Re: [PATCH V2 1/2] clk: imx: add mcore_booted module paratemter

From: Stephen Boyd
Date: Thu Mar 17 2022 - 15:37:21 EST


Quoting Peng Fan (OSS) (2022-02-28 04:41:11)
> From: Peng Fan <peng.fan@xxxxxxx>
>
> Add mcore_booted boot parameter which could simplify AMP clock
> management. To i.MX8M, there is CCM(clock control Module) to generate
> clock root clock, anatop(analog PLL module) to generate PLL, and CCGR
> (clock gating) to gate clocks to peripherals. As below:
> anatop->ccm->ccgr->peripheral
>
> Linux handles the clock management and the auxiliary core is under
> control of Linux. Although there is per hardware domain control for CCGR
> and CCM, auxiliary core normally only use CCGR hardware domain control
> to avoid linux gate off the clk to peripherals and leave CCM ana anatop
> to Linux.
>
> Per NXP hardware design, because CCGR already support gate to
> peripherals, and clk root gate power leakage is negligible. So
> when in AMP case, we could not register the clk root gate.
>
> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> ---
>
> V2:
> Switch to use module parameter, tested on i.MX8MP-EVK

Why is a module parameter being used? I'd expect this informatioon that
mcore is booted to come from devicetree/firmware somehow.