Patchwork [2/4] gpio: add support for AMS AS3722 gpio driver

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Submitter Laxman Dewangan
Date Sept. 17, 2013, 6:45 a.m.
Message ID <1379400338-20704-3-git-send-email-ldewangan@nvidia.com>
Download mbox | patch
Permalink /patch/275377/
State New
Headers show

Comments

Laxman Dewangan - Sept. 17, 2013, 6:45 a.m.
The AS3722 is a compact system PMU suitable for Mobile Phones, Tablet etc.

Add a driver to support accessing the 8 GPIOs found on the AMS AS3722
PMIC using gpiolib.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Florian Lobmaier <florian.lobmaier@ams.com>
---
 .../devicetree/bindings/gpio/gpio-as3722.txt       |   63 +++
 drivers/gpio/Kconfig                               |    6 +
 drivers/gpio/Makefile                              |    1 +
 drivers/gpio/gpio-as3722.c                         |  444 ++++++++++++++++++++
 4 files changed, 514 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-as3722.txt
 create mode 100644 drivers/gpio/gpio-as3722.c
Stephen Warren - Sept. 23, 2013, 4:53 p.m.
On 09/17/2013 12:45 AM, Laxman Dewangan wrote:
> The AS3722 is a compact system PMU suitable for Mobile Phones, Tablet etc.
> 
> Add a driver to support accessing the 8 GPIOs found on the AMS AS3722
> PMIC using gpiolib.

> diff --git a/Documentation/devicetree/bindings/gpio/gpio-as3722.txt b/Documentation/devicetree/bindings/gpio/gpio-as3722.txt

> +AMS AS3722 GPIO bindings.
> +This describe the properties of the gpio sub-node of the AMS AS3722 device tree.

Oh, I see that you document each of the PMIC's sub-nodes separately.
That's something you should explicitly mention in the top-level PMIC
binding document. You should probably also mention the filenames of the
binding documents for the child nodes.

> +Required properties:
> +--------------------
> +- compatible: Must be "ams,as3722-gpio".
> +- #address-cells: Number of address of the sub node of this node. Must be 1.

This isn't the number of addresses in the child node, but rather the
number of cells in an (a single) address.

> +- #size-cells: Size of addess cells. Must be 1.

Similarly, this is the number of cells in a size specifier, nothing to
do with address, and not the size of a cell.

You should put the GPIO properties (gpio-controller, perhaps
interrupt-controller?) here instead of at the top level, since this HW
block is what implements the GPIO controller, and perhaps a
GPIO-interrupt controller.

> +Sub node:
> +--------
> +The sub nodes provides the configuration of each gpio pins. The properties of the
> +nodes are as follows:
> +Required subnode properties:

You need a blank line there.

> +---------------------------
> +reg: The GPIO number on which the properties need to be applied.
> +
> +Optional subnode properties:
> +---------------------------
> +bias-pull-up: The Pull-up for the pin to be enable.
> +bias-pull-down: Pull down of the pins to be enable.
> +bias-high-impedance: High impedance of the pin to be enable.
> +open-drain: Pin is Open drain type.
> +function: IO functionality of the pins. The valid options are:
> +	gpio, intrrupt-output, vsup-vbat-low-undeb, interrupt-input,

intrrupt? undeb?

> +	pwm-input, voltage-stby, oc-powergood-sd0, powergood-output,

stby might be better written out in full as standby.

> +	clk32k-output, watchdog-input, soft-reset-input, pwm-output,
> +	vsup-vbat-low-deb, oc-powergood-sd6

deb?

> +    Missing the function property will set the pin in GPIO mode.
> +
> +ams,enable-gpio-invert: Enable invert of the signal on GPIO pin.

This looks very much like pinctrl. If there's a real need to be as
verbose as pinctrl, perhaps this binding should actually be a full
pinctrl binding? If not, perhaps you can just use the raw HW register
values (with appropriate #defines to simplify setting up the
properties). Something like:

pin-configuration = <0xf7348 0x5783 0x92348 ...>;

or:

pin-configruation = <
    AMS3722_PULL_UP | AMS_GPIO_INVERT ...,
    ...
    >;

Patch

diff --git a/Documentation/devicetree/bindings/gpio/gpio-as3722.txt b/Documentation/devicetree/bindings/gpio/gpio-as3722.txt
new file mode 100644
index 0000000..c94ca59
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-as3722.txt
@@ -0,0 +1,63 @@ 
+AMS AS3722 GPIO bindings.
+This describe the properties of the gpio sub-node of the AMS AS3722 device tree.
+
+Required properties:
+--------------------
+- compatible: Must be "ams,as3722-gpio".
+- #address-cells: Number of address of the sub node of this node. Must be 1.
+- #size-cells: Size of addess cells. Must be 1.
+
+Sub node:
+--------
+The sub nodes provides the configuration of each gpio pins. The properties of the
+nodes are as follows:
+Required subnode properties:
+---------------------------
+reg: The GPIO number on which the properties need to be applied.
+
+Optional subnode properties:
+---------------------------
+bias-pull-up: The Pull-up for the pin to be enable.
+bias-pull-down: Pull down of the pins to be enable.
+bias-high-impedance: High impedance of the pin to be enable.
+open-drain: Pin is Open drain type.
+function: IO functionality of the pins. The valid options are:
+	gpio, intrrupt-output, vsup-vbat-low-undeb, interrupt-input,
+	pwm-input, voltage-stby, oc-powergood-sd0, powergood-output,
+	clk32k-output, watchdog-input, soft-reset-input, pwm-output,
+	vsup-vbat-low-deb, oc-powergood-sd6
+    Missing the function property will set the pin in GPIO mode.
+
+ams,enable-gpio-invert: Enable invert of the signal on GPIO pin.
+
+Example:
+	ams3722:: ams3722 {
+		compatible = "ams,as3722";
+		...
+		gpio-controller;
+		#gpio-cells = <2>;
+
+		gpio {
+			compatible = "ams,as3722-gpio";
+			#address-cells = <1>;
+			#size-cells = <0>;
+			gpio@0 {
+				reg = <0>;
+				bias-pull-down;
+			};
+
+			gpio@1 {
+				reg = <1>;
+				bias-pull-up;
+				ams,enable-gpio-invert;
+			};
+
+			...
+			gpio@5 {
+				reg = <5>;
+				unction  = "clk32k-output";
+			};
+			...
+		};
+		...
+	};
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 5cb2181..e1f3ead 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -368,6 +368,12 @@  config GPIO_ARIZONA
 	help
 	  Support for GPIOs on Wolfson Arizona class devices.
 
+config GPIO_AS3722
+	bool "AMS AS3722 PMICs GPIO"
+	depends on MFD_AS3722
+	help
+	  Select this option to enable GPIO driver for the AMS AS3722 PMIC.
+
 config GPIO_MAX7300
 	tristate "Maxim MAX7300 GPIO expander"
 	depends on I2C
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 98e23eb..d1715a0 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -16,6 +16,7 @@  obj-$(CONFIG_GPIO_ADP5520)	+= gpio-adp5520.o
 obj-$(CONFIG_GPIO_ADP5588)	+= gpio-adp5588.o
 obj-$(CONFIG_GPIO_AMD8111)	+= gpio-amd8111.o
 obj-$(CONFIG_GPIO_ARIZONA)	+= gpio-arizona.o
+obj-$(CONFIG_GPIO_AS3722)	+= gpio-as3722.o
 obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o
 obj-$(CONFIG_GPIO_CLPS711X)	+= gpio-clps711x.o
 obj-$(CONFIG_GPIO_CS5535)	+= gpio-cs5535.o
diff --git a/drivers/gpio/gpio-as3722.c b/drivers/gpio/gpio-as3722.c
new file mode 100644
index 0000000..75cb5d5
--- /dev/null
+++ b/drivers/gpio/gpio-as3722.c
@@ -0,0 +1,444 @@ 
+/*
+ * gpiolib support for ams AS3722 PMICs
+ *
+ * Copyright (C) 2013 ams AG
+ *
+ * Author: Florian Lobmaier <florian.lobmaier@ams.com>
+ * Author: Laxman Dewangan <ldewangan@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/gpio.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/as3722.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define AS3722_MAX_GPIO				8
+#define AS3722_GPIO_MODE_PROP_PULL_UP		0x1
+#define AS3722_GPIO_MODE_PROP_PULL_DOWN		0x2
+#define AS3722_GPIO_MODE_PROP_HIGH_IMPED	0x4
+#define AS3722_GPIO_MODE_PROP_OPEN_DRAIN	0x8
+
+struct as3722_gpio_control {
+	bool enable_gpio_invert;
+	unsigned mode_prop;
+	int io_function;
+};
+
+struct as3722_gpio {
+	struct gpio_chip gpio_chip;
+	struct device *dev;
+	struct as3722 *as3722;
+	struct as3722_gpio_control gpio_control[AS3722_MAX_GPIO];
+};
+
+struct as3722_gpio_mode_property {
+	const char *prop;
+	u32 prop_val;
+};
+
+static char const *as3722_gpio_iosf[] = {
+	"gpio",
+	"intrrupt-output",
+	"vsup-vbat-low-undeb",
+	"interrupt-input",
+	"pwm-input",
+	"voltage-stby",
+	"oc-powergood-sd0",
+	"powergood-output",
+	"clk32k-output",
+	"watchdog-input",
+	"unused",
+	"soft-reset-input",
+	"pwm-output",
+	"vsup-vbat-low-deb",
+	"oc-powergood-sd6",
+	"unused1"
+};
+
+static const struct as3722_gpio_mode_property const as3722_gpio_mode_props[] = {
+	{
+		.prop = "bias-pull-up",
+		.prop_val = AS3722_GPIO_MODE_PROP_PULL_UP,
+	}, {
+		.prop = "bias-pull-down",
+		.prop_val = AS3722_GPIO_MODE_PROP_PULL_DOWN,
+	}, {
+		.prop = "bias-high-impedance",
+		.prop_val = AS3722_GPIO_MODE_PROP_HIGH_IMPED,
+	}, {
+		.prop = "open-drain",
+		.prop_val = AS3722_GPIO_MODE_PROP_OPEN_DRAIN,
+	},
+};
+
+static int as3722_gpio_get_mode(unsigned gpio_mode_prop, bool input)
+{
+	if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_HIGH_IMPED)
+		return -EINVAL;
+
+	if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_OPEN_DRAIN) {
+		if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_PULL_UP)
+			return AS3722_GPIO_MODE_IO_OPEN_DRAIN_PULL_UP;
+		return AS3722_GPIO_MODE_IO_OPEN_DRAIN;
+	}
+	if (input) {
+		if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_PULL_UP)
+			return AS3722_GPIO_MODE_INPUT_PULL_UP;
+		else if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_PULL_DOWN)
+			return AS3722_GPIO_MODE_INPUT_PULL_DOWN;
+		return AS3722_GPIO_MODE_INPUT;
+	}
+	if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_PULL_DOWN)
+		return AS3722_GPIO_MODE_OUTPUT_VDDL;
+	return AS3722_GPIO_MODE_OUTPUT_VDDH;
+}
+
+static inline struct as3722_gpio *to_as3722_gpio(struct gpio_chip *chip)
+{
+	return container_of(chip, struct as3722_gpio, gpio_chip);
+}
+
+static int as3722_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+	struct as3722 *as3722 = as3722_gpio->as3722;
+	int ret;
+	u32 reg;
+	u32 control;
+	u32 val;
+	int mode;
+	int invert_enable;
+
+	ret = as3722_read(as3722, AS3722_GPIOn_CONTROL_REG(offset), &control);
+	if (ret < 0) {
+		dev_err(as3722_gpio->dev,
+			"GPIO_CONTROL%d_REG read failed: %d\n", offset, ret);
+		return ret;
+	}
+
+	invert_enable = !!(control & AS3722_GPIO_INV);
+	mode = control & AS3722_GPIO_MODE_MASK;
+	switch (mode) {
+	case AS3722_GPIO_MODE_INPUT:
+	case AS3722_GPIO_MODE_INPUT_PULL_UP:
+	case AS3722_GPIO_MODE_INPUT_PULL_DOWN:
+	case AS3722_GPIO_MODE_IO_OPEN_DRAIN:
+	case AS3722_GPIO_MODE_IO_OPEN_DRAIN_PULL_UP:
+		reg = AS3722_GPIO_SIGNAL_IN_REG;
+		break;
+	case AS3722_GPIO_MODE_OUTPUT_VDDH:
+	case AS3722_GPIO_MODE_OUTPUT_VDDL:
+		reg = AS3722_GPIO_SIGNAL_OUT_REG;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = as3722_read(as3722, reg, &val);
+	if (ret < 0) {
+		dev_err(as3722_gpio->dev,
+			"GPIO_SIGNAL_IN_REG read failed: %d\n", ret);
+		return ret;
+	}
+
+	val = !!(val & AS3722_GPIOn_SIGNAL(offset));
+	return (invert_enable) ? !val : val;
+}
+
+static void as3722_gpio_set(struct gpio_chip *chip, unsigned offset,
+		int value)
+{
+	struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+	struct as3722 *as3722 = as3722_gpio->as3722;
+	int en_invert = as3722_gpio->gpio_control[offset].enable_gpio_invert;
+	u32 val;
+	int ret;
+
+	if (value)
+		val = (en_invert) ? 0 : AS3722_GPIOn_SIGNAL(offset);
+	else
+		val = (en_invert) ? AS3722_GPIOn_SIGNAL(offset) : 0;
+
+	ret = as3722_update_bits(as3722, AS3722_GPIO_SIGNAL_OUT_REG,
+			AS3722_GPIOn_SIGNAL(offset), val);
+	if (ret < 0)
+		dev_err(as3722_gpio->dev,
+			"GPIO_SIGNAL_OUT_REG update failed: %d\n", ret);
+}
+
+static int as3722_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+	struct as3722 *as3722 = as3722_gpio->as3722;
+	int mode;
+
+	mode = as3722_gpio_get_mode(as3722_gpio->gpio_control[offset].mode_prop,
+			true);
+	if (mode < 0) {
+		dev_err(as3722_gpio->dev,
+			"Input direction for GPIO %d not supported\n", offset);
+		return mode;
+	}
+
+	if (as3722_gpio->gpio_control[offset].enable_gpio_invert)
+		mode |= AS3722_GPIO_INV;
+
+	return as3722_write(as3722, AS3722_GPIOn_CONTROL_REG(offset), mode);
+}
+
+static int as3722_gpio_direction_output(struct gpio_chip *chip,
+		unsigned offset, int value)
+{
+	struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+	struct as3722 *as3722 = as3722_gpio->as3722;
+	int mode;
+
+	mode = as3722_gpio_get_mode(as3722_gpio->gpio_control[offset].mode_prop,
+			false);
+	if (mode < 0) {
+		dev_err(as3722_gpio->dev,
+			"Output direction for GPIO %d not supported\n", offset);
+		return mode;
+	}
+
+	as3722_gpio_set(chip, offset, value);
+	if (as3722_gpio->gpio_control[offset].enable_gpio_invert)
+		mode |= AS3722_GPIO_INV;
+	return as3722_write(as3722, AS3722_GPIOn_CONTROL_REG(offset), mode);
+}
+
+static int as3722_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+
+	return as3722_irq_get_virq(as3722_gpio->as3722, offset);
+}
+
+static int as3722_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+
+	if (as3722_gpio->gpio_control[offset].io_function)
+		return -EBUSY;
+	return 0;
+}
+
+static int as3722_gpio_set_config(struct as3722_gpio *as3722_gpio,
+		unsigned int gpio)
+{
+	struct as3722 *as3722 = as3722_gpio->as3722;
+	int ret = 0;
+	u8 val = 0;
+
+	val = AS3722_GPIO_IOSF_VAL(as3722_gpio->gpio_control[gpio].io_function);
+	ret = as3722_update_bits(as3722, AS3722_GPIOn_CONTROL_REG(gpio),
+			AS3722_GPIO_IOSF_MASK, val);
+	if (ret < 0)
+		dev_err(as3722->dev,
+			"GPIO%d_CTRL_REG update failed %d\n", gpio, ret);
+	return ret;
+}
+
+static int as3722_gpio_init_configs(struct as3722_gpio *as3722_gpio)
+{
+	int ret;
+	unsigned int i;
+
+	for (i = 0; i < AS3722_MAX_GPIO; i++) {
+		if (!as3722_gpio->gpio_control[i].io_function)
+			continue;
+
+		ret = as3722_gpio_set_config(as3722_gpio, i);
+		if (ret < 0) {
+			dev_err(as3722_gpio->dev,
+				"GPIO %d config failed %d\n", i, ret);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+static int as3722_gpio_dt_subnode(struct as3722_gpio *as3722_gpio,
+		struct device_node *child, int gpio)
+{
+	const char *iosf;
+	int i;
+	int ret;
+	bool found;
+	unsigned prop_val = 0;
+
+	for (i = 0; i < ARRAY_SIZE(as3722_gpio_mode_props); ++i) {
+		found = of_property_read_bool(child,
+					as3722_gpio_mode_props[i].prop);
+		if (found)
+			prop_val |= as3722_gpio_mode_props[i].prop_val;
+	}
+	as3722_gpio->gpio_control[gpio].mode_prop = prop_val;
+
+	ret = of_property_read_string(child, "function", &iosf);
+	if (!ret) {
+		found = false;
+		for (i = 0; i < ARRAY_SIZE(as3722_gpio_iosf); ++i) {
+			if (!strcmp(as3722_gpio_iosf[i], iosf)) {
+				found = true;
+				break;
+			}
+		}
+		if (found)
+			as3722_gpio->gpio_control[gpio].io_function = i;
+		else
+			dev_warn(as3722_gpio->dev,
+				"Child %s io function is invalid\n",
+				child->name);
+	}
+
+	as3722_gpio->gpio_control[gpio].enable_gpio_invert =
+			of_property_read_bool(child, "ams,enable-gpio-invert");
+	return 0;
+}
+
+static int as3722_get_gpio_dt_data(struct platform_device *pdev,
+		struct as3722_gpio *as3722_gpio)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *child;
+	unsigned int gpio;
+	int ret;
+
+	if (!np) {
+		dev_err(&pdev->dev, "Device does not have gpio node\n");
+		return -ENODEV;
+	}
+
+	for_each_child_of_node(np, child) {
+		ret = of_property_read_u32(child, "reg", &gpio);
+		if (ret < 0) {
+			dev_warn(&pdev->dev,
+				"reg property not present in node %s\n",
+				child->name);
+			continue;
+		}
+		if (gpio >=  AS3722_MAX_GPIO) {
+			dev_warn(&pdev->dev,
+			     "GPIO number %d is more than supported\n", gpio);
+			continue;
+		}
+		ret = as3722_gpio_dt_subnode(as3722_gpio, child, gpio);
+		if (ret < 0)
+			dev_warn(&pdev->dev, "gpio %s node parse failed: %d\n",
+				child->name, ret);
+	}
+	return 0;
+}
+
+static const struct gpio_chip as3722_gpio_chip = {
+	.label			= "as3722-gpio",
+	.owner			= THIS_MODULE,
+	.direction_input	= as3722_gpio_direction_input,
+	.get			= as3722_gpio_get,
+	.direction_output	= as3722_gpio_direction_output,
+	.set			= as3722_gpio_set,
+	.to_irq			= as3722_gpio_to_irq,
+	.request		= as3722_gpio_request,
+	.can_sleep		= 1,
+	.ngpio			= AS3722_MAX_GPIO,
+	.base			= -1,
+};
+
+static int as3722_gpio_probe(struct platform_device *pdev)
+{
+	struct as3722 *as3722 =  dev_get_drvdata(pdev->dev.parent);
+	struct as3722_gpio *as3722_gpio;
+	int ret;
+
+	as3722_gpio = devm_kzalloc(&pdev->dev, sizeof(*as3722_gpio),
+				GFP_KERNEL);
+	if (!as3722_gpio)
+		return -ENOMEM;
+
+	ret = as3722_get_gpio_dt_data(pdev, as3722_gpio);
+	if (ret < 0)
+		return ret;
+
+	as3722_gpio->as3722 = as3722;
+	as3722_gpio->dev = &pdev->dev;
+	as3722_gpio->gpio_chip = as3722_gpio_chip;
+	as3722_gpio->gpio_chip.dev = &pdev->dev;
+	as3722_gpio->gpio_chip.of_node = pdev->dev.parent->of_node;
+
+	platform_set_drvdata(pdev, as3722_gpio);
+
+	ret = as3722_gpio_init_configs(as3722_gpio);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "gpio_init_regs failed\n");
+		return ret;
+	}
+
+	ret = gpiochip_add(&as3722_gpio->gpio_chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
+				ret);
+		return ret;
+	}
+	return 0;
+}
+
+static int as3722_gpio_remove(struct platform_device *pdev)
+{
+	struct as3722_gpio *as3722_gpio = platform_get_drvdata(pdev);
+
+	return gpiochip_remove(&as3722_gpio->gpio_chip);
+}
+
+static const struct of_device_id of_as3722_gpio_match[] = {
+	{ .compatible = "ams,as3722-gpio", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_as3722_gpio_match);
+
+static struct platform_driver as3722_gpio_driver = {
+	.driver = {
+		.name = "as3722-gpio",
+		.owner = THIS_MODULE,
+		.of_match_table = of_as3722_gpio_match,
+	},
+	.probe = as3722_gpio_probe,
+	.remove = as3722_gpio_remove,
+};
+
+static int __init as3722_gpio_init(void)
+{
+	return platform_driver_register(&as3722_gpio_driver);
+}
+subsys_initcall(as3722_gpio_init);
+
+static void __exit as3722_gpio_exit(void)
+{
+	platform_driver_unregister(&as3722_gpio_driver);
+}
+module_exit(as3722_gpio_exit);
+
+MODULE_ALIAS("platform:as3722-gpio");
+MODULE_DESCRIPTION("GPIO interface for AS3722 PMICs");
+MODULE_AUTHOR("Florian Lobmaier <florian.lobmaier@ams.com>");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_LICENSE("GPL");