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linux-next/Documentation/devicetree/bindings/clock/nvidia,tegra20-car.txt
Stephen Warren 07999587b7 ARM: tegra: document reset properties in DT bindings
Update all the Tegra DT bindings to require resets/reset-names properties
where the HW module has reset inputs. Remove any entries from clocks or
clock-names that were only required to identify reset inputs, rather than
referring to real clocks.

This is a DT-ABI-incompatible change. It is the first of two changes
required for me to consider the Tegra DT bindings as stable, the other
being conversion to the common DMA DT bindings.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-By: Terje Bergstrom <tbergstrom@nvidia.com>
2013-12-11 16:42:13 -07:00

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NVIDIA Tegra20 Clock And Reset Controller
This binding uses the common clock binding:
Documentation/devicetree/bindings/clock/clock-bindings.txt
The CAR (Clock And Reset) Controller on Tegra is the HW module responsible
for muxing and gating Tegra's clocks, and setting their rates.
Required properties :
- compatible : Should be "nvidia,tegra20-car"
- reg : Should contain CAR registers location and length
- clocks : Should contain phandle and clock specifiers for two clocks:
the 32 KHz "32k_in", and the board-specific oscillator "osc".
- #clock-cells : Should be 1.
In clock consumers, this cell represents the clock ID exposed by the
CAR. The assignments may be found in header file
<dt-bindings/clock/tegra20-car.h>.
- #reset-cells : Should be 1.
In clock consumers, this cell represents the bit number in the CAR's
array of CLK_RST_CONTROLLER_RST_DEVICES_* registers.
Example SoC include file:
/ {
tegra_car: clock {
compatible = "nvidia,tegra20-car";
reg = <0x60006000 0x1000>;
#clock-cells = <1>;
#reset-cells = <1>;
};
usb@c5004000 {
clocks = <&tegra_car TEGRA20_CLK_USB2>;
};
};
Example board file:
/ {
clocks {
compatible = "simple-bus";
#address-cells = <1>;
#size-cells = <0>;
osc: clock@0 {
compatible = "fixed-clock";
reg = <0>;
#clock-cells = <0>;
clock-frequency = <12000000>;
};
clk_32k: clock@1 {
compatible = "fixed-clock";
reg = <1>;
#clock-cells = <0>;
clock-frequency = <32768>;
};
};
&tegra_car {
clocks = <&clk_32k> <&osc>;
};
};