| /* |
| * 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/twl.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"); |
| |