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author | Arnd Bergmann <arnd@arndb.de> | 2015-12-16 00:04:26 +0100 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2015-12-16 00:04:26 +0100 |
commit | 8ea1c981b6303904a2d92102f903843bda9df58c (patch) | |
tree | 9cef253e8f5d6b4279eb867f58a1defb81d7b193 /Documentation/devicetree/bindings/clock | |
parent | ee5d89239500de9eff188c26375c3512d8ac7f6f (diff) | |
parent | acde758b31f33d1599a07930b8c0ea082157cf70 (diff) | |
download | op-kernel-dev-8ea1c981b6303904a2d92102f903843bda9df58c.zip op-kernel-dev-8ea1c981b6303904a2d92102f903843bda9df58c.tar.gz |
Merge tag 'realview-base-armsoc-2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator into next/dt
Merge "Realview DT files" from Linus Walleij:
The device tree changes for the continued RealView DT
support.
* tag 'realview-base-armsoc-2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator:
ARM: realview: add device tree for PB11MPCore
clk: add ARM syscon ICST device tree bindings
ARM: add DT bindings for the ARM11MPCore CPU cluster
Diffstat (limited to 'Documentation/devicetree/bindings/clock')
-rw-r--r-- | Documentation/devicetree/bindings/clock/arm-syscon-icst.txt | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/clock/arm-syscon-icst.txt b/Documentation/devicetree/bindings/clock/arm-syscon-icst.txt new file mode 100644 index 0000000..8b7177c --- /dev/null +++ b/Documentation/devicetree/bindings/clock/arm-syscon-icst.txt @@ -0,0 +1,40 @@ +ARM System Controller ICST clocks + +The ICS525 and ICS307 oscillators are produced by Integrated Devices +Technology (IDT). ARM integrated these oscillators deeply into their +reference designs by adding special control registers that manage such +oscillators to their system controllers. + +The ARM system controller contains logic to serialize and initialize +an ICST clock request after a write to the 32 bit register at an offset +into the system controller. Furthermore, to even be able to alter one of +these frequencies, the system controller must first be unlocked by +writing a special token to another offset in the system controller. + +The ICST oscillator must be provided inside a system controller node. + +Required properties: +- lock-offset: the offset address into the system controller where the + unlocking register is located +- vco-offset: the offset address into the system controller where the + ICST control register is located (even 32 bit address) +- compatible: must be one of "arm,syscon-icst525" or "arm,syscon-icst307" +- #clock-cells: must be <0> +- clocks: parent clock, since the ICST needs a parent clock to derive its + frequency from, this attribute is compulsory. + +Example: + +syscon: syscon@10000000 { + compatible = "syscon"; + reg = <0x10000000 0x1000>; + + oscclk0: osc0@0c { + compatible = "arm,syscon-icst307"; + #clock-cells = <0>; + lock-offset = <0x20>; + vco-offset = <0x0c>; + clocks = <&xtal24mhz>; + }; + (...) +}; |