Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-2.6-microblaze.git] / drivers / watchdog / sp805_wdt.c

diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c
index 9849db0..072986d 100644 (file)
--- a/drivers/watchdog/sp805_wdt.c
+++ b/drivers/watchdog/sp805_wdt.c
@@ -11,6 +11,7 @@
  * warranty of any kind, whether express or implied.
  */
 
+#include <linux/acpi.h>
 #include <linux/device.h>
 #include <linux/resource.h>
 #include <linux/amba/bus.h>
@@ -22,6 +23,7 @@
 #include <linux/math64.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/of.h>
 #include <linux/pm.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
@@ -42,6 +44,7 @@
        /* control register masks */
        #define INT_ENABLE      (1 << 0)
        #define RESET_ENABLE    (1 << 1)
+       #define ENABLE_MASK     (INT_ENABLE | RESET_ENABLE)
 #define WDTINTCLR              0x00C
 #define WDTRIS                 0x010
 #define WDTMIS                 0x014
@@ -65,6 +68,7 @@ struct sp805_wdt {
        spinlock_t                      lock;
        void __iomem                    *base;
        struct clk                      *clk;
+       u64                             rate;
        struct amba_device              *adev;
        unsigned int                    load_val;
 };
@@ -74,13 +78,22 @@ module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout,
                "Set to 1 to keep watchdog running after device release");
 
+/* returns true if wdt is running; otherwise returns false */
+static bool wdt_is_running(struct watchdog_device *wdd)
+{
+       struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
+       u32 wdtcontrol = readl_relaxed(wdt->base + WDTCONTROL);
+
+       return (wdtcontrol & ENABLE_MASK) == ENABLE_MASK;
+}
+
 /* This routine finds load value that will reset system in required timout */
 static int wdt_setload(struct watchdog_device *wdd, unsigned int timeout)
 {
        struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
        u64 load, rate;
 
-       rate = clk_get_rate(wdt->clk);
+       rate = wdt->rate;
 
        /*
         * sp805 runs counter with given value twice, after the end of first
@@ -106,9 +119,7 @@ static int wdt_setload(struct watchdog_device *wdd, unsigned int timeout)
 static unsigned int wdt_timeleft(struct watchdog_device *wdd)
 {
        struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
-       u64 load, rate;
-
-       rate = clk_get_rate(wdt->clk);
+       u64 load;
 
        spin_lock(&wdt->lock);
        load = readl_relaxed(wdt->base + WDTVALUE);
@@ -118,7 +129,7 @@ static unsigned int wdt_timeleft(struct watchdog_device *wdd)
                load += wdt->load_val + 1;
        spin_unlock(&wdt->lock);
 
-       return div_u64(load, rate);
+       return div_u64(load, wdt->rate);
 }
 
 static int
@@ -228,11 +239,25 @@ sp805_wdt_probe(struct amba_device *adev, const struct amba_id *id)
        if (IS_ERR(wdt->base))
                return PTR_ERR(wdt->base);
 
-       wdt->clk = devm_clk_get(&adev->dev, NULL);
-       if (IS_ERR(wdt->clk)) {
-               dev_warn(&adev->dev, "Clock not found\n");
-               ret = PTR_ERR(wdt->clk);
-               goto err;
+       if (adev->dev.of_node) {
+               wdt->clk = devm_clk_get(&adev->dev, NULL);
+               if (IS_ERR(wdt->clk)) {
+                       dev_err(&adev->dev, "Clock not found\n");
+                       return PTR_ERR(wdt->clk);
+               }
+               wdt->rate = clk_get_rate(wdt->clk);
+       } else if (has_acpi_companion(&adev->dev)) {
+               /*
+                * When Driver probe with ACPI device, clock devices
+                * are not available, so watchdog rate get from
+                * clock-frequency property given in _DSD object.
+                */
+               device_property_read_u64(&adev->dev, "clock-frequency",
+                                        &wdt->rate);
+               if (!wdt->rate) {
+                       dev_err(&adev->dev, "no clock-frequency property\n");
+                       return -ENODEV;
+               }
        }
 
        wdt->adev = adev;
@@ -244,7 +269,23 @@ sp805_wdt_probe(struct amba_device *adev, const struct amba_id *id)
        watchdog_set_nowayout(&wdt->wdd, nowayout);
        watchdog_set_drvdata(&wdt->wdd, wdt);
        watchdog_set_restart_priority(&wdt->wdd, 128);
-       wdt_setload(&wdt->wdd, DEFAULT_TIMEOUT);
+
+       /*
+        * If 'timeout-sec' devicetree property is specified, use that.
+        * Otherwise, use DEFAULT_TIMEOUT
+        */
+       wdt->wdd.timeout = DEFAULT_TIMEOUT;
+       watchdog_init_timeout(&wdt->wdd, 0, &adev->dev);
+       wdt_setload(&wdt->wdd, wdt->wdd.timeout);
+
+       /*
+        * If HW is already running, enable/reset the wdt and set the running
+        * bit to tell the wdt subsystem
+        */
+       if (wdt_is_running(&wdt->wdd)) {
+               wdt_enable(&wdt->wdd);
+               set_bit(WDOG_HW_RUNNING, &wdt->wdd.status);
+       }
 
        ret = watchdog_register_device(&wdt->wdd);
        if (ret) {