diff mbox

[OpenWrt-Devel,V3,1/5] brcm63xx: add basic-mmio-gpio DT support

Message ID 54C528DE.8030504@gmail.com
State Rejected
Delegated to: Jonas Gorski
Headers show

Commit Message

Álvaro Fernández Rojas Jan. 25, 2015, 5:33 p.m. UTC 
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
---

Comments

Jonas Gorski Feb. 27, 2015, 6:13 p.m. UTC | #1 
Hi,

On Sun, Jan 25, 2015 at 6:33 PM, Álvaro Fernández Rojas
<noltari@gmail.com> wrote:
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> ---

I decided to add a basic mmio gpio based driver with its own match; to
reduce the amount ot backports/patches, I'll push it later.

Still I don't want to leave the issues in this patch(-set) uncommented:

> diff --git a/target/linux/brcm63xx/patches-3.14/374-GPIO-generic-pdata-add-label-backport.patch b/target/linux/brcm63xx/patches-3.14/374-GPIO-generic-pdata-add-label-backport.patch
> new file mode 100644
> index 0000000..cba5a0a
> --- /dev/null
> +++ b/target/linux/brcm63xx/patches-3.14/374-GPIO-generic-pdata-add-label-backport.patch
> @@ -0,0 +1,21 @@

Please do not remove the git headers when backporting commits from
upstream. Also please use 0xx- for upstream commits.

> +--- a/drivers/gpio/gpio-generic.c
> ++++ b/drivers/gpio/gpio-generic.c
> +@@ -531,6 +531,8 @@ static int bgpio_pdev_probe(struct platf
> +               return err;
> +
> +       if (pdata) {
> ++              if (pdata->label)
> ++                      bgc->gc.label = pdata->label;
> +               bgc->gc.base = pdata->base;
> +               if (pdata->ngpio > 0)
> +                       bgc->gc.ngpio = pdata->ngpio;
> +--- a/include/linux/basic_mmio_gpio.h
> ++++ b/include/linux/basic_mmio_gpio.h
> +@@ -19,6 +19,7 @@
> + #include <linux/spinlock_types.h>
> +
> + struct bgpio_pdata {
> ++      const char *label;
> +       int base;
> +       int ngpio;
> + };
> diff --git a/target/linux/brcm63xx/patches-3.14/375-GPIO-generic-driver-flags-backport.patch b/target/linux/brcm63xx/patches-3.14/375-GPIO-generic-driver-flags-backport.patch
> new file mode 100644
> index 0000000..3915d2c
> --- /dev/null
> +++ b/target/linux/brcm63xx/patches-3.14/375-GPIO-generic-driver-flags-backport.patch
> @@ -0,0 +1,39 @@
> +--- a/drivers/gpio/gpio-generic.c
> ++++ b/drivers/gpio/gpio-generic.c

Same as above.

> +@@ -488,7 +488,7 @@ static int bgpio_pdev_probe(struct platf
> +       void __iomem *dirout;
> +       void __iomem *dirin;
> +       unsigned long sz;
> +-      unsigned long flags = 0;
> ++      unsigned long flags = pdev->id_entry->driver_data;
> +       int err;
> +       struct bgpio_chip *bgc;
> +       struct bgpio_pdata *pdata = dev_get_platdata(dev);
> +@@ -519,9 +519,6 @@ static int bgpio_pdev_probe(struct platf
> +       if (err)
> +               return err;
> +
> +-      if (!strcmp(platform_get_device_id(pdev)->name, "basic-mmio-gpio-be"))
> +-              flags |= BGPIOF_BIG_ENDIAN;
> +-
> +       bgc = devm_kzalloc(&pdev->dev, sizeof(*bgc), GFP_KERNEL);
> +       if (!bgc)
> +               return -ENOMEM;
> +@@ -551,9 +548,14 @@ static int bgpio_pdev_remove(struct plat
> + }
> +
> + static const struct platform_device_id bgpio_id_table[] = {
> +-      { "basic-mmio-gpio", },
> +-      { "basic-mmio-gpio-be", },
> +-      {},
> ++      {
> ++              .name           = "basic-mmio-gpio",
> ++              .driver_data    = 0,
> ++      }, {
> ++              .name           = "basic-mmio-gpio-be",
> ++              .driver_data    = BGPIOF_BIG_ENDIAN,
> ++      },
> ++      { }
> + };
> + MODULE_DEVICE_TABLE(platform, bgpio_id_table);
> +
> diff --git a/target/linux/brcm63xx/patches-3.14/376-DT-basic-mmio-gpio.patch b/target/linux/brcm63xx/patches-3.14/376-DT-basic-mmio-gpio.patch
> new file mode 100644
> index 0000000..cda38b2
> --- /dev/null
> +++ b/target/linux/brcm63xx/patches-3.14/376-DT-basic-mmio-gpio.patch
> @@ -0,0 +1,204 @@

Please add proper git patch headers here, to make tracking code
ownership easier.

> +--- a/Documentation/devicetree/bindings/gpio/gpio.txt
> ++++ b/Documentation/devicetree/bindings/gpio/gpio.txt
> +@@ -153,3 +153,75 @@ Example 2:
> + Here, three GPIO ranges are defined wrt. two pin controllers. pinctrl1 GPIO
> + ranges are defined using pin numbers whereas the GPIO ranges wrt. pinctrl2
> + are named "foo" and "bar".
> ++
> ++3) Generic driver for memory-mapped GPIO controllers
> ++----------------------------------------------------
> ++The GPIO generic library provides support for basic platform_device
> ++memory-mapped GPIO controllers, which can be accessed by selecting Kconfig
> ++symbol GPIO_GENERIC and using library functions provided by GPIO generic
> ++driver (see drivers/gpio/gpio-generic.c).
> ++The simplest form of a GPIO controller that the driver support is just a
> ++single "data" register, where GPIO state can be read and/or written.
> ++
> ++The driver supports:
> ++- 8/16/32/64 bits registers. The number of GPIOs is determined by the width of
> ++  the registers.
> ++- GPIO controllers with clear/set registers.
> ++- GPIO controllers with a single "data" register.
> ++- Big endian bits/GPIOs ordering.
> ++
> ++For setting GPIO's there are three supported configurations:
> ++- single input/output register resource (named "dat").
> ++- set/clear pair (named "set" and "clr").
> ++- single output register resource and single input resource ("set" and dat").
> ++
> ++For setting the GPIO direction, there are three supported configurations:
> ++- simple bidirection GPIO that requires no configuration.
> ++- an output direction register (named "dirout") where a 1 bit indicates the
> ++  GPIO is an output.
> ++- an input direction register (named "dirin") where a 1 bit indicates the GPIO
> ++  is an input.
> ++
> ++Required properties:
> ++- compatible : Should be "basic-mmio-gpio".
> ++- reg : Address and length of the registers needed for the device.
> ++- reg-names : Names of the needed registers.
> ++- #gpio-cells : Should be two.  The first cell is the pin number and
> ++  the second cell is used to specify optional parameters (currently
> ++  unused).

Despite claimed for many drivers, this is not true for any controller
driver using 2+ gpio-cells and not providing a custom xlate function;
the second cell will be used as gpio flags (like active high/low).

> ++- gpio-controller : Marks the device node as a gpio controller.
> ++
> ++Optional properties:
> ++- num-gpios : Specify the number of configurable gpios.
> ++- bit-be : Use big endian order for pins.

No need for brevity, call it "big-endian-bit-order".

> ++- byte-be : Use big endian byte order for registers.

Kevin proposed generic properties for this, see
http://patchwork.linux-mips.org/patch/8566/ so I think it would be
good to use at least the same property name. For some unknown reason
it does not seem to have made it into 3.20.

> ++- regset-wo : set register is unreadable.
> ++- regdir-wo : dir register is unreadable.

Same comment regarding bit-be.

> ++
> ++Examples:
> ++
> ++gpio0: gpio-controller@10000084 {
> ++      compatible = "brcm,brcm6368", "basic-mmio-gpio";

This should probably be "brcm,brcm6368-gpio" ;p

> ++      reg = <0x10000084 0x4>, <0x1000008c 0x4>;
> ++      reg-names = "dirout", "dat";
> ++
> ++      gpio-controller;
> ++      #gpio-cells = <2>;
> ++
> ++      num-gpios = <32>;

Setting the gpios to the same as the register width seems pointless
(but probably also harmless).

> ++      byte-be;
> ++};
> ++
> ++gpio1: gpio-controller@10000180 {
> ++      compatible = "foo,bar", "basic-mmio-gpio";
> ++      reg = <0x10000180 0x4>, <0x10000184 0x4>, <0x10000188 0x4>;
> ++      reg-names = "dirin", "dirout", "dat";
> ++
> ++      gpio-controller;
> ++      #gpio-cells = <2>;
> ++
> ++      num-gpios = <20>;
> ++      bit-be;
> ++      byte-be;
> ++      regdir-wo;
> ++};
> +--- a/drivers/gpio/gpio-generic.c
> ++++ b/drivers/gpio/gpio-generic.c
> +@@ -61,6 +61,9 @@ o        `                     ~~~~\___/
> + #include <linux/platform_device.h>
> + #include <linux/mod_devicetable.h>
> + #include <linux/basic_mmio_gpio.h>
> ++#include <linux/of.h>
> ++#include <linux/of_device.h>
> ++#include <linux/of_gpio.h>
> +
> + static void bgpio_write8(void __iomem *reg, unsigned long data)
> + {
> +@@ -478,8 +481,58 @@ static void __iomem *bgpio_map(struct pl
> +       return ret;
> + }
> +
> ++#ifdef CONFIG_OF
> ++static const struct of_device_id bgpio_dt_ids[] = {
> ++      { .compatible = "basic-mmio-gpio" },
> ++};
> ++MODULE_DEVICE_TABLE(of, bgpio_dt_ids);
> ++
> ++static int bgpio_probe_dt(struct platform_device *pdev)
> ++{
> ++      u32 tmp;
> ++      struct bgpio_pdata *pdata;
> ++      struct device_node *np;
> ++
> ++      np = pdev->dev.of_node;
> ++      if (!np)
> ++              return 0;
> ++
> ++      pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> ++      if (!pdata)
> ++              return -ENOMEM;
> ++
> ++      pdata->label = dev_name(&pdev->dev);
> ++      pdata->base = -1;
> ++      if (of_find_property(np, "byte-be", NULL)) {
> ++              pdata->flags |= BGPIOF_BIG_ENDIAN_BYTE_ORDER;
> ++      }

Superfluous braces.

> ++      if (of_find_property(np, "bit-be", NULL)) {
> ++              pdata->flags |= BGPIOF_BIG_ENDIAN;
> ++      }

Superfluous braces.

> ++      if (of_find_property(np, "regset-wo", NULL)) {
> ++              pdata->flags |= BGPIOF_UNREADABLE_REG_SET;
> ++      }

Superfluous braces.

> ++      if (of_find_property(np, "regdir-wo", NULL)) {
> ++              pdata->flags |= BGPIOF_UNREADABLE_REG_DIR;
> ++      }

Superfluous braces.

> ++      if (!of_property_read_u32(np, "num-gpios", &tmp)) {
> ++              pdata->ngpio = tmp;
> ++      }

Superfluous braces.

> ++
> ++      pdev->dev.platform_data = pdata;
> ++
> ++      return 1;
> ++}
> ++#else
> ++static inline int bgpio_probe_dt(struct platform_device *pdev)
> ++{
> ++      return 0;
> ++}
> ++#endif
> ++
> + static int bgpio_pdev_probe(struct platform_device *pdev)
> + {
> ++      int status;
> +       struct device *dev = &pdev->dev;
> +       struct resource *r;
> +       void __iomem *dat;
> +@@ -488,10 +541,24 @@ static int bgpio_pdev_probe(struct platf
> +       void __iomem *dirout;
> +       void __iomem *dirin;
> +       unsigned long sz;
> +-      unsigned long flags = pdev->id_entry->driver_data;
> ++      unsigned long flags;
> +       int err;
> +       struct bgpio_chip *bgc;
> +-      struct bgpio_pdata *pdata = dev_get_platdata(dev);
> ++      struct bgpio_pdata *pdata;
> ++      bool use_of = 0;
> ++
> ++      status = bgpio_probe_dt(pdev);
> ++      if (status < 0)
> ++              return status;
> ++      if (status > 0)
> ++              use_of = 1;
> ++
> ++      pdata = dev_get_platdata(dev);
> ++
> ++      if (!use_of)
> ++              flags = pdev->id_entry->driver_data;
> ++      else if (pdata)
> ++              flags = pdata->flags;

How about instead:

if (dev->of_node)
       flags = bgpio_of_get_flags(pdev);
else
       flags = pdev->id_entry->driver_data;


and then later

if (dev->of_node) {
     of_read_property_u16(dev->of_node, "ngpios", &bgc->gc.ngpios);
else if (pdata) {
    bgc->gc.ngpios = pdata->ngpios;
    ...
}

Then you don't need to allocate any extra pdata.

> +
> +       r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
> +       if (!r)
> +@@ -537,6 +604,9 @@ static int bgpio_pdev_probe(struct platf
> +
> +       platform_set_drvdata(pdev, bgc);
> +
> ++      if (use_of)
> ++              of_gpiochip_add(&bgc->gc);
> ++

gpiochip_add will already call of_gpiochip_add, no need for this one.

> +       return gpiochip_add(&bgc->gc);
> + }
> +
> +@@ -562,6 +632,7 @@ MODULE_DEVICE_TABLE(platform, bgpio_id_t
> + static struct platform_driver bgpio_driver = {
> +       .driver = {
> +               .name = "basic-mmio-gpio",
> ++              .of_match_table = bgpio_dt_ids,

this will break compilation with !OF, you need to use
of_match_ptr(bgpio_dt_ids).

> +       },
> +       .id_table = bgpio_id_table,
> +       .probe = bgpio_pdev_probe,
> +--- a/include/linux/basic_mmio_gpio.h
> ++++ b/include/linux/basic_mmio_gpio.h
> +@@ -22,6 +22,7 @@ struct bgpio_pdata {
> +       const char *label;
> +       int base;
> +       int ngpio;
> ++      unsigned long flags;
> + };
> +
> + struct device;


Jonas
diff mbox

Patch

diff --git a/target/linux/brcm63xx/patches-3.14/374-GPIO-generic-pdata-add-label-backport.patch b/target/linux/brcm63xx/patches-3.14/374-GPIO-generic-pdata-add-label-backport.patch
new file mode 100644
index 0000000..cba5a0a
--- /dev/null
+++ b/target/linux/brcm63xx/patches-3.14/374-GPIO-generic-pdata-add-label-backport.patch
@@ -0,0 +1,21 @@ 
+--- a/drivers/gpio/gpio-generic.c
++++ b/drivers/gpio/gpio-generic.c
+@@ -531,6 +531,8 @@ static int bgpio_pdev_probe(struct platf
+ 		return err;
+ 
+ 	if (pdata) {
++		if (pdata->label)
++			bgc->gc.label = pdata->label;
+ 		bgc->gc.base = pdata->base;
+ 		if (pdata->ngpio > 0)
+ 			bgc->gc.ngpio = pdata->ngpio;
+--- a/include/linux/basic_mmio_gpio.h
++++ b/include/linux/basic_mmio_gpio.h
+@@ -19,6 +19,7 @@
+ #include <linux/spinlock_types.h>
+ 
+ struct bgpio_pdata {
++	const char *label;
+ 	int base;
+ 	int ngpio;
+ };
diff --git a/target/linux/brcm63xx/patches-3.14/375-GPIO-generic-driver-flags-backport.patch b/target/linux/brcm63xx/patches-3.14/375-GPIO-generic-driver-flags-backport.patch
new file mode 100644
index 0000000..3915d2c
--- /dev/null
+++ b/target/linux/brcm63xx/patches-3.14/375-GPIO-generic-driver-flags-backport.patch
@@ -0,0 +1,39 @@ 
+--- a/drivers/gpio/gpio-generic.c
++++ b/drivers/gpio/gpio-generic.c
+@@ -488,7 +488,7 @@ static int bgpio_pdev_probe(struct platf
+ 	void __iomem *dirout;
+ 	void __iomem *dirin;
+ 	unsigned long sz;
+-	unsigned long flags = 0;
++	unsigned long flags = pdev->id_entry->driver_data;
+ 	int err;
+ 	struct bgpio_chip *bgc;
+ 	struct bgpio_pdata *pdata = dev_get_platdata(dev);
+@@ -519,9 +519,6 @@ static int bgpio_pdev_probe(struct platf
+ 	if (err)
+ 		return err;
+ 
+-	if (!strcmp(platform_get_device_id(pdev)->name, "basic-mmio-gpio-be"))
+-		flags |= BGPIOF_BIG_ENDIAN;
+-
+ 	bgc = devm_kzalloc(&pdev->dev, sizeof(*bgc), GFP_KERNEL);
+ 	if (!bgc)
+ 		return -ENOMEM;
+@@ -551,9 +548,14 @@ static int bgpio_pdev_remove(struct plat
+ }
+ 
+ static const struct platform_device_id bgpio_id_table[] = {
+-	{ "basic-mmio-gpio", },
+-	{ "basic-mmio-gpio-be", },
+-	{},
++	{
++		.name		= "basic-mmio-gpio",
++		.driver_data	= 0,
++	}, {
++		.name		= "basic-mmio-gpio-be",
++		.driver_data	= BGPIOF_BIG_ENDIAN,
++	},
++	{ }
+ };
+ MODULE_DEVICE_TABLE(platform, bgpio_id_table);
+ 
diff --git a/target/linux/brcm63xx/patches-3.14/376-DT-basic-mmio-gpio.patch b/target/linux/brcm63xx/patches-3.14/376-DT-basic-mmio-gpio.patch
new file mode 100644
index 0000000..cda38b2
--- /dev/null
+++ b/target/linux/brcm63xx/patches-3.14/376-DT-basic-mmio-gpio.patch
@@ -0,0 +1,204 @@ 
+--- a/Documentation/devicetree/bindings/gpio/gpio.txt
++++ b/Documentation/devicetree/bindings/gpio/gpio.txt
+@@ -153,3 +153,75 @@ Example 2:
+ Here, three GPIO ranges are defined wrt. two pin controllers. pinctrl1 GPIO
+ ranges are defined using pin numbers whereas the GPIO ranges wrt. pinctrl2
+ are named "foo" and "bar".
++
++3) Generic driver for memory-mapped GPIO controllers
++----------------------------------------------------
++The GPIO generic library provides support for basic platform_device
++memory-mapped GPIO controllers, which can be accessed by selecting Kconfig
++symbol GPIO_GENERIC and using library functions provided by GPIO generic
++driver (see drivers/gpio/gpio-generic.c).
++The simplest form of a GPIO controller that the driver support is just a
++single "data" register, where GPIO state can be read and/or written.
++
++The driver supports:
++- 8/16/32/64 bits registers. The number of GPIOs is determined by the width of
++  the registers.
++- GPIO controllers with clear/set registers.
++- GPIO controllers with a single "data" register.
++- Big endian bits/GPIOs ordering.
++
++For setting GPIO's there are three supported configurations:
++- single input/output register resource (named "dat").
++- set/clear pair (named "set" and "clr").
++- single output register resource and single input resource ("set" and dat").
++
++For setting the GPIO direction, there are three supported configurations:
++- simple bidirection GPIO that requires no configuration.
++- an output direction register (named "dirout") where a 1 bit indicates the
++  GPIO is an output.
++- an input direction register (named "dirin") where a 1 bit indicates the GPIO
++  is an input.
++
++Required properties:
++- compatible : Should be "basic-mmio-gpio".
++- reg : Address and length of the registers needed for the device.
++- reg-names : Names of the needed registers.
++- #gpio-cells : Should be two.  The first cell is the pin number and
++  the second cell is used to specify optional parameters (currently
++  unused).
++- gpio-controller : Marks the device node as a gpio controller.
++
++Optional properties:
++- num-gpios : Specify the number of configurable gpios.
++- bit-be : Use big endian order for pins.
++- byte-be : Use big endian byte order for registers.
++- regset-wo : set register is unreadable.
++- regdir-wo : dir register is unreadable.
++
++Examples:
++
++gpio0: gpio-controller@10000084 {
++	compatible = "brcm,brcm6368", "basic-mmio-gpio";
++	reg = <0x10000084 0x4>, <0x1000008c 0x4>;
++	reg-names = "dirout", "dat";
++
++	gpio-controller;
++	#gpio-cells = <2>;
++
++	num-gpios = <32>;
++	byte-be;
++};
++
++gpio1: gpio-controller@10000180 {
++	compatible = "foo,bar", "basic-mmio-gpio";
++	reg = <0x10000180 0x4>, <0x10000184 0x4>, <0x10000188 0x4>;
++	reg-names = "dirin", "dirout", "dat";
++
++	gpio-controller;
++	#gpio-cells = <2>;
++
++	num-gpios = <20>;
++	bit-be;
++	byte-be;
++	regdir-wo;
++};
+--- a/drivers/gpio/gpio-generic.c
++++ b/drivers/gpio/gpio-generic.c
+@@ -61,6 +61,9 @@ o        `                     ~~~~\___/
+ #include <linux/platform_device.h>
+ #include <linux/mod_devicetable.h>
+ #include <linux/basic_mmio_gpio.h>
++#include <linux/of.h>
++#include <linux/of_device.h>
++#include <linux/of_gpio.h>
+ 
+ static void bgpio_write8(void __iomem *reg, unsigned long data)
+ {
+@@ -478,8 +481,58 @@ static void __iomem *bgpio_map(struct pl
+ 	return ret;
+ }
+ 
++#ifdef CONFIG_OF
++static const struct of_device_id bgpio_dt_ids[] = {
++	{ .compatible = "basic-mmio-gpio" },
++};
++MODULE_DEVICE_TABLE(of, bgpio_dt_ids);
++
++static int bgpio_probe_dt(struct platform_device *pdev)
++{
++	u32 tmp;
++	struct bgpio_pdata *pdata;
++	struct device_node *np;
++
++	np = pdev->dev.of_node;
++	if (!np)
++		return 0;
++
++	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
++	if (!pdata)
++		return -ENOMEM;
++
++	pdata->label = dev_name(&pdev->dev);
++	pdata->base = -1;
++	if (of_find_property(np, "byte-be", NULL)) {
++		pdata->flags |= BGPIOF_BIG_ENDIAN_BYTE_ORDER;
++	}
++	if (of_find_property(np, "bit-be", NULL)) {
++		pdata->flags |= BGPIOF_BIG_ENDIAN;
++	}
++	if (of_find_property(np, "regset-wo", NULL)) {
++		pdata->flags |= BGPIOF_UNREADABLE_REG_SET;
++	}
++	if (of_find_property(np, "regdir-wo", NULL)) {
++		pdata->flags |= BGPIOF_UNREADABLE_REG_DIR;
++	}
++	if (!of_property_read_u32(np, "num-gpios", &tmp)) {
++		pdata->ngpio = tmp;
++	}
++
++	pdev->dev.platform_data = pdata;
++
++	return 1;
++}
++#else
++static inline int bgpio_probe_dt(struct platform_device *pdev)
++{
++	return 0;
++}
++#endif
++
+ static int bgpio_pdev_probe(struct platform_device *pdev)
+ {
++	int status;
+ 	struct device *dev = &pdev->dev;
+ 	struct resource *r;
+ 	void __iomem *dat;
+@@ -488,10 +541,24 @@ static int bgpio_pdev_probe(struct platf
+ 	void __iomem *dirout;
+ 	void __iomem *dirin;
+ 	unsigned long sz;
+-	unsigned long flags = pdev->id_entry->driver_data;
++	unsigned long flags;
+ 	int err;
+ 	struct bgpio_chip *bgc;
+-	struct bgpio_pdata *pdata = dev_get_platdata(dev);
++	struct bgpio_pdata *pdata;
++	bool use_of = 0;
++
++	status = bgpio_probe_dt(pdev);
++	if (status < 0)
++		return status;
++	if (status > 0)
++		use_of = 1;
++
++	pdata = dev_get_platdata(dev);
++
++	if (!use_of)
++		flags = pdev->id_entry->driver_data;
++	else if (pdata)
++		flags = pdata->flags;
+ 
+ 	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
+ 	if (!r)
+@@ -537,6 +604,9 @@ static int bgpio_pdev_probe(struct platf
+ 
+ 	platform_set_drvdata(pdev, bgc);
+ 
++	if (use_of)
++		of_gpiochip_add(&bgc->gc);
++
+ 	return gpiochip_add(&bgc->gc);
+ }
+ 
+@@ -562,6 +632,7 @@ MODULE_DEVICE_TABLE(platform, bgpio_id_t
+ static struct platform_driver bgpio_driver = {
+ 	.driver = {
+ 		.name = "basic-mmio-gpio",
++		.of_match_table = bgpio_dt_ids,
+ 	},
+ 	.id_table = bgpio_id_table,
+ 	.probe = bgpio_pdev_probe,
+--- a/include/linux/basic_mmio_gpio.h
++++ b/include/linux/basic_mmio_gpio.h
+@@ -22,6 +22,7 @@ struct bgpio_pdata {
+ 	const char *label;
+ 	int base;
+ 	int ngpio;
++	unsigned long flags;
+ };
+ 
+ struct device;
diff --git a/target/linux/brcm63xx/patches-3.18/374-DT-basic-mmio-gpio.patch b/target/linux/brcm63xx/patches-3.18/374-DT-basic-mmio-gpio.patch
new file mode 100644
index 0000000..ba9f2ce
--- /dev/null
+++ b/target/linux/brcm63xx/patches-3.18/374-DT-basic-mmio-gpio.patch
@@ -0,0 +1,204 @@ 
+--- a/Documentation/devicetree/bindings/gpio/gpio.txt
++++ b/Documentation/devicetree/bindings/gpio/gpio.txt
+@@ -197,3 +197,75 @@ Example 2:
+ Here, three GPIO ranges are defined wrt. two pin controllers. pinctrl1 GPIO
+ ranges are defined using pin numbers whereas the GPIO ranges wrt. pinctrl2
+ are named "foo" and "bar".
++
++3) Generic driver for memory-mapped GPIO controllers
++----------------------------------------------------
++The GPIO generic library provides support for basic platform_device
++memory-mapped GPIO controllers, which can be accessed by selecting Kconfig
++symbol GPIO_GENERIC and using library functions provided by GPIO generic
++driver (see drivers/gpio/gpio-generic.c).
++The simplest form of a GPIO controller that the driver support is just a
++single "data" register, where GPIO state can be read and/or written.
++
++The driver supports:
++- 8/16/32/64 bits registers. The number of GPIOs is determined by the width of
++  the registers.
++- GPIO controllers with clear/set registers.
++- GPIO controllers with a single "data" register.
++- Big endian bits/GPIOs ordering.
++
++For setting GPIO's there are three supported configurations:
++- single input/output register resource (named "dat").
++- set/clear pair (named "set" and "clr").
++- single output register resource and single input resource ("set" and dat").
++
++For setting the GPIO direction, there are three supported configurations:
++- simple bidirection GPIO that requires no configuration.
++- an output direction register (named "dirout") where a 1 bit indicates the
++  GPIO is an output.
++- an input direction register (named "dirin") where a 1 bit indicates the GPIO
++  is an input.
++
++Required properties:
++- compatible : Should be "basic-mmio-gpio".
++- reg : Address and length of the registers needed for the device.
++- reg-names : Names of the needed registers.
++- #gpio-cells : Should be two.  The first cell is the pin number and
++  the second cell is used to specify optional parameters (currently
++  unused).
++- gpio-controller : Marks the device node as a gpio controller.
++
++Optional properties:
++- num-gpios : Specify the number of configurable gpios.
++- bit-be : Use big endian order for pins.
++- byte-be : Use big endian byte order for registers.
++- regset-wo : set register is unreadable.
++- regdir-wo : dir register is unreadable.
++
++Examples:
++
++gpio0: gpio-controller@10000084 {
++	compatible = "brcm,brcm6368", "basic-mmio-gpio";
++	reg = <0x10000084 0x4>, <0x1000008c 0x4>;
++	reg-names = "dirout", "dat";
++
++	gpio-controller;
++	#gpio-cells = <2>;
++
++	num-gpios = <32>;
++	byte-be;
++};
++
++gpio1: gpio-controller@10000180 {
++	compatible = "foo,bar", "basic-mmio-gpio";
++	reg = <0x10000180 0x4>, <0x10000184 0x4>, <0x10000188 0x4>;
++	reg-names = "dirin", "dirout", "dat";
++
++	gpio-controller;
++	#gpio-cells = <2>;
++
++	num-gpios = <20>;
++	bit-be;
++	byte-be;
++	regdir-wo;
++};
+--- a/drivers/gpio/gpio-generic.c
++++ b/drivers/gpio/gpio-generic.c
+@@ -61,6 +61,9 @@ o        `                     ~~~~\___/
+ #include <linux/platform_device.h>
+ #include <linux/mod_devicetable.h>
+ #include <linux/basic_mmio_gpio.h>
++#include <linux/of.h>
++#include <linux/of_device.h>
++#include <linux/of_gpio.h>
+ 
+ static void bgpio_write8(void __iomem *reg, unsigned long data)
+ {
+@@ -488,8 +491,58 @@ static void __iomem *bgpio_map(struct pl
+ 	return ret;
+ }
+ 
++#ifdef CONFIG_OF
++static const struct of_device_id bgpio_dt_ids[] = {
++	{ .compatible = "basic-mmio-gpio" },
++};
++MODULE_DEVICE_TABLE(of, bgpio_dt_ids);
++
++static int bgpio_probe_dt(struct platform_device *pdev)
++{
++	u32 tmp;
++	struct bgpio_pdata *pdata;
++	struct device_node *np;
++
++	np = pdev->dev.of_node;
++	if (!np)
++		return 0;
++
++	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
++	if (!pdata)
++		return -ENOMEM;
++
++	pdata->label = dev_name(&pdev->dev);
++	pdata->base = -1;
++	if (of_find_property(np, "byte-be", NULL)) {
++		pdata->flags |= BGPIOF_BIG_ENDIAN_BYTE_ORDER;
++	}
++	if (of_find_property(np, "bit-be", NULL)) {
++		pdata->flags |= BGPIOF_BIG_ENDIAN;
++	}
++	if (of_find_property(np, "regset-wo", NULL)) {
++		pdata->flags |= BGPIOF_UNREADABLE_REG_SET;
++	}
++	if (of_find_property(np, "regdir-wo", NULL)) {
++		pdata->flags |= BGPIOF_UNREADABLE_REG_DIR;
++	}
++	if (!of_property_read_u32(np, "num-gpios", &tmp)) {
++		pdata->ngpio = tmp;
++	}
++
++	pdev->dev.platform_data = pdata;
++
++	return 1;
++}
++#else
++static inline int bgpio_probe_dt(struct platform_device *pdev)
++{
++	return 0;
++}
++#endif
++
+ static int bgpio_pdev_probe(struct platform_device *pdev)
+ {
++	int status;
+ 	struct device *dev = &pdev->dev;
+ 	struct resource *r;
+ 	void __iomem *dat;
+@@ -498,10 +551,24 @@ static int bgpio_pdev_probe(struct platf
+ 	void __iomem *dirout;
+ 	void __iomem *dirin;
+ 	unsigned long sz;
+-	unsigned long flags = pdev->id_entry->driver_data;
++	unsigned long flags;
+ 	int err;
+ 	struct bgpio_chip *bgc;
+-	struct bgpio_pdata *pdata = dev_get_platdata(dev);
++	struct bgpio_pdata *pdata;
++	bool use_of = 0;
++
++	status = bgpio_probe_dt(pdev);
++	if (status < 0)
++		return status;
++	if (status > 0)
++		use_of = 1;
++
++	pdata = dev_get_platdata(dev);
++
++	if (!use_of)
++		flags = pdev->id_entry->driver_data;
++	else if (pdata)
++		flags = pdata->flags;
+ 
+ 	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
+ 	if (!r)
+@@ -547,6 +614,9 @@ static int bgpio_pdev_probe(struct platf
+ 
+ 	platform_set_drvdata(pdev, bgc);
+ 
++	if (use_of)
++		of_gpiochip_add(&bgc->gc);
++
+ 	return gpiochip_add(&bgc->gc);
+ }
+ 
+@@ -572,6 +642,7 @@ MODULE_DEVICE_TABLE(platform, bgpio_id_t
+ static struct platform_driver bgpio_driver = {
+ 	.driver = {
+ 		.name = "basic-mmio-gpio",
++		.of_match_table = bgpio_dt_ids,
+ 	},
+ 	.id_table = bgpio_id_table,
+ 	.probe = bgpio_pdev_probe,
+--- a/include/linux/basic_mmio_gpio.h
++++ b/include/linux/basic_mmio_gpio.h
+@@ -22,6 +22,7 @@ struct bgpio_pdata {
+ 	const char *label;
+ 	int base;
+ 	int ngpio;
++	unsigned long flags;
+ };
+ 
+ struct device;