dm: timer: Support 64-bit counter

There are timers with a 64-bit counter value but current timer
uclass driver assumes a 32-bit one. Modify timer_get_count()
to ask timer driver to always return a 64-bit counter value,
and provide an inline helper function timer_conv_64() to handle
the 32-bit/64-bit conversion automatically.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 12 insertions, 3 deletions

diff --git a/drivers/timer/timer-uclass.c b/drivers/timer/timer-uclass.c
index 02185912d58..aca421bdea3 100644
--- a/drivers/timer/timer-uclass.c
+++ b/drivers/timer/timer-uclass.c
@@ -13,14 +13,14 @@ DECLARE_GLOBAL_DATA_PTR;
 
 /*
  * Implement a timer uclass to work with lib/time.c. The timer is usually
- * a 32 bits free-running up counter. The get_rate() method is used to get
+ * a 32/64 bits free-running up counter. The get_rate() method is used to get
  * the input clock frequency of the timer. The get_count() method is used
- * to get the current 32 bits count value. If the hardware is counting down,
+ * to get the current 64 bits count value. If the hardware is counting down,
  * the value should be inversed inside the method. There may be no real
  * tick, and no timer interrupt.
  */
 
-int timer_get_count(struct udevice *dev, unsigned long *count)
+int timer_get_count(struct udevice *dev, u64 *count)
 {
 	const struct timer_ops *ops = device_get_ops(dev);
 
@@ -47,6 +47,15 @@ static int timer_pre_probe(struct udevice *dev)
 	return 0;
 }
 
+u64 timer_conv_64(u32 count)
+{
+	/* increment tbh if tbl has rolled over */
+	if (count < gd->timebase_l)
+		gd->timebase_h++;
+	gd->timebase_l = count;
+	return ((u64)gd->timebase_h << 32) | gd->timebase_l;
+}
+
 UCLASS_DRIVER(timer) = {
 	.id		= UCLASS_TIMER,
 	.name		= "timer",