watchdog: sp5100_tco: Convert to use watchdog subsystem

Convert to watchdog subsystem. As part of that rework, use devm functions
where possible, and replace almost all static variables with a dynamically
allocated data structure.

Cc: Zoltán Böszörményi <zboszor@pr.hu>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 102 insertions, 256 deletions

diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c
index 1123fad38fdf..bb6c4608c1c0 100644
--- a/drivers/watchdog/sp5100_tco.c
+++ b/drivers/watchdog/sp5100_tco.c
@@ -24,37 +24,31 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/types.h>
-#include <linux/miscdevice.h>
-#include <linux/watchdog.h>
-#include <linux/init.h>
-#include <linux/fs.h>
 #include <linux/pci.h>
-#include <linux/ioport.h>
 #include <linux/platform_device.h>
-#include <linux/uaccess.h>
-#include <linux/io.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
 
 #include "sp5100_tco.h"
 
-/* Module and version information */
-#define TCO_VERSION "0.05"
-#define TCO_MODULE_NAME "SP5100 TCO timer"
-#define TCO_DRIVER_NAME   TCO_MODULE_NAME ", v" TCO_VERSION
+#define TCO_DRIVER_NAME "sp5100-tco"
 
 /* internal variables */
-static u32 tcobase_phys;
-static u32 tco_wdt_fired;
-static void __iomem *tcobase;
-static DEFINE_SPINLOCK(tco_lock);       /* Guards the hardware */
-static unsigned long timer_alive;
-static char tco_expect_close;
-static struct pci_dev *sp5100_tco_pci;
+
+struct sp5100_tco {
+        struct watchdog_device wdd;
+        void __iomem *tcobase;
+};
 
 /* the watchdog platform device */
 static struct platform_device *sp5100_tco_platform_device;
+/* the associated PCI device */
+static struct pci_dev *sp5100_tco_pci;
 
 /* module parameters */
 
@@ -79,55 +73,52 @@ static bool tco_has_sp5100_reg_layout(struct pci_dev *dev)
                dev->revision < 0x40;
 }
 
-static void tco_timer_start(void)
+static int tco_timer_start(struct watchdog_device *wdd)
 {
+        struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
         u32 val;
-        unsigned long flags;
 
-        spin_lock_irqsave(&tco_lock, flags);
-        val = readl(SP5100_WDT_CONTROL(tcobase));
+        val = readl(SP5100_WDT_CONTROL(tco->tcobase));
         val |= SP5100_WDT_START_STOP_BIT;
-        writel(val, SP5100_WDT_CONTROL(tcobase));
-        spin_unlock_irqrestore(&tco_lock, flags);
+        writel(val, SP5100_WDT_CONTROL(tco->tcobase));
+
+        return 0;
 }
 
-static void tco_timer_stop(void)
+static int tco_timer_stop(struct watchdog_device *wdd)
 {
+        struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
         u32 val;
-        unsigned long flags;
 
-        spin_lock_irqsave(&tco_lock, flags);
-        val = readl(SP5100_WDT_CONTROL(tcobase));
+        val = readl(SP5100_WDT_CONTROL(tco->tcobase));
         val &= ~SP5100_WDT_START_STOP_BIT;
-        writel(val, SP5100_WDT_CONTROL(tcobase));
-        spin_unlock_irqrestore(&tco_lock, flags);
+        writel(val, SP5100_WDT_CONTROL(tco->tcobase));
+
+        return 0;
 }
 
-static void tco_timer_keepalive(void)
+static int tco_timer_ping(struct watchdog_device *wdd)
 {
+        struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
         u32 val;
-        unsigned long flags;
 
-        spin_lock_irqsave(&tco_lock, flags);
-        val = readl(SP5100_WDT_CONTROL(tcobase));
+        val = readl(SP5100_WDT_CONTROL(tco->tcobase));
         val |= SP5100_WDT_TRIGGER_BIT;
-        writel(val, SP5100_WDT_CONTROL(tcobase));
-        spin_unlock_irqrestore(&tco_lock, flags);
+        writel(val, SP5100_WDT_CONTROL(tco->tcobase));
+
+        return 0;
 }
 
-static int tco_timer_set_heartbeat(int t)
+static int tco_timer_set_timeout(struct watchdog_device *wdd,
+                                 unsigned int t)
 {
-        unsigned long flags;
-
-        if (t < 0 || t > 0xffff)
-                return -EINVAL;
+        struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
 
         /* Write new heartbeat to watchdog */
-        spin_lock_irqsave(&tco_lock, flags);
-        writel(t, SP5100_WDT_COUNT(tcobase));
-        spin_unlock_irqrestore(&tco_lock, flags);
+        writel(t, SP5100_WDT_COUNT(tco->tcobase));
+
+        wdd->timeout = t;
 
-        heartbeat = t;
         return 0;
 }
 
@@ -182,137 +173,7 @@ static void tco_timer_enable(void)
         }
 }
 
-/*
- *      /dev/watchdog handling
- */
-
-static int sp5100_tco_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 */
-        tco_timer_start();
-        tco_timer_keepalive();
-        return nonseekable_open(inode, file);
-}
-
-static int sp5100_tco_release(struct inode *inode, struct file *file)
-{
-        /* Shut off the timer. */
-        if (tco_expect_close == 42) {
-                tco_timer_stop();
-        } else {
-                pr_crit("Unexpected close, not stopping watchdog!\n");
-                tco_timer_keepalive();
-        }
-        clear_bit(0, &timer_alive);
-        tco_expect_close = 0;
-        return 0;
-}
-
-static ssize_t sp5100_tco_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... */
-                        tco_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')
-                                        tco_expect_close = 42;
-                        }
-                }
-
-                /* someone wrote to us, we should reload the timer */
-                tco_timer_keepalive();
-        }
-        return len;
-}
-
-static long sp5100_tco_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 =             TCO_MODULE_NAME,
-        };
-
-        switch (cmd) {
-        case WDIOC_GETSUPPORT:
-                return copy_to_user(argp, &ident,
-                        sizeof(ident)) ? -EFAULT : 0;
-        case WDIOC_GETSTATUS:
-        case WDIOC_GETBOOTSTATUS:
-                return put_user(0, p);
-        case WDIOC_SETOPTIONS:
-                if (get_user(new_options, p))
-                        return -EFAULT;
-                if (new_options & WDIOS_DISABLECARD) {
-                        tco_timer_stop();
-                        retval = 0;
-                }
-                if (new_options & WDIOS_ENABLECARD) {
-                        tco_timer_start();
-                        tco_timer_keepalive();
-                        retval = 0;
-                }
-                return retval;
-        case WDIOC_KEEPALIVE:
-                tco_timer_keepalive();
-                return 0;
-        case WDIOC_SETTIMEOUT:
-                if (get_user(new_heartbeat, p))
-                        return -EFAULT;
-                if (tco_timer_set_heartbeat(new_heartbeat))
-                        return -EINVAL;
-                tco_timer_keepalive();
-                /* Fall through */
-        case WDIOC_GETTIMEOUT:
-                return put_user(heartbeat, p);
-        default:
-                return -ENOTTY;
-        }
-}
-
-/*
- * Kernel Interfaces
- */
-
-static const struct file_operations sp5100_tco_fops = {
-        .owner =                THIS_MODULE,
-        .llseek =               no_llseek,
-        .write =                sp5100_tco_write,
-        .unlocked_ioctl =       sp5100_tco_ioctl,
-        .open =                 sp5100_tco_open,
-        .release =              sp5100_tco_release,
-};
-
-static struct miscdevice sp5100_tco_miscdev = {
-        .minor =        WATCHDOG_MINOR,
-        .name =         "watchdog",
-        .fops =         &sp5100_tco_fops,
-};
-
-static u8 sp5100_tco_read_pm_reg32(u8 index)
+static u32 sp5100_tco_read_pm_reg32(u8 index)
 {
         u32 val = 0;
         int i;
@@ -323,14 +184,13 @@ static u8 sp5100_tco_read_pm_reg32(u8 index)
         return val;
 }
 
-/*
- * Init & exit routines
- */
-static int sp5100_tco_setupdevice(struct device *dev)
+static int sp5100_tco_setupdevice(struct device *dev,
+                                  struct watchdog_device *wdd)
 {
-        const char *dev_name = NULL;
-        u32 val;
+        struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
+        const char *dev_name;
         u8 base_addr;
+        u32 val;
         int ret;
 
         /*
@@ -361,8 +221,8 @@ static int sp5100_tco_setupdevice(struct device *dev)
         dev_dbg(dev, "Got 0x%04x from indirect I/O\n", val);
 
         /* Check MMIO address conflict */
-        if (!request_mem_region_exclusive(val, SP5100_WDT_MEM_MAP_SIZE,
-                                          dev_name)) {
+        if (!devm_request_mem_region(dev, val, SP5100_WDT_MEM_MAP_SIZE,
+                                     dev_name)) {
                 dev_dbg(dev, "MMIO address 0x%04x already in use\n", val);
                 /*
                  * Secondly, Find the watchdog timer MMIO address
@@ -391,8 +251,8 @@ static int sp5100_tco_setupdevice(struct device *dev)
                 /* Add the Watchdog Timer offset to base address. */
                 val += SB800_PM_WDT_MMIO_OFFSET;
                 /* Check MMIO address conflict */
-                if (!request_mem_region_exclusive(val, SP5100_WDT_MEM_MAP_SIZE,
-                                                  dev_name)) {
+                if (!devm_request_mem_region(dev, val, SP5100_WDT_MEM_MAP_SIZE,
+                                             dev_name)) {
                         dev_dbg(dev, "MMIO address 0x%04x already in use\n",
                                 val);
                         ret = -EBUSY;
@@ -401,13 +261,11 @@ static int sp5100_tco_setupdevice(struct device *dev)
                 dev_dbg(dev, "Got 0x%04x from SBResource_MMIO register\n", val);
         }
 
-        tcobase_phys = val;
-
-        tcobase = ioremap(val, SP5100_WDT_MEM_MAP_SIZE);
-        if (!tcobase) {
+        tco->tcobase = devm_ioremap(dev, val, SP5100_WDT_MEM_MAP_SIZE);
+        if (!tco->tcobase) {
                 dev_err(dev, "failed to get tcobase address\n");
                 ret = -ENOMEM;
-                goto unreg_mem_region;
+                goto unreg_region;
         }
 
         dev_info(dev, "Using 0x%04x for watchdog MMIO address\n", val);
@@ -416,107 +274,95 @@ static int sp5100_tco_setupdevice(struct device *dev)
         tco_timer_enable();
 
         /* Check that the watchdog action is set to reset the system */
-        val = readl(SP5100_WDT_CONTROL(tcobase));
+        val = readl(SP5100_WDT_CONTROL(tco->tcobase));
         /*
          * Save WatchDogFired status, because WatchDogFired flag is
          * cleared here.
          */
-        tco_wdt_fired = val & SP5100_WDT_FIRED;
+        if (val & SP5100_WDT_FIRED)
+                wdd->bootstatus = WDIOF_CARDRESET;
         val &= ~SP5100_WDT_ACTION_RESET;
-        writel(val, SP5100_WDT_CONTROL(tcobase));
+        writel(val, SP5100_WDT_CONTROL(tco->tcobase));
 
         /* Set a reasonable heartbeat before we stop the timer */
-        tco_timer_set_heartbeat(heartbeat);
+        tco_timer_set_timeout(wdd, wdd->timeout);
 
         /*
          * Stop the TCO before we change anything so we don't race with
          * a zeroed timer.
          */
-        tco_timer_stop();
+        tco_timer_stop(wdd);
 
         release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
 
         return 0;
 
-unreg_mem_region:
-        release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
 unreg_region:
         release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
         return ret;
 }
 
+static struct watchdog_info sp5100_tco_wdt_info = {
+        .identity = "SP5100 TCO timer",
+        .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops sp5100_tco_wdt_ops = {
+        .owner = THIS_MODULE,
+        .start = tco_timer_start,
+        .stop = tco_timer_stop,
+        .ping = tco_timer_ping,
+        .set_timeout = tco_timer_set_timeout,
+};
+
 static int sp5100_tco_probe(struct platform_device *pdev)
 {
         struct device *dev = &pdev->dev;
+        struct watchdog_device *wdd;
+        struct sp5100_tco *tco;
         int ret;
 
-        /*
-         * Check whether or not the hardware watchdog is there. If found, then
-         * set it up.
-         */
-        ret = sp5100_tco_setupdevice(dev);
+        tco = devm_kzalloc(dev, sizeof(*tco), GFP_KERNEL);
+        if (!tco)
+                return -ENOMEM;
+
+        wdd = &tco->wdd;
+        wdd->parent = dev;
+        wdd->info = &sp5100_tco_wdt_info;
+        wdd->ops = &sp5100_tco_wdt_ops;
+        wdd->timeout = WATCHDOG_HEARTBEAT;
+        wdd->min_timeout = 1;
+        wdd->max_timeout = 0xffff;
+
+        if (watchdog_init_timeout(wdd, heartbeat, NULL))
+                dev_info(dev, "timeout value invalid, using %d\n",
+                         wdd->timeout);
+        watchdog_set_nowayout(wdd, nowayout);
+        watchdog_stop_on_reboot(wdd);
+        watchdog_stop_on_unregister(wdd);
+        watchdog_set_drvdata(wdd, tco);
+
+        ret = sp5100_tco_setupdevice(dev, wdd);
         if (ret)
                 return ret;
 
-        /* Check to see if last reboot was due to watchdog timeout */
-        dev_info(dev, "Last reboot was %striggered by watchdog.\n",
-                 tco_wdt_fired ? "" : "not ");
-
-        /*
-         * Check that the heartbeat value is within it's range.
-         * If not, reset to the default.
-         */
-        if (tco_timer_set_heartbeat(heartbeat)) {
-                heartbeat = WATCHDOG_HEARTBEAT;
-                tco_timer_set_heartbeat(heartbeat);
-        }
-
-        ret = misc_register(&sp5100_tco_miscdev);
-        if (ret != 0) {
-                dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",
-                        WATCHDOG_MINOR, ret);
-                goto exit;
+        ret = devm_watchdog_register_device(dev, wdd);
+        if (ret) {
+                dev_err(dev, "cannot register watchdog device (err=%d)\n", ret);
+                return ret;
         }
 
-        clear_bit(0, &timer_alive);
-
         /* Show module parameters */
-        dev_info(dev, "initialized (0x%p). heartbeat=%d sec (nowayout=%d)\n",
-                 tcobase, heartbeat, nowayout);
+        dev_info(dev, "initialized. heartbeat=%d sec (nowayout=%d)\n",
+                 wdd->timeout, nowayout);
 
         return 0;
-
-exit:
-        iounmap(tcobase);
-        release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
-        return ret;
-}
-
-static int sp5100_tco_remove(struct platform_device *pdev)
-{
-        /* Stop the timer before we leave */
-        if (!nowayout)
-                tco_timer_stop();
-
-        /* Deregister */
-        misc_deregister(&sp5100_tco_miscdev);
-        iounmap(tcobase);
-        release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
-
-        return 0;
-}
-
-static void sp5100_tco_shutdown(struct platform_device *pdev)
-{
-        tco_timer_stop();
 }
 
 static struct platform_driver sp5100_tco_driver = {
         .probe          = sp5100_tco_probe,
-        .remove         = sp5100_tco_remove,
-        .shutdown       = sp5100_tco_shutdown,
         .driver         = {
-                .name   = TCO_MODULE_NAME,
+                .name   = TCO_DRIVER_NAME,
         },
 };
 
@@ -555,14 +401,14 @@ static int __init sp5100_tco_init(void)
         if (!sp5100_tco_pci)
                 return -ENODEV;
 
-        pr_info("SP5100/SB800 TCO WatchDog Timer Driver v%s\n", TCO_VERSION);
+        pr_info("SP5100/SB800 TCO WatchDog Timer Driver\n");
 
         err = platform_driver_register(&sp5100_tco_driver);
         if (err)
                 return err;
 
-        sp5100_tco_platform_device = platform_device_register_simple(
-                                        TCO_MODULE_NAME, -1, NULL, 0);
+        sp5100_tco_platform_device =
+                platform_device_register_simple(TCO_DRIVER_NAME, -1, NULL, 0);
         if (IS_ERR(sp5100_tco_platform_device)) {
                 err = PTR_ERR(sp5100_tco_platform_device);
                 goto unreg_platform_driver;