xtensa: add xtensa arch oneshot ops

[zhuyanlinzyl]

As xtensa timer is common in all xtensa chips,
Use oneshot ops, implement a common xtensa oneshot timer.

Summary

Impact

Testing

[pkarashchenko]

In general LGTM.
Few optional style issues.

[Ouss4]

What timer are you using with this? Timer0 is already used for the tick. Timer1 and Timer2 have priority 3 and 5 respectively, is this the same for your configuration?

[zhuyanlinzyl]

hi @Ouss4 , We used timer2 with this, the interrupt priority is 2. And we used it as cpuload timer.

  lower = xtensa_oneshot_initialize(XTENSA_IRQ_TIMER2,
                                    CONFIG_HIFI4_CLOCK_FREQUENCY);
  nxsched_oneshot_extclk(lower);

we use Aon timer as system tick

[Ouss4]

hi @Ouss4 , We used timer2 with this, the interrupt priority is 2. And we used it as cpuload timer.

lower = xtensa_oneshot_initialize(XTENSA_IRQ_TIMER2,
CONFIG_HIFI4_CLOCK_FREQUENCY);
nxsched_oneshot_extclk(lower);
we use Aon timer as system tick

Alright, thanks for the explanation.