/* * 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 ret; ret = regmap_read(gpio->regmap, AXP20X_GPIO20_SS, &val); if (ret) return ret; return !!(val & BIT(offset + 4)); } static int axp20x_gpio_get_direction(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; /* * This shouldn't really happen if the pin is in use already, * or if it's not in use yet, it doesn't matter since we're * going to change the value soon anyway. Default to output. */ if ((val & AXP20X_GPIO_FUNCTIONS) > 2) return 0; /* * The GPIO directions are the three lowest values. * 2 is input, 0 and 1 are output */ return val & 2; } 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.get_direction = axp20x_gpio_get_direction; 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");