[U-Boot] [PATCH] Add support for Faraday RTC IP FTRTC

[Po-Yu Chuang]

Hi Detlev Zundel,

Thanks for your kindly help.

I will fix my code and submit again next time.

Thank you!

regards,

Po-Yu Chuang

2009/4/2 Detlev Zundel <dzu at denx.de>:
> Hi Chuang,
>
>> I am a newbie and I have not realized all the rules, so I
>> have some questions.
>>
>> On Tue Mar 31 12:24:03 CEST 2009, you wrote:
>>> > +static unsigned int       rtc     = CONFIG_SYS_RTC_BASE;
>>>
>>> Please use a proper C structure to describe the RTC; do not use base
>>> address plus offsets.
>>
>> Do you mean U-Boot prefers to use structure to describe
>> registers?
>
> Yes, we prefer to have this, as we then also let the compiler do for
> example type checking.
>
>> What if there were large gaps between registers?
>
> Use dummy variables.
>
>> For example, in our ethernet IP FTMAC100,  there is nothing
>> in 0x34 - 0x84, 0xa0 - 0xc0. Should I use structure to
>> describe it?
>
> Yes please, use for example u32 dummy1[20] for the first gap and u32
> dummy2[8] for the second.
>
>> I thought that placing a lot of paddings in a structure is ulgy.
>> How do you think? Is there a guideline about this?
>
> We are our own guideline ;)
>
> No, seriously, we try to use structures wherever possible as a means to
> get more information to the compiler.  It also helps preventing stupid
> errors like having one incorrect offset in a list of 40 defines which
> are *very* hard to catch.
>
>> Also in drivers/rtc/pl031.c, the RTC_WRITE_REG and
>> RTC_READ_REG use base + offset.
>>
>>> outl() is not portable across architectures?
>>> inl() is not portable across architectures?
>>
>> Sorry I don't understand.
>>
>> There are outl() and inl() in most architectures except blackfin,
>> i386 and sparc. And the outl() and the inl() I use are arm ones.
>>
>> Which macros should I use?
>
> We should really use macros specifying the expected-byteorder,
> i.e. in_be32, or out_le32, and so on.  Using these macros, we can write
> drivers even being agnostic on the cpu byte ordering if the device stays
> the same.  (Ok, ok, outl also infers a byte-ordering, but we like more
> expliciteness).
>
>
>>> > +  debug("rtc_get(): record register: %x\n", inl(rtc + FTRTC_OFFSET_RECORD));
>>>
>>> Line too long.
>>
>> Sorry, this is my fault. I will fix them.
>
> Thanks!
>  Detlev
>
> --
> I just found out that the brain is like a computer.
> If that's true, then there really aren't any stupid people.
> Just people running Windows.
> --
> DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de
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