2ce8284c31
The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it as merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Acked-by: David Lechner <david@lechnology.com> Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-by: Simon Glass <sjg@chromium.org> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
139 lines
3.5 KiB
C
139 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Toggles a GPIO pin to restart a device
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*
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* Copyright (C) 2014 Google, Inc.
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*
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* Based on the gpio-poweroff driver.
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*/
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#include <linux/reboot.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/platform_device.h>
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#include <linux/gpio/consumer.h>
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#include <linux/module.h>
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#include <linux/of.h>
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struct gpio_restart {
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struct gpio_desc *reset_gpio;
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struct notifier_block restart_handler;
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u32 active_delay_ms;
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u32 inactive_delay_ms;
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u32 wait_delay_ms;
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};
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static int gpio_restart_notify(struct notifier_block *this,
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unsigned long mode, void *cmd)
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{
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struct gpio_restart *gpio_restart =
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container_of(this, struct gpio_restart, restart_handler);
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/* drive it active, also inactive->active edge */
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gpiod_direction_output(gpio_restart->reset_gpio, 1);
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mdelay(gpio_restart->active_delay_ms);
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/* drive inactive, also active->inactive edge */
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gpiod_set_value(gpio_restart->reset_gpio, 0);
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mdelay(gpio_restart->inactive_delay_ms);
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/* drive it active, also inactive->active edge */
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gpiod_set_value(gpio_restart->reset_gpio, 1);
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/* give it some time */
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mdelay(gpio_restart->wait_delay_ms);
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WARN_ON(1);
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return NOTIFY_DONE;
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}
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static int gpio_restart_probe(struct platform_device *pdev)
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{
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struct gpio_restart *gpio_restart;
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bool open_source = false;
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u32 property;
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int ret;
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gpio_restart = devm_kzalloc(&pdev->dev, sizeof(*gpio_restart),
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GFP_KERNEL);
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if (!gpio_restart)
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return -ENOMEM;
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open_source = of_property_read_bool(pdev->dev.of_node, "open-source");
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gpio_restart->reset_gpio = devm_gpiod_get(&pdev->dev, NULL,
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open_source ? GPIOD_IN : GPIOD_OUT_LOW);
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ret = PTR_ERR_OR_ZERO(gpio_restart->reset_gpio);
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if (ret) {
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if (ret != -EPROBE_DEFER)
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dev_err(&pdev->dev, "Could not get reset GPIO\n");
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return ret;
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}
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gpio_restart->restart_handler.notifier_call = gpio_restart_notify;
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gpio_restart->restart_handler.priority = 129;
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gpio_restart->active_delay_ms = 100;
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gpio_restart->inactive_delay_ms = 100;
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gpio_restart->wait_delay_ms = 3000;
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ret = of_property_read_u32(pdev->dev.of_node, "priority", &property);
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if (!ret) {
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if (property > 255)
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dev_err(&pdev->dev, "Invalid priority property: %u\n",
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property);
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else
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gpio_restart->restart_handler.priority = property;
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}
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of_property_read_u32(pdev->dev.of_node, "active-delay",
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&gpio_restart->active_delay_ms);
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of_property_read_u32(pdev->dev.of_node, "inactive-delay",
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&gpio_restart->inactive_delay_ms);
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of_property_read_u32(pdev->dev.of_node, "wait-delay",
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&gpio_restart->wait_delay_ms);
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platform_set_drvdata(pdev, gpio_restart);
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ret = register_restart_handler(&gpio_restart->restart_handler);
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if (ret) {
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dev_err(&pdev->dev, "%s: cannot register restart handler, %d\n",
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__func__, ret);
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return -ENODEV;
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}
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return 0;
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}
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static void gpio_restart_remove(struct platform_device *pdev)
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{
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struct gpio_restart *gpio_restart = platform_get_drvdata(pdev);
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int ret;
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ret = unregister_restart_handler(&gpio_restart->restart_handler);
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if (ret) {
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dev_err(&pdev->dev,
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"%s: cannot unregister restart handler, %d\n",
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__func__, ret);
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}
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}
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static const struct of_device_id of_gpio_restart_match[] = {
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{ .compatible = "gpio-restart", },
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{},
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};
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static struct platform_driver gpio_restart_driver = {
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.probe = gpio_restart_probe,
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.remove_new = gpio_restart_remove,
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.driver = {
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.name = "restart-gpio",
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.of_match_table = of_gpio_restart_match,
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},
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};
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module_platform_driver(gpio_restart_driver);
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MODULE_AUTHOR("David Riley <davidriley@chromium.org>");
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MODULE_DESCRIPTION("GPIO restart driver");
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