diff options
Diffstat (limited to 'drivers/gpio/gpio-axp209.c')
| -rw-r--r-- | drivers/gpio/gpio-axp209.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-axp209.c b/drivers/gpio/gpio-axp209.c new file mode 100644 index 000000000000..d9c2a517c6df --- /dev/null +++ b/drivers/gpio/gpio-axp209.c @@ -0,0 +1,192 @@ +/* + * 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_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"); |