Re: [PATCH 6/8] devicetree: doc: Document ti,timer-parent property

From: Tony Lindgren
Date: Fri Nov 22 2013 - 10:58:56 EST


* Joel Fernandes <joelf@xxxxxx> [131121 18:00]:
> +Required properties for system timers (clockevents/clocksource):
> +- ti,timer-parent: System timer's parent mux clock needs to be setup.
> + This is currently hardcoded in code, for DT boot we
> + move this to DT.
> +

This can be replaced with just clk_set_rate, or clk_set_parent if needed.
Or by having a clocks = <&32k_clk> property in the dmtimer node in the
.dts file.

> Optional properties:
> - ti,timer-alwon: Indicates the timer is in an alway-on power domain.

Hmm this we may not need, this can probably be deciphered from the compatible
flag already?

Then for the users of a specific dmtimer, they can select the right one using
the interrupt-parent property:

timer1: timer@0x4800abcd {
compatible = "ti,omap5430-timer";
#interrupt-cells = <1>; /* needs irqchip implemented for dmtimer */
interrupt-controller;
#clock-cells = <1>; /* needs clocksource implemented for dmtimer */
clock-output-names = "32k", "sys_ck";
...
};

counter32k: counter@4ae04000 {
compatible = "ti,omap-counter32k";
#clock-cells = <1>; /* needs clocksource implemented for 32k counter */
clock-output-names = "32k";
...
};

timer {
compatible = "ti,omap5-timer";
interrupt-parent = <&timer1>;
interrupts = <1>;
clocks = <&timer1 0>, /* use timer1 as clockevent, clock index 0 = 32k, 1 = sys_ck ... */
<&counter32k 0>; /* use 32k counter as clocksource */
};

> - ti,timer-dsp: Indicates the timer can interrupt the on-chip DSP in

This can be probably also be mapped based on the compatible property?

Regards,

Tony
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