[PATCH 06/10] timer: rockchip_timer: Add timer_early functions

[Stefan Roese]

Currently this timer driver provides timer_get_boot_us() to support the
BOOTSTAGE functionality. This patch adds the timer_early functions so
that the "normal" timer functions can be used, when CONFIG_TIMER_EARLY
is enabled.

timer_get_boot_us() will get removed in a follow-up patch, once the
BOOTSTAGE interface is migrated to timer_get_us().

Signed-off-by: Stefan Roese <sr at denx.de>
Cc: Kever Yang <kever.yang at rock-chips.com>
Cc: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
---
 drivers/timer/rockchip_timer.c | 50 ++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/drivers/timer/rockchip_timer.c b/drivers/timer/rockchip_timer.c
index 62eacb986890..6e3483edce72 100644
--- a/drivers/timer/rockchip_timer.c
+++ b/drivers/timer/rockchip_timer.c
@@ -87,6 +87,56 @@ ulong timer_get_boot_us(void)
 }
 #endif
 
+static u64 timer_early_get_count_rate(uint32_t *rate)
+{
+	uint64_t ticks = 0;
+
+	*rate = 1;
+	if (CONFIG_IS_ENABLED(OF_REAL)) {
+		/* We have been called so early that the DM is not ready,... */
+		ofnode node = offset_to_ofnode(-1);
+		struct rk_timer *timer = NULL;
+
+		/*
+		 * ... so we try to access the raw timer, if it is specified
+		 * via the tick-timer property in /chosen.
+		 */
+		node = ofnode_get_chosen_node("tick-timer");
+		if (!ofnode_valid(node)) {
+			debug("%s: no /chosen/tick-timer\n", __func__);
+			return 0;
+		}
+
+		timer = (struct rk_timer *)ofnode_get_addr(node);
+
+		/* This timer is down-counting */
+		ticks = ~0ULL - rockchip_timer_get_curr_value(timer);
+		if (ofnode_read_u32(node, "clock-frequency", rate)) {
+			debug("%s: could not read clock-frequency\n", __func__);
+			return 0;
+		}
+	} else {
+		return 0;
+	}
+
+	return ticks;
+}
+
+unsigned long notrace timer_early_get_rate(void)
+{
+	uint32_t rate;
+
+	timer_early_get_count_rate(&rate);
+	return rate;
+}
+
+u64 notrace timer_early_get_count(void)
+{
+	uint32_t rate;
+
+	return timer_early_get_count_rate(&rate);
+}
+
 static u64 rockchip_timer_get_count(struct udevice *dev)
 {
 	struct rockchip_timer_priv *priv = dev_get_priv(dev);
-- 
2.37.3