RE: [EXT] Re: [v4 2/2] clk: ls1028a: Add clock driver for Display output interface
From: Stephen Boyd
Date: Wed Sep 18 2019 - 13:00:54 EST
Quoting Wen He (2019-09-18 02:20:26)
> > -----Original Message-----
> > From: Stephen Boyd <sboyd@xxxxxxxxxx>
> > Quoting Wen He (2019-08-29 03:59:19)
> > > diff --git a/drivers/clk/clk-plldig.c b/drivers/clk/clk-plldig.c new
> > > file mode 100644 index 000000000000..d3239bcf59de
> > > --- /dev/null
> > > +++ b/drivers/clk/clk-plldig.c
> > > @@ -0,0 +1,298 @@
[...]
>
> >
> > > +
> > > +/* Maximum of the divider */
> > > +#define MAX_RFDPHI1 63
> > > +
> > > +/* Best value of multiplication factor divider */
> > > +#define PLLDIG_DEFAULE_MULT 44
> > > +
> > > +/*
> > > + * Clock configuration relationship between the PHI1
> > > +frequency(fpll_phi) and
> > > + * the output frequency of the PLL is determined by the PLLDV,
> > > +according to
> > > + * the following equation:
> > > + * fpll_phi = (pll_ref * mfd) / div_rfdphi1 */ struct
> > > +plldig_phi1_param {
> > > + unsigned long rate;
> > > + unsigned int rfdphi1;
> > > + unsigned int mfd;
> > > +};
> > > +
> > > +enum plldig_phi1_freq_range {
> > > + PHI1_MIN = 27000000U,
> > > + PHI1_MAX = 600000000U
> > > +};
> >
> > Please just inline these values in the one place they're used.
> >
> > > +
> > > +struct clk_plldig {
> > > + struct clk_hw hw;
> > > + void __iomem *regs;
> > > + struct device *dev;
> >
> > Please remove this, it is unused.
>
> It is used for probe.
Use a local variable and don't store it away forever in the struct.
> >
> > > +
> > > + val = readl(data->regs + PLLDIG_REG_PLLDV);
> > > + val = phi1_param.mfd;
> > > + rfdphi1 = phi1_param.rfdphi1;
> > > + val |= rfdphi1;
> > > +
> > > + writel(val, data->regs + PLLDIG_REG_PLLDV);
> > > +
> > > + /* delay 200us make sure that old lock state is cleared */
> > > + udelay(200);
> > > +
> > > + /* Wait until PLL is locked or timeout (maximum 1000 usecs) */
> > > + ret = readl_poll_timeout_atomic(data->regs + PLLDIG_REG_PLLSR,
> > cond,
> > > + cond & PLLDIG_LOCK_MASK,
> > 0,
> > > + USEC_PER_MSEC);
> > > +
> > > + return ret;
> >
> > Just return readl_poll_timeout_atomic(...) here.
>
> Maybe use below code will to best describes.
>
> If (ret)
> return -ETIMEOUT;
>
> return 0;
No, just return readl_poll_timeout_atomic().