[PATCH 3/4] GPIO: Add TB10x GPIO driver

[Christian Ruppert <christian.ruppert@abilis.com>]

The GPIO driver for the Abilis Systems TB10x series of SOCs based on ARC700
CPUs. It supports GPIO control and GPIO interrupt generation.

Signed-off-by: Sascha Leuenberger <sascha.leuenberger@abilis.com>
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
---
 .../devicetree/bindings/gpio/abilis,tb10x-gpio.txt |   36 ++
 arch/arc/boot/dts/abilis_tb100.dtsi                |   42 ++-
 arch/arc/boot/dts/abilis_tb100_dvk.dts             |   24 +-
 arch/arc/boot/dts/abilis_tb101.dtsi                |   42 ++-
 arch/arc/boot/dts/abilis_tb101_dvk.dts             |   24 +-
 drivers/gpio/Kconfig                               |    4 +
 drivers/gpio/Makefile                              |    1 +
 drivers/gpio/gpio-tb10x.c                          |  341 ++++++++++++++++++++
 8 files changed, 462 insertions(+), 52 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/gpio/abilis,tb10x-gpio.txt
 create mode 100644 drivers/gpio/gpio-tb10x.c

diff --git a/Documentation/devicetree/bindings/gpio/abilis,tb10x-gpio.txt b/Documentation/devicetree/bindings/gpio/abilis,tb10x-gpio.txt
new file mode 100644
index 0000000..26a3c68
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/abilis,tb10x-gpio.txt
@@ -0,0 +1,36 @@
+* Abilis TB10x GPIO controller
+
+Required Properties:
+- compatible: Should be "abilis,tb10x-gpio"
+- reg: Address and length of the register set for the device
+- gpio-controller: Marks the device node as a gpio controller.
+- #gpio-cells: Should be <2>. The first cell is the pin number and the
+  second cell is used to specify optional parameters:
+   - bit 0 specifies polarity (0 for normal, 1 for inverted).
+- ngpio: the number of GPIO pins this driver controls.
+
+Optional Properties:
+- interrupt-controller: Marks the device node as an interrupt controller.
+- #interrupt-cells: Should be <1>. Interrupts are triggered on both edges.
+- interrupts: Defines the interrupt line connecting this GPIO controller to
+  its parent interrupt controller.
+- interrupt-parent: Defines the parent interrupt controller.
+
+GPIO ranges are specified as described in
+Documentation/devicetree/bindings/gpio/gpio.txt
+
+Example:
+
+	gpioa: gpio@FF140000 {
+		compatible = "abilis,tb10x-gpio";
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		interrupt-parent = <&tb10x_ictl>;
+		interrupts = <27 2>;
+		reg = <0xFF140000 0x1000>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		ngpio = <3>;
+		gpio-ranges = <&iomux 0 0 0>;
+		gpio-ranges-group-names = "gpioa_pins";
+	};
diff --git a/arch/arc/boot/dts/abilis_tb100.dtsi b/arch/arc/boot/dts/abilis_tb100.dtsi
index 1a42cf1..f1fa416 100644
--- a/arch/arc/boot/dts/abilis_tb100.dtsi
+++ b/arch/arc/boot/dts/abilis_tb100.dtsi
@@ -176,7 +176,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF140000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <3>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioa_pins";
 		};
@@ -188,7 +189,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF141000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <2>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiob_pins";
 		};
@@ -200,7 +202,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF142000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <3>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioc_pins";
 		};
@@ -212,7 +215,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF143000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <2>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiod_pins";
 		};
@@ -224,7 +228,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF144000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <3>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioe_pins";
 		};
@@ -236,7 +241,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF145000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <2>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiof_pins";
 		};
@@ -248,7 +254,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF146000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <3>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiog_pins";
 		};
@@ -260,7 +267,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF147000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <2>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioh_pins";
 		};
@@ -272,7 +280,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF148000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <12>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioi_pins";
 		};
@@ -284,7 +293,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF149000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <32>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioj_pins";
 		};
@@ -296,7 +306,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF14A000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <22>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiok_pins";
 		};
@@ -308,7 +319,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF14B000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <4>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiol_pins";
 		};
@@ -320,7 +332,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF14C000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <4>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiom_pins";
 		};
@@ -332,7 +345,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF14D000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <5>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpion_pins";
 		};
diff --git a/arch/arc/boot/dts/abilis_tb100_dvk.dts b/arch/arc/boot/dts/abilis_tb100_dvk.dts
index 0fa0d4a..d6af955 100644
--- a/arch/arc/boot/dts/abilis_tb100_dvk.dts
+++ b/arch/arc/boot/dts/abilis_tb100_dvk.dts
@@ -64,62 +64,62 @@
 			compatible = "gpio-leds";
 			power {
 				label = "Power";
-				gpios = <&gpioi 0>;
+				gpios = <&gpioi 0 0>;
 				linux,default-trigger = "default-on";
 			};
 			heartbeat {
 				label = "Heartbeat";
-				gpios = <&gpioi 1>;
+				gpios = <&gpioi 1 0>;
 				linux,default-trigger = "heartbeat";
 			};
 			led2 {
 				label = "LED2";
-				gpios = <&gpioi 2>;
+				gpios = <&gpioi 2 0>;
 				default-state = "off";
 			};
 			led3 {
 				label = "LED3";
-				gpios = <&gpioi 3>;
+				gpios = <&gpioi 3 0>;
 				default-state = "off";
 			};
 			led4 {
 				label = "LED4";
-				gpios = <&gpioi 4>;
+				gpios = <&gpioi 4 0>;
 				default-state = "off";
 			};
 			led5 {
 				label = "LED5";
-				gpios = <&gpioi 5>;
+				gpios = <&gpioi 5 0>;
 				default-state = "off";
 			};
 			led6 {
 				label = "LED6";
-				gpios = <&gpioi 6>;
+				gpios = <&gpioi 6 0>;
 				default-state = "off";
 			};
 			led7 {
 				label = "LED7";
-				gpios = <&gpioi 7>;
+				gpios = <&gpioi 7 0>;
 				default-state = "off";
 			};
 			led8 {
 				label = "LED8";
-				gpios = <&gpioi 8>;
+				gpios = <&gpioi 8 0>;
 				default-state = "off";
 			};
 			led9 {
 				label = "LED9";
-				gpios = <&gpioi 9>;
+				gpios = <&gpioi 9 0>;
 				default-state = "off";
 			};
 			led10 {
 				label = "LED10";
-				gpios = <&gpioi 10>;
+				gpios = <&gpioi 10 0>;
 				default-state = "off";
 			};
 			led11 {
 				label = "LED11";
-				gpios = <&gpioi 11>;
+				gpios = <&gpioi 11 0>;
 				default-state = "off";
 			};
 		};
diff --git a/arch/arc/boot/dts/abilis_tb101.dtsi b/arch/arc/boot/dts/abilis_tb101.dtsi
index 08986cd..311116f 100644
--- a/arch/arc/boot/dts/abilis_tb101.dtsi
+++ b/arch/arc/boot/dts/abilis_tb101.dtsi
@@ -185,7 +185,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF140000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <3>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioa_pins";
 		};
@@ -197,7 +198,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF141000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <2>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiob_pins";
 		};
@@ -209,7 +211,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF142000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <3>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioc_pins";
 		};
@@ -221,7 +224,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF143000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <2>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiod_pins";
 		};
@@ -233,7 +237,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF144000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <3>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioe_pins";
 		};
@@ -245,7 +250,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF145000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <2>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiof_pins";
 		};
@@ -257,7 +263,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF146000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <3>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiog_pins";
 		};
@@ -269,7 +276,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF147000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <2>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioh_pins";
 		};
@@ -281,7 +289,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF148000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <12>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioi_pins";
 		};
@@ -293,7 +302,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF149000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <32>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpioj_pins";
 		};
@@ -305,7 +315,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF14A000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <22>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiok_pins";
 		};
@@ -317,7 +328,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF14B000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <4>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiol_pins";
 		};
@@ -329,7 +341,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF14C000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <4>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpiom_pins";
 		};
@@ -341,7 +354,8 @@
 			interrupts = <27 1>;
 			reg = <0xFF14D000 0x1000>;
 			gpio-controller;
-			#gpio-cells = <1>;
+			#gpio-cells = <2>;
+			ngpio = <5>;
 			gpio-ranges = <&iomux 0 0 0>;
 			gpio-ranges-group-names = "gpion_pins";
 		};
diff --git a/arch/arc/boot/dts/abilis_tb101_dvk.dts b/arch/arc/boot/dts/abilis_tb101_dvk.dts
index a4d80ce..811a73b 100644
--- a/arch/arc/boot/dts/abilis_tb101_dvk.dts
+++ b/arch/arc/boot/dts/abilis_tb101_dvk.dts
@@ -64,62 +64,62 @@
 			compatible = "gpio-leds";
 			power {
 				label = "Power";
-				gpios = <&gpioi 0>;
+				gpios = <&gpioi 0 0>;
 				linux,default-trigger = "default-on";
 			};
 			heartbeat {
 				label = "Heartbeat";
-				gpios = <&gpioi 1>;
+				gpios = <&gpioi 1 0>;
 				linux,default-trigger = "heartbeat";
 			};
 			led2 {
 				label = "LED2";
-				gpios = <&gpioi 2>;
+				gpios = <&gpioi 2 0>;
 				default-state = "off";
 			};
 			led3 {
 				label = "LED3";
-				gpios = <&gpioi 3>;
+				gpios = <&gpioi 3 0>;
 				default-state = "off";
 			};
 			led4 {
 				label = "LED4";
-				gpios = <&gpioi 4>;
+				gpios = <&gpioi 4 0>;
 				default-state = "off";
 			};
 			led5 {
 				label = "LED5";
-				gpios = <&gpioi 5>;
+				gpios = <&gpioi 5 0>;
 				default-state = "off";
 			};
 			led6 {
 				label = "LED6";
-				gpios = <&gpioi 6>;
+				gpios = <&gpioi 6 0>;
 				default-state = "off";
 			};
 			led7 {
 				label = "LED7";
-				gpios = <&gpioi 7>;
+				gpios = <&gpioi 7 0>;
 				default-state = "off";
 			};
 			led8 {
 				label = "LED8";
-				gpios = <&gpioi 8>;
+				gpios = <&gpioi 8 0>;
 				default-state = "off";
 			};
 			led9 {
 				label = "LED9";
-				gpios = <&gpioi 9>;
+				gpios = <&gpioi 9 0>;
 				default-state = "off";
 			};
 			led10 {
 				label = "LED10";
-				gpios = <&gpioi 10>;
+				gpios = <&gpioi 10 0>;
 				default-state = "off";
 			};
 			led11 {
 				label = "LED11";
-				gpios = <&gpioi 11>;
+				gpios = <&gpioi 11 0>;
 				default-state = "off";
 			};
 		};
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 573c449..1faeb7c 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -317,6 +317,10 @@ config GPIO_GRGPIO
 	  Select this to support Aeroflex Gaisler GRGPIO cores from the GRLIB
 	  VHDL IP core library.
 
+config GPIO_TB10X
+	bool
+	select OF_GPIO
+
 comment "I2C GPIO expanders:"
 
 config GPIO_ARIZONA
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 0cb2d65..7bc567f 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -68,6 +68,7 @@ obj-$(CONFIG_GPIO_STA2X11)	+= gpio-sta2x11.o
 obj-$(CONFIG_GPIO_STMPE)	+= gpio-stmpe.o
 obj-$(CONFIG_GPIO_STP_XWAY)	+= gpio-stp-xway.o
 obj-$(CONFIG_GPIO_SX150X)	+= gpio-sx150x.o
+obj-$(CONFIG_GPIO_TB10X)	+= gpio-tb10x.o
 obj-$(CONFIG_GPIO_TC3589X)	+= gpio-tc3589x.o
 obj-$(CONFIG_ARCH_TEGRA)	+= gpio-tegra.o
 obj-$(CONFIG_GPIO_TIMBERDALE)	+= gpio-timberdale.o
diff --git a/drivers/gpio/gpio-tb10x.c b/drivers/gpio/gpio-tb10x.c
new file mode 100644
index 0000000..7f67a4c
--- /dev/null
+++ b/drivers/gpio/gpio-tb10x.c
@@ -0,0 +1,341 @@
+/* Abilis Systems MODULE DESCRIPTION
+ *
+ * Copyright (C) Abilis Systems 2013
+ *
+ * Authors: Sascha Leuenberger <sascha.leuenberger@abilis.com>
+ *          Christian Ruppert <christian.ruppert@abilis.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+#include <linux/spinlock.h>
+#include <linux/bitops.h>
+#include <linux/pinctrl/consumer.h>
+
+#define TB10X_GPIO_DIR_IN	(0x00000000)
+#define TB10X_GPIO_DIR_OUT	(0x00000001)
+#define OFFSET_TO_REG_DDR	(0x00)
+#define OFFSET_TO_REG_DATA	(0x04)
+#define OFFSET_TO_REG_INT_EN	(0x08)
+#define OFFSET_TO_REG_CHANGE	(0x0C)
+#define OFFSET_TO_REG_WRMASK	(0x10)
+#define OFFSET_TO_REG_INT_TYPE	(0x14)
+
+
+/**
+ * @spinlock: used for atomic read/modify/write of registers
+ * @base: register base address
+ * @domain: IRQ domain of GPIO generated interrupts managed by this controller
+ * @irq: Interrupt line of parent interrupt controller
+ * @gc: gpio_chip structure associated to this GPIO controller
+ */
+struct tb10x_gpio {
+	spinlock_t spinlock;
+	void __iomem *base;
+	struct irq_domain *domain;
+	int irq;
+	struct gpio_chip gc;
+};
+
+static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs)
+{
+	return ioread32(gpio->base + offs);
+}
+
+static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs,
+				u32 val)
+{
+	iowrite32(val, gpio->base + offs);
+}
+
+static inline void tb10x_set_bits(struct tb10x_gpio *gpio, unsigned int offs,
+				u32 mask, u32 val)
+{
+	u32 r;
+	unsigned long flags;
+
+	spin_lock_irqsave(&gpio->spinlock, flags);
+
+	r = tb10x_reg_read(gpio, offs);
+	r = (r & ~mask) | (val & mask);
+
+	tb10x_reg_write(gpio, offs, r);
+
+	spin_unlock_irqrestore(&gpio->spinlock, flags);
+}
+
+static inline struct tb10x_gpio *to_tb10x_gpio(struct gpio_chip *chip)
+{
+	return container_of(chip, struct tb10x_gpio, gc);
+}
+
+static int tb10x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
+{
+	struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
+	int mask = BIT(offset);
+	int val = TB10X_GPIO_DIR_IN << offset;
+
+	tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
+
+	return 0;
+}
+
+static int tb10x_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
+	int val;
+
+	val = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_DATA);
+
+	if (val & BIT(offset))
+		return 1;
+	else
+		return 0;
+}
+
+static void tb10x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
+	int mask = BIT(offset);
+	int val = value << offset;
+
+	tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DATA, mask, val);
+}
+
+static int tb10x_gpio_direction_out(struct gpio_chip *chip,
+					unsigned offset, int value)
+{
+	struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
+	int mask = BIT(offset);
+	int val = TB10X_GPIO_DIR_OUT << offset;
+
+	tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
+
+	return 0;
+}
+
+static int tb10x_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	return pinctrl_request_gpio(chip->base + offset);
+}
+
+static void tb10x_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+	pinctrl_free_gpio(chip->base + offset);
+}
+
+static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
+
+	return irq_create_mapping(tb10x_gpio->domain, offset);
+}
+
+static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
+{
+	if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
+		pr_err("Only (both) edge triggered interrupts supported.\n");
+		return -EINVAL;
+	}
+
+	irqd_set_trigger_type(data, type);
+
+	return IRQ_SET_MASK_OK;
+}
+
+static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
+{
+	struct tb10x_gpio *tb10x_gpio = data;
+	u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
+	u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
+	const unsigned long bits = r & m;
+	int i;
+
+	for_each_set_bit(i, &bits, 32)
+		generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i));
+
+	return IRQ_HANDLED;
+}
+
+static int tb10x_gpio_probe(struct platform_device *pdev)
+{
+	struct tb10x_gpio *tb10x_gpio;
+	struct resource *mem;
+	struct device_node *dn = pdev->dev.of_node;
+	int ret = -EBUSY;
+	u32 ngpio;
+
+	if (!dn)
+		return -EINVAL;
+
+	if (of_property_read_u32(dn, "ngpio", &ngpio))
+		return -EINVAL;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem) {
+		dev_err(&pdev->dev, "No memory resource defined.\n");
+		return -EINVAL;
+	}
+
+	tb10x_gpio = devm_kzalloc(&pdev->dev, sizeof(*tb10x_gpio), GFP_KERNEL);
+	if (tb10x_gpio == NULL)
+		return -ENOMEM;
+
+	spin_lock_init(&tb10x_gpio->spinlock);
+
+	tb10x_gpio->base = devm_ioremap_resource(&pdev->dev, mem);
+	if (!tb10x_gpio->base) {
+		dev_err(&pdev->dev, "Could not remap reg space.\n");
+		goto fail_ioremap;
+	}
+
+	tb10x_gpio->gc.label		= of_node_full_name(dn);
+	tb10x_gpio->gc.dev		= &pdev->dev;
+	tb10x_gpio->gc.owner		= THIS_MODULE;
+	tb10x_gpio->gc.direction_input	= tb10x_gpio_direction_in;
+	tb10x_gpio->gc.get		= tb10x_gpio_get;
+	tb10x_gpio->gc.direction_output	= tb10x_gpio_direction_out;
+	tb10x_gpio->gc.set		= tb10x_gpio_set;
+	tb10x_gpio->gc.request		= tb10x_gpio_request;
+	tb10x_gpio->gc.free		= tb10x_gpio_free;
+	tb10x_gpio->gc.base		= -1;
+	tb10x_gpio->gc.ngpio		= ngpio;
+	tb10x_gpio->gc.can_sleep	= 0;
+
+
+	ret = gpiochip_add(&tb10x_gpio->gc);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Could not add gpiochip.\n");
+		goto fail_gpiochip_registration;
+	}
+
+	platform_set_drvdata(pdev, tb10x_gpio);
+
+	if (of_find_property(dn, "interrupt-controller", NULL)) {
+		struct irq_chip_generic *gc;
+
+		ret = platform_get_irq(pdev, 0);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "No interrupt specified.\n");
+			goto fail_get_irq;
+		}
+
+		tb10x_gpio->gc.to_irq	= tb10x_gpio_to_irq;
+		tb10x_gpio->irq		= ret;
+
+		ret = devm_request_irq(&pdev->dev, ret, tb10x_gpio_irq_cascade,
+				IRQF_TRIGGER_NONE | IRQF_SHARED,
+				dev_name(&pdev->dev), tb10x_gpio);
+		if (ret != 0)
+			goto fail_request_irq;
+
+		tb10x_gpio->domain = irq_domain_add_linear(dn,
+						tb10x_gpio->gc.ngpio,
+						&irq_generic_chip_ops, NULL);
+		if (!tb10x_gpio->domain) {
+			ret = -ENOMEM;
+			goto fail_irq_domain;
+		}
+
+		ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
+				tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label,
+				handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
+				IRQ_GC_INIT_MASK_CACHE);
+		if (ret)
+			goto fail_irq_domain;
+
+		gc = tb10x_gpio->domain->gc->gc[0];
+		gc->reg_base                         = tb10x_gpio->base;
+		gc->chip_types[0].type               = IRQ_TYPE_EDGE_BOTH;
+		gc->chip_types[0].chip.irq_ack       = irq_gc_ack_set_bit;
+		gc->chip_types[0].chip.irq_mask      = irq_gc_mask_clr_bit;
+		gc->chip_types[0].chip.irq_unmask    = irq_gc_mask_set_bit;
+		gc->chip_types[0].chip.irq_set_type  = tb10x_gpio_irq_set_type;
+		gc->chip_types[0].regs.ack           = OFFSET_TO_REG_CHANGE;
+		gc->chip_types[0].regs.mask          = OFFSET_TO_REG_INT_EN;
+	}
+
+	return 0;
+
+fail_irq_domain:
+fail_request_irq:
+fail_get_irq:
+	gpiochip_remove(&tb10x_gpio->gc);
+fail_gpiochip_registration:
+fail_ioremap:
+	return ret;
+}
+
+static int __exit tb10x_gpio_remove(struct platform_device *pdev)
+{
+	struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev);
+	int ret;
+
+	if (tb10x_gpio->gc.to_irq) {
+		irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0],
+					BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0);
+		kfree(tb10x_gpio->domain->gc);
+		irq_domain_remove(tb10x_gpio->domain);
+		free_irq(tb10x_gpio->irq, tb10x_gpio);
+	}
+	ret = gpiochip_remove(&tb10x_gpio->gc);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct of_device_id tb10x_gpio_dt_ids[] = {
+	{ .compatible = "abilis,tb10x-gpio" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);
+
+static struct platform_driver tb10x_gpio_driver = {
+	.probe		= tb10x_gpio_probe,
+	.remove		= tb10x_gpio_remove,
+	.driver = {
+		.name	= "tb10x-gpio",
+		.of_match_table = of_match_ptr(tb10x_gpio_dt_ids),
+		.owner	= THIS_MODULE,
+	}
+};
+
+static int __init ab_gpio_init(void)
+{
+	return platform_driver_register(&tb10x_gpio_driver);
+}
+
+static void __exit ab_gpio_exit(void)
+{
+	platform_driver_unregister(&tb10x_gpio_driver);
+}
+
+module_init(ab_gpio_init);
+module_exit(ab_gpio_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("tb10x gpio.");
+MODULE_VERSION("0.0.1");
-- 
1.7.1