Re: [PATCH V4 08/11] clk: imx: imx8qxp-lpcg: add parsing clocks from device tree

[Dong Aisheng <dongas86@gmail.com>]

On Tue, Sep 17, 2019 at 2:45 AM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Dong Aisheng (2019-09-09 04:23:14)
> > ]On Sat, Sep 7, 2019 at 5:35 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > > Quoting Dong Aisheng (2019-08-20 04:13:22)
> > > > Add parsing clocks from device tree.
> > >
> > > Please describe some more here.
> >
> > Will improve.
> >
> > > > +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > > +       base = devm_ioremap_resource(&pdev->dev, res);
> > > > +       if (IS_ERR(base))
> > > > +               return PTR_ERR(base);
> > > > +
> > > > +       count = of_property_count_u32_elems(np, "clock-indices");
> > > > +       if (count < 0) {
> > > > +               dev_err(&pdev->dev, "failed to count clocks\n");
> > > > +               return -EINVAL;
> > > > +       }
> > >
> > > Is 'count' expected to be equal to IMX_LPCG_MAX_CLKS? Because later on
> > > in this function we set the num of clks to the MAX instead of the count
> > > from clock-indices.
> > >
> >
> > No. Here is a tricky to ease the clk getting.
> > For example, one LPCG supports up to 8 clock outputs which each of them
> > is fixed to 4 bits. Then we can easily use the bit-offset/clk-indices
> > parsed from DT
> > to fetch the corresponding clock by hws[clkspec->args[0] / 4].
> > And the cost is very limited with only a few pointers.
>
> Ok. Can you add a comment into the code to explain this?
>

Yes, added.
Thanks for the good suggestion.

Regards
Aisheng