cregit-Linux how code gets into the kernel

Release 4.14 drivers/power/reset/gpio-poweroff.c

/*
 * Toggles a GPIO pin to power down a device
 *
 * Jamie Lentin <jm@lentin.co.uk>
 * Andrew Lunn <andrew@lunn.ch>
 *
 * Copyright (C) 2012 Jamie Lentin
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/gpio/consumer.h>
#include <linux/of_platform.h>
#include <linux/module.h>

/*
 * Hold configuration here, cannot be more than one instance of the driver
 * since pm_power_off itself is global.
 */

static struct gpio_desc *reset_gpio;


static void gpio_poweroff_do_poweroff(void) { BUG_ON(!reset_gpio); /* drive it active, also inactive->active edge */ gpiod_direction_output(reset_gpio, 1); mdelay(100); /* drive inactive, also active->inactive edge */ gpiod_set_value(reset_gpio, 0); mdelay(100); /* drive it active, also inactive->active edge */ gpiod_set_value(reset_gpio, 1); /* give it some time */ mdelay(3000); WARN_ON(1); }

Contributors

PersonTokensPropCommitsCommitProp
Jamie Lentin4576.27%133.33%
Linus Walleij1016.95%133.33%
Andrew Lunn46.78%133.33%
Total59100.00%3100.00%


static int gpio_poweroff_probe(struct platform_device *pdev) { bool input = false; enum gpiod_flags flags; /* If a pm_power_off function has already been added, leave it alone */ if (pm_power_off != NULL) { dev_err(&pdev->dev, "%s: pm_power_off function already registered", __func__); return -EBUSY; } input = of_property_read_bool(pdev->dev.of_node, "input"); if (input) flags = GPIOD_IN; else flags = GPIOD_OUT_LOW; reset_gpio = devm_gpiod_get(&pdev->dev, NULL, flags); if (IS_ERR(reset_gpio)) return PTR_ERR(reset_gpio); pm_power_off = &gpio_poweroff_do_poweroff; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Jamie Lentin6864.15%125.00%
Uwe Kleine-König2220.75%125.00%
Linus Walleij1312.26%125.00%
Andrew Lunn32.83%125.00%
Total106100.00%4100.00%


static int gpio_poweroff_remove(struct platform_device *pdev) { if (pm_power_off == &gpio_poweroff_do_poweroff) pm_power_off = NULL; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Jamie Lentin25100.00%1100.00%
Total25100.00%1100.00%

static const struct of_device_id of_gpio_poweroff_match[] = { { .compatible = "gpio-poweroff", }, {}, }; static struct platform_driver gpio_poweroff_driver = { .probe = gpio_poweroff_probe, .remove = gpio_poweroff_remove, .driver = { .name = "poweroff-gpio", .of_match_table = of_gpio_poweroff_match, }, }; module_platform_driver(gpio_poweroff_driver); MODULE_AUTHOR("Jamie Lentin <jm@lentin.co.uk>"); MODULE_DESCRIPTION("GPIO poweroff driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:poweroff-gpio");

Overall Contributors

PersonTokensPropCommitsCommitProp
Jamie Lentin23579.93%125.00%
Linus Walleij289.52%125.00%
Uwe Kleine-König227.48%125.00%
Andrew Lunn93.06%125.00%
Total294100.00%4100.00%
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