--- /dev/null
+/*
+ * Copyright (C) 2008-2009 Avionic Design GmbH
+ *
+ * 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/fs.h>
+#include <linux/io.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+
+#define WATCHDOG_NAME "adx-wdt"
+
+/* register offsets */
+#define ADX_WDT_CONTROL 0x00
+#define ADX_WDT_CONTROL_ENABLE (1 << 0)
+#define ADX_WDT_CONTROL_nRESET (1 << 1)
+#define ADX_WDT_TIMEOUT 0x08
+
+static struct platform_device *adx_wdt_dev;
+static unsigned long driver_open;
+
+#define WDT_STATE_STOP 0
+#define WDT_STATE_START 1
+
+struct adx_wdt {
+ void __iomem *base;
+ unsigned long timeout;
+ unsigned int state;
+ unsigned int wake;
+ spinlock_t lock;
+};
+
+static struct watchdog_info adx_wdt_info = {
+ .identity = "Avionic Design Xanthos Watchdog",
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+};
+
+static void adx_wdt_start_locked(struct adx_wdt *wdt)
+{
+ u32 ctrl;
+
+ ctrl = readl(wdt->base + ADX_WDT_CONTROL);
+ ctrl |= ADX_WDT_CONTROL_ENABLE;
+ writel(ctrl, wdt->base + ADX_WDT_CONTROL);
+ wdt->state = WDT_STATE_START;
+}
+
+static void adx_wdt_start(struct adx_wdt *wdt)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&wdt->lock, flags);
+ adx_wdt_start_locked(wdt);
+ spin_unlock_irqrestore(&wdt->lock, flags);
+}
+
+static void adx_wdt_stop_locked(struct adx_wdt *wdt)
+{
+ u32 ctrl;
+
+ ctrl = readl(wdt->base + ADX_WDT_CONTROL);
+ ctrl &= ~ADX_WDT_CONTROL_ENABLE;
+ writel(ctrl, wdt->base + ADX_WDT_CONTROL);
+ wdt->state = WDT_STATE_STOP;
+}
+
+static void adx_wdt_stop(struct adx_wdt *wdt)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&wdt->lock, flags);
+ adx_wdt_stop_locked(wdt);
+ spin_unlock_irqrestore(&wdt->lock, flags);
+}
+
+static void adx_wdt_set_timeout(struct adx_wdt *wdt, unsigned long seconds)
+{
+ unsigned long timeout = seconds * 1000;
+ unsigned long flags;
+ unsigned int state;
+
+ spin_lock_irqsave(&wdt->lock, flags);
+ state = wdt->state;
+ adx_wdt_stop_locked(wdt);
+ writel(timeout, wdt->base + ADX_WDT_TIMEOUT);
+
+ if (state == WDT_STATE_START)
+ adx_wdt_start_locked(wdt);
+
+ wdt->timeout = timeout;
+ spin_unlock_irqrestore(&wdt->lock, flags);
+}
+
+static void adx_wdt_get_timeout(struct adx_wdt *wdt, unsigned long *seconds)
+{
+ *seconds = wdt->timeout / 1000;
+}
+
+static void adx_wdt_keepalive(struct adx_wdt *wdt)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&wdt->lock, flags);
+ writel(wdt->timeout, wdt->base + ADX_WDT_TIMEOUT);
+ spin_unlock_irqrestore(&wdt->lock, flags);
+}
+
+static int adx_wdt_open(struct inode *inode, struct file *file)
+{
+ struct adx_wdt *wdt = platform_get_drvdata(adx_wdt_dev);
+
+ if (test_and_set_bit(0, &driver_open))
+ return -EBUSY;
+
+ file->private_data = wdt;
+ adx_wdt_set_timeout(wdt, 30);
+ adx_wdt_start(wdt);
+
+ return nonseekable_open(inode, file);
+}
+
+static int adx_wdt_release(struct inode *inode, struct file *file)
+{
+ struct adx_wdt *wdt = file->private_data;
+
+ adx_wdt_stop(wdt);
+ clear_bit(0, &driver_open);
+
+ return 0;
+}
+
+static long adx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct adx_wdt *wdt = file->private_data;
+ void __user *argp = (void __user *)arg;
+ unsigned long __user *p = argp;
+ unsigned long seconds = 0;
+ unsigned int options;
+ long ret = -EINVAL;
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &adx_wdt_info, sizeof(adx_wdt_info)))
+ return -EFAULT;
+ else
+ return 0;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+
+ case WDIOC_KEEPALIVE:
+ adx_wdt_keepalive(wdt);
+ return 0;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(seconds, p))
+ return -EFAULT;
+
+ adx_wdt_set_timeout(wdt, seconds);
+
+ /* fallthrough */
+ case WDIOC_GETTIMEOUT:
+ adx_wdt_get_timeout(wdt, &seconds);
+ return put_user(seconds, p);
+
+ case WDIOC_SETOPTIONS:
+ if (copy_from_user(&options, argp, sizeof(options)))
+ return -EFAULT;
+
+ if (options & WDIOS_DISABLECARD) {
+ adx_wdt_stop(wdt);
+ ret = 0;
+ }
+
+ if (options & WDIOS_ENABLECARD) {
+ adx_wdt_start(wdt);
+ ret = 0;
+ }
+
+ return ret;
+
+ default:
+ break;
+ }
+
+ return -ENOTTY;
+}
+
+static ssize_t adx_wdt_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ struct adx_wdt *wdt = file->private_data;
+
+ if (len)
+ adx_wdt_keepalive(wdt);
+
+ return len;
+}
+
+static const struct file_operations adx_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .open = adx_wdt_open,
+ .release = adx_wdt_release,
+ .unlocked_ioctl = adx_wdt_ioctl,
+ .write = adx_wdt_write,
+};
+
+static struct miscdevice adx_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &adx_wdt_fops,
+};
+
+static int __devinit adx_wdt_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct adx_wdt *wdt;
+ int ret = 0;
+ u32 ctrl;
+
+ wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt) {
+ dev_err(&pdev->dev, "cannot allocate WDT structure\n");
+ return -ENOMEM;
+ }
+
+ spin_lock_init(&wdt->lock);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "cannot obtain I/O memory region\n");
+ return -ENXIO;
+ }
+
+ res = devm_request_mem_region(&pdev->dev, res->start,
+ res->end - res->start + 1, res->name);
+ if (!res) {
+ dev_err(&pdev->dev, "cannot request I/O memory region\n");
+ return -ENXIO;
+ }
+
+ wdt->base = devm_ioremap_nocache(&pdev->dev, res->start,
+ res->end - res->start + 1);
+ if (!wdt->base) {
+ dev_err(&pdev->dev, "cannot remap I/O memory region\n");
+ return -ENXIO;
+ }
+
+ /* disable watchdog and reboot on timeout */
+ ctrl = readl(wdt->base + ADX_WDT_CONTROL);
+ ctrl &= ~ADX_WDT_CONTROL_ENABLE;
+ ctrl &= ~ADX_WDT_CONTROL_nRESET;
+ writel(ctrl, wdt->base + ADX_WDT_CONTROL);
+
+ platform_set_drvdata(pdev, wdt);
+ adx_wdt_dev = pdev;
+
+ ret = misc_register(&adx_wdt_miscdev);
+ if (ret) {
+ dev_err(&pdev->dev, "cannot register miscdev on minor %d "
+ "(err=%d)\n", WATCHDOG_MINOR, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int __devexit adx_wdt_remove(struct platform_device *pdev)
+{
+ struct adx_wdt *wdt = platform_get_drvdata(pdev);
+
+ misc_deregister(&adx_wdt_miscdev);
+ adx_wdt_stop(wdt);
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+static void adx_wdt_shutdown(struct platform_device *pdev)
+{
+ struct adx_wdt *wdt = platform_get_drvdata(pdev);
+ adx_wdt_stop(wdt);
+}
+
+#ifdef CONFIG_PM
+static int adx_wdt_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct adx_wdt *wdt = platform_get_drvdata(pdev);
+
+ wdt->wake = (wdt->state == WDT_STATE_START) ? 1 : 0;
+ adx_wdt_stop(wdt);
+
+ return 0;
+}
+
+static int adx_wdt_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct adx_wdt *wdt = platform_get_drvdata(pdev);
+
+ if (wdt->wake)
+ adx_wdt_start(wdt);
+
+ return 0;
+}
+
+static struct dev_pm_ops adx_wdt_pm_ops = {
+ .suspend = adx_wdt_suspend,
+ .resume = adx_wdt_resume,
+};
+
+# define ADX_WDT_PM_OPS (&adx_wdt_pm_ops)
+#else
+# define ADX_WDT_PM_OPS NULL
+#endif
+
+static struct platform_driver adx_wdt_driver = {
+ .probe = adx_wdt_probe,
+ .remove = __devexit_p(adx_wdt_remove),
+ .shutdown = adx_wdt_shutdown,
+ .driver = {
+ .name = WATCHDOG_NAME,
+ .owner = THIS_MODULE,
+ .pm = ADX_WDT_PM_OPS,
+ },
+};
+
+static int __init adx_wdt_init(void)
+{
+ return platform_driver_register(&adx_wdt_driver);
+}
+
+static void __exit adx_wdt_exit(void)
+{
+ platform_driver_unregister(&adx_wdt_driver);
+}
+
+module_init(adx_wdt_init);
+module_exit(adx_wdt_exit);
+
+MODULE_DESCRIPTION("Avionic Design Xanthos Watchdog Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff