Hi Geert,
On Fri, 2022-08-12 at 11:49 +0200, Geert Uytterhoeven wrote:
> On Thu, Aug 4, 2022 at 8:10 AM Liu Ying <victor.liu@xxxxxxx> wrote:
> > Simple Power-Managed bus controller may need functional clock(s)
> > to be enabled before child devices connected to the bus can be
> > accessed. Get the clock(s) as a bulk and enable/disable the
> > clock(s) when the bus is being power managed.
> >
> > One example is that Freescale i.MX8qxp pixel link MSI bus
> > controller
> > needs MSI clock and AHB clock to be enabled before accessing child
> > devices.
> >
> > Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
> > ---
> > v1->v3:
> > * No change.
>
> Thanks for your patch!
>
> > --- a/drivers/bus/simple-pm-bus.c
> > +++ b/drivers/bus/simple-pm-bus.c
> > @@ -72,6 +89,42 @@ static int simple_pm_bus_remove(struct
> > platform_device *pdev)
> > return 0;
> > }
> >
> > +static int simple_pm_bus_runtime_suspend(struct device *dev)
> > +{
> > + struct simple_pm_bus *bus = dev_get_drvdata(dev);
> > +
> > + if (!bus)
> > + return 0;
>
> Can this really happen?
Good question. Should not happen in any cases. pm_runtime_init() sets
runtime_status to RPM_SUSPENDED and needs_force_resume to 0, so
simple_pm_bus_runtime_{suspend,resume} are only called for
simple-pm-bus, not the others. Unless I miss something, I would remove
the check here and ...
>
> > +
> > + clk_bulk_disable_unprepare(bus->num_clks, bus->clks);
> > +
> > + return 0;
> > +}
> > +
> > +static int simple_pm_bus_runtime_resume(struct device *dev)
> > +{
> > + struct simple_pm_bus *bus = dev_get_drvdata(dev);
> > + int ret;
> > +
> > + if (!bus)
> > + return 0;
>
> Likewise.
... here.
>
> > +
> > + ret = clk_bulk_prepare_enable(bus->num_clks, bus->clks);
> > + if (ret) {
> > + dev_err(dev, "failed to enable clocks: %d\n", ret);
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
>
> The rest LGTM, so
> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Thanks,
Liu Ying
