[PATCH v4 1/1] driver: watchdog: get platform clock from dt file

[Rayagonda Kokatanur]

Get the watchdog platform clock from the DTS file
using clk subsystem and use the same for calculating
ticks in msec.

Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur at broadcom.com>
Signed-off-by: Bharat Kumar Reddy Gooty <bharat.gooty at broadcom.com>
---
Changes from v3:
 -Address review comments from Stefan Roese,
  Don't return error if clk_get_by_index() fails
  becasue all platform may not have clock support.

Changes from v2:
 -Address review comments from Stefan Roese,
  Use clk subsystem to get the base frequency of device instead
  of dt parameter "clk_mhz".

Changes from v1:
 -Address review comments from Stefan Roese,
  Remove default timeout reading in probe() as it is read in include/wdt.h.
  Add paranthesis on multi-line statements.

 drivers/watchdog/sp805_wdt.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c
index ca3ccbe76c..65fd2384f1 100644
--- a/drivers/watchdog/sp805_wdt.c
+++ b/drivers/watchdog/sp805_wdt.c
@@ -7,6 +7,7 @@
 
 #include <asm/io.h>
 #include <common.h>
+#include <clk.h>
 #include <dm/device.h>
 #include <dm/fdtaddr.h>
 #include <dm/read.h>
@@ -34,6 +35,7 @@ DECLARE_GLOBAL_DATA_PTR;
 
 struct sp805_wdt_priv {
 	void __iomem *reg;
+	unsigned long clk_rate;
 };
 
 static int sp805_wdt_reset(struct udevice *dev)
@@ -63,8 +65,13 @@ static int sp805_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
 	 * set 120s, the gd->bus_clk is less than 1145MHz, the load_value will
 	 * not overflow.
 	 */
-	load_value = (gd->bus_clk) /
-		(2 * 1000 * SYS_FSL_WDT_CLK_DIV) * load_time;
+	if (gd->bus_clk) {
+		load_value = (gd->bus_clk) /
+			(2 * 1000 * SYS_FSL_WDT_CLK_DIV) * load_time;
+	} else {
+		/* platform provide clk */
+		load_value = (timeout / 2) * (priv->clk_rate / 1000);
+	}
 
 	writel(UNLOCK, priv->reg + WDTLOCK);
 	writel(load_value, priv->reg + WDTLOAD);
@@ -105,11 +112,15 @@ static int sp805_wdt_probe(struct udevice *dev)
 static int sp805_wdt_ofdata_to_platdata(struct udevice *dev)
 {
 	struct sp805_wdt_priv *priv = dev_get_priv(dev);
+	struct clk clk;
 
 	priv->reg = (void __iomem *)dev_read_addr(dev);
 	if (IS_ERR(priv->reg))
 		return PTR_ERR(priv->reg);
 
+	if (!clk_get_by_index(dev, 0, &clk))
+		priv->clk_rate = clk_get_rate(&clk);
+
 	return 0;
 }
 
-- 
2.17.1