476 lines
11 KiB
C
476 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
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* (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>,
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* All Rights Reserved.
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* Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively.
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*
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* The author(s) of this software shall not be held liable for damages
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* of any nature resulting due to the use of this software. This
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* software is provided AS-IS with no warranties.
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*
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* Changelog:
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* 20020220 Zwane Mwaikambo Code based on datasheet, no hardware.
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* 20020221 Zwane Mwaikambo Cleanups as suggested by Jeff Garzik
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* and Alan Cox.
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* 20020222 Zwane Mwaikambo Added probing.
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* 20020225 Zwane Mwaikambo Added ISAPNP support.
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* 20020412 Rob Radez Broke out start/stop functions
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* <rob@osinvestor.com> Return proper status instead of
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* temperature warning
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* Add WDIOC_GETBOOTSTATUS and
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* WDIOC_SETOPTIONS ioctls
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* Fix CONFIG_WATCHDOG_NOWAYOUT
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* 20020530 Joel Becker Add Matt Domsch's nowayout module
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* option
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* 20030116 Adam Belay Updated to the latest pnp code
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/ioport.h>
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#include <linux/spinlock.h>
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#include <linux/notifier.h>
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#include <linux/reboot.h>
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#include <linux/init.h>
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#include <linux/pnp.h>
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#include <linux/fs.h>
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#include <linux/semaphore.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#define SC1200_MODULE_VER "build 20020303"
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#define SC1200_MODULE_NAME "sc1200wdt"
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#define MAX_TIMEOUT 255 /* 255 minutes */
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#define PMIR (io) /* Power Management Index Register */
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#define PMDR (io+1) /* Power Management Data Register */
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/* Data Register indexes */
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#define FER1 0x00 /* Function enable register 1 */
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#define FER2 0x01 /* Function enable register 2 */
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#define PMC1 0x02 /* Power Management Ctrl 1 */
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#define PMC2 0x03 /* Power Management Ctrl 2 */
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#define PMC3 0x04 /* Power Management Ctrl 3 */
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#define WDTO 0x05 /* Watchdog timeout register */
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#define WDCF 0x06 /* Watchdog config register */
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#define WDST 0x07 /* Watchdog status register */
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/* WDCF bitfields - which devices assert WDO */
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#define KBC_IRQ 0x01 /* Keyboard Controller */
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#define MSE_IRQ 0x02 /* Mouse */
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#define UART1_IRQ 0x03 /* Serial0 */
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#define UART2_IRQ 0x04 /* Serial1 */
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/* 5 -7 are reserved */
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static int timeout = 1;
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static int io = -1;
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static int io_len = 2; /* for non plug and play */
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static unsigned long open_flag;
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static char expect_close;
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static DEFINE_SPINLOCK(sc1200wdt_lock); /* io port access serialisation */
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#if defined CONFIG_PNP
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static int isapnp = 1;
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static struct pnp_dev *wdt_dev;
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module_param(isapnp, int, 0);
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MODULE_PARM_DESC(isapnp,
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"When set to 0 driver ISA PnP support will be disabled");
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#endif
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module_param_hw(io, int, ioport, 0);
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MODULE_PARM_DESC(io, "io port");
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module_param(timeout, int, 0);
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MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout,
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"Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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/* Read from Data Register */
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static inline void __sc1200wdt_read_data(unsigned char index,
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unsigned char *data)
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{
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outb_p(index, PMIR);
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*data = inb(PMDR);
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}
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static void sc1200wdt_read_data(unsigned char index, unsigned char *data)
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{
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spin_lock(&sc1200wdt_lock);
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__sc1200wdt_read_data(index, data);
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spin_unlock(&sc1200wdt_lock);
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}
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/* Write to Data Register */
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static inline void __sc1200wdt_write_data(unsigned char index,
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unsigned char data)
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{
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outb_p(index, PMIR);
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outb(data, PMDR);
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}
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static inline void sc1200wdt_write_data(unsigned char index,
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unsigned char data)
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{
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spin_lock(&sc1200wdt_lock);
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__sc1200wdt_write_data(index, data);
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spin_unlock(&sc1200wdt_lock);
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}
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static void sc1200wdt_start(void)
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{
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unsigned char reg;
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spin_lock(&sc1200wdt_lock);
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__sc1200wdt_read_data(WDCF, ®);
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/* assert WDO when any of the following interrupts are triggered too */
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reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ);
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__sc1200wdt_write_data(WDCF, reg);
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/* set the timeout and get the ball rolling */
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__sc1200wdt_write_data(WDTO, timeout);
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spin_unlock(&sc1200wdt_lock);
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}
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static void sc1200wdt_stop(void)
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{
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sc1200wdt_write_data(WDTO, 0);
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}
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/* This returns the status of the WDO signal, inactive high. */
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static inline int sc1200wdt_status(void)
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{
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unsigned char ret;
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sc1200wdt_read_data(WDST, &ret);
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/* If the bit is inactive, the watchdog is enabled, so return
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* KEEPALIVEPING which is a bit of a kludge because there's nothing
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* else for enabled/disabled status
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*/
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return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING;
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}
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static int sc1200wdt_open(struct inode *inode, struct file *file)
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{
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/* allow one at a time */
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if (test_and_set_bit(0, &open_flag))
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return -EBUSY;
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if (timeout > MAX_TIMEOUT)
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timeout = MAX_TIMEOUT;
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sc1200wdt_start();
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pr_info("Watchdog enabled, timeout = %d min(s)", timeout);
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return stream_open(inode, file);
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}
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static long sc1200wdt_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int new_timeout;
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void __user *argp = (void __user *)arg;
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int __user *p = argp;
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static const struct watchdog_info ident = {
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.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
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WDIOF_MAGICCLOSE,
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.firmware_version = 0,
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.identity = "PC87307/PC97307",
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};
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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if (copy_to_user(argp, &ident, sizeof(ident)))
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return -EFAULT;
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return 0;
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case WDIOC_GETSTATUS:
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return put_user(sc1200wdt_status(), p);
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, p);
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case WDIOC_SETOPTIONS:
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{
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int options, retval = -EINVAL;
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if (get_user(options, p))
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return -EFAULT;
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if (options & WDIOS_DISABLECARD) {
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sc1200wdt_stop();
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retval = 0;
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}
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if (options & WDIOS_ENABLECARD) {
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sc1200wdt_start();
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retval = 0;
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}
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return retval;
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}
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case WDIOC_KEEPALIVE:
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sc1200wdt_write_data(WDTO, timeout);
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return 0;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_timeout, p))
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return -EFAULT;
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/* the API states this is given in secs */
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new_timeout /= 60;
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if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
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return -EINVAL;
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timeout = new_timeout;
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sc1200wdt_write_data(WDTO, timeout);
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fallthrough; /* and return the new timeout */
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case WDIOC_GETTIMEOUT:
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return put_user(timeout * 60, p);
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default:
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return -ENOTTY;
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}
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}
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static int sc1200wdt_release(struct inode *inode, struct file *file)
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{
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if (expect_close == 42) {
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sc1200wdt_stop();
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pr_info("Watchdog disabled\n");
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} else {
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sc1200wdt_write_data(WDTO, timeout);
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pr_crit("Unexpected close!, timeout = %d min(s)\n", timeout);
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}
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clear_bit(0, &open_flag);
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expect_close = 0;
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return 0;
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}
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static ssize_t sc1200wdt_write(struct file *file, const char __user *data,
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size_t len, loff_t *ppos)
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{
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if (len) {
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if (!nowayout) {
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size_t i;
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expect_close = 0;
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for (i = 0; i != len; i++) {
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char c;
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if (get_user(c, data + i))
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return -EFAULT;
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if (c == 'V')
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expect_close = 42;
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}
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}
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sc1200wdt_write_data(WDTO, timeout);
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return len;
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}
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return 0;
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}
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static int sc1200wdt_notify_sys(struct notifier_block *this,
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unsigned long code, void *unused)
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{
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if (code == SYS_DOWN || code == SYS_HALT)
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sc1200wdt_stop();
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return NOTIFY_DONE;
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}
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static struct notifier_block sc1200wdt_notifier = {
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.notifier_call = sc1200wdt_notify_sys,
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};
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static const struct file_operations sc1200wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = sc1200wdt_write,
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.unlocked_ioctl = sc1200wdt_ioctl,
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.compat_ioctl = compat_ptr_ioctl,
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.open = sc1200wdt_open,
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.release = sc1200wdt_release,
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};
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static struct miscdevice sc1200wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &sc1200wdt_fops,
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};
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static int __init sc1200wdt_probe(void)
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{
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/* The probe works by reading the PMC3 register's default value of 0x0e
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* there is one caveat, if the device disables the parallel port or any
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* of the UARTs we won't be able to detect it.
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* NB. This could be done with accuracy by reading the SID registers,
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* but we don't have access to those io regions.
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*/
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unsigned char reg;
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sc1200wdt_read_data(PMC3, ®);
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reg &= 0x0f; /* we don't want the UART busy bits */
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return (reg == 0x0e) ? 0 : -ENODEV;
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}
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#if defined CONFIG_PNP
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static const struct pnp_device_id scl200wdt_pnp_devices[] = {
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/* National Semiconductor PC87307/PC97307 watchdog component */
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{.id = "NSC0800", .driver_data = 0},
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{.id = ""},
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};
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static int scl200wdt_pnp_probe(struct pnp_dev *dev,
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const struct pnp_device_id *dev_id)
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{
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/* this driver only supports one card at a time */
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if (wdt_dev || !isapnp)
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return -EBUSY;
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wdt_dev = dev;
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io = pnp_port_start(wdt_dev, 0);
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io_len = pnp_port_len(wdt_dev, 0);
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if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
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pr_err("Unable to register IO port %#x\n", io);
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return -EBUSY;
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}
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pr_info("PnP device found at io port %#x/%d\n", io, io_len);
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return 0;
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}
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static void scl200wdt_pnp_remove(struct pnp_dev *dev)
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{
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if (wdt_dev) {
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release_region(io, io_len);
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wdt_dev = NULL;
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}
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}
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static struct pnp_driver scl200wdt_pnp_driver = {
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.name = "scl200wdt",
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.id_table = scl200wdt_pnp_devices,
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.probe = scl200wdt_pnp_probe,
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.remove = scl200wdt_pnp_remove,
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};
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#endif /* CONFIG_PNP */
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static int __init sc1200wdt_init(void)
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{
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int ret;
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pr_info("%s\n", SC1200_MODULE_VER);
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#if defined CONFIG_PNP
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if (isapnp) {
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ret = pnp_register_driver(&scl200wdt_pnp_driver);
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if (ret)
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goto out_clean;
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}
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#endif
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if (io == -1) {
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pr_err("io parameter must be specified\n");
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ret = -EINVAL;
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goto out_pnp;
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}
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#if defined CONFIG_PNP
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/* now that the user has specified an IO port and we haven't detected
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* any devices, disable pnp support */
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if (isapnp)
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pnp_unregister_driver(&scl200wdt_pnp_driver);
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isapnp = 0;
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#endif
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if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
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pr_err("Unable to register IO port %#x\n", io);
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ret = -EBUSY;
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goto out_pnp;
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}
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ret = sc1200wdt_probe();
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if (ret)
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goto out_io;
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ret = register_reboot_notifier(&sc1200wdt_notifier);
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if (ret) {
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pr_err("Unable to register reboot notifier err = %d\n", ret);
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goto out_io;
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}
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ret = misc_register(&sc1200wdt_miscdev);
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if (ret) {
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pr_err("Unable to register miscdev on minor %d\n",
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WATCHDOG_MINOR);
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goto out_rbt;
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}
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/* ret = 0 */
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out_clean:
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return ret;
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out_rbt:
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unregister_reboot_notifier(&sc1200wdt_notifier);
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out_io:
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release_region(io, io_len);
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out_pnp:
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#if defined CONFIG_PNP
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if (isapnp)
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pnp_unregister_driver(&scl200wdt_pnp_driver);
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#endif
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goto out_clean;
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}
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static void __exit sc1200wdt_exit(void)
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{
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misc_deregister(&sc1200wdt_miscdev);
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unregister_reboot_notifier(&sc1200wdt_notifier);
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#if defined CONFIG_PNP
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if (isapnp)
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pnp_unregister_driver(&scl200wdt_pnp_driver);
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else
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#endif
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release_region(io, io_len);
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}
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module_init(sc1200wdt_init);
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module_exit(sc1200wdt_exit);
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MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
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MODULE_DESCRIPTION(
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"Driver for National Semiconductor PC87307/PC97307 watchdog component");
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MODULE_LICENSE("GPL");
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