summaryrefslogtreecommitdiffstats
path: root/drivers/watchdog/pc87413_wdt.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/watchdog/pc87413_wdt.c')
-rw-r--r--drivers/watchdog/pc87413_wdt.c592
1 files changed, 592 insertions, 0 deletions
diff --git a/drivers/watchdog/pc87413_wdt.c b/drivers/watchdog/pc87413_wdt.c
new file mode 100644
index 000000000..c7f745caf
--- /dev/null
+++ b/drivers/watchdog/pc87413_wdt.c
@@ -0,0 +1,592 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * NS pc87413-wdt Watchdog Timer driver for Linux 2.6.x.x
+ *
+ * This code is based on wdt.c with original copyright.
+ *
+ * (C) Copyright 2006 Sven Anders, <anders@anduras.de>
+ * and Marcus Junker, <junker@anduras.de>
+ *
+ * Neither Sven Anders, Marcus Junker nor ANDURAS AG
+ * admit liability nor provide warranty for any of this software.
+ * This material is provided "AS-IS" and at no charge.
+ *
+ * Release 1.1
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/notifier.h>
+#include <linux/fs.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/moduleparam.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+
+/* #define DEBUG 1 */
+
+#define DEFAULT_TIMEOUT 1 /* 1 minute */
+#define MAX_TIMEOUT 255
+
+#define VERSION "1.1"
+#define MODNAME "pc87413 WDT"
+#define DPFX MODNAME " - DEBUG: "
+
+#define WDT_INDEX_IO_PORT (io+0) /* I/O port base (index register) */
+#define WDT_DATA_IO_PORT (WDT_INDEX_IO_PORT+1)
+#define SWC_LDN 0x04
+#define SIOCFG2 0x22 /* Serial IO register */
+#define WDCTL 0x10 /* Watchdog-Timer-Control-Register */
+#define WDTO 0x11 /* Watchdog timeout register */
+#define WDCFG 0x12 /* Watchdog config register */
+
+#define IO_DEFAULT 0x2E /* Address used on Portwell Boards */
+
+static int io = IO_DEFAULT;
+static int swc_base_addr = -1;
+
+static int timeout = DEFAULT_TIMEOUT; /* timeout value */
+static unsigned long timer_enabled; /* is the timer enabled? */
+
+static char expect_close; /* is the close expected? */
+
+static DEFINE_SPINLOCK(io_lock); /* to guard us from io races */
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+
+/* -- Low level function ----------------------------------------*/
+
+/* Select pins for Watchdog output */
+
+static inline void pc87413_select_wdt_out(void)
+{
+ unsigned int cr_data = 0;
+
+ /* Step 1: Select multiple pin,pin55,as WDT output */
+
+ outb_p(SIOCFG2, WDT_INDEX_IO_PORT);
+
+ cr_data = inb(WDT_DATA_IO_PORT);
+
+ cr_data |= 0x80; /* Set Bit7 to 1*/
+ outb_p(SIOCFG2, WDT_INDEX_IO_PORT);
+
+ outb_p(cr_data, WDT_DATA_IO_PORT);
+
+#ifdef DEBUG
+ pr_info(DPFX
+ "Select multiple pin,pin55,as WDT output: Bit7 to 1: %d\n",
+ cr_data);
+#endif
+}
+
+/* Enable SWC functions */
+
+static inline void pc87413_enable_swc(void)
+{
+ unsigned int cr_data = 0;
+
+ /* Step 2: Enable SWC functions */
+
+ outb_p(0x07, WDT_INDEX_IO_PORT); /* Point SWC_LDN (LDN=4) */
+ outb_p(SWC_LDN, WDT_DATA_IO_PORT);
+
+ outb_p(0x30, WDT_INDEX_IO_PORT); /* Read Index 0x30 First */
+ cr_data = inb(WDT_DATA_IO_PORT);
+ cr_data |= 0x01; /* Set Bit0 to 1 */
+ outb_p(0x30, WDT_INDEX_IO_PORT);
+ outb_p(cr_data, WDT_DATA_IO_PORT); /* Index0x30_bit0P1 */
+
+#ifdef DEBUG
+ pr_info(DPFX "pc87413 - Enable SWC functions\n");
+#endif
+}
+
+/* Read SWC I/O base address */
+
+static void pc87413_get_swc_base_addr(void)
+{
+ unsigned char addr_l, addr_h = 0;
+
+ /* Step 3: Read SWC I/O Base Address */
+
+ outb_p(0x60, WDT_INDEX_IO_PORT); /* Read Index 0x60 */
+ addr_h = inb(WDT_DATA_IO_PORT);
+
+ outb_p(0x61, WDT_INDEX_IO_PORT); /* Read Index 0x61 */
+
+ addr_l = inb(WDT_DATA_IO_PORT);
+
+ swc_base_addr = (addr_h << 8) + addr_l;
+#ifdef DEBUG
+ pr_info(DPFX
+ "Read SWC I/O Base Address: low %d, high %d, res %d\n",
+ addr_l, addr_h, swc_base_addr);
+#endif
+}
+
+/* Select Bank 3 of SWC */
+
+static inline void pc87413_swc_bank3(void)
+{
+ /* Step 4: Select Bank3 of SWC */
+ outb_p(inb(swc_base_addr + 0x0f) | 0x03, swc_base_addr + 0x0f);
+#ifdef DEBUG
+ pr_info(DPFX "Select Bank3 of SWC\n");
+#endif
+}
+
+/* Set watchdog timeout to x minutes */
+
+static inline void pc87413_programm_wdto(char pc87413_time)
+{
+ /* Step 5: Programm WDTO, Twd. */
+ outb_p(pc87413_time, swc_base_addr + WDTO);
+#ifdef DEBUG
+ pr_info(DPFX "Set WDTO to %d minutes\n", pc87413_time);
+#endif
+}
+
+/* Enable WDEN */
+
+static inline void pc87413_enable_wden(void)
+{
+ /* Step 6: Enable WDEN */
+ outb_p(inb(swc_base_addr + WDCTL) | 0x01, swc_base_addr + WDCTL);
+#ifdef DEBUG
+ pr_info(DPFX "Enable WDEN\n");
+#endif
+}
+
+/* Enable SW_WD_TREN */
+static inline void pc87413_enable_sw_wd_tren(void)
+{
+ /* Enable SW_WD_TREN */
+ outb_p(inb(swc_base_addr + WDCFG) | 0x80, swc_base_addr + WDCFG);
+#ifdef DEBUG
+ pr_info(DPFX "Enable SW_WD_TREN\n");
+#endif
+}
+
+/* Disable SW_WD_TREN */
+
+static inline void pc87413_disable_sw_wd_tren(void)
+{
+ /* Disable SW_WD_TREN */
+ outb_p(inb(swc_base_addr + WDCFG) & 0x7f, swc_base_addr + WDCFG);
+#ifdef DEBUG
+ pr_info(DPFX "pc87413 - Disable SW_WD_TREN\n");
+#endif
+}
+
+/* Enable SW_WD_TRG */
+
+static inline void pc87413_enable_sw_wd_trg(void)
+{
+ /* Enable SW_WD_TRG */
+ outb_p(inb(swc_base_addr + WDCTL) | 0x80, swc_base_addr + WDCTL);
+#ifdef DEBUG
+ pr_info(DPFX "pc87413 - Enable SW_WD_TRG\n");
+#endif
+}
+
+/* Disable SW_WD_TRG */
+
+static inline void pc87413_disable_sw_wd_trg(void)
+{
+ /* Disable SW_WD_TRG */
+ outb_p(inb(swc_base_addr + WDCTL) & 0x7f, swc_base_addr + WDCTL);
+#ifdef DEBUG
+ pr_info(DPFX "Disable SW_WD_TRG\n");
+#endif
+}
+
+/* -- Higher level functions ------------------------------------*/
+
+/* Enable the watchdog */
+
+static void pc87413_enable(void)
+{
+ spin_lock(&io_lock);
+
+ pc87413_swc_bank3();
+ pc87413_programm_wdto(timeout);
+ pc87413_enable_wden();
+ pc87413_enable_sw_wd_tren();
+ pc87413_enable_sw_wd_trg();
+
+ spin_unlock(&io_lock);
+}
+
+/* Disable the watchdog */
+
+static void pc87413_disable(void)
+{
+ spin_lock(&io_lock);
+
+ pc87413_swc_bank3();
+ pc87413_disable_sw_wd_tren();
+ pc87413_disable_sw_wd_trg();
+ pc87413_programm_wdto(0);
+
+ spin_unlock(&io_lock);
+}
+
+/* Refresh the watchdog */
+
+static void pc87413_refresh(void)
+{
+ spin_lock(&io_lock);
+
+ pc87413_swc_bank3();
+ pc87413_disable_sw_wd_tren();
+ pc87413_disable_sw_wd_trg();
+ pc87413_programm_wdto(timeout);
+ pc87413_enable_wden();
+ pc87413_enable_sw_wd_tren();
+ pc87413_enable_sw_wd_trg();
+
+ spin_unlock(&io_lock);
+}
+
+/* -- File operations -------------------------------------------*/
+
+/**
+ * pc87413_open:
+ * @inode: inode of device
+ * @file: file handle to device
+ *
+ */
+
+static int pc87413_open(struct inode *inode, struct file *file)
+{
+ /* /dev/watchdog can only be opened once */
+
+ if (test_and_set_bit(0, &timer_enabled))
+ return -EBUSY;
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ /* Reload and activate timer */
+ pc87413_refresh();
+
+ pr_info("Watchdog enabled. Timeout set to %d minute(s).\n", timeout);
+
+ return stream_open(inode, file);
+}
+
+/**
+ * pc87413_release:
+ * @inode: inode to board
+ * @file: file handle to board
+ *
+ * The watchdog has a configurable API. There is a religious dispute
+ * between people who want their watchdog to be able to shut down and
+ * those who want to be sure if the watchdog manager dies the machine
+ * reboots. In the former case we disable the counters, in the latter
+ * case you have to open it again very soon.
+ */
+
+static int pc87413_release(struct inode *inode, struct file *file)
+{
+ /* Shut off the timer. */
+
+ if (expect_close == 42) {
+ pc87413_disable();
+ pr_info("Watchdog disabled, sleeping again...\n");
+ } else {
+ pr_crit("Unexpected close, not stopping watchdog!\n");
+ pc87413_refresh();
+ }
+ clear_bit(0, &timer_enabled);
+ expect_close = 0;
+ return 0;
+}
+
+/**
+ * pc87413_status:
+ *
+ * return, if the watchdog is enabled (timeout is set...)
+ */
+
+
+static int pc87413_status(void)
+{
+ return 0; /* currently not supported */
+}
+
+/**
+ * pc87413_write:
+ * @file: file handle to the watchdog
+ * @data: data buffer to write
+ * @len: length in bytes
+ * @ppos: pointer to the position to write. No seeks allowed
+ *
+ * A write to a watchdog device is defined as a keepalive signal. Any
+ * write of data will do, as we we don't define content meaning.
+ */
+
+static ssize_t pc87413_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ /* See if we got the magic character 'V' and reload the timer */
+ if (len) {
+ if (!nowayout) {
+ size_t i;
+
+ /* reset expect flag */
+ expect_close = 0;
+
+ /* scan to see whether or not we got the
+ magic character */
+ for (i = 0; i != len; i++) {
+ char c;
+ if (get_user(c, data + i))
+ return -EFAULT;
+ if (c == 'V')
+ expect_close = 42;
+ }
+ }
+
+ /* someone wrote to us, we should reload the timer */
+ pc87413_refresh();
+ }
+ return len;
+}
+
+/**
+ * pc87413_ioctl:
+ * @file: file handle to the device
+ * @cmd: watchdog command
+ * @arg: argument pointer
+ *
+ * The watchdog API defines a common set of functions for all watchdogs
+ * according to their available features. We only actually usefully support
+ * querying capabilities and current status.
+ */
+
+static long pc87413_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int new_timeout;
+
+ union {
+ struct watchdog_info __user *ident;
+ int __user *i;
+ } uarg;
+
+ static const struct watchdog_info ident = {
+ .options = WDIOF_KEEPALIVEPING |
+ WDIOF_SETTIMEOUT |
+ WDIOF_MAGICCLOSE,
+ .firmware_version = 1,
+ .identity = "PC87413(HF/F) watchdog",
+ };
+
+ uarg.i = (int __user *)arg;
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(uarg.ident, &ident,
+ sizeof(ident)) ? -EFAULT : 0;
+ case WDIOC_GETSTATUS:
+ return put_user(pc87413_status(), uarg.i);
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, uarg.i);
+ case WDIOC_SETOPTIONS:
+ {
+ int options, retval = -EINVAL;
+ if (get_user(options, uarg.i))
+ return -EFAULT;
+ if (options & WDIOS_DISABLECARD) {
+ pc87413_disable();
+ retval = 0;
+ }
+ if (options & WDIOS_ENABLECARD) {
+ pc87413_enable();
+ retval = 0;
+ }
+ return retval;
+ }
+ case WDIOC_KEEPALIVE:
+ pc87413_refresh();
+#ifdef DEBUG
+ pr_info(DPFX "keepalive\n");
+#endif
+ return 0;
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_timeout, uarg.i))
+ 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;
+ pc87413_refresh();
+ fallthrough; /* and return the new timeout */
+ case WDIOC_GETTIMEOUT:
+ new_timeout = timeout * 60;
+ return put_user(new_timeout, uarg.i);
+ default:
+ return -ENOTTY;
+ }
+}
+
+/* -- Notifier functions -----------------------------------------*/
+
+/**
+ * pc87413_notify_sys:
+ * @this: our notifier block
+ * @code: the event being reported
+ * @unused: unused
+ *
+ * Our notifier is called on system shutdowns. We want to turn the card
+ * off at reboot otherwise the machine will reboot again during memory
+ * test or worse yet during the following fsck. This would suck, in fact
+ * trust me - if it happens it does suck.
+ */
+
+static int pc87413_notify_sys(struct notifier_block *this,
+ unsigned long code,
+ void *unused)
+{
+ if (code == SYS_DOWN || code == SYS_HALT)
+ /* Turn the card off */
+ pc87413_disable();
+ return NOTIFY_DONE;
+}
+
+/* -- Module's structures ---------------------------------------*/
+
+static const struct file_operations pc87413_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = pc87413_write,
+ .unlocked_ioctl = pc87413_ioctl,
+ .compat_ioctl = compat_ptr_ioctl,
+ .open = pc87413_open,
+ .release = pc87413_release,
+};
+
+static struct notifier_block pc87413_notifier = {
+ .notifier_call = pc87413_notify_sys,
+};
+
+static struct miscdevice pc87413_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &pc87413_fops,
+};
+
+/* -- Module init functions -------------------------------------*/
+
+/**
+ * pc87413_init: module's "constructor"
+ *
+ * Set up the WDT watchdog board. All we have to do is grab the
+ * resources we require and bitch if anyone beat us to them.
+ * The open() function will actually kick the board off.
+ */
+
+static int __init pc87413_init(void)
+{
+ int ret;
+
+ pr_info("Version " VERSION " at io 0x%X\n",
+ WDT_INDEX_IO_PORT);
+
+ if (!request_muxed_region(io, 2, MODNAME))
+ return -EBUSY;
+
+ ret = register_reboot_notifier(&pc87413_notifier);
+ if (ret != 0)
+ pr_err("cannot register reboot notifier (err=%d)\n", ret);
+
+ ret = misc_register(&pc87413_miscdev);
+ if (ret != 0) {
+ pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
+ goto reboot_unreg;
+ }
+ pr_info("initialized. timeout=%d min\n", timeout);
+
+ pc87413_select_wdt_out();
+ pc87413_enable_swc();
+ pc87413_get_swc_base_addr();
+
+ if (!request_region(swc_base_addr, 0x20, MODNAME)) {
+ pr_err("cannot request SWC region at 0x%x\n", swc_base_addr);
+ ret = -EBUSY;
+ goto misc_unreg;
+ }
+
+ pc87413_enable();
+
+ release_region(io, 2);
+ return 0;
+
+misc_unreg:
+ misc_deregister(&pc87413_miscdev);
+reboot_unreg:
+ unregister_reboot_notifier(&pc87413_notifier);
+ release_region(io, 2);
+ return ret;
+}
+
+/**
+ * pc87413_exit: module's "destructor"
+ *
+ * Unload the watchdog. You cannot do this with any file handles open.
+ * If your watchdog is set to continue ticking on close and you unload
+ * it, well it keeps ticking. We won't get the interrupt but the board
+ * will not touch PC memory so all is fine. You just have to load a new
+ * module in 60 seconds or reboot.
+ */
+
+static void __exit pc87413_exit(void)
+{
+ /* Stop the timer before we leave */
+ if (!nowayout) {
+ pc87413_disable();
+ pr_info("Watchdog disabled\n");
+ }
+
+ misc_deregister(&pc87413_miscdev);
+ unregister_reboot_notifier(&pc87413_notifier);
+ release_region(swc_base_addr, 0x20);
+
+ pr_info("watchdog component driver removed\n");
+}
+
+module_init(pc87413_init);
+module_exit(pc87413_exit);
+
+MODULE_AUTHOR("Sven Anders <anders@anduras.de>");
+MODULE_AUTHOR("Marcus Junker <junker@anduras.de>");
+MODULE_DESCRIPTION("PC87413 WDT driver");
+MODULE_LICENSE("GPL");
+
+module_param_hw(io, int, ioport, 0);
+MODULE_PARM_DESC(io, MODNAME " I/O port (default: "
+ __MODULE_STRING(IO_DEFAULT) ").");
+
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in minutes (default="
+ __MODULE_STRING(DEFAULT_TIMEOUT) ").");
+
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-13 18:53:45 +0000