Commit f72f4b44 authored by Maxime Ripard's avatar Maxime Ripard Committed by Linus Walleij
Browse files

gpio: Add AXP209 GPIO driver 



The AXP209 PMIC has a bunch of GPIOs accessible, that are usually used to
control LEDs or backlight.

Add a driver for them

Signed-off-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent e23efa31

Documentation/devicetree/bindings/gpio/gpio-axp209.txt

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AXP209 GPIO controller



This driver follows the usual GPIO bindings found in

Documentation/devicetree/bindings/gpio/gpio.txt



Required properties:

- compatible: Should be "x-powers,axp209-gpio"

- #gpio-cells: Should be two. The first cell is the pin number and the

  second is the GPIO flags.

- gpio-controller: Marks the device node as a GPIO controller.



This node must be a subnode of the axp20x PMIC, documented in

Documentation/devicetree/bindings/mfd/axp20x.txt



Example:



axp209: pmic@34 {

	compatible = "x-powers,axp209";

	reg = <0x34>;

	interrupt-parent = <&nmi_intc>;

	interrupts = <0 IRQ_TYPE_LEVEL_LOW>;

	interrupt-controller;

	#interrupt-cells = <1>;



	axp_gpio: gpio {

		compatible = "x-powers,axp209-gpio";

		gpio-controller;

		#gpio-cells = <2>;

	};

};

drivers/gpio/Kconfig

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@@ -116,6 +116,12 @@ config GPIO_ATH79 
	  Select this option to enable GPIO driver for

	  Select this option to enable GPIO driver for

	  Atheros AR71XX/AR724X/AR913X SoC devices.

	  Atheros AR71XX/AR724X/AR913X SoC devices.





config GPIO_AXP209

	tristate "X-Powers AXP209 PMIC GPIO Support"

	depends on MFD_AXP20X

	help

	  Say yes to enable GPIO support for the AXP209 PMIC



config GPIO_BCM_KONA

config GPIO_BCM_KONA

	bool "Broadcom Kona GPIO"

	bool "Broadcom Kona GPIO"

	depends on OF_GPIO && (ARCH_BCM_MOBILE || COMPILE_TEST)

	depends on OF_GPIO && (ARCH_BCM_MOBILE || COMPILE_TEST)

drivers/gpio/Makefile

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@@ -28,6 +28,7 @@ obj-$(CONFIG_GPIO_AMD8111) += gpio-amd8111.o 
obj-$(CONFIG_GPIO_AMDPT)	+= gpio-amdpt.o

obj-$(CONFIG_GPIO_AMDPT)	+= gpio-amdpt.o

obj-$(CONFIG_GPIO_ARIZONA)	+= gpio-arizona.o

obj-$(CONFIG_GPIO_ARIZONA)	+= gpio-arizona.o

obj-$(CONFIG_GPIO_ATH79)	+= gpio-ath79.o

obj-$(CONFIG_GPIO_ATH79)	+= gpio-ath79.o

obj-$(CONFIG_GPIO_AXP209)	+= gpio-axp209.o

obj-$(CONFIG_GPIO_BCM_KONA)	+= gpio-bcm-kona.o

obj-$(CONFIG_GPIO_BCM_KONA)	+= gpio-bcm-kona.o

obj-$(CONFIG_GPIO_BRCMSTB)	+= gpio-brcmstb.o

obj-$(CONFIG_GPIO_BRCMSTB)	+= gpio-brcmstb.o

obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o

obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o

drivers/gpio/gpio-axp209.c

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/*

 * AXP20x GPIO driver

 *

 * Copyright (C) 2016 Maxime Ripard <maxime.ripard@free-electrons.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.

 */



#include <linux/bitops.h>

#include <linux/device.h>

#include <linux/gpio/driver.h>

#include <linux/init.h>

#include <linux/interrupt.h>

#include <linux/kernel.h>

#include <linux/mfd/axp20x.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>

#include <linux/slab.h>



#define AXP20X_GPIO_FUNCTIONS		0x7

#define AXP20X_GPIO_FUNCTION_OUT_LOW	0

#define AXP20X_GPIO_FUNCTION_OUT_HIGH	1

#define AXP20X_GPIO_FUNCTION_INPUT	2



struct axp20x_gpio {

	struct gpio_chip	chip;

	struct regmap		*regmap;

};



static int axp20x_gpio_get_reg(unsigned offset)

{

	switch (offset) {

	case 0:

		return AXP20X_GPIO0_CTRL;

	case 1:

		return AXP20X_GPIO1_CTRL;

	case 2:

		return AXP20X_GPIO2_CTRL;

	}



	return -EINVAL;

}



static int axp20x_gpio_input(struct gpio_chip *chip, unsigned offset)

{

	struct axp20x_gpio *gpio = gpiochip_get_data(chip);

	int reg;



	reg = axp20x_gpio_get_reg(offset);

	if (reg < 0)

		return reg;



	return regmap_update_bits(gpio->regmap, reg,

				  AXP20X_GPIO_FUNCTIONS,

				  AXP20X_GPIO_FUNCTION_INPUT);

}



static int axp20x_gpio_get(struct gpio_chip *chip, unsigned offset)

{

	struct axp20x_gpio *gpio = gpiochip_get_data(chip);

	unsigned int val;

	int reg, ret;



	reg = axp20x_gpio_get_reg(offset);

	if (reg < 0)

		return reg;



	ret = regmap_read(gpio->regmap, reg, &val);

	if (ret)

		return ret;



	return !!(val & BIT(offset + 4));

}



static int axp20x_gpio_output(struct gpio_chip *chip, unsigned offset,

			      int value)

{

	struct axp20x_gpio *gpio = gpiochip_get_data(chip);

	int reg;



	reg = axp20x_gpio_get_reg(offset);

	if (reg < 0)

		return reg;



	return regmap_update_bits(gpio->regmap, reg,

				  AXP20X_GPIO_FUNCTIONS,

				  value ? AXP20X_GPIO_FUNCTION_OUT_HIGH

				  : AXP20X_GPIO_FUNCTION_OUT_LOW);

}



static void axp20x_gpio_set(struct gpio_chip *chip, unsigned offset,

			    int value)

{

	axp20x_gpio_output(chip, offset, value);

}



static int axp20x_gpio_probe(struct platform_device *pdev)

{

	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);

	struct axp20x_gpio *gpio;

	int ret;



	if (!of_device_is_available(pdev->dev.of_node))

		return -ENODEV;



	if (!axp20x) {

		dev_err(&pdev->dev, "Parent drvdata not set\n");

		return -EINVAL;

	}



	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);

	if (!gpio)

		return -ENOMEM;



	gpio->chip.base			= -1;

	gpio->chip.can_sleep		= true;

	gpio->chip.parent		= &pdev->dev;

	gpio->chip.label		= dev_name(&pdev->dev);

	gpio->chip.owner		= THIS_MODULE;

	gpio->chip.get			= axp20x_gpio_get;

	gpio->chip.set			= axp20x_gpio_set;

	gpio->chip.direction_input	= axp20x_gpio_input;

	gpio->chip.direction_output	= axp20x_gpio_output;

	gpio->chip.ngpio		= 3;



	gpio->regmap = axp20x->regmap;



	ret = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);

	if (ret) {

		dev_err(&pdev->dev, "Failed to register GPIO chip\n");

		return ret;

	}



	dev_info(&pdev->dev, "AXP209 GPIO driver loaded\n");



	return 0;

}



static const struct of_device_id axp20x_gpio_match[] = {

	{ .compatible = "x-powers,axp209-gpio" },

	{ }

};

MODULE_DEVICE_TABLE(of, axp20x_gpio_match);



static struct platform_driver axp20x_gpio_driver = {

	.probe		= axp20x_gpio_probe,

	.driver = {

		.name		= "axp20x-gpio",

		.of_match_table	= axp20x_gpio_match,

	},

};



module_platform_driver(axp20x_gpio_driver);



MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");

MODULE_DESCRIPTION("AXP20x PMIC GPIO driver");

MODULE_LICENSE("GPL");