[PATCH v2] drivers: field for new GPIO driver

[PATCH v2] drivers: field for new GPIO driver

[YD Tseng]

Dear all,

Sorry to bother you and really appreciate for the review.

>>A very simple memory-mapped I/O GPIO, you should use select GPIO_GENERIC #include<linux/basic_mmio_gpio.h>And see for example drivers/gpio/gpio-74xx-mmio.c on how to use this generic MMIO library right.
This GPIO controller is located behind PCI-E device, We refer to drivers/gpio/gpio-amd8111.c.

>>So the dirver should support the .set_debounce() method.
rename PT_DEBOUNCE_REG to PT_CLOCKRATE_REG.

>>Is it not VENDOR, and what is in these registers really?
>>From the code it seems it is pin control registers, and this driver should then be in drivers/pinctrl/*.
>>See for example drivers/pinctrl/intel/* for how to do that right.
rename PT_VENDOR0_REG to PT_SYNC_REG, remove PT_VENDOR1_REG

>>Too many local variable. Just used a->b->c directly.
>>Well this will be using the MMIO library anyway so most stuff go away.
Modify in the new patch.

>>What is this? Pin multiplexing? Then implement this properly using pin control.
It's only used to sync the gpio pins.(avoid reusing the same pin)
We modified some code in pt_gpio_request(), this routine will return EINVAL if a pin is used.

---

This patch adds a new GPIO driver for AMD Promontory chip.  This GPIO controller is enumerated by ACPI and the ACPI compliant hardware ID is AMDF030.

A new file is added and 2 files are modified.
drivers/gpio/gpio-amdpt.c            New file
drivers/gpio/Kconfig                       Modified file
drivers/gpio/Makefile                    Modified file

Signed-off-by: YD Tseng <Yd_Tseng@asmedia.com.tw>
---
 gpio-amdpt.patch | 56 ++++++++++++++++++++++++--------------------------------
 1 file changed, 24 insertions(+), 32 deletions(-)

diff --git a/gpio-amdpt.patch b/gpio-amdpt.patch
index 228c06a..46b3ee8 100644
--- a/gpio-amdpt.patch
+++ b/gpio-amdpt.patch
@@ -1,7 +1,7 @@
 diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers/gpio/gpio-amdpt.c linux-4.2/drivers/gpio/gpio-amdpt.c
 --- linux-4.2.vanilla/drivers/gpio/gpio-amdpt.c	1969-12-31 19:00:00.000000000 -0500
-+++ linux-4.2/drivers/gpio/gpio-amdpt.c	2015-09-30 07:21:13.596121358 -0400
-@@ -0,0 +1,297 @@
++++ linux-4.2/drivers/gpio/gpio-amdpt.c	2015-05-21 07:49:24.736020310 -0400
+@@ -0,0 +1,289 @@
 +/*
 + * AMD Promontory GPIO driver
 + *
@@ -16,20 +16,18 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +#include <linux/kernel.h>
 +#include <linux/module.h>
 +#include <linux/gpio.h>
-+#include <linux/pci.h>
 +#include <linux/spinlock.h>
 +#include <linux/acpi.h>
 +#include <linux/platform_device.h>
 +
 +#define TOTAL_GPIO_PINS 8
 +
-+/* memory mapped register offsets */
++/* PCI-E MMIO register offsets */
 +#define PT_DIRECTION_REG   0x00
 +#define PT_INPUTDATA_REG   0x04
 +#define PT_OUTPUTDATA_REG  0x08
-+#define PT_DEBOUNCE_REG    0x0C
-+#define PT_VENDER0_REG     0x28
-+#define PT_VENDER1_REG     0x2C
++#define PT_CLOCKRATE_REG   0x0C
++#define PT_SYNC_REG        0x28
 +
 +struct pt_gpio_chip {
 +	struct gpio_chip         gc;
@@ -44,7 +42,6 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +{
 +	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
 +	struct platform_device *pdev;
-+	void __iomem *v_reg = pt_gpio->reg_base + PT_VENDER0_REG;
 +	unsigned long flags;
 +	u32 using_pins;
 +
@@ -54,11 +51,14 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +
 +	spin_lock_irqsave(&pt_gpio->lock, flags);
 +
-+	using_pins = readl(v_reg);
-+	if (using_pins&(1<<offset))
++	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
++	if (using_pins&(1<<offset)) {
 +		dev_warn(&pdev->dev, "PT GPIO pin %x reconfigured\n", offset);
++		spin_unlock_irqrestore(&pt_gpio->lock, flags);
++		return -EINVAL; 
++	}
 +	else
-+		writel(using_pins|(1<<offset), v_reg);
++		writel(using_pins|(1<<offset), pt_gpio->reg_base + PT_SYNC_REG);
 +
 +	spin_unlock_irqrestore(&pt_gpio->lock, flags);
 +
@@ -69,7 +69,6 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +{
 +	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
 +	struct platform_device *pdev;
-+	void __iomem *v_reg = pt_gpio->reg_base + PT_VENDER0_REG;
 +	unsigned long flags;
 +	u32 using_pins;
 +
@@ -77,9 +76,9 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +
 +	spin_lock_irqsave(&pt_gpio->lock, flags);
 +
-+	using_pins = readl(v_reg);
++	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
 +	using_pins &= ~BIT(offset);
-+	writel(using_pins, v_reg);
++	writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG);
 +
 +	spin_unlock_irqrestore(&pt_gpio->lock, flags);
 +
@@ -90,7 +89,6 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +{
 +	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
 +	struct platform_device *pdev;
-+	void __iomem *reg = pt_gpio->reg_base + PT_OUTPUTDATA_REG;
 +	unsigned long flags;
 +	u32 data;
 +
@@ -101,11 +99,11 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +
 +	spin_lock_irqsave(&pt_gpio->lock, flags);
 +
-+	data = readl(reg);
++	data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG);
 +	data &= ~BIT(offset);
 +	if (value)
 +		data |= BIT(offset);
-+	writel(data, reg);
++	writel(data, pt_gpio->reg_base + PT_OUTPUTDATA_REG);
 +
 +	spin_unlock_irqrestore(&pt_gpio->lock, flags);
 +}
@@ -143,7 +141,6 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
 +	struct platform_device *pdev;
 +	unsigned long flags;
-+	void __iomem *reg = pt_gpio->reg_base + PT_DIRECTION_REG;
 +	u32 data;
 +
 +	pdev = pt_gpio->pdev;
@@ -152,9 +149,9 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +
 +	spin_lock_irqsave(&pt_gpio->lock, flags);
 +
-+	data = readl(reg);
++	data = readl(pt_gpio->reg_base + PT_DIRECTION_REG);
 +	data &= ~BIT(offset);
-+	writel(data, reg);
++	writel(data, pt_gpio->reg_base + PT_DIRECTION_REG);
 +
 +	spin_unlock_irqrestore(&pt_gpio->lock, flags);
 +
@@ -167,8 +164,6 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
 +	struct platform_device *pdev;
 +	unsigned long flags;
-+	void __iomem *dir_reg = pt_gpio->reg_base + PT_DIRECTION_REG;
-+	void __iomem *output_reg = pt_gpio->reg_base + PT_OUTPUTDATA_REG;
 +	u32 data;
 +
 +	pdev = pt_gpio->pdev;
@@ -178,15 +173,15 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +
 +	spin_lock_irqsave(&pt_gpio->lock, flags);
 +
-+	data = readl(output_reg);
++	data = readl( pt_gpio->reg_base + PT_OUTPUTDATA_REG);
 +	if (value)
-+		writel(data |= BIT(offset), output_reg);
++		writel(data |= BIT(offset),  pt_gpio->reg_base + PT_OUTPUTDATA_REG);
 +	else
-+		writel(data &= ~BIT(offset), output_reg);
++		writel(data &= ~BIT(offset),  pt_gpio->reg_base + PT_OUTPUTDATA_REG);
 +
-+	data = readl(dir_reg);
++	data = readl(pt_gpio->reg_base + PT_DIRECTION_REG);
 +	data |= BIT(offset);
-+	writel(data, dir_reg);
++	writel(data, pt_gpio->reg_base + PT_DIRECTION_REG);
 +
 +	spin_unlock_irqrestore(&pt_gpio->lock, flags);
 +
@@ -200,7 +195,6 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +	acpi_handle handle = ACPI_HANDLE(dev);
 +	struct pt_gpio_chip *pt_gpio;
 +	struct resource *res_mem;
-+	void __iomem *reg;
 +	int ret = 0;
 +
 +	if (acpi_bus_get_device(handle, &acpi_dev)) {
@@ -249,10 +243,8 @@ diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers
 +	platform_set_drvdata(pdev, pt_gpio);
 +
 +	/* initialize register setting */
-+	reg = pt_gpio->reg_base + PT_VENDER0_REG;
-+	writel(0, reg);
-+	reg = pt_gpio->reg_base + PT_DEBOUNCE_REG;
-+	writel(0, reg);
++	writel(0, pt_gpio->reg_base + PT_SYNC_REG);
++	writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG);
 +
 +	dev_dbg(&pdev->dev, "PT GPIO driver loaded\n");
 +	return ret;
-- 
2.1.4

Re: [PATCH v2] drivers: field for new GPIO driver

[Alexandre Courbot]

On Wed, Oct 7, 2015 at 8:56 PM, YD Tseng <ltyu101@gmail.com> wrote:
>
> Dear all,
>
> Sorry to bother you and really appreciate for the review.
>
> >>A very simple memory-mapped I/O GPIO, you should use select GPIO_GENERIC #include<linux/basic_mmio_gpio.h>And see for example drivers/gpio/gpio-74xx-mmio.c on how to use this generic MMIO library right.
> This GPIO controller is located behind PCI-E device, We refer to drivers/gpio/gpio-amd8111.c.
>
> >>So the dirver should support the .set_debounce() method.
> rename PT_DEBOUNCE_REG to PT_CLOCKRATE_REG.
>
> >>Is it not VENDOR, and what is in these registers really?
> >>From the code it seems it is pin control registers, and this driver should then be in drivers/pinctrl/*.
> >>See for example drivers/pinctrl/intel/* for how to do that right.
> rename PT_VENDOR0_REG to PT_SYNC_REG, remove PT_VENDOR1_REG
>
> >>Too many local variable. Just used a->b->c directly.
> >>Well this will be using the MMIO library anyway so most stuff go away.
> Modify in the new patch.
>
> >>What is this? Pin multiplexing? Then implement this properly using pin control.
> It's only used to sync the gpio pins.(avoid reusing the same pin)
> We modified some code in pt_gpio_request(), this routine will return EINVAL if a pin is used.

Do not reply to reviews in a new patch. Reply in the former thread,
*then* submit a new patch.

>
> ---
>
> This patch adds a new GPIO driver for AMD Promontory chip.  This GPIO controller is enumerated by ACPI and the ACPI compliant hardware ID is AMDF030.
>
> A new file is added and 2 files are modified.
> drivers/gpio/gpio-amdpt.c            New file
> drivers/gpio/Kconfig                       Modified file
> drivers/gpio/Makefile                    Modified file
>
> Signed-off-by: YD Tseng <Yd_Tseng@asmedia.com.tw>
> ---
>  gpio-amdpt.patch | 56 ++++++++++++++++++++++++--------------------------------
>  1 file changed, 24 insertions(+), 32 deletions(-)
>
> diff --git a/gpio-amdpt.patch b/gpio-amdpt.patch
> index 228c06a..46b3ee8 100644
> --- a/gpio-amdpt.patch
> +++ b/gpio-amdpt.patch

Errr you got to be kidding, right?

You are sending a diff to a patch. That's absolutely unusable and I
don't understand why one would even think of doing that.

Re-read Documentation/SubmittingPatches and other relevant documents,
and make sure you understand them before submitting anything else.

Re: [PATCH v2] drivers: field for new GPIO driver

[Dmitry Eremin-Solenikov]

2015-10-13 12:04 GMT+03:00 YD Tseng <ltyu101@gmail.com>:
> Dear all:
>
> This patch adds a new GPIO driver for AMD Promontory chip.  This GPIO controller is enumerated by ACPI and the ACPI compliant hardware ID is AMDF030.
>
> Signed-off-by: YD Tseng <Yd_Tseng@asmedia.com.tw>
>
> ---
> v2: 1. fixed the coding style
>     2. registers renaming
>
> A new file is added and 2 files are modified.
> drivers/gpio/gpio-amdpt.c            New file
> drivers/gpio/Kconfig                       Modified file
> drivers/gpio/Makefile                    Modified file
>
> diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers/gpio/gpio-amdpt.c linux-4.2/drivers/gpio/gpio-amdpt.c
> --- linux-4.2.vanilla/drivers/gpio/gpio-amdpt.c 1969-12-31 19:00:00.000000000 -0500
> +++ linux-4.2/drivers/gpio/gpio-amdpt.c 2015-05-21 07:49:24.736020310 -0400
> @@ -0,0 +1,289 @@
> +/*
> + * AMD Promontory GPIO driver
> + *
> + * Copyright (C) 2015 ASMedia Technology Inc.
> + * Author: YD Tseng <yd_tseng@asmedia.com.tw>
> + *
> + * 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/kernel.h>
> +#include <linux/module.h>
> +#include <linux/gpio.h>

#include <linux/gpio/driver.h> instead ?

> +#include <linux/spinlock.h>
> +#include <linux/acpi.h>
> +#include <linux/platform_device.h>
> +
> +#define TOTAL_GPIO_PINS 8
> +
> +/* PCI-E MMIO register offsets */
> +#define PT_DIRECTION_REG   0x00
> +#define PT_INPUTDATA_REG   0x04
> +#define PT_OUTPUTDATA_REG  0x08
> +#define PT_CLOCKRATE_REG   0x0C
> +#define PT_SYNC_REG        0x28
> +
> +struct pt_gpio_chip {
> +       struct gpio_chip         gc;
> +       struct platform_device   *pdev;

You don't really need pdev. You can use gc->dev for logging information instead.

> +       void __iomem             *reg_base;
> +       spinlock_t               lock;
> +};
> +
> +#define to_pt_gpio(c)  container_of(c, struct pt_gpio_chip, gc)
> +
> +static int pt_gpio_request(struct gpio_chip *gc, unsigned offset)
> +{
> +       struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
> +       struct platform_device *pdev;
> +       unsigned long flags;
> +       u32 using_pins;
> +
> +       pdev = pt_gpio->pdev;
> +
> +       dev_dbg(&pdev->dev, "pt_gpio_request offset=%x\n", offset);
> +
> +       spin_lock_irqsave(&pt_gpio->lock, flags);
> +
> +       using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
> +       if (using_pins&(1<<offset)) {

spaces? Also using_pins & BIT(offset) would be more readable.

> +               dev_warn(&pdev->dev, "PT GPIO pin %x reconfigured\n", offset);
> +               spin_unlock_irqrestore(&pt_gpio->lock, flags);
> +               return -EINVAL;
> +       }
> +       else
> +               writel(using_pins|(1<<offset), pt_gpio->reg_base + PT_SYNC_REG);

Please refer to CodingStyle document.

Also you don't need the "else" word at all here.

> +
> +       spin_unlock_irqrestore(&pt_gpio->lock, flags);
> +
> +       return 0;
> +}
> +

[skipped]

> +static int pt_gpio_get_value(struct gpio_chip *gc, unsigned offset)
> +{
> +       struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
> +       struct platform_device *pdev;
> +       unsigned long flags;
> +       u32 data;
> +
> +       pdev = pt_gpio->pdev;
> +
> +       spin_lock_irqsave(&pt_gpio->lock, flags);
> +
> +       /* configure as output */
> +       if ((readl(pt_gpio->reg_base + PT_DIRECTION_REG)>>offset)&0x1)

data = readl(...);
if (data & BIT(offset)) {
   ...
} else {
  ...
}

> +               data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG);
> +       else    /* configure as input */
> +               data = readl(pt_gpio->reg_base + PT_INPUTDATA_REG);
> +
> +       spin_unlock_irqrestore(&pt_gpio->lock, flags);
> +
> +       data >>= offset;
> +       data &= 1;

Ghm.

> +
> +       dev_dbg(&pdev->dev, "pt_gpio_get_value offset=%x, value=%x\n", offset,
> +               data);
> +
> +       return data;
> +}
> +

[skipped]

> +
> +static int pt_gpio_direction_output(struct gpio_chip *gc,
> +                                       unsigned offset, int value)
> +{
> +       struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
> +       struct platform_device *pdev;
> +       unsigned long flags;
> +       u32 data;
> +
> +       pdev = pt_gpio->pdev;
> +
> +       dev_dbg(&pdev->dev, "pt_gpio_direction_output offset=%x, value=%x\n",
> +               offset, value);
> +
> +       spin_lock_irqsave(&pt_gpio->lock, flags);
> +
> +       data = readl( pt_gpio->reg_base + PT_OUTPUTDATA_REG);
> +       if (value)
> +               writel(data |= BIT(offset),  pt_gpio->reg_base + PT_OUTPUTDATA_REG);
> +       else
> +               writel(data &= ~BIT(offset),  pt_gpio->reg_base + PT_OUTPUTDATA_REG);

data = readl(..);
if (value)
  data |= BIT(offset);
else
  data &= ~BIT(offset);
writel(...);

> +
> +       data = readl(pt_gpio->reg_base + PT_DIRECTION_REG);
> +       data |= BIT(offset);
> +       writel(data, pt_gpio->reg_base + PT_DIRECTION_REG);
> +
> +       spin_unlock_irqrestore(&pt_gpio->lock, flags);
> +
> +       return 0;
> +}

[skipped]

> +
> +static int __init pt_gpio_init(void)
> +{
> +       return platform_driver_register(&pt_gpio_driver);
> +}
> +
> +static void __exit pt_gpio_exit(void)
> +{
> +       platform_driver_unregister(&pt_gpio_driver);
> +}
> +
> +module_init(pt_gpio_init);
> +module_exit(pt_gpio_exit);

I'd suggest to use module_platform_driver() macro here.

> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("YD Tseng <yd_tseng@asmedia.com.tw>");
> +MODULE_DESCRIPTION("AMD Promontory GPIO Driver");
> +MODULE_ALIAS("platform:pt-gpio");

Do you really need this alias? For what purpose?


-- 
With best wishes
Dmitry

[PATCH v2] drivers: field for new GPIO driver

[YD Tseng]

Dear all:

This patch adds a new GPIO driver for AMD Promontory chip.  This GPIO controller is enumerated by ACPI and the ACPI compliant hardware ID is AMDF030.

Signed-off-by: YD Tseng <Yd_Tseng@asmedia.com.tw>

---
v2: 1. fixed the coding style
    2. registers renaming

A new file is added and 2 files are modified.
drivers/gpio/gpio-amdpt.c            New file
drivers/gpio/Kconfig                       Modified file
drivers/gpio/Makefile                    Modified file

diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers/gpio/gpio-amdpt.c linux-4.2/drivers/gpio/gpio-amdpt.c
--- linux-4.2.vanilla/drivers/gpio/gpio-amdpt.c	1969-12-31 19:00:00.000000000 -0500
+++ linux-4.2/drivers/gpio/gpio-amdpt.c	2015-05-21 07:49:24.736020310 -0400
@@ -0,0 +1,289 @@
+/*
+ * AMD Promontory GPIO driver
+ *
+ * Copyright (C) 2015 ASMedia Technology Inc.
+ * Author: YD Tseng <yd_tseng@asmedia.com.tw>
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/spinlock.h>
+#include <linux/acpi.h>
+#include <linux/platform_device.h>
+
+#define TOTAL_GPIO_PINS 8
+
+/* PCI-E MMIO register offsets */
+#define PT_DIRECTION_REG   0x00
+#define PT_INPUTDATA_REG   0x04
+#define PT_OUTPUTDATA_REG  0x08
+#define PT_CLOCKRATE_REG   0x0C
+#define PT_SYNC_REG        0x28
+
+struct pt_gpio_chip {
+	struct gpio_chip         gc;
+	struct platform_device   *pdev;
+	void __iomem             *reg_base;
+	spinlock_t               lock;
+};
+
+#define to_pt_gpio(c)	container_of(c, struct pt_gpio_chip, gc)
+
+static int pt_gpio_request(struct gpio_chip *gc, unsigned offset)
+{
+	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+	struct platform_device *pdev;
+	unsigned long flags;
+	u32 using_pins;
+
+	pdev = pt_gpio->pdev;
+
+	dev_dbg(&pdev->dev, "pt_gpio_request offset=%x\n", offset);
+
+	spin_lock_irqsave(&pt_gpio->lock, flags);
+
+	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
+	if (using_pins&(1<<offset)) {
+		dev_warn(&pdev->dev, "PT GPIO pin %x reconfigured\n", offset);
+		spin_unlock_irqrestore(&pt_gpio->lock, flags);
+		return -EINVAL; 
+	}
+	else
+		writel(using_pins|(1<<offset), pt_gpio->reg_base + PT_SYNC_REG);
+
+	spin_unlock_irqrestore(&pt_gpio->lock, flags);
+
+	return 0;
+}
+
+static void pt_gpio_free(struct gpio_chip *gc, unsigned offset)
+{
+	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+	struct platform_device *pdev;
+	unsigned long flags;
+	u32 using_pins;
+
+	pdev = pt_gpio->pdev;
+
+	spin_lock_irqsave(&pt_gpio->lock, flags);
+
+	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
+	using_pins &= ~BIT(offset);
+	writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG);
+
+	spin_unlock_irqrestore(&pt_gpio->lock, flags);
+
+	dev_dbg(&pdev->dev, "pt_gpio_free offset=%x\n", offset);
+}
+
+static void pt_gpio_set_value(struct gpio_chip *gc, unsigned offset, int value)
+{
+	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+	struct platform_device *pdev;
+	unsigned long flags;
+	u32 data;
+
+	pdev = pt_gpio->pdev;
+
+	dev_dbg(&pdev->dev, "pt_gpio_set_value offset=%x, value=%x\n", offset,
+		value);
+
+	spin_lock_irqsave(&pt_gpio->lock, flags);
+
+	data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG);
+	data &= ~BIT(offset);
+	if (value)
+		data |= BIT(offset);
+	writel(data, pt_gpio->reg_base + PT_OUTPUTDATA_REG);
+
+	spin_unlock_irqrestore(&pt_gpio->lock, flags);
+}
+
+static int pt_gpio_get_value(struct gpio_chip *gc, unsigned offset)
+{
+	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+	struct platform_device *pdev;
+	unsigned long flags;
+	u32 data;
+
+	pdev = pt_gpio->pdev;
+
+	spin_lock_irqsave(&pt_gpio->lock, flags);
+
+	/* configure as output */
+	if ((readl(pt_gpio->reg_base + PT_DIRECTION_REG)>>offset)&0x1)
+		data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG);
+	else	/* configure as input */
+		data = readl(pt_gpio->reg_base + PT_INPUTDATA_REG);
+
+	spin_unlock_irqrestore(&pt_gpio->lock, flags);
+
+	data >>= offset;
+	data &= 1;
+
+	dev_dbg(&pdev->dev, "pt_gpio_get_value offset=%x, value=%x\n", offset,
+		data);
+
+	return data;
+}
+
+static int pt_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+	struct platform_device *pdev;
+	unsigned long flags;
+	u32 data;
+
+	pdev = pt_gpio->pdev;
+
+	dev_dbg(&pdev->dev, "pt_gpio_dirction_input offset=%x\n", offset);
+
+	spin_lock_irqsave(&pt_gpio->lock, flags);
+
+	data = readl(pt_gpio->reg_base + PT_DIRECTION_REG);
+	data &= ~BIT(offset);
+	writel(data, pt_gpio->reg_base + PT_DIRECTION_REG);
+
+	spin_unlock_irqrestore(&pt_gpio->lock, flags);
+
+	return 0;
+}
+
+static int pt_gpio_direction_output(struct gpio_chip *gc,
+					unsigned offset, int value)
+{
+	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+	struct platform_device *pdev;
+	unsigned long flags;
+	u32 data;
+
+	pdev = pt_gpio->pdev;
+
+	dev_dbg(&pdev->dev, "pt_gpio_direction_output offset=%x, value=%x\n",
+		offset, value);
+
+	spin_lock_irqsave(&pt_gpio->lock, flags);
+
+	data = readl( pt_gpio->reg_base + PT_OUTPUTDATA_REG);
+	if (value)
+		writel(data |= BIT(offset),  pt_gpio->reg_base + PT_OUTPUTDATA_REG);
+	else
+		writel(data &= ~BIT(offset),  pt_gpio->reg_base + PT_OUTPUTDATA_REG);
+
+	data = readl(pt_gpio->reg_base + PT_DIRECTION_REG);
+	data |= BIT(offset);
+	writel(data, pt_gpio->reg_base + PT_DIRECTION_REG);
+
+	spin_unlock_irqrestore(&pt_gpio->lock, flags);
+
+	return 0;
+}
+
+static int pt_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct acpi_device *acpi_dev;
+	acpi_handle handle = ACPI_HANDLE(dev);
+	struct pt_gpio_chip *pt_gpio;
+	struct resource *res_mem;
+	int ret = 0;
+
+	if (acpi_bus_get_device(handle, &acpi_dev)) {
+		dev_err(dev, "PT GPIO device node not found\n");
+		return -ENODEV;
+	}
+
+	pt_gpio = devm_kzalloc(dev, sizeof(struct pt_gpio_chip), GFP_KERNEL);
+	if (!pt_gpio)
+		return -ENOMEM;
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res_mem) {
+		dev_err(&pdev->dev, "Failed to get MMIO resource for PT GPIO.\n");
+		return -EINVAL;
+	}
+	pt_gpio->reg_base = devm_ioremap_resource(dev, res_mem);
+	if (IS_ERR(pt_gpio->reg_base)) {
+		dev_err(&pdev->dev, "Failed to map MMIO resource for PT GPIO.\n");
+		return PTR_ERR(pt_gpio->reg_base);
+	}
+
+	pt_gpio->pdev = pdev;
+	spin_lock_init(&pt_gpio->lock);
+
+	pt_gpio->gc.label            = pdev->name;
+	pt_gpio->gc.owner            = THIS_MODULE;
+	pt_gpio->gc.dev              = dev;
+	pt_gpio->gc.request          = pt_gpio_request;
+	pt_gpio->gc.free             = pt_gpio_free;
+	pt_gpio->gc.direction_input  = pt_gpio_direction_input;
+	pt_gpio->gc.direction_output = pt_gpio_direction_output;
+	pt_gpio->gc.get              = pt_gpio_get_value;
+	pt_gpio->gc.set              = pt_gpio_set_value;
+	pt_gpio->gc.base             = -1;
+	pt_gpio->gc.ngpio            = TOTAL_GPIO_PINS;
+#if defined(CONFIG_OF_GPIO)
+	pt_gpio->gc.of_node          = pdev->dev.of_node;
+#endif
+	ret = gpiochip_add(&pt_gpio->gc);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register GPIO lib\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, pt_gpio);
+
+	/* initialize register setting */
+	writel(0, pt_gpio->reg_base + PT_SYNC_REG);
+	writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG);
+
+	dev_dbg(&pdev->dev, "PT GPIO driver loaded\n");
+	return ret;
+}
+
+static int pt_gpio_remove(struct platform_device *pdev)
+{
+	struct pt_gpio_chip *pt_gpio = platform_get_drvdata(pdev);
+
+	gpiochip_remove(&pt_gpio->gc);
+
+	return 0;
+}
+
+static const struct acpi_device_id pt_gpio_acpi_match[] = {
+	{ "AMDF030", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, pt_gpio_acpi_match);
+
+static struct platform_driver pt_gpio_driver = {
+	.driver = {
+		.name = "pt-gpio",
+		.acpi_match_table = ACPI_PTR(pt_gpio_acpi_match),
+	},
+	.probe = pt_gpio_probe,
+	.remove = pt_gpio_remove,
+};
+
+static int __init pt_gpio_init(void)
+{
+	return platform_driver_register(&pt_gpio_driver);
+}
+
+static void __exit pt_gpio_exit(void)
+{
+	platform_driver_unregister(&pt_gpio_driver);
+}
+
+module_init(pt_gpio_init);
+module_exit(pt_gpio_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("YD Tseng <yd_tseng@asmedia.com.tw>");
+MODULE_DESCRIPTION("AMD Promontory GPIO Driver");
+MODULE_ALIAS("platform:pt-gpio");
diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers/gpio/Kconfig linux-4.2/drivers/gpio/Kconfig
--- linux-4.2.vanilla/drivers/gpio/Kconfig	2015-08-30 14:34:09.000000000 -0400
+++ linux-4.2/drivers/gpio/Kconfig	2015-09-03 13:00:50.341364000 -0400
@@ -120,6 +120,13 @@ config GPIO_ALTERA
 
 	  If driver is built as a module it will be called gpio-altera.
 
+config GPIO_AMDPT
+	tristate "AMD Promontory GPIO support"
+	depends on PCI && ACPI
+	help
+	  driver for GPIO functionality on Promontory IOHub
+	  Require ACPI ASL code to enumerate as a platform device.
+
 config GPIO_BCM_KONA
 	bool "Broadcom Kona GPIO"
 	depends on OF_GPIO && (ARCH_BCM_MOBILE || COMPILE_TEST)
diff -uprN -X linux-4.2.vanilla/Documentation/dontdiff linux-4.2.vanilla/drivers/gpio/Makefile linux-4.2/drivers/gpio/Makefile
--- linux-4.2.vanilla/drivers/gpio/Makefile	2015-08-30 14:34:09.000000000 -0400
+++ linux-4.2/drivers/gpio/Makefile	2015-09-03 11:39:17.833086000 -0400
@@ -19,6 +19,7 @@ obj-$(CONFIG_GPIO_ADP5520)	+= gpio-adp55
 obj-$(CONFIG_GPIO_ADP5588)	+= gpio-adp5588.o
 obj-$(CONFIG_GPIO_ALTERA)  	+= gpio-altera.o
 obj-$(CONFIG_GPIO_AMD8111)	+= gpio-amd8111.o
+obj-$(CONFIG_GPIO_AMDPT)	+= gpio-amdpt.o
 obj-$(CONFIG_GPIO_ARIZONA)	+= gpio-arizona.o
 obj-$(CONFIG_GPIO_BCM_KONA)	+= gpio-bcm-kona.o
 obj-$(CONFIG_GPIO_BRCMSTB)	+= gpio-brcmstb.o