tree 6a77172e80c134ba4c46889e309d00494e6f8211
parent a40955167ffc34a1651ebe2e88a8c1db2987fc91
author David Gibson <dwg@au1.ibm.com> 1200021934 +1100
committer Josh Boyer <jwboyer@linux.vnet.ibm.com> 1201266446 -0600

[POWERPC] Enable RTC for Ebony and Walnut (v2)

This patch extends the Ebony and Walnut platform code to instantiate
the existing ds1742 RTC class driver for the DS1743 RTC/NVRAM chip
found on both those boards.  The patch uses a helper function to scan
the device tree and instantiate the appropriate platform_device based
on it, so it should be easy to extend for other boards which have mmio
mapped RTC chips.

Along with this, the device tree binding for the ds1743 chips is
tweaked, based on the existing DS1385 OF binding found at:
	http://playground.sun.com/1275/proposals/Closed/Remanded/Accepted/346-it.txt
Although that document covers the NVRAM portion of the chip, whereas
here we're interested in the RTC portion, so it's not entirely clear
if that's a good model.

This implements only RTC class driver support - that is /dev/rtc0, not
/dev/rtc, and the low-level get/set time callbacks remain
unimplemented.  That means in order to get at the clock you will
either need a modified version of hwclock which will look at
/dev/rtc0, or you'll need to configure udev to symlink rtc0 to rtc.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>