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: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpio-axp209.c b/drivers/gpio/gpio-axp209.c
new file mode 100644
index 0000000..3174799
--- /dev/null
+++ b/drivers/gpio/gpio-axp209.c
@@ -0,0 +1,162 @@
+/*
+ * 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");