--- /dev/null
+/*
+ * Copyright (C) Nokia Corporation
+ *
+ * Written by Timo Kokkonen <timo.t.kokkonen at nokia.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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/miscdevice.h>
+#include <linux/uaccess.h>
+#include <linux/i2c/twl4030.h>
+
+#define TWL4030_WATCHDOG_CFG_REG_OFFS 0x3
+
+#define TWL4030_WDT_STATE_OPEN 0x1
+#define TWL4030_WDT_STATE_ACTIVE 0x8
+
+static struct platform_device *twl4030_wdt_dev;
+
+struct twl4030_wdt {
+ struct miscdevice miscdev;
+ int timer_margin;
+ unsigned long state;
+};
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
+ "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static int twl4030_wdt_write(unsigned char val)
+{
+ return twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, val,
+ TWL4030_WATCHDOG_CFG_REG_OFFS);
+}
+
+static int twl4030_wdt_enable(struct twl4030_wdt *wdt)
+{
+ return twl4030_wdt_write(wdt->timer_margin + 1);
+}
+
+static int twl4030_wdt_disable(struct twl4030_wdt *wdt)
+{
+ return twl4030_wdt_write(0);
+}
+
+static int twl4030_wdt_set_timeout(struct twl4030_wdt *wdt, int timeout)
+{
+ if (timeout < 0 || timeout > 30) {
+ dev_warn(wdt->miscdev.parent,
+ "Timeout can only be in the range [0-30] seconds");
+ return -EINVAL;
+ }
+ wdt->timer_margin = timeout;
+ return twl4030_wdt_enable(wdt);
+}
+
+static ssize_t twl4030_wdt_write_fop(struct file *file,
+ const char __user *data, size_t len, loff_t *ppos)
+{
+ struct twl4030_wdt *wdt = file->private_data;
+
+ if (len)
+ twl4030_wdt_enable(wdt);
+
+ return len;
+}
+
+static long twl4030_wdt_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ int new_margin;
+ struct twl4030_wdt *wdt = file->private_data;
+
+ static const struct watchdog_info twl4030_wd_ident = {
+ .identity = "TWL4030 Watchdog",
+ .options = WDIOF_SETTIMEOUT,
+ .firmware_version = 0,
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp, &twl4030_wd_ident,
+ sizeof(twl4030_wd_ident)) ? -EFAULT : 0;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+
+ case WDIOC_KEEPALIVE:
+ twl4030_wdt_enable(wdt);
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_margin, p))
+ return -EFAULT;
+ if (twl4030_wdt_set_timeout(wdt, new_margin))
+ return -EINVAL;
+ return put_user(wdt->timer_margin, p);
+
+ case WDIOC_GETTIMEOUT:
+ return put_user(wdt->timer_margin, p);
+
+ default:
+ return -ENOTTY;
+ }
+
+ return 0;
+}
+
+static int twl4030_wdt_open(struct inode *inode, struct file *file)
+{
+ struct twl4030_wdt *wdt = platform_get_drvdata(twl4030_wdt_dev);
+
+ /* /dev/watchdog can only be opened once */
+ if (test_and_set_bit(0, &wdt->state))
+ return -EBUSY;
+
+ wdt->state |= TWL4030_WDT_STATE_ACTIVE;
+ file->private_data = (void *) wdt;
+
+ twl4030_wdt_enable(wdt);
+ return nonseekable_open(inode, file);
+}
+
+static int twl4030_wdt_release(struct inode *inode, struct file *file)
+{
+ struct twl4030_wdt *wdt = file->private_data;
+ if (nowayout) {
+ dev_alert(wdt->miscdev.parent,
+ "Unexpected close, watchdog still running!\n");
+ twl4030_wdt_enable(wdt);
+ } else {
+ if (twl4030_wdt_disable(wdt))
+ return -EFAULT;
+ wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
+ }
+
+ clear_bit(0, &wdt->state);
+ return 0;
+}
+
+static const struct file_operations twl4030_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .open = twl4030_wdt_open,
+ .release = twl4030_wdt_release,
+ .unlocked_ioctl = twl4030_wdt_ioctl,
+ .write = twl4030_wdt_write_fop,
+};
+
+static int __devinit twl4030_wdt_probe(struct platform_device *pdev)
+{
+ int ret = 0;
+ struct twl4030_wdt *wdt;
+
+ wdt = kzalloc(sizeof(struct twl4030_wdt), GFP_KERNEL);
+ if (!wdt)
+ return -ENOMEM;
+
+ wdt->state = 0;
+ wdt->timer_margin = 30;
+ wdt->miscdev.parent = &pdev->dev;
+ wdt->miscdev.fops = &twl4030_wdt_fops;
+ wdt->miscdev.minor = WATCHDOG_MINOR;
+ wdt->miscdev.name = "watchdog";
+
+ platform_set_drvdata(pdev, wdt);
+
+ twl4030_wdt_dev = pdev;
+
+ ret = misc_register(&wdt->miscdev);
+ if (ret) {
+ dev_err(wdt->miscdev.parent,
+ "Failed to register misc device\n");
+ platform_set_drvdata(pdev, NULL);
+ kfree(wdt);
+ twl4030_wdt_dev = NULL;
+ return ret;
+ }
+ return 0;
+}
+
+static int __devexit twl4030_wdt_remove(struct platform_device *pdev)
+{
+ struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
+
+ if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
+ if (twl4030_wdt_disable(wdt))
+ return -EFAULT;
+
+ wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
+ misc_deregister(&wdt->miscdev);
+
+ platform_set_drvdata(pdev, NULL);
+ kfree(wdt);
+ twl4030_wdt_dev = NULL;
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
+ if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
+ return twl4030_wdt_disable(wdt);
+
+ return 0;
+}
+
+static int twl4030_wdt_resume(struct platform_device *pdev)
+{
+ struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
+ if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
+ return twl4030_wdt_enable(wdt);
+
+ return 0;
+}
+#else
+#define twl4030_wdt_suspend NULL
+#define twl4030_wdt_resume NULL
+#endif
+
+static struct platform_driver twl4030_wdt_driver = {
+ .probe = twl4030_wdt_probe,
+ .remove = __devexit_p(twl4030_wdt_remove),
+ .suspend = twl4030_wdt_suspend,
+ .resume = twl4030_wdt_resume,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "twl4030_wdt",
+ },
+};
+
+static int __devinit twl4030_wdt_init(void)
+{
+ return platform_driver_register(&twl4030_wdt_driver);
+}
+module_init(twl4030_wdt_init);
+
+static void __devexit twl4030_wdt_exit(void)
+{
+ platform_driver_unregister(&twl4030_wdt_driver);
+}
+module_exit(twl4030_wdt_exit);
+
+MODULE_AUTHOR("Nokia Corporation");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_ALIAS("platform:twl4030_wdt");
+
projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / commitdiff