Re: [PATCH v2 1/4] clocksource: fttmr010: Parametrise shutdown

[Joel Stanley]

On Wed, 29 Jan 2020 at 11:25, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote:
>
> On 07/11/2019 10:42, Joel Stanley wrote:
> > In preparation for supporting the ast2600 which uses a different method
> > to clear bits in the control register, use a callback for performing the
> > shutdown sequence.
> >
> > Reviewed-by: CÃdric Le Goater <clg@xxxxxxxx>
> > Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> > Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
>
> It will be cleaner if you create a struct of_device_id array where you
> store the different variant data.

I agree, and that's the path I would have taken when writing a normal
driver. However as the timer drivers probe with the
TIMER_OF_DECLARE/timer_probe infrastructure, we can't register our own
.data pointer (TIMER_OF_DECLARE uses .data  to store the _init
function).

Unless I'm missing something?

Cheers,

Joel


>
> eg.
> struct myops {
>         int (*shutdown)(struct clock_event_device *evt);
> };
>
> struct fttmr010 {
>         ...
>         struct myops *ops;
> };
>
> ...
>
> static const struct of_device_id fttmr010_of_match[] = {
>         { .compatible = "faraday,fttmr010",     .data = &fttmr010_ops },
>         ...
>         { .compatible = "aspeed,ast2600-timer", .data = &as2600_ops, },
>         { /* sentinel */ }
> };
>
> Keep the generic timer_shutdown function, get the ops from there and
> then call the shutdown callback.
>
> At init time:
>
> ...
>
> const struct of_device_id *match;
>
> ...
>
> match = of_match_node(fttmr010_of_match, node);
> fttmr010->ops = (struct myops *)match->data;
>
> ...
>
> (also if you have time, remove the is_aspeed boolean test by a
> corresponding callback).
>
> > ---
> >  drivers/clocksource/timer-fttmr010.c | 19 ++++++++-----------
> >  1 file changed, 8 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/clocksource/timer-fttmr010.c b/drivers/clocksource/timer-fttmr010.c
> > index fadff7915dd9..c2d30eb9dc72 100644
> > --- a/drivers/clocksource/timer-fttmr010.c
> > +++ b/drivers/clocksource/timer-fttmr010.c
> > @@ -97,6 +97,7 @@ struct fttmr010 {
> >       bool is_aspeed;
> >       u32 t1_enable_val;
> >       struct clock_event_device clkevt;
> > +     int (*timer_shutdown)(struct clock_event_device *evt);
> >  #ifdef CONFIG_ARM
> >       struct delay_timer delay_timer;
> >  #endif
> > @@ -140,9 +141,7 @@ static int fttmr010_timer_set_next_event(unsigned long cycles,
> >       u32 cr;
> >
> >       /* Stop */
> > -     cr = readl(fttmr010->base + TIMER_CR);
> > -     cr &= ~fttmr010->t1_enable_val;
> > -     writel(cr, fttmr010->base + TIMER_CR);
> > +     fttmr010->timer_shutdown(evt);
> >
> >       if (fttmr010->is_aspeed) {
> >               /*
> > @@ -183,9 +182,7 @@ static int fttmr010_timer_set_oneshot(struct clock_event_device *evt)
> >       u32 cr;
> >
> >       /* Stop */
> > -     cr = readl(fttmr010->base + TIMER_CR);
> > -     cr &= ~fttmr010->t1_enable_val;
> > -     writel(cr, fttmr010->base + TIMER_CR);
> > +     fttmr010->timer_shutdown(evt);
> >
> >       /* Setup counter start from 0 or ~0 */
> >       writel(0, fttmr010->base + TIMER1_COUNT);
> > @@ -211,9 +208,7 @@ static int fttmr010_timer_set_periodic(struct clock_event_device *evt)
> >       u32 cr;
> >
> >       /* Stop */
> > -     cr = readl(fttmr010->base + TIMER_CR);
> > -     cr &= ~fttmr010->t1_enable_val;
> > -     writel(cr, fttmr010->base + TIMER_CR);
> > +     fttmr010->timer_shutdown(evt);
> >
> >       /* Setup timer to fire at 1/HZ intervals. */
> >       if (fttmr010->is_aspeed) {
> > @@ -350,6 +345,8 @@ static int __init fttmr010_common_init(struct device_node *np, bool is_aspeed)
> >                                    fttmr010->tick_rate);
> >       }
> >
> > +     fttmr010->timer_shutdown = fttmr010_timer_shutdown;
> > +
> >       /*
> >        * Setup clockevent timer (interrupt-driven) on timer 1.
> >        */
> > @@ -370,10 +367,10 @@ static int __init fttmr010_common_init(struct device_node *np, bool is_aspeed)
> >       fttmr010->clkevt.features = CLOCK_EVT_FEAT_PERIODIC |
> >               CLOCK_EVT_FEAT_ONESHOT;
> >       fttmr010->clkevt.set_next_event = fttmr010_timer_set_next_event;
> > -     fttmr010->clkevt.set_state_shutdown = fttmr010_timer_shutdown;
> > +     fttmr010->clkevt.set_state_shutdown = fttmr010->timer_shutdown;
> >       fttmr010->clkevt.set_state_periodic = fttmr010_timer_set_periodic;
> >       fttmr010->clkevt.set_state_oneshot = fttmr010_timer_set_oneshot;
> > -     fttmr010->clkevt.tick_resume = fttmr010_timer_shutdown;
> > +     fttmr010->clkevt.tick_resume = fttmr010->timer_shutdown;
> >       fttmr010->clkevt.cpumask = cpumask_of(0);
> >       fttmr010->clkevt.irq = irq;
> >       clockevents_config_and_register(&fttmr010->clkevt,
> >
>
>
> --
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