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path: root/drivers/watchdog/mtx-1_wdt.c
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Diffstat (limited to 'drivers/watchdog/mtx-1_wdt.c')
-rw-r--r--drivers/watchdog/mtx-1_wdt.c247
1 files changed, 247 insertions, 0 deletions
diff --git a/drivers/watchdog/mtx-1_wdt.c b/drivers/watchdog/mtx-1_wdt.c
new file mode 100644
index 0000000000..152e41ecbb
--- /dev/null
+++ b/drivers/watchdog/mtx-1_wdt.c
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for the MTX-1 Watchdog.
+ *
+ * (C) Copyright 2005 4G Systems <info@4g-systems.biz>,
+ * All Rights Reserved.
+ * http://www.4g-systems.biz
+ *
+ * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
+ * (c) Copyright 2005 4G Systems <info@4g-systems.biz>
+ *
+ * Release 0.01.
+ * Author: Michael Stickel michael.stickel@4g-systems.biz
+ *
+ * Release 0.02.
+ * Author: Florian Fainelli florian@openwrt.org
+ * use the Linux watchdog/timer APIs
+ *
+ * The Watchdog is configured to reset the MTX-1
+ * if it is not triggered for 100 seconds.
+ * It should not be triggered more often than 1.6 seconds.
+ *
+ * A timer triggers the watchdog every 5 seconds, until
+ * it is opened for the first time. After the first open
+ * it MUST be triggered every 2..95 seconds.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/ioport.h>
+#include <linux/timer.h>
+#include <linux/completion.h>
+#include <linux/jiffies.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/gpio/consumer.h>
+
+#define MTX1_WDT_INTERVAL (5 * HZ)
+
+static int ticks = 100 * HZ;
+
+static struct {
+ struct completion stop;
+ spinlock_t lock;
+ int running;
+ struct timer_list timer;
+ int queue;
+ int default_ticks;
+ unsigned long inuse;
+ struct gpio_desc *gpiod;
+ unsigned int gstate;
+} mtx1_wdt_device;
+
+static void mtx1_wdt_trigger(struct timer_list *unused)
+{
+ spin_lock(&mtx1_wdt_device.lock);
+ if (mtx1_wdt_device.running)
+ ticks--;
+
+ /* toggle wdt gpio */
+ mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
+ gpiod_set_value(mtx1_wdt_device.gpiod, mtx1_wdt_device.gstate);
+
+ if (mtx1_wdt_device.queue && ticks)
+ mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
+ else
+ complete(&mtx1_wdt_device.stop);
+ spin_unlock(&mtx1_wdt_device.lock);
+}
+
+static void mtx1_wdt_reset(void)
+{
+ ticks = mtx1_wdt_device.default_ticks;
+}
+
+
+static void mtx1_wdt_start(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
+ if (!mtx1_wdt_device.queue) {
+ mtx1_wdt_device.queue = 1;
+ mtx1_wdt_device.gstate = 1;
+ gpiod_set_value(mtx1_wdt_device.gpiod, 1);
+ mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
+ }
+ mtx1_wdt_device.running++;
+ spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
+}
+
+static int mtx1_wdt_stop(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
+ if (mtx1_wdt_device.queue) {
+ mtx1_wdt_device.queue = 0;
+ mtx1_wdt_device.gstate = 0;
+ gpiod_set_value(mtx1_wdt_device.gpiod, 0);
+ }
+ ticks = mtx1_wdt_device.default_ticks;
+ spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
+ return 0;
+}
+
+/* Filesystem functions */
+
+static int mtx1_wdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
+ return -EBUSY;
+ return stream_open(inode, file);
+}
+
+
+static int mtx1_wdt_release(struct inode *inode, struct file *file)
+{
+ clear_bit(0, &mtx1_wdt_device.inuse);
+ return 0;
+}
+
+static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = (int __user *)argp;
+ unsigned int value;
+ static const struct watchdog_info ident = {
+ .options = WDIOF_CARDRESET,
+ .identity = "MTX-1 WDT",
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &ident, sizeof(ident)))
+ return -EFAULT;
+ break;
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ put_user(0, p);
+ break;
+ case WDIOC_SETOPTIONS:
+ if (get_user(value, p))
+ return -EFAULT;
+ if (value & WDIOS_ENABLECARD)
+ mtx1_wdt_start();
+ else if (value & WDIOS_DISABLECARD)
+ mtx1_wdt_stop();
+ else
+ return -EINVAL;
+ return 0;
+ case WDIOC_KEEPALIVE:
+ mtx1_wdt_reset();
+ break;
+ default:
+ return -ENOTTY;
+ }
+ return 0;
+}
+
+
+static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
+ size_t count, loff_t *ppos)
+{
+ if (!count)
+ return -EIO;
+ mtx1_wdt_reset();
+ return count;
+}
+
+static const struct file_operations mtx1_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .unlocked_ioctl = mtx1_wdt_ioctl,
+ .compat_ioctl = compat_ptr_ioctl,
+ .open = mtx1_wdt_open,
+ .write = mtx1_wdt_write,
+ .release = mtx1_wdt_release,
+};
+
+
+static struct miscdevice mtx1_wdt_misc = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &mtx1_wdt_fops,
+};
+
+
+static int mtx1_wdt_probe(struct platform_device *pdev)
+{
+ int ret;
+
+ mtx1_wdt_device.gpiod = devm_gpiod_get(&pdev->dev,
+ NULL, GPIOD_OUT_HIGH);
+ if (IS_ERR(mtx1_wdt_device.gpiod)) {
+ dev_err(&pdev->dev, "failed to request gpio");
+ return PTR_ERR(mtx1_wdt_device.gpiod);
+ }
+
+ spin_lock_init(&mtx1_wdt_device.lock);
+ init_completion(&mtx1_wdt_device.stop);
+ mtx1_wdt_device.queue = 0;
+ clear_bit(0, &mtx1_wdt_device.inuse);
+ timer_setup(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0);
+ mtx1_wdt_device.default_ticks = ticks;
+
+ ret = misc_register(&mtx1_wdt_misc);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to register\n");
+ return ret;
+ }
+ mtx1_wdt_start();
+ dev_info(&pdev->dev, "MTX-1 Watchdog driver\n");
+ return 0;
+}
+
+static void mtx1_wdt_remove(struct platform_device *pdev)
+{
+ /* FIXME: do we need to lock this test ? */
+ if (mtx1_wdt_device.queue) {
+ mtx1_wdt_device.queue = 0;
+ wait_for_completion(&mtx1_wdt_device.stop);
+ }
+
+ misc_deregister(&mtx1_wdt_misc);
+}
+
+static struct platform_driver mtx1_wdt_driver = {
+ .probe = mtx1_wdt_probe,
+ .remove_new = mtx1_wdt_remove,
+ .driver.name = "mtx1-wdt",
+ .driver.owner = THIS_MODULE,
+};
+
+module_platform_driver(mtx1_wdt_driver);
+
+MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
+MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mtx1-wdt");