diff mbox

[RFC,v1,2/2] drivers: soc: Add support for Hisilicon Djtag driver

Message ID 1469177332-72156-3-git-send-email-tanxiaojun@huawei.com (mailing list archive)
State New, archived
Headers show

Commit Message

Tan Xiaojun July 22, 2016, 8:48 a.m. UTC
The Hisilicon Djtag is an independent module which connects with some modules
in the SoC by Debug Bus. This module can be configured to access the registers
of connecting modules (like L3 cache) during real time debugging.

This patch add the driver of Hisilicon Djtag.

Signed-off-by: Tan Xiaojun <tanxiaojun@huawei.com>
---
 drivers/soc/Kconfig                 |    1 +
 drivers/soc/Makefile                |    1 +
 drivers/soc/hisilicon/Kconfig       |   12 ++
 drivers/soc/hisilicon/Makefile      |    1 +
 drivers/soc/hisilicon/djtag.c       |  373 +++++++++++++++++++++++++++++++++++
 include/linux/soc/hisilicon/djtag.h |   18 ++
 6 files changed, 406 insertions(+)
 create mode 100644 drivers/soc/hisilicon/Kconfig
 create mode 100644 drivers/soc/hisilicon/Makefile
 create mode 100644 drivers/soc/hisilicon/djtag.c
 create mode 100644 include/linux/soc/hisilicon/djtag.h

Comments

Paul Gortmaker July 22, 2016, 8:37 p.m. UTC | #1
On Fri, Jul 22, 2016 at 4:48 AM, Tan Xiaojun <tanxiaojun@huawei.com> wrote:
> The Hisilicon Djtag is an independent module which connects with some modules
> in the SoC by Debug Bus. This module can be configured to access the registers
> of connecting modules (like L3 cache) during real time debugging.
>
> This patch add the driver of Hisilicon Djtag.
>
> Signed-off-by: Tan Xiaojun <tanxiaojun@huawei.com>
> ---
>  drivers/soc/Kconfig                 |    1 +
>  drivers/soc/Makefile                |    1 +
>  drivers/soc/hisilicon/Kconfig       |   12 ++
>  drivers/soc/hisilicon/Makefile      |    1 +
>  drivers/soc/hisilicon/djtag.c       |  373 +++++++++++++++++++++++++++++++++++
>  include/linux/soc/hisilicon/djtag.h |   18 ++
>  6 files changed, 406 insertions(+)
>  create mode 100644 drivers/soc/hisilicon/Kconfig
>  create mode 100644 drivers/soc/hisilicon/Makefile
>  create mode 100644 drivers/soc/hisilicon/djtag.c
>  create mode 100644 include/linux/soc/hisilicon/djtag.h
>
> diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
> index cb58ef0..f5982ec 100644
> --- a/drivers/soc/Kconfig
> +++ b/drivers/soc/Kconfig
> @@ -3,6 +3,7 @@ menu "SOC (System On Chip) specific Drivers"
>  source "drivers/soc/bcm/Kconfig"
>  source "drivers/soc/brcmstb/Kconfig"
>  source "drivers/soc/fsl/qe/Kconfig"
> +source "drivers/soc/hisilicon/Kconfig"
>  source "drivers/soc/mediatek/Kconfig"
>  source "drivers/soc/qcom/Kconfig"
>  source "drivers/soc/rockchip/Kconfig"
> diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
> index 380230f..373449d 100644
> --- a/drivers/soc/Makefile
> +++ b/drivers/soc/Makefile
> @@ -7,6 +7,7 @@ obj-$(CONFIG_SOC_BRCMSTB)       += brcmstb/
>  obj-$(CONFIG_ARCH_DOVE)                += dove/
>  obj-$(CONFIG_MACH_DOVE)                += dove/
>  obj-y                          += fsl/
> +obj-$(CONFIG_ARCH_HISI)                += hisilicon/
>  obj-$(CONFIG_ARCH_MEDIATEK)    += mediatek/
>  obj-$(CONFIG_ARCH_QCOM)                += qcom/
>  obj-$(CONFIG_ARCH_RENESAS)     += renesas/
> diff --git a/drivers/soc/hisilicon/Kconfig b/drivers/soc/hisilicon/Kconfig
> new file mode 100644
> index 0000000..3644aab
> --- /dev/null
> +++ b/drivers/soc/hisilicon/Kconfig
> @@ -0,0 +1,12 @@
> +#
> +# Hisilicon SoC drivers
> +#
> +config HISI_DJTAG
> +       bool "Hisilicon Djtag Support"
> +       depends on ARCH_HISI || COMPILE_TEST
> +       help
> +         Say y here to enable the Hisilicon Djtag support. It is an
> +         independent module which connects with some modules in the
> +         SoC by Debug Bus. This module can be configured to access
> +         the registers of connecting modules during real time
> +         debugging.

Choice of word "module" here is probably confusing since it normally
means a ".ko" when used in Kconfig help.   Maybe instead, use:

...independent component...

...connects with some other components....

This driver can be configured to ....

--hopefully  the above will clarify against such confusion.   Also....

> diff --git a/drivers/soc/hisilicon/Makefile b/drivers/soc/hisilicon/Makefile
> new file mode 100644
> index 0000000..35a7b4b
> --- /dev/null
> +++ b/drivers/soc/hisilicon/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_HISI_DJTAG)       += djtag.o
> diff --git a/drivers/soc/hisilicon/djtag.c b/drivers/soc/hisilicon/djtag.c
> new file mode 100644
> index 0000000..41e11ed
> --- /dev/null
> +++ b/drivers/soc/hisilicon/djtag.c
> @@ -0,0 +1,373 @@
> +/*
> + * Driver for Hisilicon Djtag r/w via System Controller.
> + *
> + * Copyright (C) 2016 Hisilicon Ltd.
> + *
> + * 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/bitops.h>
> +#include <linux/init.h>
> +#include <linux/list.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>

...since you add the driver as a bool Kconfig item, you should
avoid using module.h and any MODULE_<xyz> tags.  Use the
builtin registration functions instead.

Alternatively, if there is a genuine use case for this to really be
a dynamically loadable .ko module, then convert it to tristate.

Thanks,
Paul.
--
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +
> +#include <asm-generic/delay.h>
> +#include <linux/soc/hisilicon/djtag.h>
Tan Xiaojun July 25, 2016, 1:54 a.m. UTC | #2
On 2016/7/23 4:37, Paul Gortmaker wrote:
> On Fri, Jul 22, 2016 at 4:48 AM, Tan Xiaojun <tanxiaojun@huawei.com> wrote:
>> The Hisilicon Djtag is an independent module which connects with some modules
>> in the SoC by Debug Bus. This module can be configured to access the registers
>> of connecting modules (like L3 cache) during real time debugging.
>>
>> This patch add the driver of Hisilicon Djtag.
>>
>> Signed-off-by: Tan Xiaojun <tanxiaojun@huawei.com>
>> ---
>>  drivers/soc/Kconfig                 |    1 +
>>  drivers/soc/Makefile                |    1 +
>>  drivers/soc/hisilicon/Kconfig       |   12 ++
>>  drivers/soc/hisilicon/Makefile      |    1 +
>>  drivers/soc/hisilicon/djtag.c       |  373 +++++++++++++++++++++++++++++++++++
>>  include/linux/soc/hisilicon/djtag.h |   18 ++
>>  6 files changed, 406 insertions(+)
>>  create mode 100644 drivers/soc/hisilicon/Kconfig
>>  create mode 100644 drivers/soc/hisilicon/Makefile
>>  create mode 100644 drivers/soc/hisilicon/djtag.c
>>  create mode 100644 include/linux/soc/hisilicon/djtag.h
>>
>> diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
>> index cb58ef0..f5982ec 100644
>> --- a/drivers/soc/Kconfig
>> +++ b/drivers/soc/Kconfig
>> @@ -3,6 +3,7 @@ menu "SOC (System On Chip) specific Drivers"
>>  source "drivers/soc/bcm/Kconfig"
>>  source "drivers/soc/brcmstb/Kconfig"
>>  source "drivers/soc/fsl/qe/Kconfig"
>> +source "drivers/soc/hisilicon/Kconfig"
>>  source "drivers/soc/mediatek/Kconfig"
>>  source "drivers/soc/qcom/Kconfig"
>>  source "drivers/soc/rockchip/Kconfig"
>> diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
>> index 380230f..373449d 100644
>> --- a/drivers/soc/Makefile
>> +++ b/drivers/soc/Makefile
>> @@ -7,6 +7,7 @@ obj-$(CONFIG_SOC_BRCMSTB)       += brcmstb/
>>  obj-$(CONFIG_ARCH_DOVE)                += dove/
>>  obj-$(CONFIG_MACH_DOVE)                += dove/
>>  obj-y                          += fsl/
>> +obj-$(CONFIG_ARCH_HISI)                += hisilicon/
>>  obj-$(CONFIG_ARCH_MEDIATEK)    += mediatek/
>>  obj-$(CONFIG_ARCH_QCOM)                += qcom/
>>  obj-$(CONFIG_ARCH_RENESAS)     += renesas/
>> diff --git a/drivers/soc/hisilicon/Kconfig b/drivers/soc/hisilicon/Kconfig
>> new file mode 100644
>> index 0000000..3644aab
>> --- /dev/null
>> +++ b/drivers/soc/hisilicon/Kconfig
>> @@ -0,0 +1,12 @@
>> +#
>> +# Hisilicon SoC drivers
>> +#
>> +config HISI_DJTAG
>> +       bool "Hisilicon Djtag Support"
>> +       depends on ARCH_HISI || COMPILE_TEST
>> +       help
>> +         Say y here to enable the Hisilicon Djtag support. It is an
>> +         independent module which connects with some modules in the
>> +         SoC by Debug Bus. This module can be configured to access
>> +         the registers of connecting modules during real time
>> +         debugging.
> 
> Choice of word "module" here is probably confusing since it normally
> means a ".ko" when used in Kconfig help.   Maybe instead, use:
> 
> ...independent component...
> 
> ...connects with some other components....
> 
> This driver can be configured to ....
> 
> --hopefully  the above will clarify against such confusion.   Also....
> 

Yes, your suggestion is nice.

>> diff --git a/drivers/soc/hisilicon/Makefile b/drivers/soc/hisilicon/Makefile
>> new file mode 100644
>> index 0000000..35a7b4b
>> --- /dev/null
>> +++ b/drivers/soc/hisilicon/Makefile
>> @@ -0,0 +1 @@
>> +obj-$(CONFIG_HISI_DJTAG)       += djtag.o
>> diff --git a/drivers/soc/hisilicon/djtag.c b/drivers/soc/hisilicon/djtag.c
>> new file mode 100644
>> index 0000000..41e11ed
>> --- /dev/null
>> +++ b/drivers/soc/hisilicon/djtag.c
>> @@ -0,0 +1,373 @@
>> +/*
>> + * Driver for Hisilicon Djtag r/w via System Controller.
>> + *
>> + * Copyright (C) 2016 Hisilicon Ltd.
>> + *
>> + * 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/bitops.h>
>> +#include <linux/init.h>
>> +#include <linux/list.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/module.h>
> 
> ...since you add the driver as a bool Kconfig item, you should
> avoid using module.h and any MODULE_<xyz> tags.  Use the
> builtin registration functions instead.
> 
> Alternatively, if there is a genuine use case for this to really be
> a dynamically loadable .ko module, then convert it to tristate.
> 
> Thanks,
> Paul.
> --

It is depended by hisilicon L3 cache or other components. And some
functions of these components may be called by kernel functions. So
it need to be set "bool". It looks like "mbigen" driver.

Could you give me some examples for the builtin registration functions
what you said? Maybe it is better for me.

Thanks.
Xiaojun.

>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>> +#include <linux/slab.h>
>> +#include <linux/spinlock.h>
>> +
>> +#include <asm-generic/delay.h>
>> +#include <linux/soc/hisilicon/djtag.h>
> 
> .
>
Paul Gortmaker July 27, 2016, 8:40 p.m. UTC | #3
On Sun, Jul 24, 2016 at 9:54 PM, Tan Xiaojun <tanxiaojun@huawei.com> wrote:
> On 2016/7/23 4:37, Paul Gortmaker wrote:
>> On Fri, Jul 22, 2016 at 4:48 AM, Tan Xiaojun <tanxiaojun@huawei.com> wrote:
>>> The Hisilicon Djtag is an independent module which connects with some modules
>>> in the SoC by Debug Bus. This module can be configured to access the registers
>>> of connecting modules (like L3 cache) during real time debugging.
>>>
>>> This patch add the driver of Hisilicon Djtag.
>>>
>>> Signed-off-by: Tan Xiaojun <tanxiaojun@huawei.com>
>>> ---
>>>  drivers/soc/Kconfig                 |    1 +
>>>  drivers/soc/Makefile                |    1 +
>>>  drivers/soc/hisilicon/Kconfig       |   12 ++
>>>  drivers/soc/hisilicon/Makefile      |    1 +
>>>  drivers/soc/hisilicon/djtag.c       |  373 +++++++++++++++++++++++++++++++++++
>>>  include/linux/soc/hisilicon/djtag.h |   18 ++
>>>  6 files changed, 406 insertions(+)
>>>  create mode 100644 drivers/soc/hisilicon/Kconfig
>>>  create mode 100644 drivers/soc/hisilicon/Makefile
>>>  create mode 100644 drivers/soc/hisilicon/djtag.c
>>>  create mode 100644 include/linux/soc/hisilicon/djtag.h
>>>
>>> diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
>>> index cb58ef0..f5982ec 100644
>>> --- a/drivers/soc/Kconfig
>>> +++ b/drivers/soc/Kconfig
>>> @@ -3,6 +3,7 @@ menu "SOC (System On Chip) specific Drivers"
>>>  source "drivers/soc/bcm/Kconfig"
>>>  source "drivers/soc/brcmstb/Kconfig"
>>>  source "drivers/soc/fsl/qe/Kconfig"
>>> +source "drivers/soc/hisilicon/Kconfig"
>>>  source "drivers/soc/mediatek/Kconfig"
>>>  source "drivers/soc/qcom/Kconfig"
>>>  source "drivers/soc/rockchip/Kconfig"
>>> diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
>>> index 380230f..373449d 100644
>>> --- a/drivers/soc/Makefile
>>> +++ b/drivers/soc/Makefile
>>> @@ -7,6 +7,7 @@ obj-$(CONFIG_SOC_BRCMSTB)       += brcmstb/
>>>  obj-$(CONFIG_ARCH_DOVE)                += dove/
>>>  obj-$(CONFIG_MACH_DOVE)                += dove/
>>>  obj-y                          += fsl/
>>> +obj-$(CONFIG_ARCH_HISI)                += hisilicon/
>>>  obj-$(CONFIG_ARCH_MEDIATEK)    += mediatek/
>>>  obj-$(CONFIG_ARCH_QCOM)                += qcom/
>>>  obj-$(CONFIG_ARCH_RENESAS)     += renesas/
>>> diff --git a/drivers/soc/hisilicon/Kconfig b/drivers/soc/hisilicon/Kconfig
>>> new file mode 100644
>>> index 0000000..3644aab
>>> --- /dev/null
>>> +++ b/drivers/soc/hisilicon/Kconfig
>>> @@ -0,0 +1,12 @@
>>> +#
>>> +# Hisilicon SoC drivers
>>> +#
>>> +config HISI_DJTAG
>>> +       bool "Hisilicon Djtag Support"
>>> +       depends on ARCH_HISI || COMPILE_TEST
>>> +       help
>>> +         Say y here to enable the Hisilicon Djtag support. It is an
>>> +         independent module which connects with some modules in the
>>> +         SoC by Debug Bus. This module can be configured to access
>>> +         the registers of connecting modules during real time
>>> +         debugging.
>>
>> Choice of word "module" here is probably confusing since it normally
>> means a ".ko" when used in Kconfig help.   Maybe instead, use:
>>
>> ...independent component...
>>
>> ...connects with some other components....
>>
>> This driver can be configured to ....
>>
>> --hopefully  the above will clarify against such confusion.   Also....
>>
>
> Yes, your suggestion is nice.
>
>>> diff --git a/drivers/soc/hisilicon/Makefile b/drivers/soc/hisilicon/Makefile
>>> new file mode 100644
>>> index 0000000..35a7b4b
>>> --- /dev/null
>>> +++ b/drivers/soc/hisilicon/Makefile
>>> @@ -0,0 +1 @@
>>> +obj-$(CONFIG_HISI_DJTAG)       += djtag.o
>>> diff --git a/drivers/soc/hisilicon/djtag.c b/drivers/soc/hisilicon/djtag.c
>>> new file mode 100644
>>> index 0000000..41e11ed
>>> --- /dev/null
>>> +++ b/drivers/soc/hisilicon/djtag.c
>>> @@ -0,0 +1,373 @@
>>> +/*
>>> + * Driver for Hisilicon Djtag r/w via System Controller.
>>> + *
>>> + * Copyright (C) 2016 Hisilicon Ltd.
>>> + *
>>> + * 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/bitops.h>
>>> +#include <linux/init.h>
>>> +#include <linux/list.h>
>>> +#include <linux/mfd/syscon.h>
>>> +#include <linux/module.h>
>>
>> ...since you add the driver as a bool Kconfig item, you should
>> avoid using module.h and any MODULE_<xyz> tags.  Use the
>> builtin registration functions instead.
>>
>> Alternatively, if there is a genuine use case for this to really be
>> a dynamically loadable .ko module, then convert it to tristate.
>>
>> Thanks,
>> Paul.
>> --
>
> It is depended by hisilicon L3 cache or other components. And some
> functions of these components may be called by kernel functions. So
> it need to be set "bool". It looks like "mbigen" driver.
>
> Could you give me some examples for the builtin registration functions
> what you said? Maybe it is better for me.

You can do "git log --author=Gortmaker" to see lots of examples.  Do a
"git show" on any of the commit IDs that look relevant to this driver.

Generally, you delete the MODULE_<xyz>  and module.h and replace it
with init.h if you use __init.   Also add export.h if you use EXPORT_SYMBOL.

module_init becomes device_initcall, module_platform_driver becomes
builtin_platform_driver and so on.

Paul.
--

>
> Thanks.
> Xiaojun.
>
>>> +#include <linux/of.h>
>>> +#include <linux/of_address.h>
>>> +#include <linux/of_device.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/regmap.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/spinlock.h>
>>> +
>>> +#include <asm-generic/delay.h>
>>> +#include <linux/soc/hisilicon/djtag.h>
>>
>> .
>>
>
>
diff mbox

Patch

diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index cb58ef0..f5982ec 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -3,6 +3,7 @@  menu "SOC (System On Chip) specific Drivers"
 source "drivers/soc/bcm/Kconfig"
 source "drivers/soc/brcmstb/Kconfig"
 source "drivers/soc/fsl/qe/Kconfig"
+source "drivers/soc/hisilicon/Kconfig"
 source "drivers/soc/mediatek/Kconfig"
 source "drivers/soc/qcom/Kconfig"
 source "drivers/soc/rockchip/Kconfig"
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 380230f..373449d 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -7,6 +7,7 @@  obj-$(CONFIG_SOC_BRCMSTB)	+= brcmstb/
 obj-$(CONFIG_ARCH_DOVE)		+= dove/
 obj-$(CONFIG_MACH_DOVE)		+= dove/
 obj-y				+= fsl/
+obj-$(CONFIG_ARCH_HISI)		+= hisilicon/
 obj-$(CONFIG_ARCH_MEDIATEK)	+= mediatek/
 obj-$(CONFIG_ARCH_QCOM)		+= qcom/
 obj-$(CONFIG_ARCH_RENESAS)	+= renesas/
diff --git a/drivers/soc/hisilicon/Kconfig b/drivers/soc/hisilicon/Kconfig
new file mode 100644
index 0000000..3644aab
--- /dev/null
+++ b/drivers/soc/hisilicon/Kconfig
@@ -0,0 +1,12 @@ 
+#
+# Hisilicon SoC drivers
+#
+config HISI_DJTAG
+	bool "Hisilicon Djtag Support"
+	depends on ARCH_HISI || COMPILE_TEST
+	help
+	  Say y here to enable the Hisilicon Djtag support. It is an
+	  independent module which connects with some modules in the
+	  SoC by Debug Bus. This module can be configured to access
+	  the registers of connecting modules during real time
+	  debugging.
diff --git a/drivers/soc/hisilicon/Makefile b/drivers/soc/hisilicon/Makefile
new file mode 100644
index 0000000..35a7b4b
--- /dev/null
+++ b/drivers/soc/hisilicon/Makefile
@@ -0,0 +1 @@ 
+obj-$(CONFIG_HISI_DJTAG)	+= djtag.o
diff --git a/drivers/soc/hisilicon/djtag.c b/drivers/soc/hisilicon/djtag.c
new file mode 100644
index 0000000..41e11ed
--- /dev/null
+++ b/drivers/soc/hisilicon/djtag.c
@@ -0,0 +1,373 @@ 
+/*
+ * Driver for Hisilicon Djtag r/w via System Controller.
+ *
+ * Copyright (C) 2016 Hisilicon Ltd.
+ *
+ * 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/bitops.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <asm-generic/delay.h>
+#include <linux/soc/hisilicon/djtag.h>
+
+#define SC_DJTAG_TIMEOUT		100000	/* 100ms */
+
+/* for djtag v1 */
+#define SC_DJTAG_MSTR_EN		0x6800
+#define DJTAG_NOR_CFG			BIT(1)	/* accelerate R,W */
+#define DJTAG_MSTR_EN			BIT(0)
+#define SC_DJTAG_MSTR_START_EN		0x6804
+#define DJTAG_MSTR_START_EN		0x1
+#define SC_DJTAG_DEBUG_MODULE_SEL	0x680c
+#define SC_DJTAG_MSTR_WR		0x6810
+#define DJTAG_MSTR_W			0x1
+#define DJTAG_MSTR_R			0x0
+#define SC_DJTAG_CHAIN_UNIT_CFG_EN	0x6814
+#define CHAIN_UNIT_CFG_EN		0xFFFF
+#define SC_DJTAG_MSTR_ADDR		0x6818
+#define SC_DJTAG_MSTR_DATA		0x681c
+#define SC_DJTAG_RD_DATA_BASE		0xe800
+
+/* for djtag v2 */
+#define SC_DJTAG_SEC_ACC_EN_EX		0xd800
+#define DJTAG_SEC_ACC_EN_EX		0x1
+#define SC_DJTAG_MSTR_CFG_EX		0xd818
+#define DJTAG_MSTR_RW_SHIFT_EX		29
+#define DJTAG_MSTR_RD_EX		(0x0 << DJTAG_MSTR_RW_SHIFT_EX)
+#define DJTAG_MSTR_WR_EX		(0x1 << DJTAG_MSTR_RW_SHIFT_EX)
+#define DEBUG_MODULE_SEL_SHIFT_EX	16
+#define CHAIN_UNIT_CFG_EN_EX		0xFFFF
+#define SC_DJTAG_MSTR_ADDR_EX		0xd810
+#define SC_DJTAG_MSTR_DATA_EX		0xd814
+#define SC_DJTAG_MSTR_START_EN_EX	0xd81c
+#define DJTAG_MSTR_START_EN_EX		0x1
+#define SC_DJTAG_RD_DATA_BASE_EX	0xe800
+#define SC_DJTAG_OP_ST_EX		0xe828
+#define DJTAG_OP_DONE_EX		BIT(8)
+
+static LIST_HEAD(djtag_list);
+
+struct djtag_data {
+	spinlock_t lock;
+	struct list_head list;
+	struct regmap *scl_map;
+	struct device_node *node;
+	int (*djtag_readwrite)(struct regmap *map, u32 offset,
+			u32 mod_sel, u32 mod_mask, bool is_w,
+			u32 wval, int chain_id, u32 *rval);
+};
+
+/*
+ * djtag_readwrite_v1/v2: djtag read/write interface
+ * @regmap:	djtag base address
+ * @offset:	register's offset
+ * @mod_sel:	module selection
+ * @mod_mask:	mask to select specific modules for write
+ * @is_w:	write -> true, read -> false
+ * @wval:	value to register for write
+ * @chain_id:	which sub module for read
+ * @rval:	value in register for read
+ *
+ * Return non-zero if error, else return 0.
+ */
+static int djtag_readwrite_v1(struct regmap *map, u32 offset, u32 mod_sel,
+		u32 mod_mask, bool is_w, u32 wval, int chain_id, u32 *rval)
+{
+	u32 rd;
+	int timeout = SC_DJTAG_TIMEOUT;
+
+	if (!(mod_mask & CHAIN_UNIT_CFG_EN)) {
+		pr_warn("djtag: do nothing.\n");
+		return 0;
+	}
+
+	/* djtag mster enable & accelerate R,W */
+	regmap_write(map, SC_DJTAG_MSTR_EN, DJTAG_NOR_CFG | DJTAG_MSTR_EN);
+
+	/* select module */
+	regmap_write(map, SC_DJTAG_DEBUG_MODULE_SEL, mod_sel);
+
+	regmap_write(map, SC_DJTAG_CHAIN_UNIT_CFG_EN,
+			mod_mask & CHAIN_UNIT_CFG_EN);
+
+	if (is_w) {
+		regmap_write(map, SC_DJTAG_MSTR_WR, DJTAG_MSTR_W);
+		regmap_write(map, SC_DJTAG_MSTR_DATA, wval);
+	} else
+		regmap_write(map, SC_DJTAG_MSTR_WR, DJTAG_MSTR_R);
+
+	/* address offset */
+	regmap_write(map, SC_DJTAG_MSTR_ADDR, offset);
+
+	/* start to write to djtag register */
+	regmap_write(map, SC_DJTAG_MSTR_START_EN, DJTAG_MSTR_START_EN);
+
+	/* ensure the djtag operation is done */
+	do {
+		regmap_read(map, SC_DJTAG_MSTR_START_EN, &rd);
+
+		if (!(rd & DJTAG_MSTR_EN))
+			break;
+
+		udelay(1);
+	} while (timeout--);
+
+	if (timeout < 0) {
+		pr_err("djtag: %s timeout!\n", is_w ? "write" : "read");
+		return -EBUSY;
+	}
+
+	if (!is_w)
+		regmap_read(map, SC_DJTAG_RD_DATA_BASE + chain_id * 0x4, rval);
+
+	return 0;
+}
+
+static int djtag_readwrite_v2(struct regmap *map, u32 offset, u32 mod_sel,
+		u32 mod_mask, bool is_w, u32 wval, int chain_id, u32 *rval)
+{
+	u32 rd;
+	int timeout = SC_DJTAG_TIMEOUT;
+
+	if (!(mod_mask & CHAIN_UNIT_CFG_EN_EX)) {
+		pr_warn("djtag: do nothing.\n");
+		return 0;
+	}
+
+	/* djtag mster enable */
+	regmap_write(map, SC_DJTAG_SEC_ACC_EN_EX, DJTAG_SEC_ACC_EN_EX);
+
+	if (is_w) {
+		regmap_write(map, SC_DJTAG_MSTR_CFG_EX, DJTAG_MSTR_WR_EX
+				| (mod_sel << DEBUG_MODULE_SEL_SHIFT_EX)
+				| (mod_mask & CHAIN_UNIT_CFG_EN_EX));
+		regmap_write(map, SC_DJTAG_MSTR_DATA_EX, wval);
+	} else
+		regmap_write(map, SC_DJTAG_MSTR_CFG_EX, DJTAG_MSTR_RD_EX
+				| (mod_sel << DEBUG_MODULE_SEL_SHIFT_EX)
+				| (mod_mask & CHAIN_UNIT_CFG_EN_EX));
+
+	/* address offset */
+	regmap_write(map, SC_DJTAG_MSTR_ADDR_EX, offset);
+
+	/* start to write to djtag register */
+	regmap_write(map, SC_DJTAG_MSTR_START_EN_EX, DJTAG_MSTR_START_EN_EX);
+
+	/* ensure the djtag operation is done */
+	do {
+		regmap_read(map, SC_DJTAG_MSTR_START_EN_EX, &rd);
+
+		if (!(rd & DJTAG_MSTR_START_EN_EX))
+			break;
+
+		udelay(1);
+	} while (timeout--);
+
+	if (timeout < 0)
+		goto timeout;
+
+	timeout = SC_DJTAG_TIMEOUT;
+	do {
+		regmap_read(map, SC_DJTAG_OP_ST_EX, &rd);
+
+		if (rd & DJTAG_OP_DONE_EX)
+			break;
+
+		udelay(1);
+	} while (timeout--);
+
+	if (timeout < 0)
+		goto timeout;
+
+	if (!is_w)
+		regmap_read(map, SC_DJTAG_RD_DATA_BASE_EX + chain_id * 0x4,
+				rval);
+
+	return 0;
+
+timeout:
+	pr_err("djtag: %s timeout!\n", is_w ? "write" : "read");
+	return -EBUSY;
+}
+
+
+/**
+ * djtag_writel - write registers via djtag
+ * @node:	djtag node
+ * @offset:	register's offset
+ * @mod_sel:	module selection
+ * @mod_mask:	mask to select specific modules
+ * @val:	value to write to register
+ *
+ * If error return errno, otherwise return 0.
+ */
+int hisi_djtag_writel(struct device_node *node, u32 offset, u32 mod_sel,
+			u32 mod_mask, u32 val)
+{
+	struct regmap *map;
+	unsigned long flags;
+	struct djtag_data *tmp, *p;
+	int ret = 0;
+
+	map = NULL;
+	list_for_each_entry_safe(tmp, p, &djtag_list, list) {
+		if (tmp->node == node) {
+			map = tmp->scl_map;
+
+			spin_lock_irqsave(&tmp->lock, flags);
+			ret = tmp->djtag_readwrite(map, offset, mod_sel, mod_mask,
+					true, val, 0, NULL);
+			if (ret)
+				pr_err("djtag_writel: %s: error!\n",
+						node->full_name);
+			spin_unlock_irqrestore(&tmp->lock, flags);
+			break;
+		}
+	}
+
+	if (!map)
+		return -ENODEV;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hisi_djtag_writel);
+
+/**
+ * djtag_readl - read registers via djtag
+ * @node:	djtag node
+ * @offset:	register's offset
+ * @mod_sel:	module type selection
+ * @chain_id:	chain_id number, mostly is 0
+ * @val:	register's value
+ *
+ * If error return errno, otherwise return 0.
+ */
+int hisi_djtag_readl(struct device_node *node, u32 offset, u32 mod_sel,
+		int chain_id, u32 *val)
+{
+	struct regmap *map;
+	unsigned long flags;
+	struct djtag_data *tmp, *p;
+	int ret = 0;
+
+	map = NULL;
+	list_for_each_entry_safe(tmp, p, &djtag_list, list) {
+		if (tmp->node == node) {
+			map = tmp->scl_map;
+
+			spin_lock_irqsave(&tmp->lock, flags);
+			ret = tmp->djtag_readwrite(map, offset, mod_sel,
+					0, false, 0, chain_id, val);
+			if (ret)
+				pr_err("djtag_readl: %s: error!\n",
+						node->full_name);
+			spin_unlock_irqrestore(&tmp->lock, flags);
+			break;
+		}
+	}
+
+	if (!map)
+		return -ENODEV;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hisi_djtag_readl);
+
+static const struct of_device_id djtag_of_match[] = {
+	/* for hip05(D02) cpu die */
+	{ .compatible = "hisilicon,hip05-cpu-djtag-v1",
+		.data = (void *)djtag_readwrite_v1 },
+	/* for hip05(D02) io die */
+	{ .compatible = "hisilicon,hip05-io-djtag-v1",
+		.data = (void *)djtag_readwrite_v1 },
+	/* for hip06(D03) cpu die */
+	{ .compatible = "hisilicon,hip06-cpu-djtag-v1",
+		.data = (void *)djtag_readwrite_v1 },
+	/* for hip06(D03) io die */
+	{ .compatible = "hisilicon,hip06-io-djtag-v2",
+		.data = (void *)djtag_readwrite_v2 },
+	/* for hip07(D04) cpu die */
+	{ .compatible = "hisilicon,hip07-cpu-djtag-v2",
+		.data = (void *)djtag_readwrite_v2 },
+	/* for hip07(D04) io die */
+	{ .compatible = "hisilicon,hip07-io-djtag-v2",
+		.data = (void *)djtag_readwrite_v2 },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, djtag_of_match);
+
+static int djtag_dev_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct djtag_data *dg_data;
+	const struct of_device_id *of_id;
+
+	of_id = of_match_device(djtag_of_match, dev);
+	if (!of_id)
+		return -EINVAL;
+
+	dg_data = kzalloc(sizeof(struct djtag_data), GFP_KERNEL);
+	if (!dg_data)
+		return -ENOMEM;
+
+	dg_data->node = dev->of_node;
+	dg_data->djtag_readwrite = of_id->data;
+	spin_lock_init(&dg_data->lock);
+
+	INIT_LIST_HEAD(&dg_data->list);
+	dg_data->scl_map = syscon_regmap_lookup_by_phandle(dg_data->node,
+			"syscon");
+	if (IS_ERR(dg_data->scl_map)) {
+		dev_warn(dev, "wrong syscon register address.\n");
+		kfree(dg_data);
+		return -EINVAL;
+	}
+
+	list_add_tail(&dg_data->list, &djtag_list);
+	dev_info(dev, "%s init successfully.\n", dg_data->node->name);
+	return 0;
+}
+
+static int djtag_dev_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct djtag_data *tmp, *p;
+
+	list_for_each_entry_safe(tmp, p, &djtag_list, list) {
+		list_del(&tmp->list);
+		dev_info(dev, "%s remove successfully.\n", tmp->node->name);
+		kfree(tmp);
+	}
+
+	return 0;
+}
+
+static struct platform_driver djtag_dev_driver = {
+	.driver = {
+		.name = "hisi-djtag",
+		.of_match_table = djtag_of_match,
+	},
+	.probe = djtag_dev_probe,
+	.remove = djtag_dev_remove,
+};
+
+module_platform_driver(djtag_dev_driver);
+
+MODULE_DESCRIPTION("Hisilicon djtag driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.0");
diff --git a/include/linux/soc/hisilicon/djtag.h b/include/linux/soc/hisilicon/djtag.h
new file mode 100644
index 0000000..2d3fc61
--- /dev/null
+++ b/include/linux/soc/hisilicon/djtag.h
@@ -0,0 +1,18 @@ 
+/*
+ * Driver for Hisilicon djtag r/w via System Controller.
+ *
+ * Copyright (C) 2016-2017 Hisilicon Ltd.
+ *
+ * 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.
+ */
+
+#ifndef __HISI_DJTAG_H
+#define __HISI_DJTAG_H
+
+int hisi_djtag_readl(struct device_node *node, u32 offset, u32 mod_sel,
+						int chain_id, u32 *val);
+int hisi_djtag_writel(struct device_node *node, u32 offset, u32 mod_sel,
+						u32 mod_mask, u32 val);
+#endif /* __HISI_DJTAG_H */