PCF8563 realtime clock does not initialize

Hi all,

I have a custom board with an ppc8540 cpu.  I'm using a vanilla Linux
kernel 2.6.20.3.

The RTC chip is a PCF8563, connected to 8540's i2c controller at
address 0x51. In u-boot the clock works fine ('date' command) so the
hardware is alright.

In Linux however, I get this at boot:

(...)
i2c /dev entries driver
TCP cubic registered
NET: Registered protocol family 1
NET: Registered protocol family 17
drivers/rtc/hctosys.c: unable to open rtc device (rtc0)
(...)

I have compiled in the PCF8563 rtc driver (not as module), and have
support for RTC class, /dev, /proc and /sys. However, the entries in
/proc and /sys relevant to the RTC remain empty.

I have created a device node /dev/rtc0 with major/minor 254, 0 (254
being what is listed as rtc in /proc/devices).

For some reason, PCF8563 driver does not initialize correctly. I'm
looking for a hint where to look for finding the cause of this...

Some further info:
ARCH=ppc, CROSS_COMPILE=ppc_85xx- (from ELDK 4), boot loader is u-boot 1.2.0.

Thansk for any help.
Regards
Floris