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authorSebastian Andrzej Siewior <bigeasy@linutronix.de>2011-02-22 21:07:46 +0100
committerThomas Gleixner <tglx@linutronix.de>2011-02-23 22:27:55 +0100
commit3bcbaf6e08d8d82cde781997bd2c56dda87049b5 (patch)
tree20e53770f1aabf3023867ba1d2fe6ec3ecc54b3c /Documentation/devicetree
parent1fa4163bdc199a0b80f9e333d718b3f65e901593 (diff)
downloadblackbird-op-linux-3bcbaf6e08d8d82cde781997bd2c56dda87049b5.tar.gz
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rtc: cmos: Add OF bindings
This allows to load the OF driver based informations from the device tree. Systems without BIOS may need to perform some initialization. PowerPC creates a PNP device from the OF information and performs this kind of initialization in their private PCI quirk. This looks more generic. This patch also avoids registering the platform RTC driver on X86 if we have a device tree blob. Otherwise we would setup the device based on the hardcoded information in arch/x86 rather than the device tree based one. [ tglx: Changed "int of_have_populated_dt()" to bool as recommended by Grant ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Cc: sodaville@linutronix.de Cc: devicetree-discuss@lists.ozlabs.org Cc: rtc-linux@googlegroups.com Cc: Alessandro Zummo <a.zummo@towertech.it> LKML-Reference: <1298405266-1624-12-git-send-email-bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r--Documentation/devicetree/bindings/rtc/rtc-cmos.txt28
1 files changed, 28 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/rtc/rtc-cmos.txt b/Documentation/devicetree/bindings/rtc/rtc-cmos.txt
new file mode 100644
index 000000000000..7382989b3052
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/rtc-cmos.txt
@@ -0,0 +1,28 @@
+ Motorola mc146818 compatible RTC
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Required properties:
+ - compatible : "motorola,mc146818"
+ - reg : should contain registers location and length.
+
+Optional properties:
+ - interrupts : should contain interrupt.
+ - interrupt-parent : interrupt source phandle.
+ - ctrl-reg : Contains the initial value of the control register also
+ called "Register B".
+ - freq-reg : Contains the initial value of the frequency register also
+ called "Regsiter A".
+
+"Register A" and "B" are usually initialized by the firmware (BIOS for
+instance). If this is not done, it can be performed by the driver.
+
+ISA Example:
+
+ rtc@70 {
+ compatible = "motorola,mc146818";
+ interrupts = <8 3>;
+ interrupt-parent = <&ioapic1>;
+ ctrl-reg = <2>;
+ freq-reg = <0x26>;
+ reg = <1 0x70 2>;
+ };
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