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/Documentation/devicetree/bindings/gpio/gpio-axp209.txt b/Documentation/devicetree/bindings/gpio/gpio-axp209.txt
new file mode 100644 (file)
index 0000000..a661130
--- /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 6de9062119dfdce9fa43b7d6d35443f81bb37ffb..ed968d112399e0b16326f620d56c76a0d4caab24 100644 (file)
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -116,6 +116,12 @@ 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 2a035ed8f168196ec7596d303685b439b2c2938e..b7d509e27ed1f1feb4cc266396722e384f067d64 100644 (file)
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -28,6 +28,7 @@ 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 (file)
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");