forked from Minki/linux
ec9505a7ec
All watchdog device drivers are VFSs (Virtual File Systems). We thus return a nonseekable_open(inode, file) when we open the VFS. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
170 lines
3.6 KiB
C
170 lines
3.6 KiB
C
/*
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* mpc8xx_wdt.c - MPC8xx watchdog userspace interface
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*
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* Author: Florian Schirmer <jolt@tuxbox.org>
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*
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* 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
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* the terms of the GNU General Public License version 2. This program
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* is licensed "as is" without any warranty of any kind, whether express
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* or implied.
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*/
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/miscdevice.h>
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#include <linux/module.h>
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#include <linux/watchdog.h>
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#include <asm/8xx_immap.h>
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#include <asm/uaccess.h>
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#include <asm/io.h>
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#include <syslib/m8xx_wdt.h>
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static unsigned long wdt_opened;
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static int wdt_status;
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static void mpc8xx_wdt_handler_disable(void)
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{
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volatile uint __iomem *piscr;
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piscr = (uint *)&((immap_t*)IMAP_ADDR)->im_sit.sit_piscr;
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if (!m8xx_has_internal_rtc)
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m8xx_wdt_stop_timer();
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else
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out_be32(piscr, in_be32(piscr) & ~(PISCR_PIE | PISCR_PTE));
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printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler deactivated\n");
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}
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static void mpc8xx_wdt_handler_enable(void)
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{
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volatile uint __iomem *piscr;
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piscr = (uint *)&((immap_t*)IMAP_ADDR)->im_sit.sit_piscr;
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if (!m8xx_has_internal_rtc)
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m8xx_wdt_install_timer();
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else
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out_be32(piscr, in_be32(piscr) | PISCR_PIE | PISCR_PTE);
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printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler activated\n");
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}
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static int mpc8xx_wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, &wdt_opened))
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return -EBUSY;
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m8xx_wdt_reset();
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mpc8xx_wdt_handler_disable();
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return nonseekable_open(inode, file);
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}
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static int mpc8xx_wdt_release(struct inode *inode, struct file *file)
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{
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m8xx_wdt_reset();
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#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
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mpc8xx_wdt_handler_enable();
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#endif
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clear_bit(0, &wdt_opened);
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return 0;
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}
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static ssize_t mpc8xx_wdt_write(struct file *file, const char *data, size_t len,
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loff_t * ppos)
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{
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if (len)
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m8xx_wdt_reset();
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return len;
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}
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static int mpc8xx_wdt_ioctl(struct inode *inode, struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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int timeout;
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static struct watchdog_info info = {
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.options = WDIOF_KEEPALIVEPING,
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.firmware_version = 0,
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.identity = "MPC8xx watchdog",
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};
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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if (copy_to_user((void *)arg, &info, sizeof(info)))
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return -EFAULT;
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break;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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if (put_user(wdt_status, (int *)arg))
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return -EFAULT;
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wdt_status &= ~WDIOF_KEEPALIVEPING;
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break;
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case WDIOC_GETTEMP:
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return -EOPNOTSUPP;
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case WDIOC_SETOPTIONS:
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return -EOPNOTSUPP;
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case WDIOC_KEEPALIVE:
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m8xx_wdt_reset();
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wdt_status |= WDIOF_KEEPALIVEPING;
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break;
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case WDIOC_SETTIMEOUT:
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return -EOPNOTSUPP;
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case WDIOC_GETTIMEOUT:
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timeout = m8xx_wdt_get_timeout();
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if (put_user(timeout, (int *)arg))
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return -EFAULT;
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break;
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default:
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return -ENOTTY;
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}
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return 0;
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}
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static const struct file_operations mpc8xx_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = mpc8xx_wdt_write,
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.ioctl = mpc8xx_wdt_ioctl,
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.open = mpc8xx_wdt_open,
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.release = mpc8xx_wdt_release,
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};
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static struct miscdevice mpc8xx_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &mpc8xx_wdt_fops,
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};
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static int __init mpc8xx_wdt_init(void)
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{
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return misc_register(&mpc8xx_wdt_miscdev);
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}
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static void __exit mpc8xx_wdt_exit(void)
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{
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misc_deregister(&mpc8xx_wdt_miscdev);
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m8xx_wdt_reset();
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mpc8xx_wdt_handler_enable();
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}
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module_init(mpc8xx_wdt_init);
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module_exit(mpc8xx_wdt_exit);
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MODULE_AUTHOR("Florian Schirmer <jolt@tuxbox.org>");
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MODULE_DESCRIPTION("MPC8xx watchdog driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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