[WATCHDOG] Add SMSC SCH311x Watchdog Timer.

Add a watchdog driver for the hardware watchdog timer on the
SMSC SCH3112, SCH3114 and SCH3116 Super IO chipset.

Tested-by: Marco Chiappero <marco@absence.it>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 578 insertions, 0 deletions

diff --git a/drivers/watchdog/sch311x_wdt.c b/drivers/watchdog/sch311x_wdt.c
new file mode 100644
index 000000000000..569eb295a7a8
--- /dev/null
+++ b/drivers/watchdog/sch311x_wdt.c
@@ -0,0 +1,578 @@
+/*
+ *      sch311x_wdt.c - Driver for the SCH311x Super-I/O chips
+ *                      integrated watchdog.
+ *
+ *      (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>.
+ *
+ *      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 Wim Van Sebroeck nor Iguana vzw. admit liability nor
+ *      provide warranty for any of this software. This material is
+ *      provided "AS-IS" and at no charge.
+ */
+
+/*
+ *      Includes, defines, variables, module parameters, ...
+ */
+
+/* Includes */
+#include <linux/module.h>               /* For module specific items */
+#include <linux/moduleparam.h>          /* For new moduleparam's */
+#include <linux/types.h>                /* For standard types (like size_t) */
+#include <linux/errno.h>                /* For the -ENODEV/... values */
+#include <linux/kernel.h>               /* For printk/... */
+#include <linux/miscdevice.h>           /* For MODULE_ALIAS_MISCDEV
+                                                        (WATCHDOG_MINOR) */
+#include <linux/watchdog.h>             /* For the watchdog specific items */
+#include <linux/init.h>                 /* For __init/__exit/... */
+#include <linux/fs.h>                   /* For file operations */
+#include <linux/platform_device.h>      /* For platform_driver framework */
+#include <linux/ioport.h>               /* For io-port access */
+#include <linux/spinlock.h>             /* For spin_lock/spin_unlock/... */
+#include <linux/uaccess.h>              /* For copy_to_user/put_user/... */
+#include <linux/io.h>                   /* For inb/outb/... */
+
+/* Module and version information */
+#define DRV_NAME        "sch311x_wdt"
+#define PFX             DRV_NAME ": "
+
+/* Runtime registers */
+#define RESGEN                  0x1d
+#define GP60                    0x47
+#define WDT_TIME_OUT            0x65
+#define WDT_VAL                 0x66
+#define WDT_CFG                 0x67
+#define WDT_CTRL                0x68
+
+/* internal variables */
+static unsigned long sch311x_wdt_is_open;
+static char sch311x_wdt_expect_close;
+static struct platform_device *sch311x_wdt_pdev;
+
+static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 };
+
+static struct { /* The devices private data */
+        /* the Runtime Register base address */
+        unsigned short runtime_reg;
+        /* The card's boot status */
+        int boot_status;
+        /* the lock for io operations */
+        spinlock_t io_lock;
+} sch311x_wdt_data;
+
+/* Module load parameters */
+static unsigned short force_id;
+module_param(force_id, ushort, 0);
+MODULE_PARM_DESC(force_id, "Override the detected device ID");
+
+static unsigned short therm_trip;
+module_param(therm_trip, ushort, 0);
+MODULE_PARM_DESC(therm_trip, "Should a ThermTrip trigger the reset generator");
+
+#define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
+static int timeout = WATCHDOG_TIMEOUT;  /* in seconds */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,
+        "Watchdog timeout in seconds. 1<= timeout <=15300, default="
+                __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout,
+        "Watchdog cannot be stopped once started (default="
+                __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+/*
+ *      Super-IO functions
+ */
+
+static inline void sch311x_sio_enter(int sio_config_port)
+{
+        outb(0x55, sio_config_port);
+}
+
+static inline void sch311x_sio_exit(int sio_config_port)
+{
+        outb(0xaa, sio_config_port);
+}
+
+static inline int sch311x_sio_inb(int sio_config_port, int reg)
+{
+        outb(reg, sio_config_port);
+        return inb(sio_config_port + 1);
+}
+
+static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
+{
+        outb(reg, sio_config_port);
+        outb(val, sio_config_port + 1);
+}
+
+/*
+ *      Watchdog Operations
+ */
+
+static void sch311x_wdt_set_timeout(int t)
+{
+        unsigned char timeout_unit = 0x80;
+
+        /* When new timeout is bigger then 255 seconds, we will use minutes */
+        if (t > 255) {
+                timeout_unit = 0;
+                t /= 60;
+        }
+
+        /* -- Watchdog Timeout --
+         * Bit 0-6 (Reserved)
+         * Bit 7   WDT Time-out Value Units Select
+         *         (0 = Minutes, 1 = Seconds)
+         */
+        outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT);
+
+        /* -- Watchdog Timer Time-out Value --
+         * Bit 0-7 Binary coded units (0=Disabled, 1..255)
+         */
+        outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL);
+}
+
+static void sch311x_wdt_start(void)
+{
+        spin_lock(&sch311x_wdt_data.io_lock);
+
+        /* set watchdog's timeout */
+        sch311x_wdt_set_timeout(timeout);
+        /* enable the watchdog */
+        /* -- General Purpose I/O Bit 6.0 --
+         * Bit 0,   In/Out: 0 = Output, 1 = Input
+         * Bit 1,   Polarity: 0 = No Invert, 1 = Invert
+         * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT,
+         *                           10 = Either Edge Triggered Intr.4
+         * Bit 4-6  (Reserved)
+         * Bit 7,   Output Type: 0 = Push Pull Bit, 1 = Open Drain
+         */
+        outb(0x0e, sch311x_wdt_data.runtime_reg + GP60);
+
+        spin_unlock(&sch311x_wdt_data.io_lock);
+
+}
+
+static void sch311x_wdt_stop(void)
+{
+        spin_lock(&sch311x_wdt_data.io_lock);
+
+        /* stop the watchdog */
+        outb(0x01, sch311x_wdt_data.runtime_reg + GP60);
+        /* disable timeout by setting it to 0 */
+        sch311x_wdt_set_timeout(0);
+
+        spin_unlock(&sch311x_wdt_data.io_lock);
+}
+
+static void sch311x_wdt_keepalive(void)
+{
+        spin_lock(&sch311x_wdt_data.io_lock);
+        sch311x_wdt_set_timeout(timeout);
+        spin_unlock(&sch311x_wdt_data.io_lock);
+}
+
+static int sch311x_wdt_set_heartbeat(int t)
+{
+        if (t < 1 || t > (255*60))
+                return -EINVAL;
+
+        /* When new timeout is bigger then 255 seconds,
+         * we will round up to minutes (with a max of 255) */
+        if (t > 255)
+                t = (((t - 1) / 60) + 1) * 60;
+
+        timeout = t;
+        return 0;
+}
+
+static void sch311x_wdt_get_status(int *status)
+{
+        unsigned char new_status;
+
+        *status = 0;
+
+        spin_lock(&sch311x_wdt_data.io_lock);
+
+        /* -- Watchdog timer control --
+         * Bit 0   Status Bit: 0 = Timer counting, 1 = Timeout occured
+         * Bit 1   Reserved
+         * Bit 2   Force Timeout: 1 = Forces WD timeout event (self-cleaning)
+         * Bit 3   P20 Force Timeout enabled:
+         *          0 = P20 activity does not generate the WD timeout event
+         *          1 = P20 Allows rising edge of P20, from the keyboard
+         *              controller, to force the WD timeout event.
+         * Bit 4-7 Reserved
+         */
+        new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL);
+        if (new_status & 0x01)
+                *status |= WDIOF_CARDRESET;
+
+        spin_unlock(&sch311x_wdt_data.io_lock);
+}
+
+/*
+ *      /dev/watchdog handling
+ */
+
+static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf,
+                                                size_t count, loff_t *ppos)
+{
+        if (count) {
+                if (!nowayout) {
+                        size_t i;
+
+                        sch311x_wdt_expect_close = 0;
+
+                        for (i = 0; i != count; i++) {
+                                char c;
+                                if (get_user(c, buf + i))
+                                        return -EFAULT;
+                                if (c == 'V')
+                                        sch311x_wdt_expect_close = 42;
+                        }
+                }
+                sch311x_wdt_keepalive();
+        }
+        return count;
+}
+
+static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,
+                                                        unsigned long arg)
+{
+        int status;
+        int new_timeout;
+        void __user *argp = (void __user *)arg;
+        int __user *p = argp;
+        static struct watchdog_info ident = {
+                .options                = WDIOF_KEEPALIVEPING |
+                                          WDIOF_SETTIMEOUT |
+                                          WDIOF_MAGICCLOSE,
+                .firmware_version       = 1,
+                .identity               = DRV_NAME,
+        };
+
+        switch (cmd) {
+        case WDIOC_GETSUPPORT:
+                if (copy_to_user(argp, &ident, sizeof(ident)))
+                        return -EFAULT;
+                break;
+
+        case WDIOC_GETSTATUS:
+        {
+                sch311x_wdt_get_status(&status);
+                return put_user(status, p);
+        }
+        case WDIOC_GETBOOTSTATUS:
+                return put_user(sch311x_wdt_data.boot_status, p);
+
+        case WDIOC_SETOPTIONS:
+        {
+                int options, retval = -EINVAL;
+
+                if (get_user(options, p))
+                        return -EFAULT;
+                if (options & WDIOS_DISABLECARD) {
+                        sch311x_wdt_stop();
+                        retval = 0;
+                }
+                if (options & WDIOS_ENABLECARD) {
+                        sch311x_wdt_start();
+                        retval = 0;
+                }
+                return retval;
+        }
+        case WDIOC_KEEPALIVE:
+                sch311x_wdt_keepalive();
+                break;
+
+        case WDIOC_SETTIMEOUT:
+                if (get_user(new_timeout, p))
+                        return -EFAULT;
+                if (sch311x_wdt_set_heartbeat(new_timeout))
+                        return -EINVAL;
+                sch311x_wdt_keepalive();
+                /* Fall */
+        case WDIOC_GETTIMEOUT:
+                return put_user(timeout, p);
+        default:
+                return -ENOTTY;
+        }
+        return 0;
+}
+
+static int sch311x_wdt_open(struct inode *inode, struct file *file)
+{
+        if (test_and_set_bit(0, &sch311x_wdt_is_open))
+                return -EBUSY;
+        /*
+         *      Activate
+         */
+        sch311x_wdt_start();
+        return nonseekable_open(inode, file);
+}
+
+static int sch311x_wdt_close(struct inode *inode, struct file *file)
+{
+        if (sch311x_wdt_expect_close == 42) {
+                sch311x_wdt_stop();
+        } else {
+                printk(KERN_CRIT PFX
+                                "Unexpected close, not stopping watchdog!\n");
+                sch311x_wdt_keepalive();
+        }
+        clear_bit(0, &sch311x_wdt_is_open);
+        sch311x_wdt_expect_close = 0;
+        return 0;
+}
+
+/*
+ *      Kernel Interfaces
+ */
+
+static const struct file_operations sch311x_wdt_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .write          = sch311x_wdt_write,
+        .unlocked_ioctl = sch311x_wdt_ioctl,
+        .open           = sch311x_wdt_open,
+        .release        = sch311x_wdt_close,
+};
+
+static struct miscdevice sch311x_wdt_miscdev = {
+        .minor  = WATCHDOG_MINOR,
+        .name   = "watchdog",
+        .fops   = &sch311x_wdt_fops,
+};
+
+/*
+ *      Init & exit routines
+ */
+
+static int __devinit sch311x_wdt_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        unsigned char val;
+        int err;
+
+        spin_lock_init(&sch311x_wdt_data.io_lock);
+
+        if (!request_region(sch311x_wdt_data.runtime_reg + RESGEN, 1,
+                                                                DRV_NAME)) {
+                dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
+                        sch311x_wdt_data.runtime_reg + RESGEN,
+                        sch311x_wdt_data.runtime_reg + RESGEN);
+                err = -EBUSY;
+                goto exit;
+        }
+
+        if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) {
+                dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
+                        sch311x_wdt_data.runtime_reg + GP60,
+                        sch311x_wdt_data.runtime_reg + GP60);
+                err = -EBUSY;
+                goto exit_release_region;
+        }
+
+        if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4,
+                                                                DRV_NAME)) {
+                dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
+                        sch311x_wdt_data.runtime_reg + WDT_TIME_OUT,
+                        sch311x_wdt_data.runtime_reg + WDT_CTRL);
+                err = -EBUSY;
+                goto exit_release_region2;
+        }
+
+        /* Make sure that the watchdog is not running */
+        sch311x_wdt_stop();
+
+        /* Disable keyboard and mouse interaction and interrupt */
+        /* -- Watchdog timer configuration --
+         * Bit 0   Reserved
+         * Bit 1   Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
+         * Bit 2   Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
+         * Bit 3   Reserved
+         * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
+         *            0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
+         */
+        outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG);
+
+        /* Check that the heartbeat value is within it's range ;
+         * if not reset to the default */
+        if (sch311x_wdt_set_heartbeat(timeout)) {
+                sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT);
+                dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n",
+                        timeout);
+        }
+
+        /* Get status at boot */
+        sch311x_wdt_get_status(&sch311x_wdt_data.boot_status);
+
+        /* enable watchdog */
+        /* -- Reset Generator --
+         * Bit 0   Enable Watchdog Timer Generation: 0* = Enabled, 1 = Disabled
+         * Bit 1   Thermtrip Source Select: O* = No Source, 1 = Source
+         * Bit 2   WDT2_CTL: WDT input bit
+         * Bit 3-7 Reserved
+         */
+        outb(0, sch311x_wdt_data.runtime_reg + RESGEN);
+        val = therm_trip ? 0x06 : 0x04;
+        outb(val, sch311x_wdt_data.runtime_reg + RESGEN);
+
+        err = misc_register(&sch311x_wdt_miscdev);
+        if (err != 0) {
+                dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",
+                                                        WATCHDOG_MINOR, err);
+                goto exit_release_region3;
+        }
+
+        sch311x_wdt_miscdev.parent = dev;
+
+        dev_info(dev,
+                "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n",
+                timeout, nowayout);
+
+        return 0;
+
+exit_release_region3:
+        release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
+exit_release_region2:
+        release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
+exit_release_region:
+        release_region(sch311x_wdt_data.runtime_reg + RESGEN, 1);
+        sch311x_wdt_data.runtime_reg = 0;
+exit:
+        return err;
+}
+
+static int __devexit sch311x_wdt_remove(struct platform_device *pdev)
+{
+        /* Stop the timer before we leave */
+        if (!nowayout)
+                sch311x_wdt_stop();
+
+        /* Deregister */
+        misc_deregister(&sch311x_wdt_miscdev);
+        release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
+        release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
+        release_region(sch311x_wdt_data.runtime_reg + RESGEN, 1);
+        sch311x_wdt_data.runtime_reg = 0;
+        return 0;
+}
+
+static void sch311x_wdt_shutdown(struct platform_device *dev)
+{
+        /* Turn the WDT off if we have a soft shutdown */
+        sch311x_wdt_stop();
+}
+
+#define sch311x_wdt_suspend NULL
+#define sch311x_wdt_resume  NULL
+
+static struct platform_driver sch311x_wdt_driver = {
+        .probe          = sch311x_wdt_probe,
+        .remove         = __devexit_p(sch311x_wdt_remove),
+        .shutdown       = sch311x_wdt_shutdown,
+        .suspend        = sch311x_wdt_suspend,
+        .resume         = sch311x_wdt_resume,
+        .driver         = {
+                .owner = THIS_MODULE,
+                .name = DRV_NAME,
+        },
+};
+
+static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
+{
+        int err = 0, reg;
+        unsigned short base_addr;
+        unsigned char dev_id;
+
+        sch311x_sio_enter(sio_config_port);
+
+        /* Check device ID. We currently know about:
+         * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */
+        reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20);
+        if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {
+                err = -ENODEV;
+                goto exit;
+        }
+        dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;
+
+        /* Select logical device A (runtime registers) */
+        sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
+
+        /* Check if Logical Device Register is currently active */
+        if (sch311x_sio_inb(sio_config_port, 0x30) && 0x01 == 0)
+                printk(KERN_INFO PFX "Seems that LDN 0x0a is not active...\n");
+
+        /* Get the base address of the runtime registers */
+        base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
+                           sch311x_sio_inb(sio_config_port, 0x61);
+        if (!base_addr) {
+                printk(KERN_ERR PFX "Base address not set.\n");
+                err = -ENODEV;
+                goto exit;
+        }
+        *addr = base_addr;
+
+        printk(KERN_INFO PFX "Found an SMSC SCH311%d chip at 0x%04x\n",
+                dev_id, base_addr);
+
+exit:
+        sch311x_sio_exit(sio_config_port);
+        return err;
+}
+
+static int __init sch311x_wdt_init(void)
+{
+        int err, i, found = 0;
+        unsigned short addr = 0;
+
+        for (i = 0; !found && sch311x_ioports[i]; i++)
+                if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
+                        found++;
+
+        if (!found)
+                return -ENODEV;
+
+        sch311x_wdt_data.runtime_reg = addr;
+
+        err = platform_driver_register(&sch311x_wdt_driver);
+        if (err)
+                return err;
+
+        sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr,
+                                                                NULL, 0);
+
+        if (IS_ERR(sch311x_wdt_pdev)) {
+                err = PTR_ERR(sch311x_wdt_pdev);
+                goto unreg_platform_driver;
+        }
+
+        return 0;
+
+unreg_platform_driver:
+        platform_driver_unregister(&sch311x_wdt_driver);
+        return err;
+}
+
+static void __exit sch311x_wdt_exit(void)
+{
+        platform_device_unregister(sch311x_wdt_pdev);
+        platform_driver_unregister(&sch311x_wdt_driver);
+}
+
+module_init(sch311x_wdt_init);
+module_exit(sch311x_wdt_exit);
+
+MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
+MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+