--- /dev/null
+/*
+ * IT8712F "Smart Guardian" Watchdog support
+ *
+ * Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <jorge@dti2.net>
+ *
+ * Based on info and code taken from:
+ *
+ * drivers/char/watchdog/scx200_wdt.c
+ * drivers/hwmon/it87.c
+ * IT8712F EC-LPC I/O Preliminary Specification 0.8.2
+ * IT8712F EC-LPC I/O Preliminary Specification 0.9.3
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/fs.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+
+#define DEBUG
+#define NAME "it8712f_wdt"
+
+MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>");
+MODULE_DESCRIPTION("IT8712F Watchdog Driver");
+MODULE_LICENSE("GPL");
+
+static int max_units = 255;
+static int margin = 60; /* in seconds */
+module_param(margin, int, 0);
+MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
+
+static unsigned long wdt_open;
+static unsigned expect_close;
+static unsigned char revision;
+
+/* Dog Food address - We use the game port address */
+static unsigned short address;
+
+#define REG 0x2e /* The register to read/write */
+#define VAL 0x2f /* The value to read/write */
+
+#define LDN 0x07 /* Register: Logical device select */
+#define DEVID 0x20 /* Register: Device ID */
+#define DEVREV 0x22 /* Register: Device Revision */
+#define ACT_REG 0x30 /* LDN Register: Activation */
+#define BASE_REG 0x60 /* LDN Register: Base address */
+
+#define IT8712F_DEVID 0x8712
+
+#define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */
+#define LDN_GAME 0x09 /* Game Port */
+
+#define WDT_CONTROL 0x71 /* WDT Register: Control */
+#define WDT_CONFIG 0x72 /* WDT Register: Configuration */
+#define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */
+
+#define WDT_RESET_GAME 0x10 /* Reset timer on read or write to game port */
+#define WDT_RESET_KBD 0x20 /* Reset timer on keyboard interrupt */
+#define WDT_RESET_MOUSE 0x40 /* Reset timer on mouse interrupt */
+#define WDT_RESET_CIR 0x80 /* Reset timer on consumer IR interrupt */
+
+#define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */
+
+#define WDT_OUT_PWROK 0x10 /* Pulse PWROK on timeout */
+#define WDT_OUT_KRST 0x40 /* Pulse reset on timeout */
+
+static int wdt_control_reg = WDT_RESET_GAME;
+module_param(wdt_control_reg, int, 0);
+MODULE_PARM_DESC(wdt_control_reg, "Value to write to watchdog control "
+ "register. The default WDT_RESET_GAME resets the timer on "
+ "game port reads that this driver generates. You can also "
+ "use KBD, MOUSE or CIR if you have some external way to "
+ "generate those interrupts.");
+
+static int superio_inb(int reg)
+{
+ outb(reg, REG);
+ return inb(VAL);
+}
+
+static void superio_outb(int val, int reg)
+{
+ outb(reg, REG);
+ outb(val, VAL);
+}
+
+static int superio_inw(int reg)
+{
+ int val;
+ outb(reg++, REG);
+ val = inb(VAL) << 8;
+ outb(reg, REG);
+ val |= inb(VAL);
+ return val;
+}
+
+static inline void superio_select(int ldn)
+{
+ outb(LDN, REG);
+ outb(ldn, VAL);
+}
+
+static inline int superio_enter(void)
+{
+ /*
+ * Try to reserve REG and REG + 1 for exclusive access.
+ */
+ if (!request_muxed_region(REG, 2, NAME))
+ return -EBUSY;
+
+ outb(0x87, REG);
+ outb(0x01, REG);
+ outb(0x55, REG);
+ outb(0x55, REG);
+ return 0;
+}
+
+static inline void superio_exit(void)
+{
+ outb(0x02, REG);
+ outb(0x02, VAL);
+ release_region(REG, 2);
+}
+
+static inline void it8712f_wdt_ping(void)
+{
+ if (wdt_control_reg & WDT_RESET_GAME)
+ inb(address);
+}
+
+static void it8712f_wdt_update_margin(void)
+{
+ int config = WDT_OUT_KRST | WDT_OUT_PWROK;
+ int units = margin;
+
+ /* Switch to minutes precision if the configured margin
+ * value does not fit within the register width.
+ */
+ if (units <= max_units) {
+ config |= WDT_UNIT_SEC; /* else UNIT is MINUTES */
+ pr_info("timer margin %d seconds\n", units);
+ } else {
+ units /= 60;
+ pr_info("timer margin %d minutes\n", units);
+ }
+ superio_outb(config, WDT_CONFIG);
+
+ if (revision >= 0x08)
+ superio_outb(units >> 8, WDT_TIMEOUT + 1);
+ superio_outb(units, WDT_TIMEOUT);
+}
+
+static int it8712f_wdt_get_status(void)
+{
+ if (superio_inb(WDT_CONTROL) & 0x01)
+ return WDIOF_CARDRESET;
+ else
+ return 0;
+}
+
+static int it8712f_wdt_enable(void)
+{
+ int ret = superio_enter();
+ if (ret)
+ return ret;
+
+ pr_debug("enabling watchdog timer\n");
+ superio_select(LDN_GPIO);
+
+ superio_outb(wdt_control_reg, WDT_CONTROL);
+
+ it8712f_wdt_update_margin();
+
+ superio_exit();
+
+ it8712f_wdt_ping();
+
+ return 0;
+}
+
+static int it8712f_wdt_disable(void)
+{
+ int ret = superio_enter();
+ if (ret)
+ return ret;
+
+ pr_debug("disabling watchdog timer\n");
+ superio_select(LDN_GPIO);
+
+ superio_outb(0, WDT_CONFIG);
+ superio_outb(0, WDT_CONTROL);
+ if (revision >= 0x08)
+ superio_outb(0, WDT_TIMEOUT + 1);
+ superio_outb(0, WDT_TIMEOUT);
+
+ superio_exit();
+ return 0;
+}
+
+static int it8712f_wdt_notify(struct notifier_block *this,
+ unsigned long code, void *unused)
+{
+ if (code == SYS_HALT || code == SYS_POWER_OFF)
+ if (!nowayout)
+ it8712f_wdt_disable();
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block it8712f_wdt_notifier = {
+ .notifier_call = it8712f_wdt_notify,
+};
+
+static ssize_t it8712f_wdt_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ /* check for a magic close character */
+ if (len) {
+ size_t i;
+
+ it8712f_wdt_ping();
+
+ 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;
+ }
+ }
+
+ return len;
+}
+
+static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ static const struct watchdog_info ident = {
+ .identity = "IT8712F Watchdog",
+ .firmware_version = 1,
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+ };
+ int value;
+ int ret;
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &ident, sizeof(ident)))
+ return -EFAULT;
+ return 0;
+ case WDIOC_GETSTATUS:
+ ret = superio_enter();
+ if (ret)
+ return ret;
+ superio_select(LDN_GPIO);
+
+ value = it8712f_wdt_get_status();
+
+ superio_exit();
+
+ return put_user(value, p);
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+ case WDIOC_KEEPALIVE:
+ it8712f_wdt_ping();
+ return 0;
+ case WDIOC_SETTIMEOUT:
+ if (get_user(value, p))
+ return -EFAULT;
+ if (value < 1)
+ return -EINVAL;
+ if (value > (max_units * 60))
+ return -EINVAL;
+ margin = value;
+ ret = superio_enter();
+ if (ret)
+ return ret;
+ superio_select(LDN_GPIO);
+
+ it8712f_wdt_update_margin();
+
+ superio_exit();
+ it8712f_wdt_ping();
+ /* Fall through */
+ case WDIOC_GETTIMEOUT:
+ if (put_user(margin, p))
+ return -EFAULT;
+ return 0;
+ default:
+ return -ENOTTY;
+ }
+}
+
+static int it8712f_wdt_open(struct inode *inode, struct file *file)
+{
+ int ret;
+ /* only allow one at a time */
+ if (test_and_set_bit(0, &wdt_open))
+ return -EBUSY;
+
+ ret = it8712f_wdt_enable();
+ if (ret)
+ return ret;
+ return nonseekable_open(inode, file);
+}
+
+static int it8712f_wdt_release(struct inode *inode, struct file *file)
+{
+ if (expect_close != 42) {
+ pr_warn("watchdog device closed unexpectedly, will not disable the watchdog timer\n");
+ } else if (!nowayout) {
+ if (it8712f_wdt_disable())
+ pr_warn("Watchdog disable failed\n");
+ }
+ expect_close = 0;
+ clear_bit(0, &wdt_open);
+
+ return 0;
+}
+
+static const struct file_operations it8712f_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = it8712f_wdt_write,
+ .unlocked_ioctl = it8712f_wdt_ioctl,
+ .open = it8712f_wdt_open,
+ .release = it8712f_wdt_release,
+};
+
+static struct miscdevice it8712f_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &it8712f_wdt_fops,
+};
+
+static int __init it8712f_wdt_find(unsigned short *address)
+{
+ int err = -ENODEV;
+ int chip_type;
+ int ret = superio_enter();
+ if (ret)
+ return ret;
+
+ chip_type = superio_inw(DEVID);
+ if (chip_type != IT8712F_DEVID)
+ goto exit;
+
+ superio_select(LDN_GAME);
+ superio_outb(1, ACT_REG);
+ if (!(superio_inb(ACT_REG) & 0x01)) {
+ pr_err("Device not activated, skipping\n");
+ goto exit;
+ }
+
+ *address = superio_inw(BASE_REG);
+ if (*address == 0) {
+ pr_err("Base address not set, skipping\n");
+ goto exit;
+ }
+
+ err = 0;
+ revision = superio_inb(DEVREV) & 0x0f;
+
+ /* Later revisions have 16-bit values per datasheet 0.9.1 */
+ if (revision >= 0x08)
+ max_units = 65535;
+
+ if (margin > (max_units * 60))
+ margin = (max_units * 60);
+
+ pr_info("Found IT%04xF chip revision %d - using DogFood address 0x%x\n",
+ chip_type, revision, *address);
+
+exit:
+ superio_exit();
+ return err;
+}
+
+static int __init it8712f_wdt_init(void)
+{
+ int err = 0;
+
+ if (it8712f_wdt_find(&address))
+ return -ENODEV;
+
+ if (!request_region(address, 1, "IT8712F Watchdog")) {
+ pr_warn("watchdog I/O region busy\n");
+ return -EBUSY;
+ }
+
+ err = it8712f_wdt_disable();
+ if (err) {
+ pr_err("unable to disable watchdog timer\n");
+ goto out;
+ }
+
+ err = register_reboot_notifier(&it8712f_wdt_notifier);
+ if (err) {
+ pr_err("unable to register reboot notifier\n");
+ goto out;
+ }
+
+ err = misc_register(&it8712f_wdt_miscdev);
+ if (err) {
+ pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, err);
+ goto reboot_out;
+ }
+
+ return 0;
+
+
+reboot_out:
+ unregister_reboot_notifier(&it8712f_wdt_notifier);
+out:
+ release_region(address, 1);
+ return err;
+}
+
+static void __exit it8712f_wdt_exit(void)
+{
+ misc_deregister(&it8712f_wdt_miscdev);
+ unregister_reboot_notifier(&it8712f_wdt_notifier);
+ release_region(address, 1);
+}
+
+module_init(it8712f_wdt_init);
+module_exit(it8712f_wdt_exit);
Code Review / kvmfornfv.git / blobdiff