gpio/mxs: add device tree probe

It adds device tree probe for gpio-mxs driver.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/gpio/gpio-mxs.txt

+* Freescale MXS GPIO controller
+
+The Freescale MXS GPIO controller is part of MXS PIN controller.  The
+GPIOs are organized in port/bank.  Each port consists of 32 GPIOs.
+
+As the GPIO controller is embedded in the PIN controller and all the
+GPIO ports share the same IO space with PIN controller, the GPIO node
+will be represented as sub-nodes of MXS pinctrl node.
+
+Required properties for GPIO node:
+- compatible : Should be "fsl,<soc>-gpio".  The supported SoCs include
+  imx23 and imx28.
+- interrupts : Should be the port interrupt shared by all 32 pins.
+- gpio-controller : Marks the device node as a gpio controller.
+- #gpio-cells : Should be two.  The first cell is the pin number and
+  the second cell is used to specify optional parameters (currently
+  unused).
+- interrupt-controller: Marks the device node as an interrupt controller.
+- #interrupt-cells : Should be 2.  The first cell is the GPIO number.
+  The second cell bits[3:0] is used to specify trigger type and level flags:
+      1 = low-to-high edge triggered.
+      2 = high-to-low edge triggered.
+      4 = active high level-sensitive.
+      8 = active low level-sensitive.
+
+Note: Each GPIO port should have an alias correctly numbered in "aliases"
+node.
+
+Examples:
+
+aliases {
+	gpio0 = &gpio0;
+	gpio1 = &gpio1;
+	gpio2 = &gpio2;
+	gpio3 = &gpio3;
+	gpio4 = &gpio4;
+};
+
+pinctrl@80018000 {
+	compatible = "fsl,imx28-pinctrl", "simple-bus";
+	reg = <0x80018000 2000>;
+
+	gpio0: gpio@0 {
+		compatible = "fsl,imx28-gpio";
+		interrupts = <127>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		interrupt-controller;
+		#interrupt-cells = <2>;
+	};
+
+	gpio1: gpio@1 {
+		compatible = "fsl,imx28-gpio";
+		interrupts = <126>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		interrupt-controller;
+		#interrupt-cells = <2>;
+	};
+
+	gpio2: gpio@2 {
+		compatible = "fsl,imx28-gpio";
+		interrupts = <125>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		interrupt-controller;
+		#interrupt-cells = <2>;
+	};
+
+	gpio3: gpio@3 {
+		compatible = "fsl,imx28-gpio";
+		interrupts = <124>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		interrupt-controller;
+		#interrupt-cells = <2>;
+	};
+
+	gpio4: gpio@4 {
+		compatible = "fsl,imx28-gpio";
+		interrupts = <123>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		interrupt-controller;
+		#interrupt-cells = <2>;
+	};
+};

drivers/gpio/gpio-mxs.c

@@ -25,6 +25,9 @@
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/gpio.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/basic_mmio_gpio.h>
@@ -207,8 +210,19 @@ static struct platform_device_id mxs_gpio_ids[] = {
 };
 MODULE_DEVICE_TABLE(platform, mxs_gpio_ids);
 
+static const struct of_device_id mxs_gpio_dt_ids[] = {
+	{ .compatible = "fsl,imx23-gpio", .data = (void *) IMX23_GPIO, },
+	{ .compatible = "fsl,imx28-gpio", .data = (void *) IMX28_GPIO, },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mxs_gpio_dt_ids);
+
 static int __devinit mxs_gpio_probe(struct platform_device *pdev)
 {
+	const struct of_device_id *of_id =
+			of_match_device(mxs_gpio_dt_ids, &pdev->dev);
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *parent;
 	static void __iomem *base;
 	struct mxs_gpio_port *port;
 	struct resource *iores = NULL;
@@ -218,8 +232,15 @@ static int __devinit mxs_gpio_probe(struct platform_device *pdev)
 	if (!port)
 		return -ENOMEM;
 
-	port->id = pdev->id;
-	port->devid = pdev->id_entry->driver_data;
+	if (np) {
+		port->id = of_alias_get_id(np, "gpio");
+		if (port->id < 0)
+			return port->id;
+		port->devid = (enum mxs_gpio_id) of_id->data;
+	} else {
+		port->id = pdev->id;
+		port->devid = pdev->id_entry->driver_data;
+	}
 	port->virtual_irq_start = MXS_GPIO_IRQ_START + port->id * 32;
 
 	port->irq = platform_get_irq(pdev, 0);
@@ -231,8 +252,14 @@ static int __devinit mxs_gpio_probe(struct platform_device *pdev)
 	 * share the same one
 	 */
 	if (!base) {
-		iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-		base = devm_request_and_ioremap(&pdev->dev, iores);
+		if (np) {
+			parent = of_get_parent(np);
+			base = of_iomap(parent, 0);
+			of_node_put(parent);
+		} else {
+			iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+			base = devm_request_and_ioremap(&pdev->dev, iores);
+		}
 		if (!base)
 			return -EADDRNOTAVAIL;
 	}
@@ -278,6 +305,7 @@ static struct platform_driver mxs_gpio_driver = {
 	.driver		= {
 		.name	= "gpio-mxs",
 		.owner	= THIS_MODULE,
+		.of_match_table = mxs_gpio_dt_ids,
 	},
 	.probe		= mxs_gpio_probe,
 	.id_table	= mxs_gpio_ids,