[PATCH 1/3] ARM: OMAP2+: 32k-counter: Use hwmod lookup to check presence of 32k timer

[Felipe Balbi]

On Fri, Mar 09, 2012 at 05:58:00PM +0000, Hiremath, Vaibhav wrote:
> On Tue, Mar 06, 2012 at 04:25:30, Tony Lindgren wrote:
> > Hi,
> > 
> > * Vaibhav Hiremath <hvaibhav at ti.com> [120119 06:01]:
> > > OMAP device has 32k-sync timer which is currently used as a
> > > clocksource in the kernel (omap2plus_defconfig).
> > > The current implementation uses compile time selection between
> > > gp-timer and 32k-sync timer, which breaks multi-omap build for
> > > the devices like AM33xx, where 32k-sync timer is not available.
> > > 
> > > So use hwmod database lookup mechanism, through which at run-time
> > > we can identify availability of 32k-sync timer on the device,
> > > else fall back to gp-timer.
> > ...
> > 
> > > --- a/arch/arm/plat-omap/counter_32k.c
> > > +++ b/arch/arm/plat-omap/counter_32k.c
> > > @@ -69,52 +69,55 @@ void read_persistent_clock(struct timespec *ts)
> > >  
> > >  int __init omap_init_clocksource_32k(void)
> > >  {
> > > -	static char err[] __initdata = KERN_ERR
> > > -			"%s: can't register clocksource!\n";
> > > -
> > > -	if (cpu_is_omap16xx() || cpu_class_is_omap2()) {
> > > -		u32 pbase;
> > > -		unsigned long size = SZ_4K;
> > > -		void __iomem *base;
> > > -		struct clk *sync_32k_ick;
> > > -
> > > -		if (cpu_is_omap16xx()) {
> > > -			pbase = OMAP16XX_TIMER_32K_SYNCHRONIZED;
> > > -			size = SZ_1K;
> > > -		} else if (cpu_is_omap2420())
> > > -			pbase = OMAP2420_32KSYNCT_BASE + 0x10;
> > > -		else if (cpu_is_omap2430())
> > > -			pbase = OMAP2430_32KSYNCT_BASE + 0x10;
> > > -		else if (cpu_is_omap34xx())
> > > -			pbase = OMAP3430_32KSYNCT_BASE + 0x10;
> > > -		else if (cpu_is_omap44xx())
> > > -			pbase = OMAP4430_32KSYNCT_BASE + 0x10;
> > > -		else
> > > +	u32 pbase;
> > > +	unsigned long size = SZ_4K;
> > > +	void __iomem *base;
> > > +	struct clk *sync_32k_ick;
> > > +
> > > +	if (cpu_is_omap16xx()) {
> > > +		pbase = OMAP16XX_TIMER_32K_SYNCHRONIZED;
> > > +		size = SZ_1K;
> > > +	} else if (cpu_class_is_omap2()) {
> > > +		struct omap_hwmod *oh;
> > > +		const char *oh_name = "counter_32k";
> > > +
> > > +		oh = omap_hwmod_lookup(oh_name);
> > > +		if (!oh || oh->slaves_cnt == 0) {
> > > +			pr_err("Could not lookup %s hwmod\n", oh_name);
> > >  			return -ENODEV;
> > > +		}
> > > +		pbase = oh->slaves[0]->addr->pa_start + 0x10;
> > > +	} else {
> > > +		return -ENODEV;
> > > +	}
> > 
> > How about have separate omap1 and omap2+ init functions that
> > call a common function and passes the pbase as a parameter?
> > 
> > That way we can get rid of the cpu_is_omapxxxx tests here.
> > 
> 
> Tony,
> 
> In the morning, I replied very soon, without much thinking...
> 
> Just now I started working on the patch, I was just reviewing the code, 
> and I felt that, it is unnecessary to split the code between omap1 and 
> omap2+.
> 
> The reason is,
> 
> Currently Only OMAP16xx base-address is hardcoded with
> cpu_is_omap16xx() macro, For all other omap family of devices the
> complete information is fetched from HWDMO api's/data.

In that case, why don't you create the platform_device by hand on
arch/arm/mach-omap1/devices.c and move the omap2+ (which is based on
hwmod) to arch/arm/mach-omap2/devices.c ?

-- 
balbi
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