Re: [PATCH 06/10] ARM: EXYNOS: Add support for mapping PMU base address via DT

[Pankaj Dubey]

On 04/02/2014 08:48 PM, Sylwester Nawrocki wrote:
> On 02/04/14 09:50, Pankaj Dubey wrote:
> > From: Young-Gun Jang <yg1004.jang@xxxxxxxxxxx>
> >
> > Add support for mapping Exynos Power Management Unit (PMU) base address
> > from device tree. Code will use existing samsung pmu binding information.
> > This patch also adds "get_exynos_pmubase" a helper function to return mapped base
> > address to various other files under "mach-exynos".
> >
> > Signed-off-by: Young-Gun Jang <yg1004.jang@xxxxxxxxxxx>
> > Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
> > ---
> >   arch/arm/mach-exynos/common.h |    2 ++
> >   arch/arm/mach-exynos/exynos.c |   44 +++++++++++++++++++++++++++++++++++++++++
> >   2 files changed, 46 insertions(+)
> [...]
> >   #endif /* __ARCH_ARM_MACH_EXYNOS_COMMON_H */
> > diff --git a/arch/arm/mach-exynos/exynos.c b/arch/arm/mach-exynos/exynos.c
> > index a5e1349..a5127fb 100644
> > --- a/arch/arm/mach-exynos/exynos.c
> > +++ b/arch/arm/mach-exynos/exynos.c
> > @@ -35,6 +35,8 @@
> >   #define L2_AUX_VAL 0x7C470001
> >   #define L2_AUX_MASK 0xC200ffff
> >   
> > +static void __iomem *exynos_pmu_base __initdata;
> > +
> >   static struct map_desc exynos4_iodesc[] __initdata = {
> >   	{
> >   		.virtual	= (unsigned long)S3C_VA_SYS,
> > @@ -245,6 +247,47 @@ void __init exynos_init_late(void)
> >   	exynos_pm_init();
> >   }
> >   
> > +static char const *exynos_dt_pmu_match[] __initconst = {
> > +	"samsung,exynos4210-pmu",
> > +	"samsung,exynos4212-pmu",
> > +	"samsung,exynos4412-pmu",
> > +	"samsung,exynos5250-pmu",
> > +	NULL
> > +};
> > +
> > +static int __init exynos_fdt_map_pmu(unsigned long node,
> > +		const char *uname, int depth, void *data)
> > +{
> > +	struct map_desc iodesc;
> > +	__be32 *reg;
> > +	unsigned long len;
> > +
> > +	if (of_flat_dt_match(node, exynos_dt_pmu_match)) {
> > +		phys_addr_t phys_addr;
> > +		reg = of_get_flat_dt_prop(node, "reg", &len);
> > +		if (reg == NULL || len != (sizeof(unsigned long) * 2))
> > +			return 0;
> > +
> > +		phys_addr = be32_to_cpu(reg[0]);
> > +		iodesc.pfn = __phys_to_pfn(phys_addr);
> > +		iodesc.length = be32_to_cpu(reg[1]) - 1;
> > +		iodesc.virtual = (unsigned long)S5P_VA_PMU;
> > +		iodesc.type = MT_DEVICE;
> > +		iotable_init(&iodesc, 1);
> Are you sure...you need this in addition to ioremap() below ?
> Can't you just use the Linux syscon API ?
> There were some patches posted for syscon to make it available in earlier
> system initialization stage: https://lkml.org/lkml/2014/2/19/218
Thanks for review and suggestion.

We need ioremap() in addition to iotable_init to get virtual address,
which will be used by other files also for read/write PMU registers.

Regarding syscon early initialization, since I was not aware of any such
patch earlier I have not used it. But after you suggested I tried it and
modified this implementation to use syscon API and regmap API and it's
working fine.
I will wait for review of other patches in this series and status of above
mentioned syscon API based on that I will update this in next revision.

> > +		exynos_pmu_base = ioremap(phys_addr, be32_to_cpu(reg[1]));
> > +		if (WARN_ON(!exynos_pmu_base))
> > +			return -EFAULT;
> > +	}
> > +
> > +	return 0;
> > +}
> --
> Thanks,
> Sylwester


--
Best Regards,
Pankaj Dubey

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/