--- /dev/null
+/*
+ * Intel Atom E6xx Watchdog driver
+ *
+ * Copyright (C) 2011 Alexander Stein
+ * <alexander.stein@systec-electronic.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General
+ * Public License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE. See the GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ * The full GNU General Public License is included in this
+ * distribution in the file called COPYING.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+#include <linux/miscdevice.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/spinlock.h>
+
+#define DRIVER_NAME "ie6xx_wdt"
+
+#define PV1 0x00
+#define PV2 0x04
+
+#define RR0 0x0c
+#define RR1 0x0d
+#define WDT_RELOAD 0x01
+#define WDT_TOUT 0x02
+
+#define WDTCR 0x10
+#define WDT_PRE_SEL 0x04
+#define WDT_RESET_SEL 0x08
+#define WDT_RESET_EN 0x10
+#define WDT_TOUT_EN 0x20
+
+#define DCR 0x14
+
+#define WDTLR 0x18
+#define WDT_LOCK 0x01
+#define WDT_ENABLE 0x02
+#define WDT_TOUT_CNF 0x03
+
+#define MIN_TIME 1
+#define MAX_TIME (10 * 60) /* 10 minutes */
+#define DEFAULT_TIME 60
+
+static unsigned int timeout = DEFAULT_TIME;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+ "Default Watchdog timer setting ("
+ __MODULE_STRING(DEFAULT_TIME) "s)."
+ "The range is from 1 to 600");
+
+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) ")");
+
+static u8 resetmode = 0x10;
+module_param(resetmode, byte, 0);
+MODULE_PARM_DESC(resetmode,
+ "Resetmode bits: 0x08 warm reset (cold reset otherwise), "
+ "0x10 reset enable, 0x20 disable toggle GPIO[4] (default=0x10)");
+
+static struct {
+ unsigned short sch_wdtba;
+ struct spinlock unlock_sequence;
+#ifdef CONFIG_DEBUG_FS
+ struct dentry *debugfs;
+#endif
+} ie6xx_wdt_data;
+
+/*
+ * This is needed to write to preload and reload registers
+ * struct ie6xx_wdt_data.unlock_sequence must be used
+ * to prevent sequence interrupts
+ */
+static void ie6xx_wdt_unlock_registers(void)
+{
+ outb(0x80, ie6xx_wdt_data.sch_wdtba + RR0);
+ outb(0x86, ie6xx_wdt_data.sch_wdtba + RR0);
+}
+
+static int ie6xx_wdt_ping(struct watchdog_device *wdd)
+{
+ spin_lock(&ie6xx_wdt_data.unlock_sequence);
+ ie6xx_wdt_unlock_registers();
+ outb(WDT_RELOAD, ie6xx_wdt_data.sch_wdtba + RR1);
+ spin_unlock(&ie6xx_wdt_data.unlock_sequence);
+ return 0;
+}
+
+static int ie6xx_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t)
+{
+ u32 preload;
+ u64 clock;
+ u8 wdtcr;
+
+ /* Watchdog clock is PCI Clock (33MHz) */
+ clock = 33000000;
+ /* and the preload value is loaded into [34:15] of the down counter */
+ preload = (t * clock) >> 15;
+ /*
+ * Manual states preload must be one less.
+ * Does not wrap as t is at least 1
+ */
+ preload -= 1;
+
+ spin_lock(&ie6xx_wdt_data.unlock_sequence);
+
+ /* Set ResetMode & Enable prescaler for range 10ms to 10 min */
+ wdtcr = resetmode & 0x38;
+ outb(wdtcr, ie6xx_wdt_data.sch_wdtba + WDTCR);
+
+ ie6xx_wdt_unlock_registers();
+ outl(0, ie6xx_wdt_data.sch_wdtba + PV1);
+
+ ie6xx_wdt_unlock_registers();
+ outl(preload, ie6xx_wdt_data.sch_wdtba + PV2);
+
+ ie6xx_wdt_unlock_registers();
+ outb(WDT_RELOAD | WDT_TOUT, ie6xx_wdt_data.sch_wdtba + RR1);
+
+ spin_unlock(&ie6xx_wdt_data.unlock_sequence);
+
+ wdd->timeout = t;
+ return 0;
+}
+
+static int ie6xx_wdt_start(struct watchdog_device *wdd)
+{
+ ie6xx_wdt_set_timeout(wdd, wdd->timeout);
+
+ /* Enable the watchdog timer */
+ spin_lock(&ie6xx_wdt_data.unlock_sequence);
+ outb(WDT_ENABLE, ie6xx_wdt_data.sch_wdtba + WDTLR);
+ spin_unlock(&ie6xx_wdt_data.unlock_sequence);
+
+ return 0;
+}
+
+static int ie6xx_wdt_stop(struct watchdog_device *wdd)
+{
+ if (inb(ie6xx_wdt_data.sch_wdtba + WDTLR) & WDT_LOCK)
+ return -1;
+
+ /* Disable the watchdog timer */
+ spin_lock(&ie6xx_wdt_data.unlock_sequence);
+ outb(0, ie6xx_wdt_data.sch_wdtba + WDTLR);
+ spin_unlock(&ie6xx_wdt_data.unlock_sequence);
+
+ return 0;
+}
+
+static const struct watchdog_info ie6xx_wdt_info = {
+ .identity = "Intel Atom E6xx Watchdog",
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_MAGICCLOSE |
+ WDIOF_KEEPALIVEPING,
+};
+
+static const struct watchdog_ops ie6xx_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = ie6xx_wdt_start,
+ .stop = ie6xx_wdt_stop,
+ .ping = ie6xx_wdt_ping,
+ .set_timeout = ie6xx_wdt_set_timeout,
+};
+
+static struct watchdog_device ie6xx_wdt_dev = {
+ .info = &ie6xx_wdt_info,
+ .ops = &ie6xx_wdt_ops,
+ .min_timeout = MIN_TIME,
+ .max_timeout = MAX_TIME,
+};
+
+#ifdef CONFIG_DEBUG_FS
+
+static int ie6xx_wdt_dbg_show(struct seq_file *s, void *unused)
+{
+ seq_printf(s, "PV1 = 0x%08x\n",
+ inl(ie6xx_wdt_data.sch_wdtba + PV1));
+ seq_printf(s, "PV2 = 0x%08x\n",
+ inl(ie6xx_wdt_data.sch_wdtba + PV2));
+ seq_printf(s, "RR = 0x%08x\n",
+ inw(ie6xx_wdt_data.sch_wdtba + RR0));
+ seq_printf(s, "WDTCR = 0x%08x\n",
+ inw(ie6xx_wdt_data.sch_wdtba + WDTCR));
+ seq_printf(s, "DCR = 0x%08x\n",
+ inl(ie6xx_wdt_data.sch_wdtba + DCR));
+ seq_printf(s, "WDTLR = 0x%08x\n",
+ inw(ie6xx_wdt_data.sch_wdtba + WDTLR));
+
+ seq_printf(s, "\n");
+ return 0;
+}
+
+static int ie6xx_wdt_dbg_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, ie6xx_wdt_dbg_show, NULL);
+}
+
+static const struct file_operations ie6xx_wdt_dbg_operations = {
+ .open = ie6xx_wdt_dbg_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static void __devinit ie6xx_wdt_debugfs_init(void)
+{
+ /* /sys/kernel/debug/ie6xx_wdt */
+ ie6xx_wdt_data.debugfs = debugfs_create_file("ie6xx_wdt",
+ S_IFREG | S_IRUGO, NULL, NULL, &ie6xx_wdt_dbg_operations);
+}
+
+static void __devexit ie6xx_wdt_debugfs_exit(void)
+{
+ debugfs_remove(ie6xx_wdt_data.debugfs);
+}
+
+#else
+static void __devinit ie6xx_wdt_debugfs_init(void)
+{
+}
+
+static void __devexit ie6xx_wdt_debugfs_exit(void)
+{
+}
+#endif
+
+static int __devinit ie6xx_wdt_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ u8 wdtlr;
+ int ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (!res)
+ return -ENODEV;
+
+ if (!request_region(res->start, resource_size(res), pdev->name)) {
+ dev_err(&pdev->dev, "Watchdog region 0x%x already in use!\n",
+ res->start);
+ return -EBUSY;
+ }
+
+ ie6xx_wdt_data.sch_wdtba = res->start;
+ dev_dbg(&pdev->dev, "WDT = 0x%X\n", ie6xx_wdt_data.sch_wdtba);
+
+ ie6xx_wdt_dev.timeout = timeout;
+ watchdog_set_nowayout(&ie6xx_wdt_dev, nowayout);
+
+ spin_lock_init(&ie6xx_wdt_data.unlock_sequence);
+
+ wdtlr = inb(ie6xx_wdt_data.sch_wdtba + WDTLR);
+ if (wdtlr & WDT_LOCK)
+ dev_warn(&pdev->dev,
+ "Watchdog Timer is Locked (Reg=0x%x)\n", wdtlr);
+
+ ie6xx_wdt_debugfs_init();
+
+ ret = watchdog_register_device(&ie6xx_wdt_dev);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Watchdog timer: cannot register device (err =%d)\n",
+ ret);
+ goto misc_register_error;
+ }
+
+ return 0;
+
+misc_register_error:
+ ie6xx_wdt_debugfs_exit();
+ release_region(res->start, resource_size(res));
+ ie6xx_wdt_data.sch_wdtba = 0;
+ return ret;
+}
+
+static int __devexit ie6xx_wdt_remove(struct platform_device *pdev)
+{
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ ie6xx_wdt_stop(NULL);
+ watchdog_unregister_device(&ie6xx_wdt_dev);
+ ie6xx_wdt_debugfs_exit();
+ release_region(res->start, resource_size(res));
+ ie6xx_wdt_data.sch_wdtba = 0;
+
+ return 0;
+}
+
+static struct platform_driver ie6xx_wdt_driver = {
+ .probe = ie6xx_wdt_probe,
+ .remove = __devexit_p(ie6xx_wdt_remove),
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init ie6xx_wdt_init(void)
+{
+ /* Check boot parameters to verify that their initial values */
+ /* are in range. */
+ if ((timeout < MIN_TIME) ||
+ (timeout > MAX_TIME)) {
+ pr_err("Watchdog timer: value of timeout %d (dec) "
+ "is out of range from %d to %d (dec)\n",
+ timeout, MIN_TIME, MAX_TIME);
+ return -EINVAL;
+ }
+
+ return platform_driver_register(&ie6xx_wdt_driver);
+}
+
+static void __exit ie6xx_wdt_exit(void)
+{
+ platform_driver_unregister(&ie6xx_wdt_driver);
+}
+
+late_initcall(ie6xx_wdt_init);
+module_exit(ie6xx_wdt_exit);
+
+MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
+MODULE_DESCRIPTION("Intel Atom E6xx Watchdog Device Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_ALIAS("platform:" DRIVER_NAME);
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