6300ESB watchdog driver
From: David Härdeman
Date: Sun Feb 20 2005 - 15:41:19 EST
Hi
I wrote earlier to the list[1] asking for a driver for the watchdog
included in the 6300ESB chipset. I got a 2.4 driver via private email
from Ross Biro which I've changed into what I hope resembles a 2.6
driver (which was done by looking a lot at the watchdog drivers already
in the 2.6 tree).
I've attached the result, and I'm hoping to get some feedback on the
coding as a first step. I can't actually test it on the hardware right
now as I won't have physical access until April. So my own tests have
been limited to "compiles-without-warnings" and
"can-be-insmodded-in-other-machine-without-oops".
As I said, it's the first thing I've ever written, so I'm guessing it
has a few rough edges. Feedback welcome :-)
Re,
David
[1] http://marc.theaimsgroup.com/?l=linux-kernel&m=110711079825794&w=2
[2] http://marc.theaimsgroup.com/?l=linux-kernel&m=110711973917746&w=2
diff -Nur linux-2.6.10.orig/drivers/char/watchdog/i6300esb.c linux-2.6.10/drivers/char/watchdog/i6300esb.c
--- linux-2.6.10.orig/drivers/char/watchdog/i6300esb.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.10/drivers/char/watchdog/i6300esb.c 2005-02-07 23:27:08.000000000 +0100
@@ -0,0 +1,508 @@
+/*
+ * i6300esb 0.03: Watchdog timer driver for Intel 6300ESB chipset
+ *
+ * (c) Copyright 2004 Google Inc.
+ *
+ * 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.
+ *
+ * based on i810-tco.c which is
+ *
+ * (c) Copyright 2000 kernel concepts <nils@xxxxxxxxxxxxxxxxx>
+ * developed for
+ * Jentro AG, Haar/Munich (Germany)
+ *
+ * which is in turn based on softdog.c by Alan Cox <alan@xxxxxxxxxx>
+ *
+ * The timer is implemented in the following I/O controller hubs:
+ * (See the intel documentation on http://developer.intel.com.)
+ * 6300ESB chip : document number 300641-003
+ *
+ * 2004YYZZ Ross Biro
+ * Initial version 0.01
+ * 2004YYZZ Ross Biro
+ * Version 0.02
+ * 20050210 David Härdeman <david@xxxxxxxx>
+ * Ported driver to kernel 2.6
+ */
+
+/*
+ * Includes, defines, variables, module parameters, ...
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/ioport.h>
+
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#include "i6300esb.h"
+
+/* Module and version information */
+#define ESB_VERSION "0.03"
+#define ESB_MODULE_NAME "i6300ESB timer"
+#define ESB_DRIVER_NAME ESB_MODULE_NAME ", v" ESB_VERSION
+#define PFX ESB_MODULE_NAME ": "
+
+/* internal variables */
+static void __iomem *BASEADDR;
+static spinlock_t esb_lock; /* Guards the hardware */
+static unsigned long timer_alive;
+static struct pci_dev *esb_pci;
+static unsigned short triggered; /* The status of the watchdog upon boot */
+static char esb_expect_close;
+
+/* module parameters */
+#define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat (1<heartbeat<2*1023) */
+static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (1<heartbeat<2046, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+/*
+ * Some i6300ESB specific functions
+ */
+
+/*
+ * Prepare for reloading the timer by unlocking the proper registers.
+ * This is performed by first writing 0x80 followed by 0x86 to the
+ * reload register. After this the appropriate registers can be written
+ * to once before they need to be unlocked again.
+ */
+static inline void esb_unlock_registers(void) {
+ writeb(ESB_UNLOCK1, ESB_RELOAD_REG);
+ writeb(ESB_UNLOCK2, ESB_RELOAD_REG);
+}
+
+static void esb_timer_start(void)
+{
+ u8 val;
+
+ /* Enable or Enable + Lock? */
+ val = 0x02 | nowayout ? 0x01 : 0x00;
+
+ pci_write_config_byte(esb_pci, ESB_LOCK_REG, val);
+}
+
+static int esb_timer_stop(void)
+{
+ u8 val;
+
+ spin_lock(&esb_lock);
+ /* First, reset timers as suggested by the docs */
+ esb_unlock_registers();
+ writew(0x10, ESB_RELOAD_REG);
+ /* Then disable the WDT */
+ pci_write_config_byte(esb_pci, ESB_LOCK_REG, 0x0);
+ pci_read_config_byte(esb_pci, ESB_LOCK_REG, &val);
+ spin_unlock(&esb_lock);
+
+ /* Returns 0 if the timer was disabled, non-zero otherwise */
+ return (val & 0x01);
+}
+
+static void esb_timer_keepalive(void)
+{
+ spin_lock(&esb_lock);
+ esb_unlock_registers();
+ writew(0x10, ESB_RELOAD_REG);
+ /* FIXME: Do we need to flush anything here? */
+ spin_unlock(&esb_lock);
+}
+
+static int esb_timer_set_heartbeat(int time)
+{
+ u32 val;
+
+ if (time < 0x1 || time > (2 * 0x03ff))
+ return -EINVAL;
+
+ spin_lock(&esb_lock);
+
+ /* We shift by 9, so if we are passed a value of 1 sec,
+ * val will be 1 << 9 = 512, then write that to two
+ * timers => 2 * 512 = 1024 (which is decremented at 1KHz)
+ */
+ val = time << 9;
+
+ /* Write timer 1 */
+ esb_unlock_registers();
+ writel(val, ESB_TIMER1_REG);
+
+ /* Write timer 2 */
+ esb_unlock_registers();
+ writel(val, ESB_TIMER2_REG);
+
+ /* Reload */
+ esb_unlock_registers();
+ writew(0x10, ESB_RELOAD_REG);
+
+ /* FIXME: Do we need to flush everything out? */
+
+ /* Done */
+ heartbeat = time;
+ spin_unlock(&esb_lock);
+ return 0;
+}
+
+static int esb_timer_read (void)
+{
+ u32 count;
+
+ /* This isn't documented, and doesn't take into
+ * acount which stage is running, but it looks
+ * like a 20 bit count down, so we might as well report it.
+ */
+ pci_read_config_dword(esb_pci, 0x64, &count);
+ return (int)count;
+}
+
+/*
+ * /dev/watchdog handling
+ */
+
+static int esb_open (struct inode *inode, struct file *file)
+{
+ /* /dev/watchdog can only be opened once */
+ if (test_and_set_bit(0, &timer_alive))
+ return -EBUSY;
+
+ /* Reload and activate timer */
+ esb_timer_keepalive ();
+ esb_timer_start ();
+
+ return nonseekable_open(inode, file);
+}
+
+static int esb_release (struct inode *inode, struct file *file)
+{
+ /* Shut off the timer. */
+ if (esb_expect_close == 42) {
+ esb_timer_stop ();
+ } else {
+ printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
+ esb_timer_keepalive ();
+ }
+ clear_bit(0, &timer_alive);
+ esb_expect_close = 0;
+ return 0;
+}
+
+static ssize_t esb_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;
+
+ /* note: just in case someone wrote the magic character
+ * five months ago... */
+ esb_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')
+ esb_expect_close = 42;
+ }
+ }
+
+ /* someone wrote to us, we should reload the timer */
+ esb_timer_keepalive ();
+ }
+ return len;
+}
+
+static int esb_ioctl (struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int new_options, retval = -EINVAL;
+ int new_heartbeat;
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ static struct watchdog_info ident = {
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+ .firmware_version = 0,
+ .identity = ESB_MODULE_NAME,
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp, &ident,
+ sizeof (ident)) ? -EFAULT : 0;
+
+ case WDIOC_GETSTATUS:
+ return put_user (esb_timer_read(), p);
+
+ case WDIOC_GETBOOTSTATUS:
+ return put_user (triggered, p);
+
+ case WDIOC_KEEPALIVE:
+ esb_timer_keepalive ();
+ return 0;
+
+ case WDIOC_SETOPTIONS:
+ {
+ if (get_user (new_options, p))
+ return -EFAULT;
+
+ if (new_options & WDIOS_DISABLECARD) {
+ esb_timer_stop ();
+ retval = 0;
+ }
+
+ if (new_options & WDIOS_ENABLECARD) {
+ esb_timer_keepalive ();
+ esb_timer_start ();
+ retval = 0;
+ }
+
+ return retval;
+ }
+
+ case WDIOC_SETTIMEOUT:
+ {
+ if (get_user(new_heartbeat, p))
+ return -EFAULT;
+
+ if (esb_timer_set_heartbeat(new_heartbeat))
+ return -EINVAL;
+
+ esb_timer_keepalive ();
+ /* Fall */
+ }
+
+ case WDIOC_GETTIMEOUT:
+ return put_user(heartbeat, p);
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
+/*
+ * Notify system
+ */
+
+static int esb_notify_sys (struct notifier_block *this, unsigned long code, void *unused)
+{
+ if (code==SYS_DOWN || code==SYS_HALT) {
+ /* Turn the WDT off */
+ esb_timer_stop ();
+ }
+
+ return NOTIFY_DONE;
+}
+
+/*
+ * Kernel Interfaces
+ */
+
+static struct file_operations esb_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = esb_write,
+ .ioctl = esb_ioctl,
+ .open = esb_open,
+ .release = esb_release,
+};
+
+static struct miscdevice esb_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &esb_fops,
+};
+
+static struct notifier_block esb_notifier = {
+ .notifier_call = esb_notify_sys,
+};
+
+/*
+ * Data for PCI driver interface
+ *
+ * This data only exists for exporting the supported
+ * PCI ids via MODULE_DEVICE_TABLE. We do not actually
+ * register a pci_driver, because someone else might one day
+ * want to register another driver on the same PCI id.
+ */
+static struct pci_device_id esb_pci_tbl[] = {
+ { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_9, PCI_ANY_ID, PCI_ANY_ID, },
+ { 0, }, /* End of list */
+};
+MODULE_DEVICE_TABLE (pci, esb_pci_tbl);
+
+/*
+ * Init & exit routines
+ */
+
+static unsigned char __init esb_getdevice (void)
+{
+ u8 val1;
+ unsigned short val2;
+
+ struct pci_dev *dev = NULL;
+ /*
+ * Find the PCI device
+ */
+
+ while ((dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
+ if (pci_match_device(esb_pci_tbl, dev)) {
+ esb_pci = dev;
+ break;
+ }
+ }
+
+ if (esb_pci) {
+ if (pci_enable_device(esb_pci)) {
+ printk (KERN_ERR PFX "failed to enable device\n");
+ goto out;
+ }
+
+ if (pci_request_region(esb_pci, 0, ESB_MODULE_NAME)) {
+ printk (KERN_ERR PFX "failed to request region\n");
+ goto err_disable;
+ }
+
+ BASEADDR = ioremap(pci_resource_start(esb_pci, 0),
+ pci_resource_len(esb_pci, 0));
+ if (BASEADDR == NULL) {
+ /* Something's wrong here, BASEADDR has to be set */
+ printk (KERN_ERR PFX "failed to get BASEADDR\n");
+ goto err_release;
+ }
+
+ /*
+ * The watchdog has two timers, it can be setup so that the
+ * expiry of timer1 results in an interrupt and the expiry of
+ * timer2 results in a reboot. We set it to not generate
+ * any interrupts as there is not much we can do with it
+ * right now.
+ *
+ * We also enable reboots and set the timer frequency to
+ * the PCI clock divided by 2^15 (approx 1KHz).
+ */
+ pci_write_config_word(esb_pci, ESB_CONFIG_REG, 0x0003);
+
+ /* Check that the WDT isn't already locked */
+ pci_read_config_byte(esb_pci, ESB_LOCK_REG, &val1);
+ if (val1 & ESB_WDT_LOCK)
+ printk (KERN_WARNING PFX "nowayout already set\n");
+
+ /* Set the timer to watchdog mode and disable it for now */
+ pci_write_config_byte(esb_pci, ESB_LOCK_REG, 0x00);
+
+ /* Check if the watchdog was previously triggered */
+ esb_unlock_registers();
+ val2 = readw(ESB_RELOAD_REG);
+ triggered = (val2 & (0x01 << 9) >> 9);
+
+ /* Reset trigger flag and timers */
+ esb_unlock_registers();
+ writew((0x11 << 8), ESB_RELOAD_REG);
+
+ /* Done */
+ return 1;
+
+err_release:
+ pci_release_region(esb_pci, 0);
+err_disable:
+ pci_disable_device(esb_pci);
+ }
+out:
+ return 0;
+}
+
+static int __init watchdog_init (void)
+{
+ int ret;
+
+ spin_lock_init(&esb_lock);
+
+ /* Check whether or not the hardware watchdog is there */
+ if (!esb_getdevice () || esb_pci == NULL)
+ return -ENODEV;
+
+ /* Check that the heartbeat value is within it's range ; if not reset to the default */
+ if (esb_timer_set_heartbeat (heartbeat)) {
+ esb_timer_set_heartbeat (WATCHDOG_HEARTBEAT);
+ printk(KERN_INFO PFX "heartbeat value must be 1<heartbeat<2046, using %d\n",
+ heartbeat);
+ }
+
+ ret = register_reboot_notifier(&esb_notifier);
+ if (ret != 0) {
+ printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+ ret);
+ goto err_unmap;
+ }
+
+ ret = misc_register(&esb_miscdev);
+ if (ret != 0) {
+ printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
+ goto err_notifier;
+ }
+
+ esb_timer_stop ();
+
+ printk (KERN_INFO PFX "initialized (0x%p). heartbeat=%d sec (nowayout=%d)\n",
+ BASEADDR, heartbeat, nowayout);
+
+ return 0;
+
+err_notifier:
+ unregister_reboot_notifier(&esb_notifier);
+err_unmap:
+ iounmap(BASEADDR);
+/* err_release: */
+ pci_release_region(esb_pci, 0);
+/* err_disable: */
+ pci_disable_device(esb_pci);
+/* out: */
+ return ret;
+}
+
+static void __exit watchdog_cleanup (void)
+{
+ /* Stop the timer before we leave */
+ if (!nowayout)
+ esb_timer_stop ();
+
+ /* Deregister */
+ misc_deregister(&esb_miscdev);
+ unregister_reboot_notifier(&esb_notifier);
+ iounmap(BASEADDR);
+ pci_release_region(esb_pci, 0);
+ pci_disable_device(esb_pci);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_cleanup);
+
+MODULE_AUTHOR("Ross Biro and David Härdeman");
+MODULE_DESCRIPTION("Watchdog driver for Intel 6300ESB chipsets");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
diff -Nur linux-2.6.10.orig/drivers/char/watchdog/i6300esb.h linux-2.6.10/drivers/char/watchdog/i6300esb.h
--- linux-2.6.10.orig/drivers/char/watchdog/i6300esb.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.10/drivers/char/watchdog/i6300esb.h 2005-02-07 23:26:15.000000000 +0100
@@ -0,0 +1,62 @@
+/*
+ * i8xx_tco: TCO timer driver for i8xx chipsets
+ *
+ * (c) Copyright 2000 kernel concepts <nils@xxxxxxxxxxxxxxxxx>, All Rights Reserved.
+ * http://www.kernelconcepts.de
+ *
+ * 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.
+ *
+ * Neither kernel concepts nor Nils Faerber admit liability nor provide
+ * warranty for any of this software. This material is provided
+ * "AS-IS" and at no charge.
+ *
+ * (c) Copyright 2000 kernel concepts <nils@xxxxxxxxxxxxxxxxx>
+ * developed for
+ * Jentro AG, Haar/Munich (Germany)
+ *
+ * TCO timer driver for i8xx chipsets
+ * based on softdog.c by Alan Cox <alan@xxxxxxxxxx>
+ *
+ * For history and the complete list of supported I/O Controller Hub's
+ * see i8xx_tco.c
+ */
+
+
+/*
+ * Some address definitions for the TCO
+ */
+
+/* PCI configuration registers */
+#define ESB_CONFIG_REG 0x60 /* Config register */
+#define ESB_LOCK_REG 0x68 /* WDT lock register */
+
+/* Memory mapped registers */
+#define ESB_TIMER1_REG BASEADDR + 0x00 /* Timer1 value after each reset */
+#define ESB_TIMER2_REG BASEADDR + 0x04 /* Timer2 value after each reset */
+#define ESB_GINTSR_REG BASEADDR + 0x08 /* General Interrupt Status Register */
+#define ESB_RELOAD_REG BASEADDR + 0x0c /* Reload register */
+
+
+/*
+ * Some register bits
+ */
+
+/* Lock register bits */
+#define ESB_WDT_FUNC ( 0x01 << 2 ) /* Watchdog functionality */
+#define ESB_WDT_ENABLE ( 0x01 << 1 ) /* Enable WDT */
+#define ESB_WDT_LOCK ( 0x01 << 0 ) /* Lock (nowayout) */
+
+/* Config register bits */
+#define ESB_WDT_REBOOT ( 0x01 << 5 ) /* Enable reboot on timeout */
+#define ESB_WDT_FREQ ( 0x01 << 2 ) /* Decrement frequency */
+#define ESB_WDT_INTTYPE ( 0x11 << 0 ) /* Interrupt type on timer1 timeout */
+
+
+/*
+ * Some magic constants
+ */
+#define ESB_UNLOCK1 0x80 /* Step 1 to unlock reset registers */
+#define ESB_UNLOCK2 0x86 /* Step 2 to unlock reset registers */
diff -Nur linux-2.6.10.orig/drivers/char/watchdog/Kconfig linux-2.6.10/drivers/char/watchdog/Kconfig
--- linux-2.6.10.orig/drivers/char/watchdog/Kconfig 2004-12-24 22:35:01.000000000 +0100
+++ linux-2.6.10/drivers/char/watchdog/Kconfig 2005-02-07 23:26:21.000000000 +0100
@@ -247,6 +247,16 @@
To compile this driver as a module, choose M here: the
module will be called i8xx_tco.
+config I6300ESB_WDT
+ tristate "Intel 6300ESB Timer/Watchdog"
+ depends on WATCHDOG && X86 && PCI
+ ---help---
+ Hardware driver for the watchdog timer built into the Intel
+ 6300ESB controller hub.
+
+ To compile this driver as a module, choose M here: the
+ module will be called i6300esb.
+
config SC1200_WDT
tristate "National Semiconductor PC87307/PC97307 (ala SC1200) Watchdog"
depends on WATCHDOG && X86
diff -Nur linux-2.6.10.orig/drivers/char/watchdog/Makefile linux-2.6.10/drivers/char/watchdog/Makefile
--- linux-2.6.10.orig/drivers/char/watchdog/Makefile 2004-12-24 22:35:23.000000000 +0100
+++ linux-2.6.10/drivers/char/watchdog/Makefile 2005-02-07 23:26:25.000000000 +0100
@@ -19,6 +19,7 @@
obj-$(CONFIG_21285_WATCHDOG) += wdt285.o
obj-$(CONFIG_977_WATCHDOG) += wdt977.o
obj-$(CONFIG_I8XX_TCO) += i8xx_tco.o
+obj-$(CONFIG_I6300ESB_WDT) += i6300esb.o
obj-$(CONFIG_MACHZ_WDT) += machzwd.o
obj-$(CONFIG_SH_WDT) += shwdt.o
obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o