staging: mt7621-gpio: avoid use banks in device tree

Banks shouldn't be defined in DT if number of resources
per bank is not variable. We actually know that this SoC
has three banks so take that into account in order to don't
overspecify the device tree. Device tree will only have one
node making it simple. Update device tree, binding doc and
code accordly.
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/mt7621-dts/gbpc1.dts

@@ -29,7 +29,7 @@ gpio-keys {
 
 		reset {
 			label = "reset";
-			gpios = <&gpio0 18 GPIO_ACTIVE_HIGH>;
+			gpios = <&gpio 18 GPIO_ACTIVE_HIGH>;
 			linux,code = <KEY_RESTART>;
 		};
 	};
@@ -39,22 +39,22 @@ gpio-leds {
 
 		system {
 			label = "gb-pc1:green:system";
-			gpios = <&gpio0 6 GPIO_ACTIVE_LOW>;
+			gpios = <&gpio 6 GPIO_ACTIVE_LOW>;
 		};
 
 		status {
 			label = "gb-pc1:green:status";
-			gpios = <&gpio0 8 GPIO_ACTIVE_LOW>;
+			gpios = <&gpio 8 GPIO_ACTIVE_LOW>;
 		};
 
 		lan1 {
 			label = "gb-pc1:green:lan1";
-			gpios = <&gpio0 24 GPIO_ACTIVE_LOW>;
+			gpios = <&gpio 24 GPIO_ACTIVE_LOW>;
 		};
 
 		lan2 {
 			label = "gb-pc1:green:lan2";
-			gpios = <&gpio0 25 GPIO_ACTIVE_LOW>;
+			gpios = <&gpio 25 GPIO_ACTIVE_LOW>;
 		};
 	};
 };

drivers/staging/mt7621-dts/mt7621.dtsi

@@ -61,37 +61,14 @@ wdt: wdt@100 {
 		};
 
 		gpio: gpio@600 {
-			#address-cells = <1>;
-			#size-cells = <0>;
-
+			#gpio-cells = <2>;
+			#interrupt-cells = <2>;
 			compatible = "mediatek,mt7621-gpio";
+			gpio-controller;
+			interrupt-controller;
 			reg = <0x600 0x100>;
-
 			interrupt-parent = <&gic>;
 			interrupts = <GIC_SHARED 12 IRQ_TYPE_LEVEL_HIGH>;
-			interrupt-controller;
-			#interrupt-cells = <2>;
-
-			gpio0: bank@0 {
-				reg = <0>;
-				compatible = "mediatek,mt7621-gpio-bank";
-				gpio-controller;
-				#gpio-cells = <2>;
-			};
-
-			gpio1: bank@1 {
-				reg = <1>;
-				compatible = "mediatek,mt7621-gpio-bank";
-				gpio-controller;
-				#gpio-cells = <2>;
-			};
-
-			gpio2: bank@2 {
-				reg = <2>;
-				compatible = "mediatek,mt7621-gpio-bank";
-				gpio-controller;
-				#gpio-cells = <2>;
-			};
 		};
 
 		i2c: i2c@900 {

drivers/staging/mt7621-gpio/gpio-mt7621.c

@@ -206,23 +206,20 @@ static inline const char * const mediatek_gpio_bank_name(int bank)
 }
 
 static int
-mediatek_gpio_bank_probe(struct platform_device *pdev, struct device_node *bank)
+mediatek_gpio_bank_probe(struct platform_device *pdev,
+			 struct device_node *node, int bank)
 {
 	struct mtk_data *gpio = dev_get_drvdata(&pdev->dev);
-	const __be32 *id = of_get_property(bank, "reg", NULL);
 	struct mtk_gc *rg;
 	void __iomem *dat, *set, *ctrl, *diro;
 	int ret;
 
-	if (!id || be32_to_cpu(*id) >= MTK_BANK_CNT)
-		return -EINVAL;
-
-	rg = &gpio->gc_map[be32_to_cpu(*id)];
+	rg = &gpio->gc_map[bank];
 	memset(rg, 0, sizeof(*rg));
 
 	spin_lock_init(&rg->lock);
-	rg->chip.of_node = bank;
-	rg->bank = be32_to_cpu(*id);
+	rg->chip.of_node = node;
+	rg->bank = bank;
 	rg->chip.label = mediatek_gpio_bank_name(rg->bank);
 
 	dat = gpio->gpio_membase + GPIO_REG_DATA + (rg->bank * GPIO_BANK_WIDE);
@@ -283,9 +280,10 @@ mediatek_gpio_bank_probe(struct platform_device *pdev, struct device_node *bank)
 static int
 mediatek_gpio_probe(struct platform_device *pdev)
 {
-	struct device_node *bank, *np = pdev->dev.of_node;
+	struct device_node *np = pdev->dev.of_node;
 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	struct mtk_data *gpio_data;
+	int i;
 
 	gpio_data = devm_kzalloc(&pdev->dev, sizeof(*gpio_data), GFP_KERNEL);
 	if (!gpio_data)
@@ -299,9 +297,8 @@ mediatek_gpio_probe(struct platform_device *pdev)
 	gpio_data->dev = &pdev->dev;
 	platform_set_drvdata(pdev, gpio_data);
 
-	for_each_child_of_node(np, bank)
-		if (of_device_is_compatible(bank, "mediatek,mt7621-gpio-bank"))
-			mediatek_gpio_bank_probe(pdev, bank);
+	for (i = 0; i < MTK_BANK_CNT; i++)
+		mediatek_gpio_bank_probe(pdev, np, i);
 
 	return 0;
 }

drivers/staging/mt7621-gpio/mediatek,mt7621-gpio.txt

-Mediatek SoC GPIO controller bindings
+Mediatek MT7621 SoC GPIO controller bindings
 
 The IP core used inside these SoCs has 3 banks of 32 GPIOs each.
 The registers of all the banks are interwoven inside one single IO range.
-We load one GPIO controller instance per bank. To make this possible
-we support 2 types of nodes. The parent node defines the memory I/O range and
-has 3 children each describing a single bank. Also the GPIO controller can receive
+We load one GPIO controller instance per bank. Also the GPIO controller can receive
 interrupts on any of the GPIOs, either edge or level. It then interrupts the CPU
 using GIC INT12.
 
 Required properties for the top level node:
+- #gpio-cells : Should be two. The first cell is the GPIO pin number and the
+   second cell specifies GPIO flags, as defined in <dt-bindings/gpio/gpio.h>.
+   Only the GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW flags are supported.
+- #interrupt-cells : Specifies the number of cells needed to encode an
+   interrupt. Should be 2. The first cell defines the interrupt number,
+   the second encodes the triger flags encoded as described in
+   Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
 - compatible:
   - "mediatek,mt7621-gpio" for Mediatek controllers
 - reg : Physical base address and length of the controller's registers
 - interrupt-parent : phandle of the parent interrupt controller.
 - interrupts : Interrupt specifier for the controllers interrupt.
 - interrupt-controller : Mark the device node as an interrupt controller.
-- #interrupt-cells : Should be 2. The first cell defines the interrupt number.
-   The second cell bits[3:0] is used to specify trigger type as follows:
-	- 1 = low-to-high edge triggered.
-	- 2 = high-to-low edge triggered.
-	- 4 = active high level-sensitive.
-	- 8 = active low level-sensitive.
-
-
-Required properties for the GPIO bank node:
-- compatible:
-  - "mediatek,mt7621-gpio-bank" for Mediatek banks
-- #gpio-cells : Should be two. The first cell is the GPIO pin number and the
-   second cell specifies GPIO flags, as defined in <dt-bindings/gpio/gpio.h>.
-   Only the GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW flags are supported.
 - gpio-controller : Marks the device node as a GPIO controller.
-- reg : The id of the bank that the node describes.
 
 Example:
 	gpio@600 {
-		#address-cells = <1>;
-		#size-cells = <0>;
-
+		#gpio-cells = <2>;
+		#interrupt-cells = <2>;
 		compatible = "mediatek,mt7621-gpio";
+		gpio-controller;
+		interrupt-controller;
 		reg = <0x600 0x100>;
-
 		interrupt-parent = <&gic>;
 		interrupts = <GIC_SHARED 12 IRQ_TYPE_LEVEL_HIGH>;
-		interrupt-controller;
-		#interrupt-cells = <2>;
-
-		gpio0: bank@0 {
-			reg = <0>;
-			compatible = "mediatek,mt7621-gpio-bank";
-			gpio-controller;
-			#gpio-cells = <2>;
-		};
-
-		gpio1: bank@1 {
-			reg = <1>;
-			compatible = "mediatek,mt7621-gpio-bank";
-			gpio-controller;
-			#gpio-cells = <2>;
-		};
-
-		gpio2: bank@2 {
-			reg = <2>;
-			compatible = "mediatek,mt7621-gpio-bank";
-			gpio-controller;
-			#gpio-cells = <2>;
-		};
 	};