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-rw-r--r--drivers/watchdog/sc1200wdt.c475
1 files changed, 475 insertions, 0 deletions
diff --git a/drivers/watchdog/sc1200wdt.c b/drivers/watchdog/sc1200wdt.c
new file mode 100644
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+++ b/drivers/watchdog/sc1200wdt.c
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+// 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, &reg);
+ /* 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);
+ 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");