linux/Documentation/devicetree/bindings/clock/vt8500.txt

75 lines
1.9 KiB
Plaintext
Raw Normal View History

Device Tree Clock bindings for arch-vt8500
This binding uses the common clock binding[1].
[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
Required properties:
- compatible : shall be one of the following:
"via,vt8500-pll-clock" - for a VT8500/WM8505 PLL clock
"wm,wm8650-pll-clock" - for a WM8650 PLL clock
"wm,wm8750-pll-clock" - for a WM8750 PLL clock
"wm,wm8850-pll-clock" - for a WM8850 PLL clock
"via,vt8500-device-clock" - for a VT/WM device clock
Required properties for PLL clocks:
- reg : shall be the control register offset from PMC base for the pll clock.
- clocks : shall be the input parent clock phandle for the clock. This should
be the reference clock.
- #clock-cells : from common clock binding; shall be set to 0.
Required properties for device clocks:
- clocks : shall be the input parent clock phandle for the clock. This should
be a pll output.
- #clock-cells : from common clock binding; shall be set to 0.
Device Clocks
Device clocks are required to have one or both of the following sets of
properties:
Gated device clocks:
Required properties:
- enable-reg : shall be the register offset from PMC base for the enable
register.
- enable-bit : shall be the bit within enable-reg to enable/disable the clock.
Divisor device clocks:
Required property:
- divisor-reg : shall be the register offset from PMC base for the divisor
register.
Optional property:
- divisor-mask : shall be the mask for the divisor register. Defaults to 0x1f
if not specified.
For example:
ref25: ref25M {
#clock-cells = <0>;
compatible = "fixed-clock";
clock-frequency = <25000000>;
};
plla: plla {
#clock-cells = <0>;
compatible = "wm,wm8650-pll-clock";
clocks = <&ref25>;
reg = <0x200>;
};
sdhc: sdhc {
#clock-cells = <0>;
compatible = "via,vt8500-device-clock";
clocks = <&pllb>;
divisor-reg = <0x328>;
divisor-mask = <0x3f>;
enable-reg = <0x254>;
enable-bit = <18>;
};