diff mbox

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

Message ID 1396425058-4012-7-git-send-email-pankaj.dubey@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Pankaj Dubey April 2, 2014, 7:50 a.m. UTC
From: Young-Gun Jang <yg1004.jang@samsung.com>

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@samsung.com>
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
---
 arch/arm/mach-exynos/common.h |    2 ++
 arch/arm/mach-exynos/exynos.c |   44 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+)

Comments

On 02/04/14 09:50, Pankaj Dubey wrote:
> From: Young-Gun Jang <yg1004.jang@samsung.com>
> 
> 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@samsung.com>
> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
> ---
>  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

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

--
Thanks,
Sylwester
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Michal Simek April 2, 2014, 12:15 p.m. UTC | #2
On 04/02/2014 01:48 PM, Sylwester Nawrocki wrote:
> On 02/04/14 09:50, Pankaj Dubey wrote:
>> From: Young-Gun Jang <yg1004.jang@samsung.com>
>>
>> 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@samsung.com>
>> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
>> ---
>>  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

I haven't finished this yet. I have to look at it again.

Thanks,
Michal
On 02/04/14 14:15, Michal Simek wrote:
>> There were some patches posted for syscon to make it available in earlier
>> system initialization stage: https://lkml.org/lkml/2014/2/19/218
>
> I haven't finished this yet. I have to look at it again.

Thanks for the information, I assume this would be also useful
on the Exynos SoC series, so I'd be happy to see continuation
of those works.

--
Thanks,
Sylwester
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Pankaj Dubey April 5, 2014, 10:53 a.m. UTC | #4
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@samsung.com>
>>
>> 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@samsung.com>
>> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
>> ---
>>   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
>
Pankaj Dubey April 5, 2014, 10:58 a.m. UTC | #5
On 04/03/2014 06:07 PM, Sylwester Nawrocki wrote:
> On 02/04/14 14:15, Michal Simek wrote:
>>> There were some patches posted for syscon to make it available in earlier
>>> system initialization stage: https://lkml.org/lkml/2014/2/19/218
>> I haven't finished this yet. I have to look at it again.
> Thanks for the information, I assume this would be also useful
> on the Exynos SoC series, so I'd be happy to see continuation
> of those works.

It is useful for Exynos SoC series and I have modified this patch series to use 
early syscon
initialization API and I can see it's working.
I have some observation for early initialization of syscon API which I will
update in corresponding message thread.

> --
> Thanks,
> Sylwester
>
Michal Simek April 7, 2014, 6:02 a.m. UTC | #6
On 04/05/2014 12:58 PM, Pankaj Dubey wrote:
> On 04/03/2014 06:07 PM, Sylwester Nawrocki wrote:
>> On 02/04/14 14:15, Michal Simek wrote:
>>>> There were some patches posted for syscon to make it available in earlier
>>>> system initialization stage: https://lkml.org/lkml/2014/2/19/218
>>> I haven't finished this yet. I have to look at it again.
>> Thanks for the information, I assume this would be also useful
>> on the Exynos SoC series, so I'd be happy to see continuation
>> of those works.
> 
> It is useful for Exynos SoC series and I have modified this patch series to use early syscon
> initialization API and I can see it's working.
> I have some observation for early initialization of syscon API which I will
> update in corresponding message thread.

Great. Please update that thread we should finish this implementation
to be useful for everybody.

Thanks,
Michal
Vikas Sajjan April 23, 2014, 1:02 p.m. UTC | #7
Hi,

On Wed, Apr 2, 2014 at 1:20 PM, Pankaj Dubey <pankaj.dubey@samsung.com> wrote:
> From: Young-Gun Jang <yg1004.jang@samsung.com>
>
> 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@samsung.com>
> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
> ---
>  arch/arm/mach-exynos/common.h |    2 ++
>  arch/arm/mach-exynos/exynos.c |   44 +++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 46 insertions(+)
>
> diff --git a/arch/arm/mach-exynos/common.h b/arch/arm/mach-exynos/common.h
> index ff28334..9a55cf6 100644
> --- a/arch/arm/mach-exynos/common.h
> +++ b/arch/arm/mach-exynos/common.h
> @@ -61,4 +61,6 @@ struct exynos_pmu_conf {
>
>  extern void exynos_sys_powerdown_conf(enum sys_powerdown mode);
>
> +extern void __iomem *get_exynos_pmubase(void);
> +
>  #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;

Are you sure you want to keep exynos_pmu_base in .init section.
I am seeing a crash in platform_do_lowpower()
I think you should remove __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);
> +
> +               exynos_pmu_base = ioremap(phys_addr, be32_to_cpu(reg[1]));
> +               if (WARN_ON(!exynos_pmu_base))
> +                       return -EFAULT;
> +       }
> +
> +       return 0;
> +}
> +
> +inline void __iomem *get_exynos_pmubase()
> +{
> +       return exynos_pmu_base;
> +}
> +
>  static int __init exynos_fdt_map_chipid(unsigned long node, const char *uname,
>                                         int depth, void *data)
>  {
> @@ -301,6 +344,7 @@ void __init exynos_init_io(void)
>         debug_ll_io_init();
>
>         of_scan_flat_dt(exynos_fdt_map_chipid, NULL);
> +       of_scan_flat_dt(exynos_fdt_map_pmu, NULL);
>
>         /* detect cpu id and rev. */
>         s5p_init_cpu(S5P_VA_CHIPID);
> --
> 1.7.10.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Pankaj Dubey April 24, 2014, 2:45 a.m. UTC | #8
Hi Vikas,

On 04/23/2014 10:02 PM, Vikas Sajjan wrote:
> Hi,
>
> On Wed, Apr 2, 2014 at 1:20 PM, Pankaj Dubey <pankaj.dubey@samsung.com> wrote:
>> From: Young-Gun Jang <yg1004.jang@samsung.com>
>>
>> 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@samsung.com>
>> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
>> ---
>>   arch/arm/mach-exynos/common.h |    2 ++
>>   arch/arm/mach-exynos/exynos.c |   44 +++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 46 insertions(+)
>>
>> diff --git a/arch/arm/mach-exynos/common.h b/arch/arm/mach-exynos/common.h
>> index ff28334..9a55cf6 100644
>> --- a/arch/arm/mach-exynos/common.h
>> +++ b/arch/arm/mach-exynos/common.h
>> @@ -61,4 +61,6 @@ struct exynos_pmu_conf {
>>
>>   extern void exynos_sys_powerdown_conf(enum sys_powerdown mode);
>>
>> +extern void __iomem *get_exynos_pmubase(void);
>> +
>>   #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;
> Are you sure you want to keep exynos_pmu_base in .init section.
> I am seeing a crash in platform_do_lowpower()
> I think you should remove __initdata.

Thanks for review and testing.
You are right we do not need __initdata here.
I will take care of this in V2.

>> +
>>   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);
>> +
>> +               exynos_pmu_base = ioremap(phys_addr, be32_to_cpu(reg[1]));
>> +               if (WARN_ON(!exynos_pmu_base))
>> +                       return -EFAULT;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +inline void __iomem *get_exynos_pmubase()
>> +{
>> +       return exynos_pmu_base;
>> +}
>> +
>>   static int __init exynos_fdt_map_chipid(unsigned long node, const char *uname,
>>                                          int depth, void *data)
>>   {
>> @@ -301,6 +344,7 @@ void __init exynos_init_io(void)
>>          debug_ll_io_init();
>>
>>          of_scan_flat_dt(exynos_fdt_map_chipid, NULL);
>> +       of_scan_flat_dt(exynos_fdt_map_pmu, NULL);
>>
>>          /* detect cpu id and rev. */
>>          s5p_init_cpu(S5P_VA_CHIPID);
>> --
>> 1.7.10.4
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at  http://www.tux.org/lkml/
diff mbox

Patch

diff --git a/arch/arm/mach-exynos/common.h b/arch/arm/mach-exynos/common.h
index ff28334..9a55cf6 100644
--- a/arch/arm/mach-exynos/common.h
+++ b/arch/arm/mach-exynos/common.h
@@ -61,4 +61,6 @@  struct exynos_pmu_conf {
 
 extern void exynos_sys_powerdown_conf(enum sys_powerdown mode);
 
+extern void __iomem *get_exynos_pmubase(void);
+
 #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);
+
+		exynos_pmu_base = ioremap(phys_addr, be32_to_cpu(reg[1]));
+		if (WARN_ON(!exynos_pmu_base))
+			return -EFAULT;
+	}
+
+	return 0;
+}
+
+inline void __iomem *get_exynos_pmubase()
+{
+	return exynos_pmu_base;
+}
+
 static int __init exynos_fdt_map_chipid(unsigned long node, const char *uname,
 					int depth, void *data)
 {
@@ -301,6 +344,7 @@  void __init exynos_init_io(void)
 	debug_ll_io_init();
 
 	of_scan_flat_dt(exynos_fdt_map_chipid, NULL);
+	of_scan_flat_dt(exynos_fdt_map_pmu, NULL);
 
 	/* detect cpu id and rev. */
 	s5p_init_cpu(S5P_VA_CHIPID);