diff mbox

[v3] platform:x86: add Intel P-Unit mailbox IPC driver

Message ID 1440607117-57683-1-git-send-email-qipeng.zha@intel.com (mailing list archive)
State Superseded, archived
Headers show

Commit Message

qipeng.zha Aug. 26, 2015, 4:38 p.m. UTC
This driver provides support for P-Unit mailbox IPC on Intel platforms.
The heart of the P-Unit is the Foxton microcontroller and its firmware,
which provide mailbox interface for power management usage.

Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>

---
change in v3
 Fix compile issue in intel_punit_ipc.h, it happened when built-in
and the header file is included in other source file.

change in v2
 Fix issues in code style and comments;
 Remove "default y" in Kconfig;
 Remove some header files;
 Replace request_mem_region with devm_request_mem_region,
and same for request_irq;
 Change to use prefix of IPC_PUNIT_ to define commands;
---
 MAINTAINERS                            |   4 +-
 arch/x86/include/asm/intel_punit_ipc.h | 101 ++++++++++
 drivers/platform/x86/Kconfig           |   6 +
 drivers/platform/x86/Makefile          |   1 +
 drivers/platform/x86/intel_punit_ipc.c | 353 +++++++++++++++++++++++++++++++++
 5 files changed, 464 insertions(+), 1 deletion(-)
 create mode 100644 arch/x86/include/asm/intel_punit_ipc.h
 create mode 100644 drivers/platform/x86/intel_punit_ipc.c

Comments

Darren Hart Aug. 31, 2015, 7:38 p.m. UTC | #1
On Thu, Aug 27, 2015 at 12:38:37AM +0800, Qipeng Zha wrote:
> This driver provides support for P-Unit mailbox IPC on Intel platforms.
> The heart of the P-Unit is the Foxton microcontroller and its firmware,
> which provide mailbox interface for power management usage.
> 
> Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
> 

Thanks Qipeng. In the future, please remember to Cc the people who have reviewed
previous versions so they can provide their Reviewed-by if they are satisfied
with the changes.

> ---
> change in v3
>  Fix compile issue in intel_punit_ipc.h, it happened when built-in
> and the header file is included in other source file.
> 
> change in v2
>  Fix issues in code style and comments;
>  Remove "default y" in Kconfig;
>  Remove some header files;
>  Replace request_mem_region with devm_request_mem_region,
> and same for request_irq;
>  Change to use prefix of IPC_PUNIT_ to define commands;

Thanks for including the changelog.

...

>  IOC3 ETHERNET DRIVER
>  M:	Ralf Baechle <ralf@linux-mips.org>
> diff --git a/arch/x86/include/asm/intel_punit_ipc.h b/arch/x86/include/asm/intel_punit_ipc.h
> new file mode 100644
> index 0000000..0537434
> --- /dev/null
> +++ b/arch/x86/include/asm/intel_punit_ipc.h
> @@ -0,0 +1,101 @@
> +#ifndef _ASM_X86_INTEL_PUNIT_IPC_H_
> +#define  _ASM_X86_INTEL_PUNIT_IPC_H_
> +
> +/* Commands supported on CPU core, are handled by different bars,
> + * unify these commands together here
> + */

Always include a leading /* empty line for multi-line comments please, this is
in CodingStyle, but checkpatch missed it - likely because /net has its own
rules. I've fixed this in the version I queued to "testing".

...

> +static int intel_punit_get_bars(struct platform_device *pdev)
> +{
> +	struct resource *res0, *res1;
> +	void __iomem *addr;
> +	int size;
> +
> +	res0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res0) {
> +		dev_err(&pdev->dev, "Failed to get iomem resource\n");
> +		return -EINVAL;
> +	}
> +	size = resource_size(res0);
> +	if (!devm_request_mem_region(&pdev->dev, res0->start,
> +				     size, pdev->name)) {
> +		dev_err(&pdev->dev, "Failed to request iomem resouce\n");
> +		return -EBUSY;
> +	}
> +
> +	res1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +	if (!res1) {
> +		dev_err(&pdev->dev, "Failed to get iomem resource1\n");
> +		return -EINVAL;
> +	}
> +	size = resource_size(res1);
> +	if (!devm_request_mem_region(&pdev->dev, res1->start,
> +				     size, pdev->name)) {
> +		dev_err(&pdev->dev, "Failed to request iomem resouce1\n");
> +		return -EBUSY;
> +	}

These return codes, -EINVAL and -EBUSY caught my eye. -EINVAL in particular
seemed odd, I would have expected -ENXIO or -EIO. Checking intel_pmc_ipc.c, I
see it uses -ENXIO for the comparable routine. Is there a justification for the
variability here? If not, I'd prefer to see continuity across these similar
drivers.

> +
> +	addr = ioremap_nocache(res0->start,
> +			       resource_size(res0) + resource_size(res1));
> +	if (!addr) {
> +		dev_err(&pdev->dev, "Failed to ioremap ipc base\n");
> +		return  -ENOMEM;
> +	}
> +	ipcdev.base[BIOS_MAILBOX] = addr;
> +	addr += MAILBOX_REGISTER_SPACE;
> +	ipcdev.base[GTDRIVER_MAILBOX] = addr;
> +	addr += MAILBOX_REGISTER_SPACE;
> +	ipcdev.base[ISPDRIVER_MAILBOX] = addr;
> +
> +	return 0;
> +}
> +
> +static int intel_punit_ipc_probe(struct platform_device *pdev)
> +{
> +	int irq, ret;
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0) {
> +		ipcdev.irq = 0;
> +		dev_warn(&pdev->dev, "Invalid IRQ\n");
> +	} else {
> +		if (devm_request_irq(&pdev->dev, irq, intel_punit_ioc,
> +				     IRQF_NO_SUSPEND, "intel_punit_ipc",
> +				     &ipcdev)) {
> +			dev_err(&pdev->dev, "Failed to request irq: %d\n", irq);
> +			return -EBUSY;
> +		}
> +		ipcdev.irq = irq;
> +	}
> +
> +	ret = intel_punit_get_bars(pdev);
> +	if (ret)
> +		return ret;
> +

This white space usage of the ret, if(ret) return ret block is typical and
nicely separates the logical blocks of the function. There are many throughout
this file that do not use any whitespace. This is fairly minor, but if we're
respinning, please do a pass and add some newlines around similar blocks.
Andy Shevchenko Sept. 1, 2015, 8:11 a.m. UTC | #2
On Mon, 2015-08-31 at 12:38 -0700, Darren Hart wrote:
> On Thu, Aug 27, 2015 at 12:38:37AM +0800, Qipeng Zha wrote:

> > This driver provides support for P-Unit mailbox IPC on Intel 

> > platforms.

> > The heart of the P-Unit is the Foxton microcontroller and its 

> > firmware,

> > which provide mailbox interface for power management usage.

> > 

> > Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>

> > 

> 

> Thanks Qipeng. In the future, please remember to Cc the people who 

> have reviewed

> previous versions so they can provide their Reviewed-by if they are 

> satisfied

> with the changes.


It would be nice to see the full version before pushing anywhere.

> 

> > ---

> > change in v3

> >  Fix compile issue in intel_punit_ipc.h, it happened when built-in

> > and the header file is included in other source file.

> > 

> > change in v2

> >  Fix issues in code style and comments;

> >  Remove "default y" in Kconfig;

> >  Remove some header files;

> >  Replace request_mem_region with devm_request_mem_region,

> > and same for request_irq;

> >  Change to use prefix of IPC_PUNIT_ to define commands;

> 

> Thanks for including the changelog.

> 

> ...

> 

> >  IOC3 ETHERNET DRIVER

> >  M:	Ralf Baechle <ralf@linux-mips.org>

> > diff --git a/arch/x86/include/asm/intel_punit_ipc.h 

> > b/arch/x86/include/asm/intel_punit_ipc.h

> > new file mode 100644

> > index 0000000..0537434

> > --- /dev/null

> > +++ b/arch/x86/include/asm/intel_punit_ipc.h

> > @@ -0,0 +1,101 @@

> > +#ifndef _ASM_X86_INTEL_PUNIT_IPC_H_

> > +#define  _ASM_X86_INTEL_PUNIT_IPC_H_

> > +

> > +/* Commands supported on CPU core, are handled by different bars,

> > + * unify these commands together here

> > + */

> 

> Always include a leading /* empty line for multi-line comments 

> please, this is

> in CodingStyle, but checkpatch missed it - likely because /net has 

> its own

> rules. I've fixed this in the version I queued to "testing".

> 

> ...

> 

> > +static int intel_punit_get_bars(struct platform_device *pdev)

> > +{

> > +	struct resource *res0, *res1;

> > +	void __iomem *addr;

> > +	int size;

> > +

> > +	res0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);

> > +	if (!res0) {

> > +		dev_err(&pdev->dev, "Failed to get iomem 

> > resource\n");

> > +		return -EINVAL;

> > +	}

> > +	size = resource_size(res0);

> > +	if (!devm_request_mem_region(&pdev->dev, res0->start,

> > +				     size, pdev->name)) {


Shouldn't be devm_ioremap_resource() in both cases?

> > +		dev_err(&pdev->dev, "Failed to request iomem 

> > resouce\n");

> > +		return -EBUSY;

> > +	}

> > +

> > +	res1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);

> > +	if (!res1) {

> > +		dev_err(&pdev->dev, "Failed to get iomem 

> > resource1\n");

> > +		return -EINVAL;

> > +	}

> > +	size = resource_size(res1);

> > +	if (!devm_request_mem_region(&pdev->dev, res1->start,

> > +				     size, pdev->name)) {

> > +		dev_err(&pdev->dev, "Failed to request iomem 

> > resouce1\n");

> > +		return -EBUSY;

> > +	}

> 

> These return codes, -EINVAL and -EBUSY caught my eye. -EINVAL in 

> particular

> seemed odd, I would have expected -ENXIO or -EIO. Checking 

> intel_pmc_ipc.c, I

> see it uses -ENXIO for the comparable routine. Is there a 

> justification for the

> variability here? If not, I'd prefer to see continuity across these 

> similar

> drivers.

> 

> > +

> > +	addr = ioremap_nocache(res0->start,

> > +			       resource_size(res0) + 

> > resource_size(res1));

> > +	if (!addr) {

> > +		dev_err(&pdev->dev, "Failed to ioremap ipc 

> > base\n");

> > +		return  -ENOMEM;

> > +	}

> > +	ipcdev.base[BIOS_MAILBOX] = addr;

> > +	addr += MAILBOX_REGISTER_SPACE;

> > +	ipcdev.base[GTDRIVER_MAILBOX] = addr;

> > +	addr += MAILBOX_REGISTER_SPACE;

> > +	ipcdev.base[ISPDRIVER_MAILBOX] = addr;

> > +

> > +	return 0;

> > +}

> > +

> > +static int intel_punit_ipc_probe(struct platform_device *pdev)

> > +{

> > +	int irq, ret;

> > +

> > +	irq = platform_get_irq(pdev, 0);

> > +	if (irq < 0) {

> > +		ipcdev.irq = 0;

> > +		dev_warn(&pdev->dev, "Invalid IRQ\n");

> > +	} else {

> > +		if (devm_request_irq(&pdev->dev, irq, 

> > intel_punit_ioc,

> > +				     IRQF_NO_SUSPEND, 

> > "intel_punit_ipc",

> > +				     &ipcdev)) {

> > +			dev_err(&pdev->dev, "Failed to request 

> > irq: %d\n", irq);

> > +			return -EBUSY;

> > +		}

> > +		ipcdev.irq = irq;

> > +	}

> > +

> > +	ret = intel_punit_get_bars(pdev);

> > +	if (ret)

> > +		return ret;

> > +

> 

> This white space usage of the ret, if(ret) return ret block is 

> typical and

> nicely separates the logical blocks of the function. There are many 

> throughout

> this file that do not use any whitespace. This is fairly minor, but 

> if we're

> respinning, please do a pass and add some newlines around similar 

> blocks.

> 

> 


-- 
Andy Shevchenko <andriy.shevchenko@intel.com>
Intel Finland Oy
---------------------------------------------------------------------
Intel Finland Oy
Registered Address: PL 281, 00181 Helsinki 
Business Identity Code: 0357606 - 4 
Domiciled in Helsinki 

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.
Darren Hart Sept. 6, 2015, 5:48 p.m. UTC | #3
On Tue, Sep 01, 2015 at 08:11:26AM +0000, Andriy Shevchenko wrote:
> On Mon, 2015-08-31 at 12:38 -0700, Darren Hart wrote:
> > On Thu, Aug 27, 2015 at 12:38:37AM +0800, Qipeng Zha wrote:
> > > This driver provides support for P-Unit mailbox IPC on Intel 
> > > platforms.
> > > The heart of the P-Unit is the Foxton microcontroller and its 
> > > firmware,
> > > which provide mailbox interface for power management usage.
> > > 
> > > Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
> > > 
> > 
> > Thanks Qipeng. In the future, please remember to Cc the people who 
> > have reviewed
> > previous versions so they can provide their Reviewed-by if they are 
> > satisfied
> > with the changes.
> 
> It would be nice to see the full version before pushing anywhere.

Hi Qipeng,

Given the latest feedback and what follows from Andriy, would you please submit
a version 4 with all the current feedback rolled into one for final review?

Thanks,

> 
> > 
> > > ---
> > > change in v3
> > >  Fix compile issue in intel_punit_ipc.h, it happened when built-in
> > > and the header file is included in other source file.
> > > 
> > > change in v2
> > >  Fix issues in code style and comments;
> > >  Remove "default y" in Kconfig;
> > >  Remove some header files;
> > >  Replace request_mem_region with devm_request_mem_region,
> > > and same for request_irq;
> > >  Change to use prefix of IPC_PUNIT_ to define commands;
> > 
> > Thanks for including the changelog.
> > 
> > ...
> > 
> > >  IOC3 ETHERNET DRIVER
> > >  M:	Ralf Baechle <ralf@linux-mips.org>
> > > diff --git a/arch/x86/include/asm/intel_punit_ipc.h 
> > > b/arch/x86/include/asm/intel_punit_ipc.h
> > > new file mode 100644
> > > index 0000000..0537434
> > > --- /dev/null
> > > +++ b/arch/x86/include/asm/intel_punit_ipc.h
> > > @@ -0,0 +1,101 @@
> > > +#ifndef _ASM_X86_INTEL_PUNIT_IPC_H_
> > > +#define  _ASM_X86_INTEL_PUNIT_IPC_H_
> > > +
> > > +/* Commands supported on CPU core, are handled by different bars,
> > > + * unify these commands together here
> > > + */
> > 
> > Always include a leading /* empty line for multi-line comments 
> > please, this is
> > in CodingStyle, but checkpatch missed it - likely because /net has 
> > its own
> > rules. I've fixed this in the version I queued to "testing".
> > 
> > ...
> > 
> > > +static int intel_punit_get_bars(struct platform_device *pdev)
> > > +{
> > > +	struct resource *res0, *res1;
> > > +	void __iomem *addr;
> > > +	int size;
> > > +
> > > +	res0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > +	if (!res0) {
> > > +		dev_err(&pdev->dev, "Failed to get iomem 
> > > resource\n");
> > > +		return -EINVAL;
> > > +	}
> > > +	size = resource_size(res0);
> > > +	if (!devm_request_mem_region(&pdev->dev, res0->start,
> > > +				     size, pdev->name)) {
> 
> Shouldn't be devm_ioremap_resource() in both cases?
> 
> > > +		dev_err(&pdev->dev, "Failed to request iomem 
> > > resouce\n");
> > > +		return -EBUSY;
> > > +	}
> > > +
> > > +	res1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> > > +	if (!res1) {
> > > +		dev_err(&pdev->dev, "Failed to get iomem 
> > > resource1\n");
> > > +		return -EINVAL;
> > > +	}
> > > +	size = resource_size(res1);
> > > +	if (!devm_request_mem_region(&pdev->dev, res1->start,
> > > +				     size, pdev->name)) {
> > > +		dev_err(&pdev->dev, "Failed to request iomem 
> > > resouce1\n");
> > > +		return -EBUSY;
> > > +	}
> > 
> > These return codes, -EINVAL and -EBUSY caught my eye. -EINVAL in 
> > particular
> > seemed odd, I would have expected -ENXIO or -EIO. Checking 
> > intel_pmc_ipc.c, I
> > see it uses -ENXIO for the comparable routine. Is there a 
> > justification for the
> > variability here? If not, I'd prefer to see continuity across these 
> > similar
> > drivers.
> > 
> > > +
> > > +	addr = ioremap_nocache(res0->start,
> > > +			       resource_size(res0) + 
> > > resource_size(res1));
> > > +	if (!addr) {
> > > +		dev_err(&pdev->dev, "Failed to ioremap ipc 
> > > base\n");
> > > +		return  -ENOMEM;
> > > +	}
> > > +	ipcdev.base[BIOS_MAILBOX] = addr;
> > > +	addr += MAILBOX_REGISTER_SPACE;
> > > +	ipcdev.base[GTDRIVER_MAILBOX] = addr;
> > > +	addr += MAILBOX_REGISTER_SPACE;
> > > +	ipcdev.base[ISPDRIVER_MAILBOX] = addr;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int intel_punit_ipc_probe(struct platform_device *pdev)
> > > +{
> > > +	int irq, ret;
> > > +
> > > +	irq = platform_get_irq(pdev, 0);
> > > +	if (irq < 0) {
> > > +		ipcdev.irq = 0;
> > > +		dev_warn(&pdev->dev, "Invalid IRQ\n");
> > > +	} else {
> > > +		if (devm_request_irq(&pdev->dev, irq, 
> > > intel_punit_ioc,
> > > +				     IRQF_NO_SUSPEND, 
> > > "intel_punit_ipc",
> > > +				     &ipcdev)) {
> > > +			dev_err(&pdev->dev, "Failed to request 
> > > irq: %d\n", irq);
> > > +			return -EBUSY;
> > > +		}
> > > +		ipcdev.irq = irq;
> > > +	}
> > > +
> > > +	ret = intel_punit_get_bars(pdev);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > 
> > This white space usage of the ret, if(ret) return ret block is 
> > typical and
> > nicely separates the logical blocks of the function. There are many 
> > throughout
> > this file that do not use any whitespace. This is fairly minor, but 
> > if we're
> > respinning, please do a pass and add some newlines around similar 
> > blocks.
> > 
> > 
> 
> -- 
> Andy Shevchenko <andriy.shevchenko@intel.com>
> Intel Finland Oy
> ---------------------------------------------------------------------
> Intel Finland Oy
> Registered Address: PL 281, 00181 Helsinki 
> Business Identity Code: 0357606 - 4 
> Domiciled in Helsinki 
> 
> This e-mail and any attachments may contain confidential material for
> the sole use of the intended recipient(s). Any review or distribution
> by others is strictly prohibited. If you are not the intended
> recipient, please contact the sender and delete all copies.
diff mbox

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 13ac861..cf71387 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5207,12 +5207,14 @@  F:	include/uapi/linux/mei.h
 F:	drivers/misc/mei/*
 F:	Documentation/misc-devices/mei/*
 
-INTEL PMC IPC DRIVER
+INTEL PMC/P-Unit IPC DRIVER
 M:	Zha Qipeng<qipeng.zha@intel.com>
 L:	platform-driver-x86@vger.kernel.org
 S:	Maintained
 F:	drivers/platform/x86/intel_pmc_ipc.c
+F:	drivers/platform/x86/intel_punit_ipc.c
 F:	arch/x86/include/asm/intel_pmc_ipc.h
+F:	arch/x86/include/asm/intel_punit_ipc.h
 
 IOC3 ETHERNET DRIVER
 M:	Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/x86/include/asm/intel_punit_ipc.h b/arch/x86/include/asm/intel_punit_ipc.h
new file mode 100644
index 0000000..0537434
--- /dev/null
+++ b/arch/x86/include/asm/intel_punit_ipc.h
@@ -0,0 +1,101 @@ 
+#ifndef _ASM_X86_INTEL_PUNIT_IPC_H_
+#define  _ASM_X86_INTEL_PUNIT_IPC_H_
+
+/* Commands supported on CPU core, are handled by different bars,
+ * unify these commands together here
+ */
+#define IPC_PUNIT_BIOS_CMD_BASE			0x00
+#define IPC_PUNIT_GTD_CMD_BASE			0x20
+#define IPC_PUNIT_ISPD_CMD_BASE			0x40
+
+/* BIOS => Pcode commands */
+#define IPC_PUNIT_BIOS_CMD_ZERO			(IPC_PUNIT_BIOS_CMD_BASE + 0x00)
+#define IPC_PUNIT_BIOS_CMD_VR_INTERFACE		(IPC_PUNIT_BIOS_CMD_BASE + 0x01)
+#define IPC_PUNIT_BIOS_CMD_READ_PCS		(IPC_PUNIT_BIOS_CMD_BASE + 0x02)
+#define IPC_PUNIT_BIOS_CMD_WRITE_PCS		(IPC_PUNIT_BIOS_CMD_BASE + 0x03)
+#define IPC_PUNIT_BIOS_CMD_READ_PCU_CONFIG	(IPC_PUNIT_BIOS_CMD_BASE + 0x04)
+#define IPC_PUNIT_BIOS_CMD_WRITE_PCU_CONFIG	(IPC_PUNIT_BIOS_CMD_BASE + 0x05)
+#define IPC_PUNIT_BIOS_CMD_READ_PL1_SETTING	(IPC_PUNIT_BIOS_CMD_BASE + 0x06)
+#define IPC_PUNIT_BIOS_WRITE_PL1_SETTING	(IPC_PUNIT_BIOS_CMD_BASE + 0x07)
+#define IPC_PUNIT_BIOS_CMD_TRIGGER_VDD_RAM	(IPC_PUNIT_BIOS_CMD_BASE + 0x08)
+#define IPC_PUNIT_BIOS_CMD_READ_TELE_INFO	(IPC_PUNIT_BIOS_CMD_BASE + 0x09)
+#define IPC_PUNIT_BIOS_CMD_READ_TELE_TRACE_CTRL	(IPC_PUNIT_BIOS_CMD_BASE + 0x0a)
+#define IPC_PUNIT_BIOS_CMD_WRITE_TELE_TRACE_CTRL \
+						(IPC_PUNIT_BIOS_CMD_BASE + 0x0b)
+#define IPC_PUNIT_BIOS_CMD_READ_TELE_EVENT_CTRL	(IPC_PUNIT_BIOS_CMD_BASE + 0x0c)
+#define IPC_PUNIT_BIOS_CMD_WRITE_TELE_EVENT_CTRL \
+						(IPC_PUNIT_BIOS_CMD_BASE + 0x0d)
+#define IPC_PUNIT_BIOS_CMD_READ_TELE_TRACE	(IPC_PUNIT_BIOS_CMD_BASE + 0x0e)
+#define IPC_PUNIT_BIOS_CMD_WRITE_TELE_TRACE	(IPC_PUNIT_BIOS_CMD_BASE + 0x0f)
+#define IPC_PUNIT_BIOS_CMD_READ_TELE_EVENT	(IPC_PUNIT_BIOS_CMD_BASE + 0x10)
+#define IPC_PUNIT_BIOS_CMD_WRITE_TELE_EVENT	(IPC_PUNIT_BIOS_CMD_BASE + 0x11)
+#define IPC_PUNIT_BIOS_CMD_READ_MODULE_TEMP	(IPC_PUNIT_BIOS_CMD_BASE + 0x12)
+#define IPC_PUNIT_BIOS_CMD_RESERVED		(IPC_PUNIT_BIOS_CMD_BASE + 0x13)
+#define IPC_PUNIT_BIOS_CMD_READ_VOLTAGE_OVER	(IPC_PUNIT_BIOS_CMD_BASE + 0x14)
+#define IPC_PUNIT_BIOS_CMD_WRITE_VOLTAGE_OVER	(IPC_PUNIT_BIOS_CMD_BASE + 0x15)
+#define IPC_PUNIT_BIOS_CMD_READ_RATIO_OVER	(IPC_PUNIT_BIOS_CMD_BASE + 0x16)
+#define IPC_PUNIT_BIOS_CMD_WRITE_RATIO_OVER	(IPC_PUNIT_BIOS_CMD_BASE + 0x17)
+#define IPC_PUNIT_BIOS_CMD_READ_VF_GL_CTRL	(IPC_PUNIT_BIOS_CMD_BASE + 0x18)
+#define IPC_PUNIT_BIOS_CMD_WRITE_VF_GL_CTRL	(IPC_PUNIT_BIOS_CMD_BASE + 0x19)
+#define IPC_PUNIT_BIOS_CMD_READ_FM_SOC_TEMP_THRESH \
+						(IPC_PUNIT_BIOS_CMD_BASE + 0x1a)
+#define IPC_PUNIT_BIOS_CMD_WRITE_FM_SOC_TEMP_THRESH \
+						(IPC_PUNIT_BIOS_CMD_BASE + 0x1b)
+
+/*GT Driver => Pcode commands*/
+#define IPC_PUNIT_GTD_CMD_ZERO			(IPC_PUNIT_GTD_CMD_BASE + 0x00)
+#define IPC_PUNIT_GTD_CMD_CONFIG		(IPC_PUNIT_GTD_CMD_BASE + 0x01)
+#define IPC_PUNIT_GTD_CMD_READ_ICCP_LIC_CDYN_SCAL \
+						(IPC_PUNIT_GTD_CMD_BASE + 0x02)
+#define IPC_PUNIT_GTD_CMD_WRITE_ICCP_LIC_CDYN_SCAL \
+						(IPC_PUNIT_GTD_CMD_BASE + 0x03)
+#define IPC_PUNIT_GTD_CMD_GET_WM_VAL		(IPC_PUNIT_GTD_CMD_BASE + 0x06)
+#define IPC_PUNIT_GTD_CMD_WRITE_CONFIG_WISHREQ	(IPC_PUNIT_GTD_CMD_BASE + 0x07)
+#define IPC_PUNIT_GTD_CMD_READ_REQ_DUTY_CYCLE	(IPC_PUNIT_GTD_CMD_BASE + 0x16)
+#define IPC_PUNIT_GTD_CMD_DIS_VOL_FREQ_CHANGE_REQUEST \
+						(IPC_PUNIT_GTD_CMD_BASE + 0x17)
+#define IPC_PUNIT_GTD_CMD_DYNA_DUTY_CYCLE_CTRL	(IPC_PUNIT_GTD_CMD_BASE + 0x1a)
+#define IPC_PUNIT_GTD_CMD_DYNA_DUTY_CYCLE_TUNING \
+						(IPC_PUNIT_GTD_CMD_BASE + 0x1c)
+
+/* ISP Driver => Pcode commands */
+#define IPC_PUNIT_ISPD_CMD_ZERO			(IPC_PUNIT_ISPD_CMD_BASE + 0x00)
+#define IPC_PUNIT_ISPD_CMD_CONFIG		(IPC_PUNIT_ISPD_CMD_BASE + 0x01)
+#define IPC_PUNIT_ISPD_CMD_GET_ISP_LTR_VAL	(IPC_PUNIT_ISPD_CMD_BASE + 0x02)
+#define IPC_PUNIT_ISPD_CMD_ACCESS_IU_FREQ_BOUNDS \
+						(IPC_PUNIT_ISPD_CMD_BASE + 0x03)
+#define IPC_PUNIT_ISPD_CMD_READ_CDYN_LEVEL	(IPC_PUNIT_ISPD_CMD_BASE + 0x04)
+#define IPC_PUNIT_ISPD_CMD_WRITE_CDYN_LEVEL	(IPC_PUNIT_ISPD_CMD_BASE + 0x05)
+#define IPC_PUNIT_ISPD_CMD_MAX			(IPC_PUNIT_ISPD_CMD_BASE + 0x06)
+
+/* Error codes */
+#define IPC_PUNIT_ERR_SUCCESS			0
+#define IPC_PUNIT_ERR_INVALID_CMD		1
+#define IPC_PUNIT_ERR_INVALID_PARAMETER		2
+#define IPC_PUNIT_ERR_CMD_TIMEOUT		3
+#define IPC_PUNIT_ERR_CMD_LOCKED		4
+#define IPC_PUNIT_ERR_INVALID_VR_ID		5
+#define IPC_PUNIT_ERR_VR_ERR			6
+
+#if IS_ENABLED(CONFIG_INTEL_PUNIT_IPC)
+
+int intel_punit_ipc_simple_command(int cmd, int para1, int para2);
+int intel_punit_ipc_command(u32 cmd, u32 para1, u32 para2, u32 *in, u32 *out);
+
+#else
+
+static inline int intel_punit_ipc_simple_command(int cmd,
+						  int para1, int para2)
+{
+	return -EINVAL;
+}
+
+static inline int intel_punit_ipc_command(u32 cmd, u32 para1, u32 para2,
+					  u32 *in, u32 *out)
+{
+	return -EINVAL;
+}
+
+#endif /*CONFIG_INTEL_PUNIT_IPC*/
+
+#endif
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 346f1fd..9948369 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -891,4 +891,10 @@  config INTEL_PMC_IPC
 	The PMC is an ARC processor which defines IPC commands for communication
 	with other entities in the CPU.
 
+config INTEL_PUNIT_IPC
+	tristate "Intel P-Unit IPC Driver"
+	---help---
+	  This driver provides support for Intel P-Unit Mailbox IPC mechanism,
+	  which is used to bridge the communications between kernel and P-Unit.
+
 endif # X86_PLATFORM_DEVICES
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 1051372..eea765f 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -59,3 +59,4 @@  obj-$(CONFIG_INTEL_SMARTCONNECT)	+= intel-smartconnect.o
 obj-$(CONFIG_PVPANIC)           += pvpanic.o
 obj-$(CONFIG_ALIENWARE_WMI)	+= alienware-wmi.o
 obj-$(CONFIG_INTEL_PMC_IPC)	+= intel_pmc_ipc.o
+obj-$(CONFIG_INTEL_PUNIT_IPC)	+= intel_punit_ipc.o
diff --git a/drivers/platform/x86/intel_punit_ipc.c b/drivers/platform/x86/intel_punit_ipc.c
new file mode 100644
index 0000000..2d48bc0
--- /dev/null
+++ b/drivers/platform/x86/intel_punit_ipc.c
@@ -0,0 +1,353 @@ 
+/*
+ * Driver for the Intel P-Unit Mailbox IPC mechanism
+ *
+ * (C) Copyright 2015 Intel Corporation
+ *
+ * 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.
+ *
+ * The heart of the P-Unit is the Foxton microcontroller and its firmware,
+ * which provide mailbox interface for power management usage.
+ */
+
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <asm/intel_punit_ipc.h>
+
+/* Mailbox registers */
+#define MAILBOX_DATA_LOW		0x0
+#define MAILBOX_INTERFACE		0x4
+#define		CMD_RUN			(1 << 31)
+#define		CMD_ERRCODE_MASK	0xFF
+#define		CMD_PARA1_SHIFT		8
+#define		CMD_PARA2_SHIFT		16
+#define		CMD_MASK		0xFF
+#define MAILBOX_DATA_HIGH		0x8
+
+#define MAILBOX_REGISTER_SPACE		0x10
+
+#define CMD_TIMEOUT_SECONDS		3
+
+/* Three external mailbox */
+enum mailbox_type {
+	BIOS_MAILBOX,
+	GTDRIVER_MAILBOX,
+	ISPDRIVER_MAILBOX,
+	RESERVED_MAILBOX,
+};
+
+static char *ipc_err_sources[] = {
+	[IPC_PUNIT_ERR_SUCCESS] =
+		"no error",
+	[IPC_PUNIT_ERR_INVALID_CMD] =
+		"invalid command",
+	[IPC_PUNIT_ERR_INVALID_PARAMETER] =
+		"invalid parameter",
+	[IPC_PUNIT_ERR_CMD_TIMEOUT] =
+		"command timeout",
+	[IPC_PUNIT_ERR_CMD_LOCKED] =
+		"command locked",
+	[IPC_PUNIT_ERR_INVALID_VR_ID] =
+		"invalid vr id",
+	[IPC_PUNIT_ERR_VR_ERR] =
+		"vr error",
+};
+
+struct intel_punit_ipc_controller {
+	struct platform_device *pdev;
+	struct mutex lock;
+	void __iomem *base[RESERVED_MAILBOX];
+	struct completion cmd_complete;
+	int irq;
+
+	int cmd;
+	enum mailbox_type type;
+} ipcdev;
+
+static inline u32 ipc_read_status(void)
+{
+	return readl(ipcdev.base[ipcdev.type] + MAILBOX_INTERFACE);
+}
+
+static inline void ipc_write_cmd(u32 cmd)
+{
+	writel(cmd, ipcdev.base[ipcdev.type] + MAILBOX_INTERFACE);
+}
+
+static inline u32 ipc_read_data_low(void)
+{
+	return readl(ipcdev.base[ipcdev.type] + MAILBOX_DATA_LOW);
+}
+
+static inline u32 ipc_read_data_high(void)
+{
+	return readl(ipcdev.base[ipcdev.type] + MAILBOX_DATA_HIGH);
+}
+
+static inline void ipc_write_data_low(u32 data)
+{
+	writel(data, ipcdev.base[ipcdev.type] + MAILBOX_DATA_LOW);
+}
+
+static inline void ipc_write_data_high(u32 data)
+{
+	writel(data, ipcdev.base[ipcdev.type] + MAILBOX_DATA_HIGH);
+}
+
+static int intel_punit_ipc_send_command(u32 cmd)
+{
+	ipcdev.cmd = cmd;
+
+	cmd &= CMD_MASK;
+	if (cmd < IPC_PUNIT_BIOS_CMD_BASE)
+		return -EINVAL;
+	else if (cmd < IPC_PUNIT_GTD_CMD_BASE)
+		ipcdev.type = BIOS_MAILBOX;
+	else if (cmd < IPC_PUNIT_ISPD_CMD_BASE) {
+		ipcdev.type = GTDRIVER_MAILBOX;
+		ipcdev.cmd -= IPC_PUNIT_GTD_CMD_BASE;
+	} else if (cmd < IPC_PUNIT_ISPD_CMD_MAX) {
+		ipcdev.type = ISPDRIVER_MAILBOX;
+		ipcdev.cmd -= IPC_PUNIT_ISPD_CMD_BASE;
+	} else
+		return -EINVAL;
+
+	reinit_completion(&ipcdev.cmd_complete);
+	ipc_write_cmd(ipcdev.cmd);
+
+	return 0;
+}
+
+static int intel_punit_ipc_check_status(void)
+{
+	int loops = CMD_TIMEOUT_SECONDS * USEC_PER_SEC;
+	int errcode;
+	int status;
+
+	if (ipcdev.irq) {
+		if (!wait_for_completion_timeout(
+				&ipcdev.cmd_complete,
+				CMD_TIMEOUT_SECONDS * HZ)) {
+			dev_err(&ipcdev.pdev->dev,
+				"IPC timed out, IPC_CMD=0x%x\n", ipcdev.cmd);
+			return -ETIMEDOUT;
+		}
+	} else {
+		while ((ipc_read_status() & CMD_RUN) && --loops)
+			udelay(1);
+		if (!loops) {
+			dev_err(&ipcdev.pdev->dev,
+				"IPC timed out, IPC_CMD=0x%x\n", ipcdev.cmd);
+			return -ETIMEDOUT;
+		}
+	}
+
+	status = ipc_read_status();
+	errcode = status & CMD_ERRCODE_MASK;
+	if (errcode) {
+		if (errcode < ARRAY_SIZE(ipc_err_sources))
+			dev_err(&ipcdev.pdev->dev,
+				"IPC failed: %s, IPC_STS=0x%x, IPC_CMD=0x%x\n",
+				ipc_err_sources[errcode], status, ipcdev.cmd);
+		else
+			dev_err(&ipcdev.pdev->dev,
+				"IPC failed: unknown err,STS=0x%x, CMD=0x%x\n",
+				status, ipcdev.cmd);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/**
+ * intel_punit_ipc_simple_command() - Simple IPC command
+ * @cmd:	IPC command code.
+ * @para1:	First 8bit parameter, set 0 if invalid.
+ * @para2:	Second 8bit parameter, set 0 if invalid.
+ *
+ * Send a IPC command to P-Unit when there is no data transaction
+ *
+ * Return:	IPC error code or 0 on success.
+ */
+int intel_punit_ipc_simple_command(int cmd, int para1, int para2)
+{
+	int ret;
+
+	mutex_lock(&ipcdev.lock);
+	ret = intel_punit_ipc_send_command(CMD_RUN |
+					   para2 << CMD_PARA2_SHIFT |
+					   para1 << CMD_PARA1_SHIFT | cmd);
+	if (ret)
+		goto out;
+	ret = intel_punit_ipc_check_status();
+out:
+	mutex_unlock(&ipcdev.lock);
+	return ret;
+}
+EXPORT_SYMBOL(intel_punit_ipc_simple_command);
+
+/**
+ * intel_punit_ipc_command() - IPC command with data and pointers
+ * @cmd:	IPC command code.
+ * @para1:	First 8bit parameter, set 0 if invalid.
+ * @para2:	Second 8bit parameter, set 0 if invalid.
+ * @in:		Input data, 32bit for BIOS cmd, two 32bit for GTD and ISPD.
+ * @out:	Output data.
+ *
+ * Send a IPC command to P-Unit with data transaction
+ *
+ * Return:	IPC error code or 0 on success.
+ */
+int intel_punit_ipc_command(u32 cmd, u32 para1, u32 para2, u32 *in, u32 *out)
+{
+	int ret;
+
+	mutex_lock(&ipcdev.lock);
+	ipc_write_data_low(*in);
+	if (ipcdev.type == GTDRIVER_MAILBOX ||
+			ipcdev.type == ISPDRIVER_MAILBOX) {
+		in++;
+		ipc_write_data_high(*in);
+	}
+	ret = intel_punit_ipc_send_command(CMD_RUN |
+					   para2 << CMD_PARA2_SHIFT |
+					   para1 << CMD_PARA1_SHIFT | cmd);
+	if (ret)
+		goto out;
+	ret = intel_punit_ipc_check_status();
+	if (ret)
+		goto out;
+	*out = ipc_read_data_low();
+	if (ipcdev.type == GTDRIVER_MAILBOX ||
+			ipcdev.type == ISPDRIVER_MAILBOX) {
+		out++;
+		*out = ipc_read_data_high();
+	}
+out:
+	mutex_unlock(&ipcdev.lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(intel_punit_ipc_command);
+
+static irqreturn_t intel_punit_ioc(int irq, void *dev_id)
+{
+	complete(&ipcdev.cmd_complete);
+	return IRQ_HANDLED;
+}
+
+static int intel_punit_get_bars(struct platform_device *pdev)
+{
+	struct resource *res0, *res1;
+	void __iomem *addr;
+	int size;
+
+	res0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res0) {
+		dev_err(&pdev->dev, "Failed to get iomem resource\n");
+		return -EINVAL;
+	}
+	size = resource_size(res0);
+	if (!devm_request_mem_region(&pdev->dev, res0->start,
+				     size, pdev->name)) {
+		dev_err(&pdev->dev, "Failed to request iomem resouce\n");
+		return -EBUSY;
+	}
+
+	res1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res1) {
+		dev_err(&pdev->dev, "Failed to get iomem resource1\n");
+		return -EINVAL;
+	}
+	size = resource_size(res1);
+	if (!devm_request_mem_region(&pdev->dev, res1->start,
+				     size, pdev->name)) {
+		dev_err(&pdev->dev, "Failed to request iomem resouce1\n");
+		return -EBUSY;
+	}
+
+	addr = ioremap_nocache(res0->start,
+			       resource_size(res0) + resource_size(res1));
+	if (!addr) {
+		dev_err(&pdev->dev, "Failed to ioremap ipc base\n");
+		return  -ENOMEM;
+	}
+	ipcdev.base[BIOS_MAILBOX] = addr;
+	addr += MAILBOX_REGISTER_SPACE;
+	ipcdev.base[GTDRIVER_MAILBOX] = addr;
+	addr += MAILBOX_REGISTER_SPACE;
+	ipcdev.base[ISPDRIVER_MAILBOX] = addr;
+
+	return 0;
+}
+
+static int intel_punit_ipc_probe(struct platform_device *pdev)
+{
+	int irq, ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		ipcdev.irq = 0;
+		dev_warn(&pdev->dev, "Invalid IRQ\n");
+	} else {
+		if (devm_request_irq(&pdev->dev, irq, intel_punit_ioc,
+				     IRQF_NO_SUSPEND, "intel_punit_ipc",
+				     &ipcdev)) {
+			dev_err(&pdev->dev, "Failed to request irq: %d\n", irq);
+			return -EBUSY;
+		}
+		ipcdev.irq = irq;
+	}
+
+	ret = intel_punit_get_bars(pdev);
+	if (ret)
+		return ret;
+
+	ipcdev.pdev = pdev;
+	mutex_init(&ipcdev.lock);
+	init_completion(&ipcdev.cmd_complete);
+
+	return ret;
+}
+
+static int intel_punit_ipc_remove(struct platform_device *pdev)
+{
+	iounmap(ipcdev.base[BIOS_MAILBOX]);
+
+	return 0;
+}
+
+static const struct acpi_device_id punit_ipc_acpi_ids[] = {
+	{"INT34D4", 0}
+};
+
+static struct platform_driver intel_punit_ipc_driver = {
+	.probe = intel_punit_ipc_probe,
+	.remove = intel_punit_ipc_remove,
+	.driver = {
+		.name = "intel_punit_ipc",
+		.acpi_match_table = ACPI_PTR(punit_ipc_acpi_ids),
+	},
+};
+
+static int __init intel_punit_ipc_init(void)
+{
+	return platform_driver_register(&intel_punit_ipc_driver);
+}
+
+static void __exit intel_punit_ipc_exit(void)
+{
+	platform_driver_unregister(&intel_punit_ipc_driver);
+}
+
+MODULE_AUTHOR("Zha Qipeng <qipeng.zha@intel.com>");
+MODULE_DESCRIPTION("Intel P-Unit IPC driver");
+MODULE_LICENSE("GPL v2");
+
+/* Some modules are dependent on this, so init earlier */
+fs_initcall(intel_punit_ipc_init);
+module_exit(intel_punit_ipc_exit);