Re: RTC: add RTC class interface to m41t00 driver

From: Alexander Bigga
Date: Mon Aug 07 2006 - 10:59:19 EST

On Saturday 05 August 2006 22:23, you wrote:
> Discussion is now started. :)

Hope to hear more arguments ;-)

> I suspect not all that board support is upstream yet; I can't see
> anything creating the m41t00 platform devices as required by the
> current m41t00.c driver ... neither on katana, nor any other board.

Your're right. First, I was confused too, but then Mark pointed me to a patch,
which is never gone into mainline:

Be aware of the different names: m41t00 and m41txx!

> Plus, Mr. Grep tells me there's a separate m41t81 driver in
> mips/sibyte/swarm/rtc_m41t81.c ...

Oh, yes. I found it too, but didn't checked it further.

> You may end up doing more "switch (chip_type) {...}" than testing of
> the feature bits, if you get beyond those three chips.

In deed. If I want to support all.

> I noticed that the katana board uses a different scheme for the "initialize
> the system time/date" problem addressed by CONFIG_RTC_HCTOSYS, and that
> seems to be the reason for the m41t00.c driver to export an API. (Much the
> same way that the PC-style "cmos clock" exports an API used early in x86
> booting, which likewise bypasses the RTC framework ...)
> I suspect there are arch-specific issues to work through there, both for
> initializing the clock at boot and for re-initializing it after resume.
> (CONFIG_RTC_HCTOSYS doesn't currently address the latter...)

This question, only Mark can unswer, or?

Alexander Bigga Tel: +49 4873 90 10 866
mycable GmbH Fax: +49 4873 901 976
Boeker Stieg 43
D-24613 Aukrug eMail: ab@xxxxxxxxxx

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