linux/drivers/watchdog/cpu5wdt.c
Jean Delvare 487722cf2d watchdog: Get rid of MODULE_ALIAS_MISCDEV statements
I just can't find any value in MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR)
and MODULE_ALIAS_MISCDEV(TEMP_MINOR) statements.

Either the device is enumerated and the driver already has a module
alias (e.g. PCI, USB etc.) that will get the right driver loaded
automatically.

Or the device is not enumerated and loading its driver will lead to
more or less intrusive hardware poking. Such hardware poking should be
limited to a bare minimum, so the user should really decide which
drivers should be tried and in what order. Trying them all in
arbitrary order can't do any good.

On top of that, loading that many drivers at once bloats the kernel
log. Also many drivers will stay loaded afterward, bloating the output
of "lsmod" and wasting memory. Some modules (cs5535_mfgpt which gets
loaded as a dependency) can't even be unloaded!

If defining char-major-10-130 is needed then it should happen in
user-space.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Cc: Jim Cromie <jim.cromie@gmail.com>
2013-11-17 19:38:13 +01:00

301 lines
6.7 KiB
C

/*
* 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.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/timer.h>
#include <linux/completion.h>
#include <linux/jiffies.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
/* adjustable parameters */
static int verbose;
static int port = 0x91;
static int ticks = 10000;
static DEFINE_SPINLOCK(cpu5wdt_lock);
#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)
/* some device data */
static struct {
struct completion stop;
int running;
struct timer_list timer;
int queue;
int default_ticks;
unsigned long inuse;
} cpu5wdt_device;
/* generic helper functions */
static void cpu5wdt_trigger(unsigned long unused)
{
if (verbose > 2)
pr_debug("trigger at %i ticks\n", ticks);
if (cpu5wdt_device.running)
ticks--;
spin_lock(&cpu5wdt_lock);
/* keep watchdog alive */
outb(1, port + CPU5WDT_TRIGGER_REG);
/* requeue?? */
if (cpu5wdt_device.queue && ticks)
mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
else {
/* ticks doesn't matter anyway */
complete(&cpu5wdt_device.stop);
}
spin_unlock(&cpu5wdt_lock);
}
static void cpu5wdt_reset(void)
{
ticks = cpu5wdt_device.default_ticks;
if (verbose)
pr_debug("reset (%i ticks)\n", (int) ticks);
}
static void cpu5wdt_start(void)
{
unsigned long flags;
spin_lock_irqsave(&cpu5wdt_lock, flags);
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);
mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
}
/* if process dies, counter is not decremented */
cpu5wdt_device.running++;
spin_unlock_irqrestore(&cpu5wdt_lock, flags);
}
static int cpu5wdt_stop(void)
{
unsigned long flags;
spin_lock_irqsave(&cpu5wdt_lock, flags);
if (cpu5wdt_device.running)
cpu5wdt_device.running = 0;
ticks = cpu5wdt_device.default_ticks;
spin_unlock_irqrestore(&cpu5wdt_lock, flags);
if (verbose)
pr_crit("stop not possible\n");
return -EIO;
}
/* filesystem operations */
static int cpu5wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &cpu5wdt_device.inuse))
return -EBUSY;
return nonseekable_open(inode, file);
}
static int cpu5wdt_release(struct inode *inode, struct file *file)
{
clear_bit(0, &cpu5wdt_device.inuse);
return 0;
}
static long cpu5wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
unsigned int value;
static const struct watchdog_info ident = {
.options = WDIOF_CARDRESET,
.identity = "CPU5 WDT",
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
break;
case WDIOC_GETSTATUS:
value = inb(port + CPU5WDT_STATUS_REG);
value = (value >> 2) & 1;
return put_user(value, p);
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_SETOPTIONS:
if (get_user(value, p))
return -EFAULT;
if (value & WDIOS_ENABLECARD)
cpu5wdt_start();
if (value & WDIOS_DISABLECARD)
cpu5wdt_stop();
break;
case WDIOC_KEEPALIVE:
cpu5wdt_reset();
break;
default:
return -ENOTTY;
}
return 0;
}
static ssize_t cpu5wdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (!count)
return -EIO;
cpu5wdt_reset();
return count;
}
static const struct file_operations cpu5wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.unlocked_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 cpu5wdt_init(void)
{
unsigned int val;
int err;
if (verbose)
pr_debug("port=0x%x, verbose=%i\n", port, verbose);
init_completion(&cpu5wdt_device.stop);
cpu5wdt_device.queue = 0;
setup_timer(&cpu5wdt_device.timer, cpu5wdt_trigger, 0);
cpu5wdt_device.default_ticks = ticks;
if (!request_region(port, CPU5WDT_EXTENT, PFX)) {
pr_err("request_region failed\n");
err = -EBUSY;
goto no_port;
}
/* watchdog reboot? */
val = inb(port + CPU5WDT_STATUS_REG);
val = (val >> 2) & 1;
if (!val)
pr_info("sorry, was my fault\n");
err = misc_register(&cpu5wdt_misc);
if (err < 0) {
pr_err("misc_register failed\n");
goto no_misc;
}
pr_info("init success\n");
return 0;
no_misc:
release_region(port, CPU5WDT_EXTENT);
no_port:
return err;
}
static int cpu5wdt_init_module(void)
{
return cpu5wdt_init();
}
static void cpu5wdt_exit(void)
{
if (cpu5wdt_device.queue) {
cpu5wdt_device.queue = 0;
wait_for_completion(&cpu5wdt_device.stop);
del_timer(&cpu5wdt_device.timer);
}
misc_deregister(&cpu5wdt_misc);
release_region(port, CPU5WDT_EXTENT);
}
static void 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_param(port, int, 0);
MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
module_param(verbose, int, 0);
MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
module_param(ticks, int, 0);
MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");