timer: Support clocks via phandle

Earlier timer driver needed a clock-frequency property in compatible
device-tree nodes. Another way is to reference a clock via a phandle.

So now timer_pre_probe tries to get clock by reference through device
tree. In case it is impossible to get clock device through the
reference, clock-frequency property of the timer node is read to provide
backward compatibility.

Signed-off-by: Vlad Zakharov <vzakhar@synopsys.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/timer/timer-uclass.c b/drivers/timer/timer-uclass.c
index f8ddf93cf8157fcf2a2de60fcab046914829d66e..5c63e6b41014ea92a43535a617d988492796420f 100644 (file)
--- a/drivers/timer/timer-uclass.c
+++ b/drivers/timer/timer-uclass.c
@@ -8,6 +8,7 @@
 #include <dm.h>
 #include <dm/lists.h>
 #include <dm/device-internal.h>
+#include <clk.h>
 #include <errno.h>
 #include <timer.h>
 
@@ -42,9 +43,19 @@ unsigned long notrace timer_get_rate(struct udevice *dev)
 static int timer_pre_probe(struct udevice *dev)
 {
        struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
-
-       uc_priv->clock_rate = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
-                                            "clock-frequency", 0);
+       struct clk timer_clk;
+       int err;
+       ulong ret;
+
+       err = clk_get_by_index(dev, 0, &timer_clk);
+       if (!err) {
+               ret = clk_get_rate(&timer_clk);
+               if (IS_ERR_VALUE(ret))
+                       return ret;
+               uc_priv->clock_rate = ret;
+       } else
+               uc_priv->clock_rate = fdtdec_get_int(gd->fdt_blob,
+                               dev->of_offset, "clock-frequency", 0);
 
        return 0;
 }