RE: [PATCH 2/5] Clocksource: Flextimer: Use internal clocksource read API.

From: Li.Xiubo@xxxxxxxxxxxxx
Date: Thu Sep 04 2014 - 04:43:51 EST


> >
> > Since the FTM will be in BE mode on LS1 platform, but will be in LE mode
> > On LS2 platform.
> >
> > And ftm_clocksource_read_up() will adapt to this different.
>
> You are missing the point. Why do you want a conditional in a hot
> path? You know at init time whether the thing is BE or LE, so you can
> have separate functions for BE/LE or whatever and register that with
> clocksource_mmio_init(). i.e.
>
> if (be)
> clocksource_mmio_init(....., cs_read_be);
> else if (le)
> clocksource_mmio_init(....., cs_read_le);
> else if (magic)
> clocksource_mmio_init(....., cs_read_magic);
>

There already has the following access interfaces:

static inline u32 ftm_readl(void __iomem *addr)
{
if (priv->big_endian)
return ioread32be(addr);
else
return ioread32(addr);
}

static inline void ftm_writel(u32 val, void __iomem *addr)
{
if (priv->big_endian)
iowrite32be(val, addr);
else
iowrite32(val, addr);
}

So I added the following code:

static cycle_t ftm_clocksource_read_up(struct clocksource *c)
{
return ftm_readl(priv->clksrc_base + FTM_CNT) & 0xffff;
}

clocksource_mmio_init(.....,ftm_clocksource_read_up);

Is this okay ?

Thanks,

BRs
Xiubo


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