watchdog: sp5100_tco: Convert to use watchdog subsystem
authorGuenter Roeck <linux@roeck-us.net>
Sun, 24 Dec 2017 21:04:14 +0000 (13:04 -0800)
committerWim Van Sebroeck <wim@iguana.be>
Sun, 21 Jan 2018 11:56:36 +0000 (12:56 +0100)
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>
drivers/watchdog/sp5100_tco.c

index 1123fad..bb6c460 100644 (file)
 
 #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;