48 lines
1.7 KiB
Plaintext
48 lines
1.7 KiB
Plaintext
|
* NVIDIA Tegra Watchdog controller
|
||
|
|
|
||
|
|
Required properties:
|
||
|
|
|
||
|
|
- compatible: Should be "nvidia,tegra-wdt"
|
||
|
|
- reg: Should contain WDT and corresponding timer source
|
||
|
|
registers location and length.
|
||
|
|
|
||
|
|
Optional properties:
|
||
|
|
|
||
|
|
- interrupts: interrupt number to the cpu
|
||
|
|
- nvidia,expiry-count: total expiry count of WDT (1 if not specified)
|
||
|
|
- nvidia,enable-on-init: Toggle switch for enable during init
|
||
|
|
- nvidia,heartbeat-init: default timeout in secs (120 secs if not specified)
|
||
|
|
- nvidia,timer-index: timer source index for WDT
|
||
|
|
|
||
|
|
Timer source index:
|
||
|
|
|
||
|
|
There are three ways by which WDT timer source index can be specified
|
||
|
|
and timer source selection happens with below given priorty order (decending)
|
||
|
|
(a) Bootloader programs WDT and timer source
|
||
|
|
(b) "nvidia,timer-index" property in DT
|
||
|
|
(c) Timer source base address in DT (old method)
|
||
|
|
|
||
|
|
Method (a) is of highest priority, because bootloader can program the WDT timer
|
||
|
|
source and lock to prevent any further modification of timer source by kernel.
|
||
|
|
In order to calculate the timer source address in runtime in this case timer
|
||
|
|
base address is required and hence Timer base address should be provided in
|
||
|
|
timer resource property in DT.
|
||
|
|
|
||
|
|
Either timer base address or timer source address is expected in timer resource
|
||
|
|
property in DT for case (b).
|
||
|
|
|
||
|
|
Note: If method (c) is used it should correspond to the timer source index provided
|
||
|
|
in method (a) or (b) or make sure that method (a) or (b) is not in use.
|
||
|
|
|
||
|
|
Examples:
|
||
|
|
|
||
|
|
watchdog@60005100 {
|
||
|
|
compatible = "nvidia,tegra-wdt";
|
||
|
|
reg = <0x0 0x60005100 0x0 0x20 /* WDT0 registers */
|
||
|
|
0x0 0x60005088 0x0 0x8>; /* TMR0 registers */
|
||
|
|
interrupts = <0 123 0x04>;
|
||
|
|
nvidia,expiry-count = <4>;
|
||
|
|
nvidia,timer-index = <7>;
|
||
|
|
status = "disabled";
|
||
|
|
};
|