arm: add support for arch timer
>>
>> Hi Masahiro,
>>
>>> -----Original Message-----
>>> From: u-boot-bounces at lists.denx.de [mailto:u-boot-
>>> bounces at lists.denx.de] On Behalf Of Masahiro Yamada
>>> Sent: Wednesday, April 02, 2014 9:46 PM
>>> To: Karicheri, Muralidharan
>>> Cc: Rini, Tom; u-boot at lists.denx.de
>>> Subject: Re: [U-Boot] [PATCH v5 3/9] arm: add support for arch timer
>>>
>>> Hi Murali,
>>>
>>> On Tue, 1 Apr 2014 14:44:23 -0400
>>> Murali Karicheri <m-karicheri2 at ti.com> wrote:
>>>
>>>> From: Vitaly Andrianov <vitalya at ti.com>
>>>>
>>>> This patch add basic support for the architecture timer found on
>>>> recent
>>>> ARMv7 based SoCs.
>>>>
>>>> Signed-off-by: Vitaly Andrianov <vitalya at ti.com>
>>>> Signed-off-by: Murali Karicheri <m-karicheri2 at ti.com>
>>>> Acked-by: Tom Rini <trini at ti.com>
>>>> ---
>>>>   arch/arm/lib/Makefile     |    1 +
>>>>   arch/arm/lib/arch_timer.c |   58
>>> +++++++++++++++++++++++++++++++++++++++++++++
>>>
>>>
>>>
>>> I am not familiar with this timer, but your commit description implies
>>> it is specific to ARMv7.
>>>
>>> If so, it looks like it should go to arch/arm/cpu/armv7/ .
>>> Is this right?
>> This is for arch timer implemented in ARM Cortex-A15 which is ARMv7.
>> I believe the same arch timer is in ARMv8. So, it is not specific to
>> ARMv7 only. The commit description mentioned only ARMv7 because the
>> driver was designed and tested on ARMv7.
>>
> If we want to apply the arch_timer.c to armv8,  the get_ticks() function should be modified
> due to mrrc instuction.
> Furthermore, armv8 now make use of timer infrastructure of lib/time.c.
> Only get_tbclk() and timer_read_counter() are architecture specific and declared in generic_timer.c.
> We'd better construct a common arch timer structure across arm platform.
>
> Best regards,
> David
>
>
>
>
>
The v6 of the series just posted has moved the arch_timer.c to 
arch/arm/cpu/armv7 folder
as requested by you.

Regards,

Murali


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