watchdog: sp805: Add clock-frequency property

Use clock-frequency property given in _DSD object
of ACPI device to calculate Watchdog rate as binding
clock devices are not available as device tree.

Note: There is no formal review process for _DSD
properties

Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c
index b202138b7ecb230a84987da98607966206529dd8..072986d461b765df24c06a8ab09d3f6e2857c48d 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>
@@ -66,6 +68,7 @@ struct sp805_wdt {
        spinlock_t                      lock;
        void __iomem                    *base;
        struct clk                      *clk;
+       u64                             rate;
        struct amba_device              *adev;
        unsigned int                    load_val;
 };
@@ -90,7 +93,7 @@ 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
@@ -116,9 +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);
@@ -128,7 +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
@@ -238,11 +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;