Initial import

1 files changed, 498 insertions, 0 deletions

diff --git a/drivers/watchdog/i6300esb.c b/drivers/watchdog/i6300esb.c
new file mode 100644
index 000000000..d7befd58b
--- /dev/null
+++ b/drivers/watchdog/i6300esb.c
@@ -0,0 +1,498 @@
+/*
+ *	i6300esb:	Watchdog timer driver for Intel 6300ESB chipset
+ *
+ *	(c) Copyright 2004 Google Inc.
+ *	(c) Copyright 2005 David Härdeman <david@2gen.com>
+ *
+ *	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 in turn based on softdog.c
+ *
+ *	The timer is implemented in the following I/O controller hubs:
+ *	(See the intel documentation on http://developer.intel.com.)
+ *	6300ESB chip : document number 300641-004
+ *
+ *  2004YYZZ Ross Biro
+ *	Initial version 0.01
+ *  2004YYZZ Ross Biro
+ *	Version 0.02
+ *  20050210 David Härdeman <david@2gen.com>
+ *	Ported driver to kernel 2.6
+ */
+
+/*
+ *      Includes, defines, variables, module parameters, ...
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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/pci.h>
+#include <linux/ioport.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+
+/* Module and version information */
+#define ESB_VERSION "0.05"
+#define ESB_MODULE_NAME "i6300ESB timer"
+#define ESB_DRIVER_NAME ESB_MODULE_NAME ", v" ESB_VERSION
+
+/* 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                   */
+
+/* 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 (0x03 << 0)   /* Interrupt type on timer1 timeout  */
+
+/* Reload register bits */
+#define ESB_WDT_TIMEOUT (0x01 << 9)    /* Watchdog timed out                */
+#define ESB_WDT_RELOAD  (0x01 << 8)    /* prevent timeout                   */
+
+/* Magic constants */
+#define ESB_UNLOCK1     0x80            /* Step 1 to unlock reset registers  */
+#define ESB_UNLOCK2     0x86            /* Step 2 to unlock reset registers  */
+
+/* internal variables */
+static void __iomem *BASEADDR;
+static DEFINE_SPINLOCK(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;
+
+/* We can only use 1 card due to the /dev/watchdog restriction */
+static int cards_found;
+
+/* module parameters */
+/* 30 sec default heartbeat (1 < heartbeat < 2*1023) */
+#define WATCHDOG_HEARTBEAT 30
+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) ")");
+
+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) ")");
+
+/*
+ * 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)
+{
+	writew(ESB_UNLOCK1, ESB_RELOAD_REG);
+	writew(ESB_UNLOCK2, ESB_RELOAD_REG);
+}
+
+static int esb_timer_start(void)
+{
+	u8 val;
+
+	spin_lock(&esb_lock);
+	esb_unlock_registers();
+	writew(ESB_WDT_RELOAD, ESB_RELOAD_REG);
+	/* Enable or Enable + Lock? */
+	val = ESB_WDT_ENABLE | (nowayout ? ESB_WDT_LOCK : 0x00);
+	pci_write_config_byte(esb_pci, ESB_LOCK_REG, val);
+	spin_unlock(&esb_lock);
+	return 0;
+}
+
+static int esb_timer_stop(void)
+{
+	u8 val;
+
+	spin_lock(&esb_lock);
+	/* First, reset timers as suggested by the docs */
+	esb_unlock_registers();
+	writew(ESB_WDT_RELOAD, 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 & ESB_WDT_ENABLE;
+}
+
+static void esb_timer_keepalive(void)
+{
+	spin_lock(&esb_lock);
+	esb_unlock_registers();
+	writew(ESB_WDT_RELOAD, 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(ESB_WDT_RELOAD, ESB_RELOAD_REG);
+
+	/* FIXME: Do we need to flush everything out? */
+
+	/* Done */
+	heartbeat = time;
+	spin_unlock(&esb_lock);
+	return 0;
+}
+
+/*
+ *	/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_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 {
+		pr_crit("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 long esb_ioctl(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 const 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(0, p);
+
+	case WDIOC_GETBOOTSTATUS:
+		return put_user(triggered, p);
+
+	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_start();
+			retval = 0;
+		}
+		return retval;
+	}
+	case WDIOC_KEEPALIVE:
+		esb_timer_keepalive();
+		return 0;
+
+	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 -ENOTTY;
+	}
+}
+
+/*
+ *      Kernel Interfaces
+ */
+
+static const struct file_operations esb_fops = {
+	.owner = THIS_MODULE,
+	.llseek = no_llseek,
+	.write = esb_write,
+	.unlocked_ioctl = esb_ioctl,
+	.open = esb_open,
+	.release = esb_release,
+};
+
+static struct miscdevice esb_miscdev = {
+	.minor = WATCHDOG_MINOR,
+	.name = "watchdog",
+	.fops = &esb_fops,
+};
+
+/*
+ * Data for PCI driver interface
+ */
+static const struct pci_device_id esb_pci_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_9), },
+	{ 0, },                 /* End of list */
+};
+MODULE_DEVICE_TABLE(pci, esb_pci_tbl);
+
+/*
+ *      Init & exit routines
+ */
+
+static unsigned char esb_getdevice(struct pci_dev *pdev)
+{
+	if (pci_enable_device(pdev)) {
+		pr_err("failed to enable device\n");
+		goto err_devput;
+	}
+
+	if (pci_request_region(pdev, 0, ESB_MODULE_NAME)) {
+		pr_err("failed to request region\n");
+		goto err_disable;
+	}
+
+	BASEADDR = pci_ioremap_bar(pdev, 0);
+	if (BASEADDR == NULL) {
+		/* Something's wrong here, BASEADDR has to be set */
+		pr_err("failed to get BASEADDR\n");
+		goto err_release;
+	}
+
+	/* Done */
+	esb_pci = pdev;
+	return 1;
+
+err_release:
+	pci_release_region(pdev, 0);
+err_disable:
+	pci_disable_device(pdev);
+err_devput:
+	return 0;
+}
+
+static void esb_initdevice(void)
+{
+	u8 val1;
+	u16 val2;
+
+	/*
+	 * Config register:
+	 * Bit    5 : 0 = Enable WDT_OUTPUT
+	 * Bit    2 : 0 = set the timer frequency to the PCI clock
+	 * divided by 2^15 (approx 1KHz).
+	 * Bits 1:0 : 11 = WDT_INT_TYPE Disabled.
+	 * 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.
+	 */
+	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)
+		pr_warn("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);
+	if (val2 & ESB_WDT_TIMEOUT)
+		triggered = WDIOF_CARDRESET;
+
+	/* Reset WDT_TIMEOUT flag and timers */
+	esb_unlock_registers();
+	writew((ESB_WDT_TIMEOUT | ESB_WDT_RELOAD), ESB_RELOAD_REG);
+
+	/* And set the correct timeout value */
+	esb_timer_set_heartbeat(heartbeat);
+}
+
+static int esb_probe(struct pci_dev *pdev,
+		const struct pci_device_id *ent)
+{
+	int ret;
+
+	cards_found++;
+	if (cards_found == 1)
+		pr_info("Intel 6300ESB WatchDog Timer Driver v%s\n",
+			ESB_VERSION);
+
+	if (cards_found > 1) {
+		pr_err("This driver only supports 1 device\n");
+		return -ENODEV;
+	}
+
+	/* Check whether or not the hardware watchdog is there */
+	if (!esb_getdevice(pdev) || esb_pci == NULL)
+		return -ENODEV;
+
+	/* Check that the heartbeat value is within it's range;
+	   if not reset to the default */
+	if (heartbeat < 0x1 || heartbeat > 2 * 0x03ff) {
+		heartbeat = WATCHDOG_HEARTBEAT;
+		pr_info("heartbeat value must be 1<heartbeat<2046, using %d\n",
+			heartbeat);
+	}
+
+	/* Initialize the watchdog and make sure it does not run */
+	esb_initdevice();
+
+	/* Register the watchdog so that userspace has access to it */
+	ret = misc_register(&esb_miscdev);
+	if (ret != 0) {
+		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+		       WATCHDOG_MINOR, ret);
+		goto err_unmap;
+	}
+	pr_info("initialized (0x%p). heartbeat=%d sec (nowayout=%d)\n",
+		BASEADDR, heartbeat, nowayout);
+	return 0;
+
+err_unmap:
+	iounmap(BASEADDR);
+	pci_release_region(esb_pci, 0);
+	pci_disable_device(esb_pci);
+	esb_pci = NULL;
+	return ret;
+}
+
+static void esb_remove(struct pci_dev *pdev)
+{
+	/* Stop the timer before we leave */
+	if (!nowayout)
+		esb_timer_stop();
+
+	/* Deregister */
+	misc_deregister(&esb_miscdev);
+	iounmap(BASEADDR);
+	pci_release_region(esb_pci, 0);
+	pci_disable_device(esb_pci);
+	esb_pci = NULL;
+}
+
+static void esb_shutdown(struct pci_dev *pdev)
+{
+	esb_timer_stop();
+}
+
+static struct pci_driver esb_driver = {
+	.name		= ESB_MODULE_NAME,
+	.id_table	= esb_pci_tbl,
+	.probe          = esb_probe,
+	.remove         = esb_remove,
+	.shutdown       = esb_shutdown,
+};
+
+module_pci_driver(esb_driver);
+
+MODULE_AUTHOR("Ross Biro and David Härdeman");
+MODULE_DESCRIPTION("Watchdog driver for Intel 6300ESB chipsets");
+MODULE_LICENSE("GPL");