Re: [PATCH v4 4/8] drm/msm/dsi: 14nm PHY: Get ref clock from the DT

From: Stephen Boyd
Date: Wed Dec 19 2018 - 17:32:23 EST


Quoting Matthias Kaehlcke (2018-12-19 14:22:22)
> On Mon, Dec 10, 2018 at 07:51:19AM -0800, Stephen Boyd wrote:
> > Quoting Matthias Kaehlcke (2018-12-04 14:42:30)
> > > diff --git a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_14nm.c b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_14nm.c
> > > index 71fe60e5f01f1..032bf3e8614bd 100644
> > > --- a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_14nm.c
> > > +++ b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_14nm.c
> > > @@ -40,7 +40,6 @@
> > >
> > > #define NUM_PROVIDED_CLKS 2
> > >
> > > -#define VCO_REF_CLK_RATE 19200000
> > > #define VCO_MIN_RATE 1300000000UL
> > > #define VCO_MAX_RATE 2600000000UL
> > >
> > > @@ -139,6 +138,7 @@ struct dsi_pll_14nm {
> > > /* protects REG_DSI_14nm_PHY_CMN_CLK_CFG0 register */
> > > spinlock_t postdiv_lock;
> > >
> > > + struct clk *vco_ref_clk;
> >
> > Is there any need to keep it in the struct? Or just get the clk, find
> > the rate, and then put the clk and call pll_14nm_postdiv_register()?
>
> I suppose you mean passing the clock name to pll_14nm_register()?

Yes, whatever makes it possible to avoid storing the pointer in the
struct.

>
> Is putting the clock really needed or preferable, or is it just fine
> to auto-put it when the device is deleted?

Up to you. If you don't have a need for the clk anymore it seems fine to
just put the clk and be done.