RTC woes

Clemens Koller clemens.koller at anagramm.de
Wed Feb 20 09:30:54 EST 2008

Marc LeFevre schrieb:
> I’m new to the list.

Welcome! :-)

 > I have an e500-based embedded Linux system running
> a 2.6.22 kernel.  I have a PCF8563T i2c based RTC chip attached to the 
> PPC i2c bus.  In my kernel config file I have selected 
> CONFIG_RTC_INTF_DEV=y and CONFIG_RTC_DRV_PCF8563=y.  I do a mknod  for 
> /dev/rtc as c 10 135 (standard Linux) and link /dev/rtc0 to it.
  > When I boot, get the following message:
> drivers/rtc/hctosys.c: unable to open rtc device (rtc0)

2.6.22.x and 2.6.23.x i2c rtc code was quite messy around PCF8563.

> 3)       Does the PPC have some quirks regarding i2c operation that are 
> at the root of this problem?

The RTC subsystem was improved quite a bit lately. Try 2.6.24' powerpc
architecture with a proper device tree instead. It works over here on
mpc8540 / mpc8548 whereas the older ones were just a waste of time.



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