linux_dsm_epyc7002/Documentation/devicetree/bindings/clock/ti/dpll.txt
Nishanth Menon b4be018921 CLK: TI: dpll: support OMAP5 MPU DPLL that need special handling for higher frequencies
MPU DPLL on OMAP5, DRA75x, DRA72x has a limitation on the maximum
frequency it can be locked at. Duty Cycle Correction circuit is used
to recover a correct duty cycle for achieving higher frequencies
(hardware internally switches output to M3 output(CLKOUTHIF) from M2
output (CLKOUT)).

So provide support to setup required data to handle Duty cycle by
the setting up the minimum frequency for DPLL. 1.4GHz is common
for all these devices and is based on Technical Reference Manual
information for OMAP5432((SWPU282U) chapter 3.6.3.3.1 "DPLLs Output
Clocks Parameters", and equivalent information from DRA75x, DRA72x
documentation(SPRUHP2E, SPRUHI2P).

Signed-off-by: Nishanth Menon <nm@ti.com>
[t-kristo@ti.com: updated for latest dpll init API call]
Signed-off-by: Tero Kristo <t-kristo@ti.com>
2014-06-06 20:33:39 +03:00

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Binding for Texas Instruments DPLL clock.
Binding status: Unstable - ABI compatibility may be broken in the future
This binding uses the common clock binding[1]. It assumes a
register-mapped DPLL with usually two selectable input clocks
(reference clock and bypass clock), with digital phase locked
loop logic for multiplying the input clock to a desired output
clock. This clock also typically supports different operation
modes (locked, low power stop etc.) This binding has several
sub-types, which effectively result in slightly different setup
for the actual DPLL clock.
[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
Required properties:
- compatible : shall be one of:
"ti,omap3-dpll-clock",
"ti,omap3-dpll-core-clock",
"ti,omap3-dpll-per-clock",
"ti,omap3-dpll-per-j-type-clock",
"ti,omap4-dpll-clock",
"ti,omap4-dpll-x2-clock",
"ti,omap4-dpll-core-clock",
"ti,omap4-dpll-m4xen-clock",
"ti,omap4-dpll-j-type-clock",
"ti,omap5-mpu-dpll-clock",
"ti,am3-dpll-no-gate-clock",
"ti,am3-dpll-j-type-clock",
"ti,am3-dpll-no-gate-j-type-clock",
"ti,am3-dpll-clock",
"ti,am3-dpll-core-clock",
"ti,am3-dpll-x2-clock",
"ti,omap2-dpll-core-clock",
- #clock-cells : from common clock binding; shall be set to 0.
- clocks : link phandles of parent clocks, first entry lists reference clock
and second entry bypass clock
- reg : offsets for the register set for controlling the DPLL.
Registers are listed in following order:
"control" - contains the control register base address
"idlest" - contains the idle status register base address
"mult-div1" - contains the multiplier / divider register base address
"autoidle" - contains the autoidle register base address (optional)
ti,am3-* dpll types do not have autoidle register
ti,omap2-* dpll type does not support idlest / autoidle registers
Optional properties:
- DPLL mode setting - defining any one or more of the following overrides
default setting.
- ti,low-power-stop : DPLL supports low power stop mode, gating output
- ti,low-power-bypass : DPLL output matches rate of parent bypass clock
- ti,lock : DPLL locks in programmed rate
Examples:
dpll_core_ck: dpll_core_ck@44e00490 {
#clock-cells = <0>;
compatible = "ti,omap4-dpll-core-clock";
clocks = <&sys_clkin_ck>, <&sys_clkin_ck>;
reg = <0x490>, <0x45c>, <0x488>, <0x468>;
};
dpll2_ck: dpll2_ck@48004004 {
#clock-cells = <0>;
compatible = "ti,omap3-dpll-clock";
clocks = <&sys_ck>, <&dpll2_fck>;
ti,low-power-stop;
ti,low-power-bypass;
ti,lock;
reg = <0x4>, <0x24>, <0x34>, <0x40>;
};
dpll_core_ck: dpll_core_ck@44e00490 {
#clock-cells = <0>;
compatible = "ti,am3-dpll-core-clock";
clocks = <&sys_clkin_ck>, <&sys_clkin_ck>;
reg = <0x90>, <0x5c>, <0x68>;
};
dpll_ck: dpll_ck {
#clock-cells = <0>;
compatible = "ti,omap2-dpll-core-clock";
clocks = <&sys_ck>, <&sys_ck>;
reg = <0x0500>, <0x0540>;
};