xref: /freebsd/sys/contrib/device-tree/Bindings/timer/arm,twd.txt (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
1*c66ec88fSEmmanuel Vadot* ARM Timer Watchdog
2*c66ec88fSEmmanuel Vadot
3*c66ec88fSEmmanuel VadotARM 11MP, Cortex-A5 and Cortex-A9 are often associated with a per-core
4*c66ec88fSEmmanuel VadotTimer-Watchdog (aka TWD), which provides both a per-cpu local timer
5*c66ec88fSEmmanuel Vadotand watchdog.
6*c66ec88fSEmmanuel Vadot
7*c66ec88fSEmmanuel VadotThe TWD is usually attached to a GIC to deliver its two per-processor
8*c66ec88fSEmmanuel Vadotinterrupts.
9*c66ec88fSEmmanuel Vadot
10*c66ec88fSEmmanuel Vadot** Timer node required properties:
11*c66ec88fSEmmanuel Vadot
12*c66ec88fSEmmanuel Vadot- compatible : Should be one of:
13*c66ec88fSEmmanuel Vadot	"arm,cortex-a9-twd-timer"
14*c66ec88fSEmmanuel Vadot	"arm,cortex-a5-twd-timer"
15*c66ec88fSEmmanuel Vadot	"arm,arm11mp-twd-timer"
16*c66ec88fSEmmanuel Vadot
17*c66ec88fSEmmanuel Vadot- interrupts : One interrupt to each core
18*c66ec88fSEmmanuel Vadot
19*c66ec88fSEmmanuel Vadot- reg : Specify the base address and the size of the TWD timer
20*c66ec88fSEmmanuel Vadot	register window.
21*c66ec88fSEmmanuel Vadot
22*c66ec88fSEmmanuel VadotOptional
23*c66ec88fSEmmanuel Vadot
24*c66ec88fSEmmanuel Vadot- always-on : a boolean property. If present, the timer is powered through
25*c66ec88fSEmmanuel Vadot  an always-on power domain, therefore it never loses context.
26*c66ec88fSEmmanuel Vadot
27*c66ec88fSEmmanuel VadotExample:
28*c66ec88fSEmmanuel Vadot
29*c66ec88fSEmmanuel Vadot	twd-timer@2c000600 {
30*c66ec88fSEmmanuel Vadot		compatible = "arm,arm11mp-twd-timer"";
31*c66ec88fSEmmanuel Vadot		reg = <0x2c000600 0x20>;
32*c66ec88fSEmmanuel Vadot		interrupts = <1 13 0xf01>;
33*c66ec88fSEmmanuel Vadot	};
34*c66ec88fSEmmanuel Vadot
35*c66ec88fSEmmanuel Vadot** Watchdog node properties:
36*c66ec88fSEmmanuel Vadot
37*c66ec88fSEmmanuel Vadot- compatible : Should be one of:
38*c66ec88fSEmmanuel Vadot	"arm,cortex-a9-twd-wdt"
39*c66ec88fSEmmanuel Vadot	"arm,cortex-a5-twd-wdt"
40*c66ec88fSEmmanuel Vadot	"arm,arm11mp-twd-wdt"
41*c66ec88fSEmmanuel Vadot
42*c66ec88fSEmmanuel Vadot- interrupts : One interrupt to each core
43*c66ec88fSEmmanuel Vadot
44*c66ec88fSEmmanuel Vadot- reg : Specify the base address and the size of the TWD watchdog
45*c66ec88fSEmmanuel Vadot	register window.
46*c66ec88fSEmmanuel Vadot
47*c66ec88fSEmmanuel VadotExample:
48*c66ec88fSEmmanuel Vadot
49*c66ec88fSEmmanuel Vadot	twd-watchdog@2c000620 {
50*c66ec88fSEmmanuel Vadot		compatible = "arm,arm11mp-twd-wdt";
51*c66ec88fSEmmanuel Vadot		reg = <0x2c000620 0x20>;
52*c66ec88fSEmmanuel Vadot		interrupts = <1 14 0xf01>;
53*c66ec88fSEmmanuel Vadot	};
54