[PATCH v2] gpio: samsung: add devicetree init for s3c24xx arches

---
changes since v1:
update bindings documentation to address SoC specific issues

  .../devicetree/bindings/gpio/gpio-samsung.txt      |   43 +++++++++++++
  drivers/gpio/gpio-samsung.c                        |   63 ++++++++++++++++++++
  2 files changed, 106 insertions(+), 0 deletions(-)

diff --git a/Documentation/devicetree/bindings/gpio/gpio-samsung.txt b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt
index 5375625..f1e5dfe 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-samsung.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt

@@ -39,3 +39,46 @@ Example:
  		#gpio-cells =<4>;
  		gpio-controller;
  	};
+
+
+Samsung S3C24XX GPIO Controller
+
+Required properties:
+- compatible: Compatible property value should be "samsung,s3c24xx-gpio".
+
+- reg: Physical base address of the controller and length of memory mapped
+  region.
+
+- #gpio-cells: Should be 3. The syntax of the gpio specifier used by client nodes
+  should be the following with values derived from the SoC user manual.
+<[phandle of the gpio controller node]
+      [pin number within the gpio controller]
+      [mux function]
+      [flags and pull up/down]
+
+  Values for gpio specifier:
+  - Pin number: depending on the controller a number from 0 up to 15.
+  - Mux function: Depending on the SoC and the gpio bank the gpio can be set
+                  as input, output or a special function
+  - Flags and Pull Up/Down: the values to use differ for the individual SoCs
+                    example S3C2416/S3C2450:
+                            0 - Pull Up/Down Disabled.
+                            1 - Pull Down Enabled.
+                            2 - Pull Up Enabled.
+          Bit 16 (0x00010000) - Input is active low.
+  Consult the user manual for the correct values of Mux and Pull Up/Down.
+
+- gpio-controller: Specifies that the node is a gpio controller.
+- #address-cells: should be 1.
+- #size-cells: should be 1.
+
+Example:
+
+	gpa: gpio-controller at 56000000 {
+		#address-cells =<1>;
+		#size-cells =<1>;
+		compatible = "samsung,s3c24xx-gpio";
+		reg =<0x56000000 0x10>;
+		#gpio-cells =<3>;
+		gpio-controller;
+	};

diff --git a/drivers/gpio/gpio-samsung.c b/drivers/gpio/gpio-samsung.c
index ba126cc..54f6663 100644
--- a/drivers/gpio/gpio-samsung.c
+++ b/drivers/gpio/gpio-samsung.c

@@ -938,6 +938,67 @@ static void __init samsung_gpiolib_add(struct samsung_gpio_chip *chip)
  		s3c_gpiolib_track(chip);
  }

+#if defined(CONFIG_PLAT_S3C24XX)&&  defined(CONFIG_OF)
+static int s3c24xx_gpio_xlate(struct gpio_chip *gc,
+			const struct of_phandle_args *gpiospec, u32 *flags)
+{
+	unsigned int pin;
+
+	if (WARN_ON(gc->of_gpio_n_cells<  3))
+		return -EINVAL;
+
+	if (WARN_ON(gpiospec->args_count<  gc->of_gpio_n_cells))
+		return -EINVAL;
+
+	if (gpiospec->args[0]>  gc->ngpio)
+		return -EINVAL;
+
+	pin = gc->base + gpiospec->args[0];
+
+	if (s3c_gpio_cfgpin(pin, S3C_GPIO_SFN(gpiospec->args[1])))
+		pr_warn("gpio_xlate: failed to set pin function\n");
+	if (s3c_gpio_setpull(pin, gpiospec->args[2]&  0xffff))
+		pr_warn("gpio_xlate: failed to set pin pull up/down\n");
+
+	if (flags)
+		*flags = gpiospec->args[2]>>  16;
+
+	return gpiospec->args[0];
+}
+
+static const struct of_device_id s3c24xx_gpio_dt_match[] __initdata = {
+	{ .compatible = "samsung,s3c24xx-gpio", },
+	{}
+};
+
+static __init void s3c24xx_gpiolib_attach_ofnode(struct samsung_gpio_chip *chip,
+						 u64 base, u64 offset)
+{
+	struct gpio_chip *gc =&chip->chip;
+	u64 address;
+
+	if (!of_have_populated_dt())
+		return;
+
+	address = chip->base ? base + ((u32)chip->base&  0xfff) : base + offset;
+	gc->of_node = of_find_matching_node_by_address(NULL,
+			s3c24xx_gpio_dt_match, address);
+	if (!gc->of_node) {
+		pr_info("gpio: device tree node not found for gpio controller"
+			" with base address %08llx\n", address);
+		return;
+	}
+	gc->of_gpio_n_cells = 3;
+	gc->of_xlate = s3c24xx_gpio_xlate;
+}
+#elif defined(CONFIG_PLAT_S3C24XX)
+static __init void s3c24xx_gpiolib_attach_ofnode(struct samsung_gpio_chip *chip,
+						 u64 base, u64 offset)
+{
+	return;
+}
+#endif /* defined(CONFIG_PLAT_S3C24XX)&&  defined(CONFIG_OF) */
+
  static void __init s3c24xx_gpiolib_add_chips(struct samsung_gpio_chip *chip,
  					     int nr_chips, void __iomem *base)
  {

@@ -962,6 +1023,8 @@ static void __init s3c24xx_gpiolib_add_chips(struct samsung_gpio_chip *chip,
  			gc->direction_output = samsung_gpiolib_2bit_output;

  		samsung_gpiolib_add(chip);
+
+		s3c24xx_gpiolib_attach_ofnode(chip, S3C24XX_PA_GPIO, i * 0x10);
  	}
  }

+static __init void s3c24xx_gpiolib_attach_ofnode(struct samsung_gpio_chip
*chip,
+						 u64 base, u64 offset)
+{
+	return;
+}
+#endif /* defined(CONFIG_PLAT_S3C24XX) && defined(CONFIG_OF) */
+
 static void __init s3c24xx_gpiolib_add_chips(struct samsung_gpio_chip
*chip,
 					     int nr_chips, void __iomem *base)
 {

@@ -962,6 +1023,8 @@ static void __init s3c24xx_gpiolib_add_chips(struct

samsung_gpio_chip *chip,
 			gc->direction_output = samsung_gpiolib_2bit_output;

 		samsung_gpiolib_add(chip);
+
+		s3c24xx_gpiolib_attach_ofnode(chip, S3C24XX_PA_GPIO, i *
0x10);
 	}
 }

--
1.7.2.3