diff options
Diffstat (limited to 'drivers/watchdog/sc1200wdt.c')
| -rw-r--r-- | drivers/watchdog/sc1200wdt.c | 475 |
1 files changed, 475 insertions, 0 deletions
diff --git a/drivers/watchdog/sc1200wdt.c b/drivers/watchdog/sc1200wdt.c new file mode 100644 index 0000000000..f22ebe89fe --- /dev/null +++ b/drivers/watchdog/sc1200wdt.c @@ -0,0 +1,475 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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. + * + * 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_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, + .llseek = no_llseek, + .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 <zwane@commfireservices.com>"); +MODULE_DESCRIPTION( + "Driver for National Semiconductor PC87307/PC97307 watchdog component"); +MODULE_LICENSE("GPL"); |