Re: [PATCH 07/14] clock: milbeaut: Add Milbeaut M10V clock control

[Sugaya, Taichi]

Hi

On 2018/12/28 9:39, Stephen Boyd wrote:
> Quoting Sugaya, Taichi (2018-12-25 17:35:27)
> > Hi
> >
> > On 2018/11/30 17:31, Stephen Boyd wrote:
> > > > +       init.num_parents = parents;
> > > > +       init.parent_names = parent_names;
> > > > +
> > > > +       mcm->cname = clk_name;
> > > > +       mcm->parent = 0;
> > > > +       mcm->hw.init = &init;
> > > > +
> > > > +       clk = clk_register(NULL, &mcm->hw);
> > > > +       if (IS_ERR(clk))
> > > > +               goto err_clk;
> > > > +
> > > > +       of_clk_add_provider(node, of_clk_src_simple_get, clk);
> > > > +       return;
> > > > +
> > > > +err_clk:
> > > > +       kfree(mcm);
> > > > +err_mcm:
> > > > +       kfree(parent_names);
> > > > +}
> > > > +CLK_OF_DECLARE(m10v_clk_mux, "socionext,milbeaut-m10v-clk-mux",
> > > > +                       m10v_clk_mux_setup);
> > >
> > > Any chance you can use a platform driver?
> >
> > Excuse me to re-ask you.
> > Why do you recommend to use a platform driver? Is that current fad?
>
> Not exactly a fad. We've been doing it for some time now. From an older
> email on the list:
>
> Reasons (in no particular order):
>
>    1. We get a dev pointer to use with clk_hw_register()
>
>    2. We can handle probe defer if some resource is not available
>
>    3. Using device model gets us a hook into power management frameworks
>       like runtime PM and system PM for things like suspend and hibernate
>
>    4. It encourages a single DT node clk controller style binding
>       instead of a single node per clk style binding
>
>    5. We can use non-DT specific functions like devm_ioremap_resource() to map
>       registers and acquire other resources, leading to more portable and
>       generic code
>
>    6. We may be able to make the device driver a module, which will
>       make distros happy if we don't have to compile in all
>       these clk drivers to the resulting vmlinux

Great thanks for answering. I strongly understand.
#It takes a bit of time to send v2.

Best Regards,
Sugaya Taichi