/* * Copyright (C) Nokia Corporation * * Written by Timo Kokkonen * * 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 #include #include #include #include #include #include #include #include #include #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 twl_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; twl4030_wdt_disable(wdt); 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");