[PATCH V4 5/5] clk: imx8qxp: Support building i.MX8QXP clock driver as module

[Anson Huang]

> Subject: Re: [PATCH V4 5/5] clk: imx8qxp: Support building i.MX8QXP clock
> driver as module
> 
> On Thu, Jul 2, 2020 at 11:55 AM Anson Huang <anson.huang at nxp.com>
> wrote:
> [...]
> > > > +{
> > > > +       return platform_driver_register(&imx8qxp_lpcg_clk_driver);
> > > > +}
> > > > +device_initcall(imx8qxp_lpcg_clk_init);
> > >
> > > Any reason to change to device_initcall which looks a bit strange?
> > > Is it because the following line?
> > > +obj-$(CONFIG_MXC_CLK_SCU) += clk-imx-scu.o clk-imx-lpcg-scu.o
> > > But it looks to me they're still two modules. Aren't they?
> >
> > It is suggested by Arnd to NOT use builtin_platform_driver(), in order
> > to support module unload, although the clock driver normally does NOT
> > support remove, but it is better to follow the right way.
> >
> 
> By expanding builtin_platform_driver() marcro, you will find your patch is
> exactly doing the same thing as buildin_platform_driver() which obivously is
> unneccesary.
> 
> #define builtin_platform_driver(__platform_driver) \
>         builtin_driver(__platform_driver, platform_driver_register) #define
> builtin_driver(__driver, __register, ...) \
> 
> static int __init __driver##_init(void) \ { \
>         return __register(&(__driver) , ##__VA_ARGS__); \ } \
> device_initcall(__driver##_init);
> 
> If we want to support unload, we need a .remove() callback as current clocks
> are not allocated by devm_().
> If don't support,  we probably can use builtin_platform_driver() first and
> switch to module_platform_driver() in the future once the driver supports
> release resource properly.
> 

Yes, that is why I use the device_initcall() to make it exactly same as builtin_driver(),
and also yes that i.MX clock driver does NOT support module unload, so .remove()
is NOT implemented, I am fine with either way, just try to address Arnd's comment.

Hi, Arnd
	What do you think? Do you agree to keep using the builtin_driver()?

Thanks,
Anson