[U-Boot] [PATCH 04/10] dm: timer: Support 64-bit counter

[Bin Meng]

There are timers with a 64-bit counter value but current timer
uclass driver assumes a 32-bit one. Introduce a device tree
property "counter-64bit", and modify timer_get_count() in the
timer uclass driver to handle the 32-bit/64-bit conversion
automatically.

Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
---

 drivers/timer/altera_timer.c |  2 +-
 drivers/timer/timer-uclass.c | 28 ++++++++++++++++++++++++----
 include/timer.h              |  6 ++++--
 lib/time.c                   |  9 ++++++---
 4 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/drivers/timer/altera_timer.c b/drivers/timer/altera_timer.c
index e4d0301..b363b19 100644
--- a/drivers/timer/altera_timer.c
+++ b/drivers/timer/altera_timer.c
@@ -34,7 +34,7 @@ struct altera_timer_platdata {
 #define ALTERA_TIMER_START	(1 << 2)	/* Start timer */
 #define ALTERA_TIMER_STOP	(1 << 3)	/* Stop timer */
 
-static int altera_timer_get_count(struct udevice *dev, unsigned long *count)
+static int altera_timer_get_count(struct udevice *dev, u64 *count)
 {
 	struct altera_timer_platdata *plat = dev->platdata;
 	struct altera_timer_regs *const regs = plat->regs;
diff --git a/drivers/timer/timer-uclass.c b/drivers/timer/timer-uclass.c
index 0218591..8451b40 100644
--- a/drivers/timer/timer-uclass.c
+++ b/drivers/timer/timer-uclass.c
@@ -13,21 +13,39 @@ 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 32/64 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);
+	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	u32 now;
+	int ret;
 
 	if (!ops->get_count)
 		return -ENOSYS;
 
-	return ops->get_count(dev, count);
+	if (uc_priv->counter_64) {
+		return ops->get_count(dev, count);
+	} else {
+		ret = ops->get_count(dev, count);
+		if (ret)
+			return ret;
+
+		now = *count;
+		/* increment tbh if tbl has rolled over */
+		if (now < gd->timebase_l)
+			gd->timebase_h++;
+		gd->timebase_l = now;
+		*count = ((u64)gd->timebase_h << 32) | gd->timebase_l;
+
+		return 0;
+	}
 }
 
 unsigned long timer_get_rate(struct udevice *dev)
@@ -43,6 +61,8 @@ static int timer_pre_probe(struct udevice *dev)
 
 	uc_priv->clock_rate = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
 					     "clock-frequency", 0);
+	uc_priv->counter_64 = fdtdec_get_bool(gd->fdt_blob, dev->of_offset,
+					      "counter-64bit");
 
 	return 0;
 }
diff --git a/include/timer.h b/include/timer.h
index ed5c685..4e061ed 100644
--- a/include/timer.h
+++ b/include/timer.h
@@ -14,7 +14,7 @@
  * @count: pointer that returns the current timer count
  * @return: 0 if OK, -ve on error
  */
-int timer_get_count(struct udevice *dev, unsigned long *count);
+int timer_get_count(struct udevice *dev, u64 *count);
 
 /*
  * Get the timer input clock frequency
@@ -38,16 +38,18 @@ struct timer_ops {
 	 * @count: pointer that returns the current timer count
 	 * @return: 0 if OK, -ve on error
 	 */
-	int (*get_count)(struct udevice *dev, unsigned long *count);
+	int (*get_count)(struct udevice *dev, u64 *count);
 };
 
 /*
  * struct timer_dev_priv - information about a device used by the uclass
  *
  * @clock_rate: the timer input clock frequency
+ * @counter_64: the timer counter is a 64-bit value or not
  */
 struct timer_dev_priv {
 	unsigned long clock_rate;
+	bool counter_64;
 };
 
 #endif	/* _TIMER_H_ */
diff --git a/lib/time.c b/lib/time.c
index b001745..f37a662 100644
--- a/lib/time.c
+++ b/lib/time.c
@@ -69,9 +69,9 @@ ulong notrace get_tbclk(void)
 	return timer_get_rate(gd->timer);
 }
 
-unsigned long notrace timer_read_counter(void)
+uint64_t notrace get_ticks(void)
 {
-	unsigned long count;
+	u64 count;
 	int ret;
 
 	ret = dm_timer_init();
@@ -84,7 +84,8 @@ unsigned long notrace timer_read_counter(void)
 
 	return count;
 }
-#endif /* CONFIG_TIMER */
+
+#else /* !CONFIG_TIMER */
 
 uint64_t __weak notrace get_ticks(void)
 {
@@ -97,6 +98,8 @@ uint64_t __weak notrace get_ticks(void)
 	return ((uint64_t)gd->timebase_h << 32) | gd->timebase_l;
 }
 
+#endif /* CONFIG_TIMER */
+
 /* Returns time in milliseconds */
 static uint64_t notrace tick_to_time(uint64_t tick)
 {
-- 
1.8.2.1