I2C RTC with MPC8xx?

I2C RTC with MPC8xx?

[Steven Scholz]

Hi there,

what do I have to do to use an I2C RTC (like Dallas DS1337) within LinuxPPC?

I know there're drivers for PPCBoot / U-Boot.

But how could I access them from Linux?

drivers/char/rtc_8xx.c is not suitable.

Thanks,

Steven


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Re: I2C RTC with MPC8xx?

[Wolfgang Denk]

In message <3E37CB15.50307@imc-berlin.de> you wrote:
>
> what do I have to do to use an I2C RTC (like Dallas DS1337) within LinuxPPC?

Use drivers/i2c/i2c-algo-8xx.c and add your own version of
drivers/i2c/i2c-ds1337.c ?

> I know there're drivers for PPCBoot / U-Boot.

There are also drivers for Linux.

> But how could I access them from Linux?

You cannot access or use any U-Boot code from LInux.


Viele Grüße,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
The only thing necessary for the triumph of evil is for good  men  to
do nothing.                                            - Edmund Burke

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Re: I2C RTC with MPC8xx?

[Steven Scholz]

Wolfgang Denk schrieb:
> In message <3E37CB15.50307@imc-berlin.de> you wrote:
>
>>what do I have to do to use an I2C RTC (like Dallas DS1337) within LinuxPPC?
>
> Use drivers/i2c/i2c-algo-8xx.c and add your own version of
> drivers/i2c/i2c-ds1337.c ?
Hmm. But there must be at least one excample!?
Someone must have done that before!?
After all I don't want to reinvent the wheel... (Ooh, how much I love that
phrase!) :o)

>>I know there're drivers for PPCBoot / U-Boot.
>
>
> There are also drivers for Linux.
I bet there are drivers for Linux!
How else should all the people using PPCBoot/U-Boot and I2C RTCs on MPC8xx
platforms access them from Linux...

But where could I find one? Isn't LWMON using an I2C RTC? But I just can't find
the driver...

Thanks,

Steven


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RE: I2C RTC with MPC8xx?

[Keith Outwater]

Hi Stephen -

I am successfully using a DS1337 RTC with PPCBoot/U-Boot and a
linux-2.4.4-10-06 kernel from the Denx FTP site. I haven't gotten around
to submitting it, but let me know if you want the patch.

Keith

Keith Outwater
Sr. Staff Engineer
Microvision, Inc.
19910 N. Creek Parkway
Bothell, WA 98011


> -----Original Message-----
> From: Steven Scholz [mailto:steven.scholz@imc-berlin.de]
> Sent: Wednesday, January 29, 2003 4:38 AM
> To: Linuxppc-Embedded
> Subject: I2C RTC with MPC8xx?
>
>
>
> Hi there,
>
> what do I have to do to use an I2C RTC (like Dallas DS1337)
> within LinuxPPC?
>
> I know there're drivers for PPCBoot / U-Boot.
>
> But how could I access them from Linux?
>
> drivers/char/rtc_8xx.c is not suitable.
>
> Thanks,
>
> Steven
>
>
>
>


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Re: I2C RTC with MPC8xx?

[Steven Scholz]

Keith Outwater schrieb:
> Hi Stephen -
>
> I am successfully using a DS1337 RTC with PPCBoot/U-Boot and a
> linux-2.4.4-10-06 kernel from the Denx FTP site. I haven't gotten around
> to submitting it, but let me know if you want the patch.

I actually wouldn't mind! :o)

I guess it's not to hard to put it onto 2.4.20.
Yesterday I received a file from Jocke. I would be more than happy to compare them.

Maybe Wolfgang is putting that on his 2.4.20 CVS someday!

BTW I think I'll need the DS1307. Hope it's only a differnt pinout. It has a
dedicated battery pin and no irq output.

Is the driver or linux using RTC interrupts?

Thanks a million,

Steven


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Re: I2C RTC with MPC8xx?

[Wolfgang Denk]

In message <3E37D18D.7080900@imc-berlin.de> you wrote:
>
> > Use drivers/i2c/i2c-algo-8xx.c and add your own version of
> > drivers/i2c/i2c-ds1337.c ?
> Hmm. But there must be at least one excample!?

Of course there are examples. Just look in drivers/i2c/

> How else should all the people using PPCBoot/U-Boot and I2C RTCs on MPC8xx
> platforms access them from Linux...
>
> But where could I find one? Isn't LWMON using an I2C RTC? But I just can't find
> the driver...

LWMON uses a Philips PCF8563 RTC, but the LWMON board uses a  special
(lean,  non-standard)  I2C  driver  (drivers/i2c/i2c-simple.c) so the
driver as used on LWMON ("drivers/char/pcf8563_rtc.c") will not  help
you  much.  But there is also a standard drivers fopr other RTC chips
in our source tree.

Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
Let's say the docs present a simplified view of reality...    :-)
                      - Larry Wall in  <6940@jpl-devvax.JPL.NASA.GOV>

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