[PATCH 1/4] gpio: Add AXP209 GPIO driver

Maxime Ripard
2016-03-09T11:05:08Z

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: Maxime Ripard <maxime.ripard@free-electrons.com>
---
.../devicetree/bindings/gpio/gpio-axp209.txt | 30 ++++
drivers/gpio/Kconfig | 6 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-axp209.c | 166 +++++++++++++++++++++
4 files changed, 203 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/gpio-axp209.txt
create mode 100644 drivers/gpio/gpio-axp209.c

diff --git a/Documentation/devicetree/bindings/gpio/gpio-axp209.txt b/Documentation/devicetree/bindings/gpio/gpio-axp209.txt
new file mode 100644
index 000000000000..a6611304dd3c
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-axp209.txt
@@ -0,0 +1,30 @@
+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>;
+ };
+};
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 1118fef45a86..cd5ab93ac197 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -136,6 +136,12 @@ config GPIO_ATH79
Select this option to enable GPIO driver for
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
bool "Broadcom Kona GPIO"
depends on OF_GPIO && (ARCH_BCM_MOBILE || COMPILE_TEST)
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 6f969df1431a..e9e7fbe80ab7 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_GPIO_AMD8111) += gpio-amd8111.o
obj-$(CONFIG_GPIO_AMDPT) += gpio-amdpt.o
obj-$(CONFIG_GPIO_ARIZONA) += gpio-arizona.o
obj-$(CONFIG_GPIO_ATH79) += gpio-ath79.o
+obj-$(CONFIG_GPIO_AXP209) += gpio-axp209.o
obj-$(CONFIG_GPIO_BCM_KONA) += gpio-bcm-kona.o
obj-$(CONFIG_GPIO_BRCMSTB) += gpio-brcmstb.o
obj-$(CONFIG_GPIO_BT8XX) += gpio-bt8xx.o
diff --git a/drivers/gpio/gpio-axp209.c b/drivers/gpio/gpio-axp209.c
new file mode 100644
index 000000000000..822f39faaadf
--- /dev/null
+++ b/drivers/gpio/gpio-axp209.c
@@ -0,0 +1,166 @@
+/*
+ * 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/device.h>
+#include <linux/gpio.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;
+};
+
+struct axp20x_gpio *to_axp20x_gpio(struct gpio_chip *chip)
+{
+ return container_of(chip, struct axp20x_gpio, chip);
+}
+
+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 = to_axp20x_gpio(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 = to_axp20x_gpio(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 & (1 << (offset + 4));
+}
+
+static int axp20x_gpio_output(struct gpio_chip *chip, unsigned offset,
+ int value)
+{
+ struct axp20x_gpio *gpio = to_axp20x_gpio(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.dev = &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 = gpiochip_add(&gpio->chip);
+ 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");
--
2.7.2