| /* |
| * National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver |
| * (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>, |
| * All Rights Reserved. |
| * Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively. |
| * |
| * 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. |
| * |
| * The author(s) of this software shall not be held liable for damages |
| * of any nature resulting due to the use of this software. This |
| * software is provided AS-IS with no warranties. |
| * |
| * Changelog: |
| * 20020220 Zwane Mwaikambo Code based on datasheet, no hardware. |
| * 20020221 Zwane Mwaikambo Cleanups as suggested by Jeff Garzik |
| * and Alan Cox. |
| * 20020222 Zwane Mwaikambo Added probing. |
| * 20020225 Zwane Mwaikambo Added ISAPNP support. |
| * 20020412 Rob Radez Broke out start/stop functions |
| * <rob@osinvestor.com> Return proper status instead of |
| * temperature warning |
| * Add WDIOC_GETBOOTSTATUS and |
| * WDIOC_SETOPTIONS ioctls |
| * Fix CONFIG_WATCHDOG_NOWAYOUT |
| * 20020530 Joel Becker Add Matt Domsch's nowayout module |
| * option |
| * 20030116 Adam Belay Updated to the latest pnp code |
| * |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/miscdevice.h> |
| #include <linux/watchdog.h> |
| #include <linux/ioport.h> |
| #include <linux/spinlock.h> |
| #include <linux/notifier.h> |
| #include <linux/reboot.h> |
| #include <linux/init.h> |
| #include <linux/pnp.h> |
| #include <linux/fs.h> |
| #include <linux/semaphore.h> |
| #include <linux/io.h> |
| #include <linux/uaccess.h> |
| |
| #define SC1200_MODULE_VER "build 20020303" |
| #define SC1200_MODULE_NAME "sc1200wdt" |
| |
| #define MAX_TIMEOUT 255 /* 255 minutes */ |
| #define PMIR (io) /* Power Management Index Register */ |
| #define PMDR (io+1) /* Power Management Data Register */ |
| |
| /* Data Register indexes */ |
| #define FER1 0x00 /* Function enable register 1 */ |
| #define FER2 0x01 /* Function enable register 2 */ |
| #define PMC1 0x02 /* Power Management Ctrl 1 */ |
| #define PMC2 0x03 /* Power Management Ctrl 2 */ |
| #define PMC3 0x04 /* Power Management Ctrl 3 */ |
| #define WDTO 0x05 /* Watchdog timeout register */ |
| #define WDCF 0x06 /* Watchdog config register */ |
| #define WDST 0x07 /* Watchdog status register */ |
| |
| /* WDCF bitfields - which devices assert WDO */ |
| #define KBC_IRQ 0x01 /* Keyboard Controller */ |
| #define MSE_IRQ 0x02 /* Mouse */ |
| #define UART1_IRQ 0x03 /* Serial0 */ |
| #define UART2_IRQ 0x04 /* Serial1 */ |
| /* 5 -7 are reserved */ |
| |
| static int timeout = 1; |
| static int io = -1; |
| static int io_len = 2; /* for non plug and play */ |
| static unsigned long open_flag; |
| static char expect_close; |
| static DEFINE_SPINLOCK(sc1200wdt_lock); /* io port access serialisation */ |
| |
| #if defined CONFIG_PNP |
| static int isapnp = 1; |
| static struct pnp_dev *wdt_dev; |
| |
| module_param(isapnp, int, 0); |
| MODULE_PARM_DESC(isapnp, |
| "When set to 0 driver ISA PnP support will be disabled"); |
| #endif |
| |
| module_param(io, int, 0); |
| MODULE_PARM_DESC(io, "io port"); |
| module_param(timeout, int, 0); |
| MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1"); |
| |
| static bool nowayout = WATCHDOG_NOWAYOUT; |
| module_param(nowayout, bool, 0); |
| MODULE_PARM_DESC(nowayout, |
| "Watchdog cannot be stopped once started (default=" |
| __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
| |
| |
| |
| /* Read from Data Register */ |
| static inline void __sc1200wdt_read_data(unsigned char index, |
| unsigned char *data) |
| { |
| outb_p(index, PMIR); |
| *data = inb(PMDR); |
| } |
| |
| static void sc1200wdt_read_data(unsigned char index, unsigned char *data) |
| { |
| spin_lock(&sc1200wdt_lock); |
| __sc1200wdt_read_data(index, data); |
| spin_unlock(&sc1200wdt_lock); |
| } |
| |
| /* Write to Data Register */ |
| static inline void __sc1200wdt_write_data(unsigned char index, |
| unsigned char data) |
| { |
| outb_p(index, PMIR); |
| outb(data, PMDR); |
| } |
| |
| static inline void sc1200wdt_write_data(unsigned char index, |
| unsigned char data) |
| { |
| spin_lock(&sc1200wdt_lock); |
| __sc1200wdt_write_data(index, data); |
| spin_unlock(&sc1200wdt_lock); |
| } |
| |
| |
| static void sc1200wdt_start(void) |
| { |
| unsigned char reg; |
| spin_lock(&sc1200wdt_lock); |
| |
| __sc1200wdt_read_data(WDCF, ®); |
| /* assert WDO when any of the following interrupts are triggered too */ |
| reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ); |
| __sc1200wdt_write_data(WDCF, reg); |
| /* set the timeout and get the ball rolling */ |
| __sc1200wdt_write_data(WDTO, timeout); |
| |
| spin_unlock(&sc1200wdt_lock); |
| } |
| |
| static void sc1200wdt_stop(void) |
| { |
| sc1200wdt_write_data(WDTO, 0); |
| } |
| |
| /* This returns the status of the WDO signal, inactive high. */ |
| static inline int sc1200wdt_status(void) |
| { |
| unsigned char ret; |
| |
| sc1200wdt_read_data(WDST, &ret); |
| /* If the bit is inactive, the watchdog is enabled, so return |
| * KEEPALIVEPING which is a bit of a kludge because there's nothing |
| * else for enabled/disabled status |
| */ |
| return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING; |
| } |
| |
| static int sc1200wdt_open(struct inode *inode, struct file *file) |
| { |
| /* allow one at a time */ |
| if (test_and_set_bit(0, &open_flag)) |
| return -EBUSY; |
| |
| if (timeout > MAX_TIMEOUT) |
| timeout = MAX_TIMEOUT; |
| |
| sc1200wdt_start(); |
| pr_info("Watchdog enabled, timeout = %d min(s)", timeout); |
| |
| return nonseekable_open(inode, file); |
| } |
| |
| |
| static long sc1200wdt_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| int new_timeout; |
| void __user *argp = (void __user *)arg; |
| int __user *p = argp; |
| static const struct watchdog_info ident = { |
| .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | |
| WDIOF_MAGICCLOSE, |
| .firmware_version = 0, |
| .identity = "PC87307/PC97307", |
| }; |
| |
| switch (cmd) { |
| case WDIOC_GETSUPPORT: |
| if (copy_to_user(argp, &ident, sizeof(ident))) |
| return -EFAULT; |
| return 0; |
| |
| case WDIOC_GETSTATUS: |
| return put_user(sc1200wdt_status(), p); |
| |
| case WDIOC_GETBOOTSTATUS: |
| return put_user(0, p); |
| |
| case WDIOC_SETOPTIONS: |
| { |
| int options, retval = -EINVAL; |
| |
| if (get_user(options, p)) |
| return -EFAULT; |
| |
| if (options & WDIOS_DISABLECARD) { |
| sc1200wdt_stop(); |
| retval = 0; |
| } |
| |
| if (options & WDIOS_ENABLECARD) { |
| sc1200wdt_start(); |
| retval = 0; |
| } |
| |
| return retval; |
| } |
| case WDIOC_KEEPALIVE: |
| sc1200wdt_write_data(WDTO, timeout); |
| return 0; |
| |
| case WDIOC_SETTIMEOUT: |
| if (get_user(new_timeout, p)) |
| return -EFAULT; |
| /* the API states this is given in secs */ |
| new_timeout /= 60; |
| if (new_timeout < 0 || new_timeout > MAX_TIMEOUT) |
| return -EINVAL; |
| timeout = new_timeout; |
| sc1200wdt_write_data(WDTO, timeout); |
| /* fall through and return the new timeout */ |
| |
| case WDIOC_GETTIMEOUT: |
| return put_user(timeout * 60, p); |
| |
| default: |
| return -ENOTTY; |
| } |
| } |
| |
| |
| static int sc1200wdt_release(struct inode *inode, struct file *file) |
| { |
| if (expect_close == 42) { |
| sc1200wdt_stop(); |
| pr_info("Watchdog disabled\n"); |
| } else { |
| sc1200wdt_write_data(WDTO, timeout); |
| pr_crit("Unexpected close!, timeout = %d min(s)\n", timeout); |
| } |
| clear_bit(0, &open_flag); |
| expect_close = 0; |
| |
| return 0; |
| } |
| |
| |
| static ssize_t sc1200wdt_write(struct file *file, const char __user *data, |
| size_t len, loff_t *ppos) |
| { |
| if (len) { |
| if (!nowayout) { |
| size_t i; |
| |
| expect_close = 0; |
| |
| for (i = 0; i != len; i++) { |
| char c; |
| |
| if (get_user(c, data + i)) |
| return -EFAULT; |
| if (c == 'V') |
| expect_close = 42; |
| } |
| } |
| |
| sc1200wdt_write_data(WDTO, timeout); |
| return len; |
| } |
| |
| return 0; |
| } |
| |
| |
| static int sc1200wdt_notify_sys(struct notifier_block *this, |
| unsigned long code, void *unused) |
| { |
| if (code == SYS_DOWN || code == SYS_HALT) |
| sc1200wdt_stop(); |
| |
| return NOTIFY_DONE; |
| } |
| |
| |
| static struct notifier_block sc1200wdt_notifier = { |
| .notifier_call = sc1200wdt_notify_sys, |
| }; |
| |
| static const struct file_operations sc1200wdt_fops = { |
| .owner = THIS_MODULE, |
| .llseek = no_llseek, |
| .write = sc1200wdt_write, |
| .unlocked_ioctl = sc1200wdt_ioctl, |
| .open = sc1200wdt_open, |
| .release = sc1200wdt_release, |
| }; |
| |
| static struct miscdevice sc1200wdt_miscdev = { |
| .minor = WATCHDOG_MINOR, |
| .name = "watchdog", |
| .fops = &sc1200wdt_fops, |
| }; |
| |
| |
| static int __init sc1200wdt_probe(void) |
| { |
| /* The probe works by reading the PMC3 register's default value of 0x0e |
| * there is one caveat, if the device disables the parallel port or any |
| * of the UARTs we won't be able to detect it. |
| * NB. This could be done with accuracy by reading the SID registers, |
| * but we don't have access to those io regions. |
| */ |
| |
| unsigned char reg; |
| |
| sc1200wdt_read_data(PMC3, ®); |
| reg &= 0x0f; /* we don't want the UART busy bits */ |
| return (reg == 0x0e) ? 0 : -ENODEV; |
| } |
| |
| |
| #if defined CONFIG_PNP |
| |
| static struct pnp_device_id scl200wdt_pnp_devices[] = { |
| /* National Semiconductor PC87307/PC97307 watchdog component */ |
| {.id = "NSC0800", .driver_data = 0}, |
| {.id = ""}, |
| }; |
| |
| static int scl200wdt_pnp_probe(struct pnp_dev *dev, |
| const struct pnp_device_id *dev_id) |
| { |
| /* this driver only supports one card at a time */ |
| if (wdt_dev || !isapnp) |
| return -EBUSY; |
| |
| wdt_dev = dev; |
| io = pnp_port_start(wdt_dev, 0); |
| io_len = pnp_port_len(wdt_dev, 0); |
| |
| if (!request_region(io, io_len, SC1200_MODULE_NAME)) { |
| pr_err("Unable to register IO port %#x\n", io); |
| return -EBUSY; |
| } |
| |
| pr_info("PnP device found at io port %#x/%d\n", io, io_len); |
| return 0; |
| } |
| |
| static void scl200wdt_pnp_remove(struct pnp_dev *dev) |
| { |
| if (wdt_dev) { |
| release_region(io, io_len); |
| wdt_dev = NULL; |
| } |
| } |
| |
| static struct pnp_driver scl200wdt_pnp_driver = { |
| .name = "scl200wdt", |
| .id_table = scl200wdt_pnp_devices, |
| .probe = scl200wdt_pnp_probe, |
| .remove = scl200wdt_pnp_remove, |
| }; |
| |
| #endif /* CONFIG_PNP */ |
| |
| |
| static int __init sc1200wdt_init(void) |
| { |
| int ret; |
| |
| pr_info("%s\n", SC1200_MODULE_VER); |
| |
| #if defined CONFIG_PNP |
| if (isapnp) { |
| ret = pnp_register_driver(&scl200wdt_pnp_driver); |
| if (ret) |
| goto out_clean; |
| } |
| #endif |
| |
| if (io == -1) { |
| pr_err("io parameter must be specified\n"); |
| ret = -EINVAL; |
| goto out_pnp; |
| } |
| |
| #if defined CONFIG_PNP |
| /* now that the user has specified an IO port and we haven't detected |
| * any devices, disable pnp support */ |
| if (isapnp) |
| pnp_unregister_driver(&scl200wdt_pnp_driver); |
| isapnp = 0; |
| #endif |
| |
| if (!request_region(io, io_len, SC1200_MODULE_NAME)) { |
| pr_err("Unable to register IO port %#x\n", io); |
| ret = -EBUSY; |
| goto out_pnp; |
| } |
| |
| ret = sc1200wdt_probe(); |
| if (ret) |
| goto out_io; |
| |
| ret = register_reboot_notifier(&sc1200wdt_notifier); |
| if (ret) { |
| pr_err("Unable to register reboot notifier err = %d\n", ret); |
| goto out_io; |
| } |
| |
| ret = misc_register(&sc1200wdt_miscdev); |
| if (ret) { |
| pr_err("Unable to register miscdev on minor %d\n", |
| WATCHDOG_MINOR); |
| goto out_rbt; |
| } |
| |
| /* ret = 0 */ |
| |
| out_clean: |
| return ret; |
| |
| out_rbt: |
| unregister_reboot_notifier(&sc1200wdt_notifier); |
| |
| out_io: |
| release_region(io, io_len); |
| |
| out_pnp: |
| #if defined CONFIG_PNP |
| if (isapnp) |
| pnp_unregister_driver(&scl200wdt_pnp_driver); |
| #endif |
| goto out_clean; |
| } |
| |
| |
| static void __exit sc1200wdt_exit(void) |
| { |
| misc_deregister(&sc1200wdt_miscdev); |
| unregister_reboot_notifier(&sc1200wdt_notifier); |
| |
| #if defined CONFIG_PNP |
| if (isapnp) |
| pnp_unregister_driver(&scl200wdt_pnp_driver); |
| else |
| #endif |
| release_region(io, io_len); |
| } |
| |
| module_init(sc1200wdt_init); |
| module_exit(sc1200wdt_exit); |
| |
| MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>"); |
| MODULE_DESCRIPTION( |
| "Driver for National Semiconductor PC87307/PC97307 watchdog component"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |