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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Servergy CTS-1000 Setup
*
* Maintained by Ben Collins <ben.c@servergy.com>
*
* Copyright 2012 by Servergy, Inc.
*/
#define pr_fmt(fmt) "gpio-halt: " fmt
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/workqueue.h>
#include <linux/reboot.h>
#include <linux/interrupt.h>
#include <asm/machdep.h>
static struct gpio_desc *halt_gpio;
static int halt_irq;
static const struct of_device_id child_match[] = {
{
.compatible = "sgy,gpio-halt",
},
{},
};
static void gpio_halt_wfn(struct work_struct *work)
{
/* Likely wont return */
orderly_poweroff(true);
}
static DECLARE_WORK(gpio_halt_wq, gpio_halt_wfn);
static void __noreturn gpio_halt_cb(void)
{
pr_info("triggering GPIO.\n");
/* Probably wont return */
gpiod_set_value(halt_gpio, 1);
panic("Halt failed\n");
}
/* This IRQ means someone pressed the power button and it is waiting for us
* to handle the shutdown/poweroff. */
static irqreturn_t gpio_halt_irq(int irq, void *__data)
{
struct platform_device *pdev = __data;
dev_info(&pdev->dev, "scheduling shutdown due to power button IRQ\n");
schedule_work(&gpio_halt_wq);
return IRQ_HANDLED;
};
static int __gpio_halt_probe(struct platform_device *pdev,
struct device_node *halt_node)
{
int err;
halt_gpio = fwnode_gpiod_get_index(of_fwnode_handle(halt_node),
NULL, 0, GPIOD_OUT_LOW, "gpio-halt");
err = PTR_ERR_OR_ZERO(halt_gpio);
if (err) {
dev_err(&pdev->dev, "failed to request halt GPIO: %d\n", err);
return err;
}
/* Now get the IRQ which tells us when the power button is hit */
halt_irq = irq_of_parse_and_map(halt_node, 0);
err = request_irq(halt_irq, gpio_halt_irq,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
"gpio-halt", pdev);
if (err) {
dev_err(&pdev->dev, "failed to request IRQ %d: %d\n",
halt_irq, err);
gpiod_put(halt_gpio);
halt_gpio = NULL;
return err;
}
/* Register our halt function */
ppc_md.halt = gpio_halt_cb;
pm_power_off = gpio_halt_cb;
dev_info(&pdev->dev, "registered halt GPIO, irq: %d\n", halt_irq);
return 0;
}
static int gpio_halt_probe(struct platform_device *pdev)
{
struct device_node *halt_node;
int ret;
if (!pdev->dev.of_node)
return -ENODEV;
/* If there's no matching child, this isn't really an error */
halt_node = of_find_matching_node(pdev->dev.of_node, child_match);
if (!halt_node)
return -ENODEV;
ret = __gpio_halt_probe(pdev, halt_node);
of_node_put(halt_node);
return ret;
}
static void gpio_halt_remove(struct platform_device *pdev)
{
free_irq(halt_irq, pdev);
cancel_work_sync(&gpio_halt_wq);
ppc_md.halt = NULL;
pm_power_off = NULL;
gpiod_put(halt_gpio);
halt_gpio = NULL;
}
static const struct of_device_id gpio_halt_match[] = {
/* We match on the gpio bus itself and scan the children since they
* wont be matched against us. We know the bus wont match until it
* has been registered too. */
{
.compatible = "fsl,qoriq-gpio",
},
{},
};
MODULE_DEVICE_TABLE(of, gpio_halt_match);
static struct platform_driver gpio_halt_driver = {
.driver = {
.name = "gpio-halt",
.of_match_table = gpio_halt_match,
},
.probe = gpio_halt_probe,
.remove_new = gpio_halt_remove,
};
module_platform_driver(gpio_halt_driver);
MODULE_DESCRIPTION("Driver to support GPIO triggered system halt for Servergy CTS-1000 Systems.");
MODULE_VERSION("1.0");
MODULE_AUTHOR("Ben Collins <ben.c@servergy.com>");
MODULE_LICENSE("GPL");
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