Re: [PATCH v3 3/3] clocksource/drivers/ostm: Use unique device name instead of ostm

[Geert Uytterhoeven]

Hi Simon,

On Fri, Aug 16, 2019 at 3:11 PM Simon Horman <horms@xxxxxxxxxxxx> wrote:
> On Wed, Aug 07, 2019 at 10:46:35AM +0200, Geert Uytterhoeven wrote:
> > Currently all OSTM devices are called "ostm", also in kernel messages.
> >
> > As there can be multiple instances in an SoC, this can confuse the user.
> > Hence construct a unique name from the DT node name, like is done for
> > platform devices.
> >
> > On RSK+RZA1, the boot log changes like:
> >
> >     -clocksource: ostm: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 57352151442 ns
> >     +clocksource: ostm fcfec000.timer: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 57352151442 ns
> >      sched_clock: 32 bits at 33MHz, resolution 30ns, wraps every 64440619504ns
> >     -ostm: used for clocksource
> >     -ostm: used for clock events
> >     +ostm fcfec000.timer: used for clocksource
> >     +ostm fcfec400.timer: used for clock events
> >
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > ---
> > v3:
> >   - Make the name format similar to the one used for platform devices,
> >   - Use kasprintf() instead of buffer size guessing,
> >   - Use a real example from rskrza1.
> >
> > v2 (by Jacopo):
> >   - Use np->full_name.
> > ---
> >  drivers/clocksource/renesas-ostm.c | 45 ++++++++++++++++++++----------
> >  1 file changed, 30 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/clocksource/renesas-ostm.c b/drivers/clocksource/renesas-ostm.c
> > index 1e22e54d7b0df40d..659e3ec7b86714e3 100644
> > --- a/drivers/clocksource/renesas-ostm.c
> > +++ b/drivers/clocksource/renesas-ostm.c

> > @@ -195,22 +195,35 @@ static int __init ostm_init(struct device_node *np)
> >       if (!ostm)
> >               return -ENOMEM;
> >
> > -     ostm->base = of_iomap(np, 0);
> > -     if (!ostm->base) {
> > +     ret = of_address_to_resource(np, 0, &res);
> > +     if (ret) {
> > +             pr_err("ostm: Failed to obtain I/O memory\n");
> > +             goto err_free;
> > +     }
> > +
> > +     ostm->name = kasprintf(GFP_KERNEL, "ostm %llx.%s",
> > +                            (unsigned long long)res.start, np->name);
>
> I'm not sure, but looking at printk-formats.rst it seems that
> %pa[p] as a format specifier for resource_size_t. If so it may
> allow dropping the cast above.

Using "%pa" adds a "0x" prefix, which we don't want here.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds