Messages in this thread | | | Subject | Re: [PATCH][DRIVER][RFC] CPU5 watchdog driver for 2.5 | From | Rusty Lynch <> | Date | 10 Feb 2003 20:38:14 -0800 |
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On Tue, 2003-02-11 at 04:26, Heiko Ronsdorf wrote: > Rusty Lynch schrieb am Mon, Feb 10, 2003 at 02:33:27PM -0800: <snip> > > * I'm pretty sure that in general adding new code to /proc (that has > > nothing to do with processes) is frowned on. > > I don't know how to track the watchdog. Suggestions are welcome. > > Heiko >
I CC'ed Patrick Mochel to get his opinion on this, but if I am interpreting the new driver model documentation correctly, then it would be appropriate to make an IO controlled watchdog timer a "platform_device". That will let user space see your device in sysfs as $YOUR_SYSFS_ROOT/devices/legacy/watchdog0/, and then you can use device_create_file() to add a new file inside the the watchdog0 directory.
Here is your cpu5wdt.c file with the procfs stuff replaced with code that adds an embedded platform_device to your basic data structure, registers the driver as a platform device, and then creates a file called $YOUR_SYSFS_ROOT/devices/legacy/watchdog0/statistics that will read the same as your original procfs file. (Or at least I think it will. It at least compiles :->)
--rustyl
/* * sma cpu5 watchdog driver * * Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de> * * 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., 675 Mass Ave, Cambridge, MA 02139, USA. * */
#include <linux/config.h> #include <linux/module.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/miscdevice.h> #include <linux/kernel.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/ioport.h> #include <linux/timer.h> #include <asm/io.h> #include <asm/uaccess.h>
#include <linux/watchdog.h> #include <linux/kobject.h> #include <linux/device.h>
/* adjustable parameters */
static int verbose = 0; static int port = 0x91; static volatile int ticks = 10000;
#define PFX "cpu5wdt: "
#define CPU5WDT_EXTENT 0x0A
#define CPU5WDT_STATUS_REG 0x00 #define CPU5WDT_TIME_A_REG 0x02 #define CPU5WDT_TIME_B_REG 0x03 #define CPU5WDT_MODE_REG 0x04 #define CPU5WDT_TRIGGER_REG 0x07 #define CPU5WDT_ENABLE_REG 0x08 #define CPU5WDT_RESET_REG 0x09
#define CPU5WDT_INTERVAL (HZ/10+1)
#define to_platform_device(n) container_of(n, struct platform_device, dev) #define to_wdt_device(n) container_of(n, struct wdt_device, dev)
/* some device data */
struct wdt_device { struct semaphore stop; volatile int running; struct timer_list timer; volatile int queue; int default_ticks; int min_ticks; unsigned long inuse; struct platform_device dev; };
static struct wdt_device cpu5wdt_device = { .dev = { .name = "watchdog", .id = 0, .dev = { .name = "CPU5 Watchdog Device", }, }, };
ssize_t statistics_show(struct device * dev, char * buf) { size_t len; struct wdt_device *d = to_wdt_device(to_platform_device(dev)); len = sprintf(buf, "activation: %i\n", d->queue); len += sprintf(buf+len, "status: %i\n", d->running); len += sprintf(buf+len, "current ticks: %i\n", ticks); len += sprintf(buf+len, "min ticks: %i\n", d->min_ticks); return len;
} DEVICE_ATTR(statistics,S_IRUGO,statistics_show,NULL);
/* generic helper functions */
static void cpu5wdt_trigger(unsigned long unused) { if ( verbose > 2 ) printk(KERN_DEBUG PFX "trigger at %i ticks\n", ticks);
if( cpu5wdt_device.running ) ticks--;
/* keep watchdog alive */ outb(1, port + CPU5WDT_TRIGGER_REG);
/* requeue?? */ if( cpu5wdt_device.queue && ticks ) { cpu5wdt_device.timer.expires = jiffies + CPU5WDT_INTERVAL; add_timer(&cpu5wdt_device.timer); } else { /* ticks doesn't matter anyway */ up(&cpu5wdt_device.stop); }
}
static void cpu5wdt_reset(void) { if ( ticks < cpu5wdt_device.min_ticks ) cpu5wdt_device.min_ticks = ticks;
ticks = cpu5wdt_device.default_ticks;
if ( verbose ) printk(KERN_DEBUG PFX "reset (%i ticks)\n", (int) ticks);
}
static void cpu5wdt_start(void) { if ( !cpu5wdt_device.queue ) { cpu5wdt_device.queue = 1; outb(0, port + CPU5WDT_TIME_A_REG); outb(0, port + CPU5WDT_TIME_B_REG); outb(1, port + CPU5WDT_MODE_REG); outb(0, port + CPU5WDT_RESET_REG); outb(0, port + CPU5WDT_ENABLE_REG); cpu5wdt_device.timer.expires = jiffies + CPU5WDT_INTERVAL; add_timer(&cpu5wdt_device.timer); } /* if process dies, counter is not decremented */ cpu5wdt_device.running++; }
static int cpu5wdt_stop(void) { if ( cpu5wdt_device.running ) cpu5wdt_device.running = 0;
ticks = cpu5wdt_device.default_ticks;
if ( verbose ) printk(KERN_CRIT PFX "stop not possible\n");
return -EIO; }
/* filesystem operations */
static int cpu5wdt_open(struct inode *inode, struct file *file) { switch(minor(inode->i_rdev)) { case WATCHDOG_MINOR: if ( test_and_set_bit(0, &cpu5wdt_device.inuse) ) return -EBUSY; break; default: return -ENODEV; } return 0;
}
static int cpu5wdt_release(struct inode *inode, struct file *file) { if(minor(inode->i_rdev)==WATCHDOG_MINOR) { clear_bit(0, &cpu5wdt_device.inuse); } return 0; }
static int cpu5wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { unsigned int value; static struct watchdog_info ident = { .options = WDIOF_CARDRESET, .identity = "CPU5 WDT" }; switch(cmd) { case WDIOC_KEEPALIVE: cpu5wdt_reset(); break; case WDIOC_GETSTATUS: value = inb(port + CPU5WDT_STATUS_REG); value = (value >> 2) & 1; if ( copy_to_user((int *)arg, (int *)&value, sizeof(int)) ) return -EFAULT; break; case WDIOC_GETSUPPORT: if ( copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)) ) return -EFAULT; break; case WDIOC_SETOPTIONS: if ( copy_from_user(&value, (int *)arg, sizeof(int)) ) return -EFAULT; switch(value) { case WDIOS_ENABLECARD: cpu5wdt_start(); break; case WDIOS_DISABLECARD: return cpu5wdt_stop(); default: return -EINVAL; } break; default: return -EINVAL; } return 0; }
static ssize_t cpu5wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos) { if ( !count ) return -EIO; cpu5wdt_reset(); return count;
}
static struct file_operations cpu5wdt_fops = { .owner = THIS_MODULE, .ioctl = cpu5wdt_ioctl, .open = cpu5wdt_open, .write = cpu5wdt_write, .release = cpu5wdt_release, };
static struct miscdevice cpu5wdt_misc = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &cpu5wdt_fops };
/* init/exit function */
static int __devinit cpu5wdt_init(void) { unsigned int val; int err;
if ( verbose ) printk(KERN_DEBUG PFX "port=0x%x, verbose=%i\n", port, verbose);
if ( (err = misc_register(&cpu5wdt_misc)) < 0 ) { printk(KERN_ERR PFX "misc_register failed\n"); goto no_misc; }
if ( !request_region(port, CPU5WDT_EXTENT, PFX) ) { printk(KERN_ERR PFX "request_region failed\n"); err = -EBUSY; goto no_port; }
/* watchdog reboot? */ val = inb(port + CPU5WDT_STATUS_REG); val = (val >> 2) & 1; if ( !val ) printk(KERN_INFO PFX "sorry, was my fault\n");
init_MUTEX_LOCKED(&cpu5wdt_device.stop); cpu5wdt_device.queue = 0; cpu5wdt_device.min_ticks = ticks;
clear_bit(0, &cpu5wdt_device.inuse);
platform_device_register(&cpu5wdt_device.dev); device_create_file(&cpu5wdt_device.dev.dev, &dev_attr_statistics);
init_timer(&cpu5wdt_device.timer); cpu5wdt_device.timer.function = cpu5wdt_trigger; cpu5wdt_device.timer.data = 0;
cpu5wdt_device.default_ticks = ticks;
printk(KERN_INFO PFX "init success\n");
return 0;
no_port: misc_deregister(&cpu5wdt_misc); no_misc: return err; }
static int __devinit cpu5wdt_init_module(void) { return cpu5wdt_init(); }
static void __devexit cpu5wdt_exit(void) { if ( cpu5wdt_device.queue ) { cpu5wdt_device.queue = 0; down(&cpu5wdt_device.stop); }
platform_device_unregister(&cpu5wdt_device.dev); device_remove_file(&cpu5wdt_device.dev.dev, &dev_attr_statistics); misc_deregister(&cpu5wdt_misc);
release_region(port, CPU5WDT_EXTENT);
}
static void __devexit cpu5wdt_exit_module(void) { cpu5wdt_exit(); }
/* module entry points */
module_init(cpu5wdt_init_module); module_exit(cpu5wdt_exit_module);
MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>"); MODULE_DESCRIPTION("sma cpu5 watchdog driver"); MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog"); MODULE_LICENSE("GPL");
MODULE_PARM(port, "i"); MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
MODULE_PARM(verbose, "i"); MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
MODULE_PARM(ticks, "i"); MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");
EXPORT_NO_SYMBOLS;
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