[U-Boot] [PATCH v4 1/9] sunxi: clk: enable clk and reset for CCU devices

[Andre Przywara]

On Tue, 29 Jan 2019 23:40:26 +0530
Jagan Teki <jagan at amarulasolutions.com> wrote:

> On Tue, Jan 29, 2019 at 9:25 PM Andre Przywara
> <andre.przywara at arm.com> wrote:
> >
> > Some Allwinner clock devices have parent clocks and reset gates
> > itself, which need to be activated for them to work.
> >
> > Add some code to just assert all resets and enable all clocks given.
> > This should enable the A80 MMC config clock, which requires both to
> > be activated. The full CCU devices typically don't require resets,
> > and have just fixed clocks as their parents. Since we treat both as
> > optional and enabling fixed clocks is a NOP, this works for all
> > cases, without the need to differentiate between those clock types.
> >
> > Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> > ---
> >  drivers/clk/sunxi/clk_sunxi.c | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> >
> > diff --git a/drivers/clk/sunxi/clk_sunxi.c
> > b/drivers/clk/sunxi/clk_sunxi.c index 62ce2994e4..6d4aeb5315 100644
> > --- a/drivers/clk/sunxi/clk_sunxi.c
> > +++ b/drivers/clk/sunxi/clk_sunxi.c
> > @@ -8,6 +8,7 @@
> >  #include <clk-uclass.h>
> >  #include <dm.h>
> >  #include <errno.h>
> > +#include <reset.h>
> >  #include <asm/io.h>
> >  #include <asm/arch/ccu.h>
> >  #include <linux/log2.h>
> > @@ -61,6 +62,9 @@ struct clk_ops sunxi_clk_ops = {
> >  int sunxi_clk_probe(struct udevice *dev)
> >  {
> >         struct ccu_priv *priv = dev_get_priv(dev);
> > +       struct clk_bulk clk_bulk;
> > +       struct reset_ctl_bulk rst_bulk;
> > +       int ret;
> >
> >         priv->base = dev_read_addr_ptr(dev);
> >         if (!priv->base)
> > @@ -70,5 +74,13 @@ int sunxi_clk_probe(struct udevice *dev)
> >         if (!priv->desc)
> >                 return -EINVAL;
> >
> > +       ret = clk_get_bulk(dev, &clk_bulk);
> > +       if (!ret)
> > +               clk_enable_bulk(&clk_bulk);
> > +
> > +       ret = reset_get_bulk(dev, &rst_bulk);
> > +       if (!ret)
> > +               reset_deassert_bulk(&rst_bulk);
> > +  
> 
> Can't we do this locally to clk_a80 probe?

That's the point: there is no such thing. For all SoCs we use the shared
sunxi_clk_probe() function. Doing this only for the A80 would mean to
split this up, which is duplicating a lot of code for very little
effect. The code here just enables every clock and reset given, which
is generic and should always be the right thing.

Cheers,
Andre.