// SPDX-License-Identifier: GPL-2.0-or-later /* * National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver * (c) Copyright 2002 Zwane Mwaikambo , * All Rights Reserved. * Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively. * * 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 * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #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_hw(io, int, ioport, 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 stream_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); fallthrough; /* 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, .write = sc1200wdt_write, .unlocked_ioctl = sc1200wdt_ioctl, .compat_ioctl = compat_ptr_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 const 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 "); MODULE_DESCRIPTION( "Driver for National Semiconductor PC87307/PC97307 watchdog component"); MODULE_LICENSE("GPL");