diff options
Diffstat (limited to 'drivers/watchdog/cpu5wdt.c')
| -rw-r--r-- | drivers/watchdog/cpu5wdt.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/drivers/watchdog/cpu5wdt.c b/drivers/watchdog/cpu5wdt.c new file mode 100644 index 0000000000..688b112e71 --- /dev/null +++ b/drivers/watchdog/cpu5wdt.c @@ -0,0 +1,285 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * sma cpu5 watchdog driver + * + * Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de> + */ + +#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/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(struct timer_list *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 stream_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, + .compat_ioctl = compat_ptr_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; + timer_setup(&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_LICENSE("GPL"); + +module_param_hw(port, int, ioport, 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"); |