1 files changed, 64 insertions, 94 deletions

diff --git a/drivers/watchdog/rc32434_wdt.c b/drivers/watchdog/rc32434_wdt.c
index 57027f4653ce..f1f98cd757c6 100644
--- a/drivers/watchdog/rc32434_wdt.c
+++ b/drivers/watchdog/rc32434_wdt.c
@@ -34,104 +34,89 @@
 #include <asm/time.h>
 #include <asm/mach-rc32434/integ.h>
 
-#define MAX_TIMEOUT                     20
-#define RC32434_WDT_INTERVAL            (15 * HZ)
-
-#define VERSION "0.2"
+#define VERSION "0.3"
 
 static struct {
-        struct completion stop;
-        int running;
-        struct timer_list timer;
-        int queue;
-        int default_ticks;
         unsigned long inuse;
 } rc32434_wdt_device;
 
 static struct integ __iomem *wdt_reg;
-static int ticks = 100 * HZ;
 
 static int expect_close;
-static int timeout;
+
+/* Board internal clock speed in Hz,
+ * the watchdog timer ticks at. */
+extern unsigned int idt_cpu_freq;
+
+/* translate wtcompare value to seconds and vice versa */
+#define WTCOMP2SEC(x)   (x / idt_cpu_freq)
+#define SEC2WTCOMP(x)   (x * idt_cpu_freq)
+
+/* Use a default timeout of 20s. This should be
+ * safe for CPU clock speeds up to 400MHz, as
+ * ((2 ^ 32) - 1) / (400MHz / 2) = 21s.  */
+#define WATCHDOG_TIMEOUT 20
+
+static int timeout = 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) ")");
 
+/* apply or and nand masks to data read from addr and write back */
+#define SET_BITS(addr, or, nand) \
+        writel((readl(&addr) | or) & ~nand, &addr)
 
 static void rc32434_wdt_start(void)
 {
-        u32 val;
-
-        if (!rc32434_wdt_device.inuse) {
-                writel(0, &wdt_reg->wtcount);
+        u32 or, nand;
 
-                val = RC32434_ERR_WRE;
-                writel(readl(&wdt_reg->errcs) | val, &wdt_reg->errcs);
+        /* zero the counter before enabling */
+        writel(0, &wdt_reg->wtcount);
 
-                val = RC32434_WTC_EN;
-                writel(readl(&wdt_reg->wtc) | val, &wdt_reg->wtc);
-        }
-        rc32434_wdt_device.running++;
-}
+        /* don't generate a non-maskable interrupt,
+         * do a warm reset instead */
+        nand = 1 << RC32434_ERR_WNE;
+        or = 1 << RC32434_ERR_WRE;
 
-static void rc32434_wdt_stop(void)
-{
-        u32 val;
+        /* reset the ERRCS timeout bit in case it's set */
+        nand |= 1 << RC32434_ERR_WTO;
 
-        if (rc32434_wdt_device.running) {
+        SET_BITS(wdt_reg->errcs, or, nand);
 
-                val = ~RC32434_WTC_EN;
-                writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);
+        /* reset WTC timeout bit and enable WDT */
+        nand = 1 << RC32434_WTC_TO;
+        or = 1 << RC32434_WTC_EN;
 
-                val = ~RC32434_ERR_WRE;
-                writel(readl(&wdt_reg->errcs) & val, &wdt_reg->errcs);
+        SET_BITS(wdt_reg->wtc, or, nand);
+}
 
-                rc32434_wdt_device.running = 0;
-        }
+static void rc32434_wdt_stop(void)
+{
+        /* Disable WDT */
+        SET_BITS(wdt_reg->wtc, 0, 1 << RC32434_WTC_EN);
 }
 
-static void rc32434_wdt_set(int new_timeout)
+static int rc32434_wdt_set(int new_timeout)
 {
-        u32 cmp = new_timeout * HZ;
-        u32 state, val;
+        int max_to = WTCOMP2SEC((u32)-1);
 
+        if (new_timeout < 0 || new_timeout > max_to) {
+                printk(KERN_ERR KBUILD_MODNAME
+                        ": timeout value must be between 0 and %d",
+                        max_to);
+                return -EINVAL;
+        }
         timeout = new_timeout;
-        /*
-         * store and disable WTC
-         */
-        state = (u32)(readl(&wdt_reg->wtc) & RC32434_WTC_EN);
-        val = ~RC32434_WTC_EN;
-        writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);
-
-        writel(0, &wdt_reg->wtcount);
-        writel(cmp, &wdt_reg->wtcompare);
-
-        /*
-         * restore WTC
-         */
-
-        writel(readl(&wdt_reg->wtc) | state, &wdt_reg);
-}
+        writel(SEC2WTCOMP(timeout), &wdt_reg->wtcompare);
 
-static void rc32434_wdt_reset(void)
-{
-        ticks = rc32434_wdt_device.default_ticks;
+        return 0;
 }
 
-static void rc32434_wdt_update(unsigned long unused)
+static void rc32434_wdt_ping(void)
 {
-        if (rc32434_wdt_device.running)
-                ticks--;
-
         writel(0, &wdt_reg->wtcount);
-
-        if (rc32434_wdt_device.queue && ticks)
-                mod_timer(&rc32434_wdt_device.timer,
-                        jiffies + RC32434_WDT_INTERVAL);
-        else
-                complete(&rc32434_wdt_device.stop);
 }
 
 static int rc32434_wdt_open(struct inode *inode, struct file *file)
@@ -142,19 +127,23 @@ static int rc32434_wdt_open(struct inode *inode, struct file *file)
         if (nowayout)
                 __module_get(THIS_MODULE);
 
+        rc32434_wdt_start();
+        rc32434_wdt_ping();
+
         return nonseekable_open(inode, file);
 }
 
 static int rc32434_wdt_release(struct inode *inode, struct file *file)
 {
-        if (expect_close && nowayout == 0) {
+        if (expect_close == 42) {
                 rc32434_wdt_stop();
                 printk(KERN_INFO KBUILD_MODNAME ": disabling watchdog timer\n");
                 module_put(THIS_MODULE);
-        } else
+        } else {
                 printk(KERN_CRIT KBUILD_MODNAME
                         ": device closed unexpectedly. WDT will not stop !\n");
-
+                rc32434_wdt_ping();
+        }
         clear_bit(0, &rc32434_wdt_device.inuse);
         return 0;
 }
@@ -174,10 +163,10 @@ static ssize_t rc32434_wdt_write(struct file *file, const char *data,
                                 if (get_user(c, data + i))
                                         return -EFAULT;
                                 if (c == 'V')
-                                        expect_close = 1;
+                                        expect_close = 42;
                         }
                 }
-                rc32434_wdt_update(0);
+                rc32434_wdt_ping();
                 return len;
         }
         return 0;
@@ -197,11 +186,11 @@ static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
         };
         switch (cmd) {
         case WDIOC_KEEPALIVE:
-                rc32434_wdt_reset();
+                rc32434_wdt_ping();
                 break;
         case WDIOC_GETSTATUS:
         case WDIOC_GETBOOTSTATUS:
-                value = readl(&wdt_reg->wtcount);
+                value = 0;
                 if (copy_to_user(argp, &value, sizeof(int)))
                         return -EFAULT;
                 break;
@@ -218,6 +207,7 @@ static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
                         break;
                 case WDIOS_DISABLECARD:
                         rc32434_wdt_stop();
+                        break;
                 default:
                         return -EINVAL;
                 }
@@ -225,11 +215,9 @@ static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
         case WDIOC_SETTIMEOUT:
                 if (copy_from_user(&new_timeout, argp, sizeof(int)))
                         return -EFAULT;
-                if (new_timeout < 1)
+                if (rc32434_wdt_set(new_timeout))
                         return -EINVAL;
-                if (new_timeout > MAX_TIMEOUT)
-                        return -EINVAL;
-                rc32434_wdt_set(new_timeout);
+                /* Fall through */
         case WDIOC_GETTIMEOUT:
                 return copy_to_user(argp, &timeout, sizeof(int));
         default:
@@ -262,7 +250,7 @@ static int rc32434_wdt_probe(struct platform_device *pdev)
         int ret;
         struct resource *r;
 
-        r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb500_wdt_res");
+        r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb532_wdt_res");
         if (!r) {
                 printk(KERN_ERR KBUILD_MODNAME
                         "failed to retrieve resources\n");
@@ -277,24 +265,12 @@ static int rc32434_wdt_probe(struct platform_device *pdev)
         }
 
         ret = misc_register(&rc32434_wdt_miscdev);
-
         if (ret < 0) {
                 printk(KERN_ERR KBUILD_MODNAME
                         "failed to register watchdog device\n");
                 goto unmap;
         }
 
-        init_completion(&rc32434_wdt_device.stop);
-        rc32434_wdt_device.queue = 0;
-
-        clear_bit(0, &rc32434_wdt_device.inuse);
-
-        setup_timer(&rc32434_wdt_device.timer, rc32434_wdt_update, 0L);
-
-        rc32434_wdt_device.default_ticks = ticks;
-
-        rc32434_wdt_start();
-
         printk(banner, timeout);
 
         return 0;
@@ -306,14 +282,8 @@ unmap:
 
 static int rc32434_wdt_remove(struct platform_device *pdev)
 {
-        if (rc32434_wdt_device.queue) {
-                rc32434_wdt_device.queue = 0;
-                wait_for_completion(&rc32434_wdt_device.stop);
-        }
         misc_deregister(&rc32434_wdt_miscdev);
-
         iounmap(wdt_reg);
-
         return 0;
 }