watchdog: ftwdt010: Make interrupt optional

The Moxart does not appear to be using the interrupt from the
watchdog timer, maybe it's not even routed, so as to support
more architectures with this driver, make the interrupt
optional.

While we are at it: actually enable the use of the interrupt
if present by setting the right bit in the control register
and define the missing control register bits.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

diff --git a/drivers/watchdog/ftwdt010_wdt.c b/drivers/watchdog/ftwdt010_wdt.c
index 637ffd812f0b98d96511b162afca84c96a959c4b..a9c2912ee28029192d1be1e8f525dc6adb250b1a 100644 (file)
--- a/drivers/watchdog/ftwdt010_wdt.c
+++ b/drivers/watchdog/ftwdt010_wdt.c
@@ -30,6 +30,8 @@
 #define WDRESTART_MAGIC                0x5AB9
 
 #define WDCR_CLOCK_5MHZ                BIT(4)
+#define WDCR_WDEXT             BIT(3)
+#define WDCR_WDINTR            BIT(2)
 #define WDCR_SYS_RST           BIT(1)
 #define WDCR_ENABLE            BIT(0)
 
@@ -39,6 +41,7 @@ struct ftwdt010_wdt {
        struct watchdog_device  wdd;
        struct device           *dev;
        void __iomem            *base;
+       bool                    has_irq;
 };
 
 static inline
@@ -50,14 +53,17 @@ struct ftwdt010_wdt *to_ftwdt010_wdt(struct watchdog_device *wdd)
 static int ftwdt010_wdt_start(struct watchdog_device *wdd)
 {
        struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd);
+       u32 enable;
 
        writel(wdd->timeout * WDT_CLOCK, gwdt->base + FTWDT010_WDLOAD);
        writel(WDRESTART_MAGIC, gwdt->base + FTWDT010_WDRESTART);
        /* set clock before enabling */
-       writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST,
-                       gwdt->base + FTWDT010_WDCR);
-       writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST | WDCR_ENABLE,
-                       gwdt->base + FTWDT010_WDCR);
+       enable = WDCR_CLOCK_5MHZ | WDCR_SYS_RST;
+       writel(enable, gwdt->base + FTWDT010_WDCR);
+       if (gwdt->has_irq)
+               enable |= WDCR_WDINTR;
+       enable |= WDCR_ENABLE;
+       writel(enable, gwdt->base + FTWDT010_WDCR);
 
        return 0;
 }
@@ -133,10 +139,6 @@ static int ftwdt010_wdt_probe(struct platform_device *pdev)
        if (IS_ERR(gwdt->base))
                return PTR_ERR(gwdt->base);
 
-       irq = platform_get_irq(pdev, 0);
-       if (!irq)
-               return -EINVAL;
-
        gwdt->dev = dev;
        gwdt->wdd.info = &ftwdt010_wdt_info;
        gwdt->wdd.ops = &ftwdt010_wdt_ops;
@@ -158,10 +160,14 @@ static int ftwdt010_wdt_probe(struct platform_device *pdev)
                writel(reg, gwdt->base + FTWDT010_WDCR);
        }
 
-       ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
-                              "watchdog bark", gwdt);
-       if (ret)
-               return ret;
+       irq = platform_get_irq(pdev, 0);
+       if (irq) {
+               ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0,
+                                      "watchdog bark", gwdt);
+               if (ret)
+                       return ret;
+               gwdt->has_irq = true;
+       }
 
        ret = devm_watchdog_register_device(dev, &gwdt->wdd);
        if (ret) {