zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/drivers/watchdog/watchdog_dev.c b/ap/os/linux/linux-3.4.x/drivers/watchdog/watchdog_dev.c
new file mode 100644
index 0000000..8558da9
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/watchdog/watchdog_dev.c
@@ -0,0 +1,399 @@
+/*
+ * watchdog_dev.c
+ *
+ * (c) Copyright 2008-2011 Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ * All Rights Reserved.
+ *
+ * (c) Copyright 2008-2011 Wim Van Sebroeck <wim@iguana.be>.
+ *
+ *
+ * This source code is part of the generic code that can be used
+ * by all the watchdog timer drivers.
+ *
+ * This part of the generic code takes care of the following
+ * misc device: /dev/watchdog.
+ *
+ * Based on source code of the following authors:
+ * Matt Domsch <Matt_Domsch@dell.com>,
+ * Rob Radez <rob@osinvestor.com>,
+ * Rusty Lynch <rusty@linux.co.intel.com>
+ * Satyam Sharma <satyam@infradead.org>
+ * Randy Dunlap <randy.dunlap@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Neither Alan Cox, CymruNet Ltd., Wim Van Sebroeck nor Iguana vzw.
+ * admit liability nor provide warranty for any of this software.
+ * This material is provided "AS-IS" and at no charge.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h> /* For module stuff/... */
+#include <linux/types.h> /* For standard types (like size_t) */
+#include <linux/errno.h> /* For the -ENODEV/... values */
+#include <linux/kernel.h> /* For printk/panic/... */
+#include <linux/fs.h> /* For file operations */
+#include <linux/watchdog.h> /* For watchdog specific items */
+#include <linux/miscdevice.h> /* For handling misc devices */
+#include <linux/init.h> /* For __init/__exit/... */
+#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
+
+/* make sure we only register one /dev/watchdog device */
+static unsigned long watchdog_dev_busy;
+/* the watchdog device behind /dev/watchdog */
+static struct watchdog_device *wdd;
+
+/*
+ * watchdog_ping: ping the watchdog.
+ * @wddev: the watchdog device to ping
+ *
+ * If the watchdog has no own ping operation then it needs to be
+ * restarted via the start operation. This wrapper function does
+ * exactly that.
+ * We only ping when the watchdog device is running.
+ */
+
+static int watchdog_ping(struct watchdog_device *wddev)
+{
+ if (test_bit(WDOG_ACTIVE, &wddev->status)) {
+ if (wddev->ops->ping)
+ return wddev->ops->ping(wddev); /* ping the watchdog */
+ else
+ return wddev->ops->start(wddev); /* restart watchdog */
+ }
+ return 0;
+}
+
+/*
+ * watchdog_start: wrapper to start the watchdog.
+ * @wddev: the watchdog device to start
+ *
+ * Start the watchdog if it is not active and mark it active.
+ * This function returns zero on success or a negative errno code for
+ * failure.
+ */
+
+static int watchdog_start(struct watchdog_device *wddev)
+{
+ int err;
+
+ if (!test_bit(WDOG_ACTIVE, &wddev->status)) {
+ err = wddev->ops->start(wddev);
+ if (err < 0)
+ return err;
+
+ set_bit(WDOG_ACTIVE, &wddev->status);
+ }
+ return 0;
+}
+
+/*
+ * watchdog_stop: wrapper to stop the watchdog.
+ * @wddev: the watchdog device to stop
+ *
+ * Stop the watchdog if it is still active and unmark it active.
+ * This function returns zero on success or a negative errno code for
+ * failure.
+ * If the 'nowayout' feature was set, the watchdog cannot be stopped.
+ */
+
+static int watchdog_stop(struct watchdog_device *wddev)
+{
+ int err = -EBUSY;
+
+ if (test_bit(WDOG_NO_WAY_OUT, &wddev->status)) {
+ pr_info("%s: nowayout prevents watchdog to be stopped!\n",
+ wddev->info->identity);
+ return err;
+ }
+
+ if (test_bit(WDOG_ACTIVE, &wddev->status)) {
+ err = wddev->ops->stop(wddev);
+ if (err < 0)
+ return err;
+
+ clear_bit(WDOG_ACTIVE, &wddev->status);
+ }
+ return 0;
+}
+
+/*
+ * watchdog_write: writes to the watchdog.
+ * @file: file from VFS
+ * @data: user address of data
+ * @len: length of data
+ * @ppos: pointer to the file offset
+ *
+ * A write to a watchdog device is defined as a keepalive ping.
+ * Writing the magic 'V' sequence allows the next close to turn
+ * off the watchdog (if 'nowayout' is not set).
+ */
+
+static ssize_t watchdog_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ size_t i;
+ char c;
+
+ if (len == 0)
+ return 0;
+
+ /*
+ * Note: just in case someone wrote the magic character
+ * five months ago...
+ */
+ clear_bit(WDOG_ALLOW_RELEASE, &wdd->status);
+
+ /* scan to see whether or not we got the magic character */
+ for (i = 0; i != len; i++) {
+ if (get_user(c, data + i))
+ return -EFAULT;
+ if (c == 'V')
+ set_bit(WDOG_ALLOW_RELEASE, &wdd->status);
+ }
+
+ /* someone wrote to us, so we send the watchdog a keepalive ping */
+ watchdog_ping(wdd);
+
+ return len;
+}
+
+/*
+ * watchdog_ioctl: handle the different ioctl's for the watchdog device.
+ * @file: file handle to the device
+ * @cmd: watchdog command
+ * @arg: argument pointer
+ *
+ * The watchdog API defines a common set of functions for all watchdogs
+ * according to their available features.
+ */
+
+static long watchdog_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ unsigned int val;
+ int err;
+
+ if (wdd->ops->ioctl) {
+ err = wdd->ops->ioctl(wdd, cmd, arg);
+ if (err != -ENOIOCTLCMD)
+ return err;
+ }
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp, wdd->info,
+ sizeof(struct watchdog_info)) ? -EFAULT : 0;
+ case WDIOC_GETSTATUS:
+ val = wdd->ops->status ? wdd->ops->status(wdd) : 0;
+ return put_user(val, p);
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(wdd->bootstatus, p);
+ case WDIOC_SETOPTIONS:
+ if (get_user(val, p))
+ return -EFAULT;
+ if (val & WDIOS_DISABLECARD) {
+ err = watchdog_stop(wdd);
+ if (err < 0)
+ return err;
+ }
+ if (val & WDIOS_ENABLECARD) {
+ err = watchdog_start(wdd);
+ if (err < 0)
+ return err;
+ }
+ return 0;
+ case WDIOC_KEEPALIVE:
+ if (!(wdd->info->options & WDIOF_KEEPALIVEPING))
+ return -EOPNOTSUPP;
+ watchdog_ping(wdd);
+ return 0;
+ case WDIOC_SETTIMEOUT:
+ if ((wdd->ops->set_timeout == NULL) ||
+ !(wdd->info->options & WDIOF_SETTIMEOUT))
+ return -EOPNOTSUPP;
+ if (get_user(val, p))
+ return -EFAULT;
+ if ((wdd->max_timeout != 0) &&
+ (val < wdd->min_timeout || val > wdd->max_timeout))
+ return -EINVAL;
+ err = wdd->ops->set_timeout(wdd, val);
+ if (err < 0)
+ return err;
+ /* If the watchdog is active then we send a keepalive ping
+ * to make sure that the watchdog keep's running (and if
+ * possible that it takes the new timeout) */
+ watchdog_ping(wdd);
+ /* Fall */
+ case WDIOC_GETTIMEOUT:
+ /* timeout == 0 means that we don't know the timeout */
+ if (wdd->timeout == 0)
+ return -EOPNOTSUPP;
+ return put_user(wdd->timeout, p);
+ case WDIOC_GETTIMELEFT:
+ if (!wdd->ops->get_timeleft)
+ return -EOPNOTSUPP;
+
+ return put_user(wdd->ops->get_timeleft(wdd), p);
+ default:
+ return -ENOTTY;
+ }
+}
+
+/*
+ * watchdog_open: open the /dev/watchdog device.
+ * @inode: inode of device
+ * @file: file handle to device
+ *
+ * When the /dev/watchdog device gets opened, we start the watchdog.
+ * Watch out: the /dev/watchdog device is single open, so we make sure
+ * it can only be opened once.
+ */
+
+static int watchdog_open(struct inode *inode, struct file *file)
+{
+ int err = -EBUSY;
+
+ /* the watchdog is single open! */
+ if (test_and_set_bit(WDOG_DEV_OPEN, &wdd->status))
+ return -EBUSY;
+
+ /*
+ * If the /dev/watchdog device is open, we don't want the module
+ * to be unloaded.
+ */
+ if (!try_module_get(wdd->ops->owner))
+ goto out;
+
+ err = watchdog_start(wdd);
+ if (err < 0)
+ goto out_mod;
+
+ /* dev/watchdog is a virtual (and thus non-seekable) filesystem */
+ return nonseekable_open(inode, file);
+
+out_mod:
+ module_put(wdd->ops->owner);
+out:
+ clear_bit(WDOG_DEV_OPEN, &wdd->status);
+ return err;
+}
+
+/*
+ * watchdog_release: release the /dev/watchdog device.
+ * @inode: inode of device
+ * @file: file handle to device
+ *
+ * This is the code for when /dev/watchdog gets closed. We will only
+ * stop the watchdog when we have received the magic char (and nowayout
+ * was not set), else the watchdog will keep running.
+ */
+
+static int watchdog_release(struct inode *inode, struct file *file)
+{
+ int err = -EBUSY;
+
+ /*
+ * We only stop the watchdog if we received the magic character
+ * or if WDIOF_MAGICCLOSE is not set. If nowayout was set then
+ * watchdog_stop will fail.
+ */
+ if (test_and_clear_bit(WDOG_ALLOW_RELEASE, &wdd->status) ||
+ !(wdd->info->options & WDIOF_MAGICCLOSE))
+ err = watchdog_stop(wdd);
+
+ /* If the watchdog was not stopped, send a keepalive ping */
+ if (err < 0) {
+ pr_crit("%s: watchdog did not stop!\n", wdd->info->identity);
+ watchdog_ping(wdd);
+ }
+
+ /* Allow the owner module to be unloaded again */
+ module_put(wdd->ops->owner);
+
+ /* make sure that /dev/watchdog can be re-opened */
+ clear_bit(WDOG_DEV_OPEN, &wdd->status);
+
+ return 0;
+}
+
+static const struct file_operations watchdog_fops = {
+ .owner = THIS_MODULE,
+ .write = watchdog_write,
+ .unlocked_ioctl = watchdog_ioctl,
+ .open = watchdog_open,
+ .release = watchdog_release,
+};
+
+static struct miscdevice watchdog_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &watchdog_fops,
+};
+
+/*
+ * watchdog_dev_register:
+ * @watchdog: watchdog device
+ *
+ * Register a watchdog device as /dev/watchdog. /dev/watchdog
+ * is actually a miscdevice and thus we set it up like that.
+ */
+
+int watchdog_dev_register(struct watchdog_device *watchdog)
+{
+ int err;
+
+ /* Only one device can register for /dev/watchdog */
+ if (test_and_set_bit(0, &watchdog_dev_busy)) {
+ pr_err("only one watchdog can use /dev/watchdog\n");
+ return -EBUSY;
+ }
+
+ wdd = watchdog;
+
+ err = misc_register(&watchdog_miscdev);
+ if (err != 0) {
+ pr_err("%s: cannot register miscdev on minor=%d (err=%d)\n",
+ watchdog->info->identity, WATCHDOG_MINOR, err);
+ goto out;
+ }
+
+ return 0;
+
+out:
+ wdd = NULL;
+ clear_bit(0, &watchdog_dev_busy);
+ return err;
+}
+
+/*
+ * watchdog_dev_unregister:
+ * @watchdog: watchdog device
+ *
+ * Deregister the /dev/watchdog device.
+ */
+
+int watchdog_dev_unregister(struct watchdog_device *watchdog)
+{
+ /* Check that a watchdog device was registered in the past */
+ if (!test_bit(0, &watchdog_dev_busy) || !wdd)
+ return -ENODEV;
+
+ /* We can only unregister the watchdog device that was registered */
+ if (watchdog != wdd) {
+ pr_err("%s: watchdog was not registered as /dev/watchdog\n",
+ watchdog->info->identity);
+ return -ENODEV;
+ }
+
+ misc_deregister(&watchdog_miscdev);
+ wdd = NULL;
+ clear_bit(0, &watchdog_dev_busy);
+ return 0;
+}