diff mbox

[v7,1/2] soc: samsung: add exynos chipid driver support

Message ID 1478347427-28409-2-git-send-email-pankaj.dubey@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Pankaj Dubey Nov. 5, 2016, 12:03 p.m. UTC 
Exynos SoCs have Chipid, for identification of product IDs
and SoC revisions. This patch intends to provide initialization
code for all these functionalities, at the same time it provides some
sysfs entries for accessing these information to user-space.

This driver uses existing binding for exynos-chipid.

CC: Grant Likely <grant.likely@linaro.org>
CC: Rob Herring <robh+dt@kernel.org>
CC: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
---
 drivers/soc/samsung/Kconfig         |   5 ++
 drivers/soc/samsung/Makefile        |   1 +
 drivers/soc/samsung/exynos-chipid.c | 148 ++++++++++++++++++++++++++++++++++++
 3 files changed, 154 insertions(+)
 create mode 100644 drivers/soc/samsung/exynos-chipid.c

Comments

Marek Szyprowski Nov. 7, 2016, 7:35 a.m. UTC | #1 
Hi Pankaj,


On 2016-11-05 13:03, Pankaj Dubey wrote:
> Exynos SoCs have Chipid, for identification of product IDs
> and SoC revisions. This patch intends to provide initialization
> code for all these functionalities, at the same time it provides some
> sysfs entries for accessing these information to user-space.
>
> This driver uses existing binding for exynos-chipid.
>
> CC: Grant Likely <grant.likely@linaro.org>
> CC: Rob Herring <robh+dt@kernel.org>
> CC: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
> ---
>   drivers/soc/samsung/Kconfig         |   5 ++
>   drivers/soc/samsung/Makefile        |   1 +
>   drivers/soc/samsung/exynos-chipid.c | 148 ++++++++++++++++++++++++++++++++++++
>   3 files changed, 154 insertions(+)
>   create mode 100644 drivers/soc/samsung/exynos-chipid.c
>
> diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
> index 2455339..f9ab858 100644
> --- a/drivers/soc/samsung/Kconfig
> +++ b/drivers/soc/samsung/Kconfig
> @@ -14,4 +14,9 @@ config EXYNOS_PM_DOMAINS
>   	bool "Exynos PM domains" if COMPILE_TEST
>   	depends on PM_GENERIC_DOMAINS || COMPILE_TEST
>   
> +config EXYNOS_CHIPID
> +	bool "Exynos Chipid controller driver" if COMPILE_TEST
> +	depends on (ARM && ARCH_EXYNOS) || ((ARM || ARM64) && COMPILE_TEST)
> +	select SOC_BUS
> +
>   endif
> diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
> index 3619f2e..2a8a85e 100644
> --- a/drivers/soc/samsung/Makefile
> +++ b/drivers/soc/samsung/Makefile
> @@ -1,3 +1,4 @@
>   obj-$(CONFIG_EXYNOS_PMU)	+= exynos-pmu.o exynos3250-pmu.o exynos4-pmu.o \
>   					exynos5250-pmu.o exynos5420-pmu.o
>   obj-$(CONFIG_EXYNOS_PM_DOMAINS) += pm_domains.o
> +obj-$(CONFIG_EXYNOS_CHIPID)	+= exynos-chipid.o
> diff --git a/drivers/soc/samsung/exynos-chipid.c b/drivers/soc/samsung/exynos-chipid.c
> new file mode 100644
> index 0000000..9761e54
> --- /dev/null
> +++ b/drivers/soc/samsung/exynos-chipid.c
> @@ -0,0 +1,148 @@
> +/*
> + * Copyright (c) 2016 Samsung Electronics Co., Ltd.
> + *	      http://www.samsung.com/
> + *
> + * EXYNOS - CHIP ID support
> + * Author: Pankaj Dubey <pankaj.dubey@samsung.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/sys_soc.h>
> +
> +#define EXYNOS3250_SOC_ID	0xE3472000
> +#define EXYNOS4210_SOC_ID	0x43210000
> +#define EXYNOS4212_SOC_ID	0x43220000
> +#define EXYNOS4412_SOC_ID	0xE4412000
> +#define EXYNOS4415_SOC_ID	0xE4415000
> +#define EXYNOS5250_SOC_ID	0x43520000
> +#define EXYNOS5260_SOC_ID	0xE5260000
> +#define EXYNOS5410_SOC_ID	0xE5410000
> +#define EXYNOS5420_SOC_ID	0xE5420000
> +#define EXYNOS5440_SOC_ID	0xE5440000
> +#define EXYNOS5800_SOC_ID	0xE5422000
> +
> +#define EXYNOS_SOC_MASK		0xFFFFF000
> +
> +#define EXYNOS4210_REV_0	0x0
> +#define EXYNOS4210_REV_1_0	0x10
> +#define EXYNOS4210_REV_1_1	0x11

EXYNOS4210_REV* defines are not used at all in this driver.

> +
> +#define EXYNOS_SUBREV_MASK	(0xF << 4)
> +#define EXYNOS_MAINREV_MASK	(0xF << 0)
> +#define EXYNOS_REV_MASK		(EXYNOS_SUBREV_MASK | EXYNOS_MAINREV_MASK)
> +
> +
> +static const char * __init product_id_to_soc_id(unsigned int product_id)
> +{
> +	const char *soc_name;
> +	unsigned int soc_id = product_id & EXYNOS_SOC_MASK;
> +
> +	switch (soc_id) {
> +	case EXYNOS3250_SOC_ID:
> +		soc_name = "EXYNOS3250";
> +		break;
> +	case EXYNOS4210_SOC_ID:
> +		soc_name = "EXYNOS4210";
> +		break;
> +	case EXYNOS4212_SOC_ID:
> +		soc_name = "EXYNOS4212";
> +		break;
> +	case EXYNOS4412_SOC_ID:
> +		soc_name = "EXYNOS4412";
> +		break;
> +	case EXYNOS4415_SOC_ID:
> +		soc_name = "EXYNOS4415";
> +		break;
> +	case EXYNOS5250_SOC_ID:
> +		soc_name = "EXYNOS5250";
> +		break;
> +	case EXYNOS5260_SOC_ID:
> +		soc_name = "EXYNOS5260";
> +		break;
> +	case EXYNOS5420_SOC_ID:
> +		soc_name = "EXYNOS5420";
> +		break;
> +	case EXYNOS5440_SOC_ID:
> +		soc_name = "EXYNOS5440";
> +		break;
> +	case EXYNOS5800_SOC_ID:
> +		soc_name = "EXYNOS5800";
> +		break;
> +	default:
> +		soc_name = "UNKNOWN";
> +	}
> +	return soc_name;
> +}

This approach is a bit error prone. You have already missed Exynos5410
and early Exynos 4210 are not detected because of the incorrect SOC MASK.
IMHO you should replace above code and defines with a simple array,
where each ID is present only once, so it will be much easier to add
future SoCs:

static const struct exynos_soc_id {
         const char *name;
         unsigned int id;
         unsigned int mask;
} soc_ids[] = {
         { "EXYNOS3250", 0xE3472000, 0xFFFFF000 },
         { "EXYNOS4210", 0x43200000, 0xFFFE0000 },
         { "EXYNOS4212", 0x43220000, 0xFFFE0000 },
         { "EXYNOS4412", 0xE4412000, 0xFFFE0000 },
         { "EXYNOS4415", 0xE4415000, 0xFFFE0000 },
         { "EXYNOS5250", 0x43520000, 0xFFFFF000 },
         { "EXYNOS5260", 0xE5260000, 0xFFFFF000 },
         { "EXYNOS5410", 0xE5410000, 0xFFFFF000 },
         { "EXYNOS5420", 0xE5420000, 0xFFFFF000 },
         { "EXYNOS5440", 0xE5440000, 0xFFFFF000 },
         { "EXYNOS5800", 0xE5422000, 0xFFFFF000 },
};

static const char * __init product_id_to_soc_id(unsigned int product_id)
{
         int i;

         for (i = 0; i < ARRAY_SIZE(soc_ids); i++)
                 if ((product_id & soc_ids[i].mask) == soc_ids[i].id)
                         return soc_ids[i].name;
         return "UNKNOWN";
}

I'm also not sure about Exynos 4415, which has been scheduled for removal.

> +
> +static const struct of_device_id of_exynos_chipid_ids[] = {
> +	{
> +		.compatible	= "samsung,exynos4210-chipid",
> +	},
> +	{},
> +};
> +
> +/**
> + *  exynos_chipid_early_init: Early chipid initialization
> + */
> +int __init exynos_chipid_early_init(void)
> +{
> +	struct soc_device_attribute *soc_dev_attr;
> +	struct soc_device *soc_dev;
> +	struct device_node *root;
> +	struct device_node *np;
> +	void __iomem *exynos_chipid_base;
> +	const struct of_device_id *match;
> +	u32 product_id;
> +	u32 revision;
> +
> +	np = of_find_matching_node_and_match(NULL,
> +			of_exynos_chipid_ids, &match);
> +	if (!np)
> +		return -ENODEV;
> +
> +	exynos_chipid_base = of_iomap(np, 0);
> +
> +	if (!exynos_chipid_base)
> +		return PTR_ERR(exynos_chipid_base);
> +
> +	product_id  = __raw_readl(exynos_chipid_base);
> +	revision = product_id & EXYNOS_REV_MASK;
> +	iounmap(exynos_chipid_base);
> +
> +	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
> +	if (!soc_dev_attr)
> +		return -ENODEV;
> +
> +	soc_dev_attr->family = "Samsung Exynos";
> +
> +	root = of_find_node_by_path("/");
> +	of_property_read_string(root, "model", &soc_dev_attr->machine);
> +	of_node_put(root);
> +
> +	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%x", revision);
> +	soc_dev_attr->soc_id = product_id_to_soc_id(product_id);
> +
> +
> +	pr_info("Exynos: CPU[%s] CPU_REV[0x%x] Detected\n",
> +			product_id_to_soc_id(product_id), revision);
> +
> +	soc_dev = soc_device_register(soc_dev_attr);
> +	if (IS_ERR(soc_dev)) {
> +		kfree(soc_dev_attr->revision);
> +		kfree_const(soc_dev_attr->soc_id);
> +		kfree(soc_dev_attr);
> +		return PTR_ERR(soc_dev);
> +	}
> +
> +	return 0;
> +}
> +early_initcall(exynos_chipid_early_init);

Best regards
Arnd Bergmann Nov. 7, 2016, 8:32 a.m. UTC | #2 
On Monday, November 7, 2016 8:35:47 AM CET Marek Szyprowski wrote:
> This approach is a bit error prone. You have already missed Exynos5410
> and early Exynos 4210 are not detected because of the incorrect SOC MASK.
> IMHO you should replace above code and defines with a simple array,
> where each ID is present only once, so it will be much easier to add
> future SoCs:
> 
> static const struct exynos_soc_id {
>          const char *name;
>          unsigned int id;
>          unsigned int mask;
> } soc_ids[] = {
>          { "EXYNOS3250", 0xE3472000, 0xFFFFF000 },
>          { "EXYNOS4210", 0x43200000, 0xFFFE0000 },
>          { "EXYNOS4212", 0x43220000, 0xFFFE0000 },
>          { "EXYNOS4412", 0xE4412000, 0xFFFE0000 },
>          { "EXYNOS4415", 0xE4415000, 0xFFFE0000 },
>          { "EXYNOS5250", 0x43520000, 0xFFFFF000 },
>          { "EXYNOS5260", 0xE5260000, 0xFFFFF000 },
>          { "EXYNOS5410", 0xE5410000, 0xFFFFF000 },
>          { "EXYNOS5420", 0xE5420000, 0xFFFFF000 },
>          { "EXYNOS5440", 0xE5440000, 0xFFFFF000 },
>          { "EXYNOS5800", 0xE5422000, 0xFFFFF000 },
> };

Good idea

> 
> I'm also not sure about Exynos 4415, which has been scheduled for removal.

I'd vote for leaving it in the driver, and possibly adding other
models even if we don't support them in the other drivers, if
only for documentation purposes.

	Arnd
Arnd Bergmann Nov. 7, 2016, 8:35 a.m. UTC | #3 
On Saturday, November 5, 2016 5:33:46 PM CET Pankaj Dubey wrote:
> Exynos SoCs have Chipid, for identification of product IDs
> and SoC revisions. This patch intends to provide initialization
> code for all these functionalities, at the same time it provides some
> sysfs entries for accessing these information to user-space.
> 
> This driver uses existing binding for exynos-chipid.
> 
> CC: Grant Likely <grant.likely@linaro.org>
> CC: Rob Herring <robh+dt@kernel.org>
> CC: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
> ---
>  drivers/soc/samsung/Kconfig         |   5 ++
>  drivers/soc/samsung/Makefile        |   1 +
>  drivers/soc/samsung/exynos-chipid.c | 148 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 154 insertions(+)
>  create mode 100644 drivers/soc/samsung/exynos-chipid.c
> 
> diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
> index 2455339..f9ab858 100644
> --- a/drivers/soc/samsung/Kconfig
> +++ b/drivers/soc/samsung/Kconfig
> @@ -14,4 +14,9 @@ config EXYNOS_PM_DOMAINS
>  	bool "Exynos PM domains" if COMPILE_TEST
>  	depends on PM_GENERIC_DOMAINS || COMPILE_TEST
>  
> +config EXYNOS_CHIPID
> +	bool "Exynos Chipid controller driver" if COMPILE_TEST
> +	depends on (ARM && ARCH_EXYNOS) || ((ARM || ARM64) && COMPILE_TEST)
> +	select SOC_BUS
> +

Please add a help text.

Why is this not enabled for ARM64 EXYNOS?

> +	exynos_chipid_base = of_iomap(np, 0);
> +
> +	if (!exynos_chipid_base)
> +		return PTR_ERR(exynos_chipid_base);
> +
> +	product_id  = __raw_readl(exynos_chipid_base);
> +	revision = product_id & EXYNOS_REV_MASK;
> +	iounmap(exynos_chipid_base);

Never use __raw_readl/__raw_writel in device drivers, they are not endian
safe, and we just removed all instances for Exynos a while back.

> +	return 0;
> +}
> +early_initcall(exynos_chipid_early_init);
> 

Why is this early? Please add a code comment if it's really needed to be
an early_initcall, otherwise make it a device_initcall.

	Arnd
Pankaj Dubey Nov. 8, 2016, 3:26 a.m. UTC | #4 
Hi Marek,

On Monday 07 November 2016 01:05 PM, Marek Szyprowski wrote:
> Hi Pankaj,
> 
> 
> On 2016-11-05 13:03, Pankaj Dubey wrote:
>> Exynos SoCs have Chipid, for identification of product IDs
>> and SoC revisions. This patch intends to provide initialization
>> code for all these functionalities, at the same time it provides some
>> sysfs entries for accessing these information to user-space.
>>
>> This driver uses existing binding for exynos-chipid.
>>
>> CC: Grant Likely <grant.likely@linaro.org>
>> CC: Rob Herring <robh+dt@kernel.org>
>> CC: Linus Walleij <linus.walleij@linaro.org>
>> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
>> ---
>>   drivers/soc/samsung/Kconfig         |   5 ++
>>   drivers/soc/samsung/Makefile        |   1 +
>>   drivers/soc/samsung/exynos-chipid.c | 148
>> ++++++++++++++++++++++++++++++++++++
>>   3 files changed, 154 insertions(+)
>>   create mode 100644 drivers/soc/samsung/exynos-chipid.c
>>
>> diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
>> index 2455339..f9ab858 100644
>> --- a/drivers/soc/samsung/Kconfig
>> +++ b/drivers/soc/samsung/Kconfig
>> @@ -14,4 +14,9 @@ config EXYNOS_PM_DOMAINS
>>       bool "Exynos PM domains" if COMPILE_TEST
>>       depends on PM_GENERIC_DOMAINS || COMPILE_TEST
>>   +config EXYNOS_CHIPID
>> +    bool "Exynos Chipid controller driver" if COMPILE_TEST
>> +    depends on (ARM && ARCH_EXYNOS) || ((ARM || ARM64) && COMPILE_TEST)
>> +    select SOC_BUS
>> +
>>   endif
>> diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
>> index 3619f2e..2a8a85e 100644
>> --- a/drivers/soc/samsung/Makefile
>> +++ b/drivers/soc/samsung/Makefile
>> @@ -1,3 +1,4 @@
>>   obj-$(CONFIG_EXYNOS_PMU)    += exynos-pmu.o exynos3250-pmu.o
>> exynos4-pmu.o \
>>                       exynos5250-pmu.o exynos5420-pmu.o
>>   obj-$(CONFIG_EXYNOS_PM_DOMAINS) += pm_domains.o
>> +obj-$(CONFIG_EXYNOS_CHIPID)    += exynos-chipid.o
>> diff --git a/drivers/soc/samsung/exynos-chipid.c
>> b/drivers/soc/samsung/exynos-chipid.c
>> new file mode 100644
>> index 0000000..9761e54
>> --- /dev/null
>> +++ b/drivers/soc/samsung/exynos-chipid.c
>> @@ -0,0 +1,148 @@
>> +/*
>> + * Copyright (c) 2016 Samsung Electronics Co., Ltd.
>> + *          http://www.samsung.com/
>> + *
>> + * EXYNOS - CHIP ID support
>> + * Author: Pankaj Dubey <pankaj.dubey@samsung.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/io.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/slab.h>
>> +#include <linux/sys_soc.h>
>> +
>> +#define EXYNOS3250_SOC_ID    0xE3472000
>> +#define EXYNOS4210_SOC_ID    0x43210000
>> +#define EXYNOS4212_SOC_ID    0x43220000
>> +#define EXYNOS4412_SOC_ID    0xE4412000
>> +#define EXYNOS4415_SOC_ID    0xE4415000
>> +#define EXYNOS5250_SOC_ID    0x43520000
>> +#define EXYNOS5260_SOC_ID    0xE5260000
>> +#define EXYNOS5410_SOC_ID    0xE5410000
>> +#define EXYNOS5420_SOC_ID    0xE5420000
>> +#define EXYNOS5440_SOC_ID    0xE5440000
>> +#define EXYNOS5800_SOC_ID    0xE5422000
>> +
>> +#define EXYNOS_SOC_MASK        0xFFFFF000
>> +
>> +#define EXYNOS4210_REV_0    0x0
>> +#define EXYNOS4210_REV_1_0    0x10
>> +#define EXYNOS4210_REV_1_1    0x11
> 
> EXYNOS4210_REV* defines are not used at all in this driver.
> 
>> +
>> +#define EXYNOS_SUBREV_MASK    (0xF << 4)
>> +#define EXYNOS_MAINREV_MASK    (0xF << 0)
>> +#define EXYNOS_REV_MASK        (EXYNOS_SUBREV_MASK |
>> EXYNOS_MAINREV_MASK)
>> +
>> +
>> +static const char * __init product_id_to_soc_id(unsigned int product_id)
>> +{
>> +    const char *soc_name;
>> +    unsigned int soc_id = product_id & EXYNOS_SOC_MASK;
>> +
>> +    switch (soc_id) {
>> +    case EXYNOS3250_SOC_ID:
>> +        soc_name = "EXYNOS3250";
>> +        break;
>> +    case EXYNOS4210_SOC_ID:
>> +        soc_name = "EXYNOS4210";
>> +        break;
>> +    case EXYNOS4212_SOC_ID:
>> +        soc_name = "EXYNOS4212";
>> +        break;
>> +    case EXYNOS4412_SOC_ID:
>> +        soc_name = "EXYNOS4412";
>> +        break;
>> +    case EXYNOS4415_SOC_ID:
>> +        soc_name = "EXYNOS4415";
>> +        break;
>> +    case EXYNOS5250_SOC_ID:
>> +        soc_name = "EXYNOS5250";
>> +        break;
>> +    case EXYNOS5260_SOC_ID:
>> +        soc_name = "EXYNOS5260";
>> +        break;
>> +    case EXYNOS5420_SOC_ID:
>> +        soc_name = "EXYNOS5420";
>> +        break;
>> +    case EXYNOS5440_SOC_ID:
>> +        soc_name = "EXYNOS5440";
>> +        break;
>> +    case EXYNOS5800_SOC_ID:
>> +        soc_name = "EXYNOS5800";
>> +        break;
>> +    default:
>> +        soc_name = "UNKNOWN";
>> +    }
>> +    return soc_name;
>> +}
> 
> This approach is a bit error prone. You have already missed Exynos5410
> and early Exynos 4210 are not detected because of the incorrect SOC MASK.

Yes I missed to update Exynos4210 SoC Mask, thanks for pointing out.

> IMHO you should replace above code and defines with a simple array,
> where each ID is present only once, so it will be much easier to add
> future SoCs:
> 

Well, this looks good to me as well. I will incorporate these changes in
v2 as suggested by you and reuse your code, along with your
Signed-off-by for this part :)

> static const struct exynos_soc_id {
>         const char *name;
>         unsigned int id;
>         unsigned int mask;
> } soc_ids[] = {
>         { "EXYNOS3250", 0xE3472000, 0xFFFFF000 },
>         { "EXYNOS4210", 0x43200000, 0xFFFE0000 },
>         { "EXYNOS4212", 0x43220000, 0xFFFE0000 },
>         { "EXYNOS4412", 0xE4412000, 0xFFFE0000 },
>         { "EXYNOS4415", 0xE4415000, 0xFFFE0000 },
>         { "EXYNOS5250", 0x43520000, 0xFFFFF000 },
>         { "EXYNOS5260", 0xE5260000, 0xFFFFF000 },
>         { "EXYNOS5410", 0xE5410000, 0xFFFFF000 },
>         { "EXYNOS5420", 0xE5420000, 0xFFFFF000 },
>         { "EXYNOS5440", 0xE5440000, 0xFFFFF000 },
>         { "EXYNOS5800", 0xE5422000, 0xFFFFF000 },
> };
> 
> static const char * __init product_id_to_soc_id(unsigned int product_id)
> {
>         int i;
> 
>         for (i = 0; i < ARRAY_SIZE(soc_ids); i++)
>                 if ((product_id & soc_ids[i].mask) == soc_ids[i].id)
>                         return soc_ids[i].name;
>         return "UNKNOWN";
> }
> 
> I'm also not sure about Exynos 4415, which has been scheduled for removal.
> 

As suggested by Arnd, I will keep entry for Exynos 4415 in the driver.


Thanks,
Pankaj Dubey
diff mbox

Patch

diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
index 2455339..f9ab858 100644
--- a/drivers/soc/samsung/Kconfig
+++ b/drivers/soc/samsung/Kconfig
@@ -14,4 +14,9 @@  config EXYNOS_PM_DOMAINS
 	bool "Exynos PM domains" if COMPILE_TEST
 	depends on PM_GENERIC_DOMAINS || COMPILE_TEST
 
+config EXYNOS_CHIPID
+	bool "Exynos Chipid controller driver" if COMPILE_TEST
+	depends on (ARM && ARCH_EXYNOS) || ((ARM || ARM64) && COMPILE_TEST)
+	select SOC_BUS
+
 endif
diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
index 3619f2e..2a8a85e 100644
--- a/drivers/soc/samsung/Makefile
+++ b/drivers/soc/samsung/Makefile
@@ -1,3 +1,4 @@ 
 obj-$(CONFIG_EXYNOS_PMU)	+= exynos-pmu.o exynos3250-pmu.o exynos4-pmu.o \
 					exynos5250-pmu.o exynos5420-pmu.o
 obj-$(CONFIG_EXYNOS_PM_DOMAINS) += pm_domains.o
+obj-$(CONFIG_EXYNOS_CHIPID)	+= exynos-chipid.o
diff --git a/drivers/soc/samsung/exynos-chipid.c b/drivers/soc/samsung/exynos-chipid.c
new file mode 100644
index 0000000..9761e54
--- /dev/null
+++ b/drivers/soc/samsung/exynos-chipid.c
@@ -0,0 +1,148 @@ 
+/*
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ *	      http://www.samsung.com/
+ *
+ * EXYNOS - CHIP ID support
+ * Author: Pankaj Dubey <pankaj.dubey@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+#define EXYNOS3250_SOC_ID	0xE3472000
+#define EXYNOS4210_SOC_ID	0x43210000
+#define EXYNOS4212_SOC_ID	0x43220000
+#define EXYNOS4412_SOC_ID	0xE4412000
+#define EXYNOS4415_SOC_ID	0xE4415000
+#define EXYNOS5250_SOC_ID	0x43520000
+#define EXYNOS5260_SOC_ID	0xE5260000
+#define EXYNOS5410_SOC_ID	0xE5410000
+#define EXYNOS5420_SOC_ID	0xE5420000
+#define EXYNOS5440_SOC_ID	0xE5440000
+#define EXYNOS5800_SOC_ID	0xE5422000
+
+#define EXYNOS_SOC_MASK		0xFFFFF000
+
+#define EXYNOS4210_REV_0	0x0
+#define EXYNOS4210_REV_1_0	0x10
+#define EXYNOS4210_REV_1_1	0x11
+
+#define EXYNOS_SUBREV_MASK	(0xF << 4)
+#define EXYNOS_MAINREV_MASK	(0xF << 0)
+#define EXYNOS_REV_MASK		(EXYNOS_SUBREV_MASK | EXYNOS_MAINREV_MASK)
+
+
+static const char * __init product_id_to_soc_id(unsigned int product_id)
+{
+	const char *soc_name;
+	unsigned int soc_id = product_id & EXYNOS_SOC_MASK;
+
+	switch (soc_id) {
+	case EXYNOS3250_SOC_ID:
+		soc_name = "EXYNOS3250";
+		break;
+	case EXYNOS4210_SOC_ID:
+		soc_name = "EXYNOS4210";
+		break;
+	case EXYNOS4212_SOC_ID:
+		soc_name = "EXYNOS4212";
+		break;
+	case EXYNOS4412_SOC_ID:
+		soc_name = "EXYNOS4412";
+		break;
+	case EXYNOS4415_SOC_ID:
+		soc_name = "EXYNOS4415";
+		break;
+	case EXYNOS5250_SOC_ID:
+		soc_name = "EXYNOS5250";
+		break;
+	case EXYNOS5260_SOC_ID:
+		soc_name = "EXYNOS5260";
+		break;
+	case EXYNOS5420_SOC_ID:
+		soc_name = "EXYNOS5420";
+		break;
+	case EXYNOS5440_SOC_ID:
+		soc_name = "EXYNOS5440";
+		break;
+	case EXYNOS5800_SOC_ID:
+		soc_name = "EXYNOS5800";
+		break;
+	default:
+		soc_name = "UNKNOWN";
+	}
+	return soc_name;
+}
+
+static const struct of_device_id of_exynos_chipid_ids[] = {
+	{
+		.compatible	= "samsung,exynos4210-chipid",
+	},
+	{},
+};
+
+/**
+ *  exynos_chipid_early_init: Early chipid initialization
+ */
+int __init exynos_chipid_early_init(void)
+{
+	struct soc_device_attribute *soc_dev_attr;
+	struct soc_device *soc_dev;
+	struct device_node *root;
+	struct device_node *np;
+	void __iomem *exynos_chipid_base;
+	const struct of_device_id *match;
+	u32 product_id;
+	u32 revision;
+
+	np = of_find_matching_node_and_match(NULL,
+			of_exynos_chipid_ids, &match);
+	if (!np)
+		return -ENODEV;
+
+	exynos_chipid_base = of_iomap(np, 0);
+
+	if (!exynos_chipid_base)
+		return PTR_ERR(exynos_chipid_base);
+
+	product_id  = __raw_readl(exynos_chipid_base);
+	revision = product_id & EXYNOS_REV_MASK;
+	iounmap(exynos_chipid_base);
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		return -ENODEV;
+
+	soc_dev_attr->family = "Samsung Exynos";
+
+	root = of_find_node_by_path("/");
+	of_property_read_string(root, "model", &soc_dev_attr->machine);
+	of_node_put(root);
+
+	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%x", revision);
+	soc_dev_attr->soc_id = product_id_to_soc_id(product_id);
+
+
+	pr_info("Exynos: CPU[%s] CPU_REV[0x%x] Detected\n",
+			product_id_to_soc_id(product_id), revision);
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev)) {
+		kfree(soc_dev_attr->revision);
+		kfree_const(soc_dev_attr->soc_id);
+		kfree(soc_dev_attr);
+		return PTR_ERR(soc_dev);
+	}
+
+	return 0;
+}
+early_initcall(exynos_chipid_early_init);