riscv: timer: Add support for an early timer

Added support for timer_early_get_count() and timer_early_get_rate()
This is mostly useful in tracing.

Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com>
Reviewed-by: Rick Chen <rick@andestech.com>

3 files changed, 60 insertions, 3 deletions

diff --git a/drivers/timer/andes_plmt_timer.c b/drivers/timer/andes_plmt_timer.c
index db2cf86f63..a3797b22c7 100644
--- a/drivers/timer/andes_plmt_timer.c
+++ b/drivers/timer/andes_plmt_timer.c
@@ -18,11 +18,30 @@
 /* mtime register */
 #define MTIME_REG(base)			((ulong)(base))
 
-static u64 andes_plmt_get_count(struct udevice *dev)
+static u64 notrace andes_plmt_get_count(struct udevice *dev)
 {
 	return readq((void __iomem *)MTIME_REG(dev_get_priv(dev)));
 }
 
+#if CONFIG_IS_ENABLED(RISCV_MMODE) && IS_ENABLED(CONFIG_TIMER_EARLY)
+/**
+ * timer_early_get_rate() - Get the timer rate before driver model
+ */
+unsigned long notrace timer_early_get_rate(void)
+{
+	return RISCV_MMODE_TIMER_FREQ;
+}
+
+/**
+ * timer_early_get_count() - Get the timer count before driver model
+ *
+ */
+u64 notrace timer_early_get_count(void)
+{
+	return readq((void __iomem *)MTIME_REG(RISCV_MMODE_TIMERBASE));
+}
+#endif
+
 static const struct timer_ops andes_plmt_ops = {
 	.get_count = andes_plmt_get_count,
 };
diff --git a/drivers/timer/riscv_timer.c b/drivers/timer/riscv_timer.c
index 21ae184057..3627ed79b8 100644
--- a/drivers/timer/riscv_timer.c
+++ b/drivers/timer/riscv_timer.c
@@ -16,7 +16,7 @@
 #include <timer.h>
 #include <asm/csr.h>
 
-static u64 riscv_timer_get_count(struct udevice *dev)
+static u64 notrace riscv_timer_get_count(struct udevice *dev)
 {
 	__maybe_unused u32 hi, lo;
 
@@ -31,6 +31,25 @@ static u64 riscv_timer_get_count(struct udevice *dev)
 	return ((u64)hi << 32) | lo;
 }
 
+#if CONFIG_IS_ENABLED(RISCV_SMODE) && IS_ENABLED(CONFIG_TIMER_EARLY)
+/**
+ * timer_early_get_rate() - Get the timer rate before driver model
+ */
+unsigned long notrace timer_early_get_rate(void)
+{
+	return RISCV_SMODE_TIMER_FREQ;
+}
+
+/**
+ * timer_early_get_count() - Get the timer count before driver model
+ *
+ */
+u64 notrace timer_early_get_count(void)
+{
+	return riscv_timer_get_count(NULL);
+}
+#endif
+
 static int riscv_timer_probe(struct udevice *dev)
 {
 	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
diff --git a/drivers/timer/sifive_clint_timer.c b/drivers/timer/sifive_clint_timer.c
index de23b85404..de7b4b95c9 100644
--- a/drivers/timer/sifive_clint_timer.c
+++ b/drivers/timer/sifive_clint_timer.c
@@ -15,11 +15,30 @@
 /* mtime register */
 #define MTIME_REG(base)			((ulong)(base) + 0xbff8)
 
-static u64 sifive_clint_get_count(struct udevice *dev)
+static u64 notrace sifive_clint_get_count(struct udevice *dev)
 {
 	return readq((void __iomem *)MTIME_REG(dev_get_priv(dev)));
 }
 
+#if CONFIG_IS_ENABLED(RISCV_MMODE) && IS_ENABLED(CONFIG_TIMER_EARLY)
+/**
+ * timer_early_get_rate() - Get the timer rate before driver model
+ */
+unsigned long notrace timer_early_get_rate(void)
+{
+	return RISCV_MMODE_TIMER_FREQ;
+}
+
+/**
+ * timer_early_get_count() - Get the timer count before driver model
+ *
+ */
+u64 notrace timer_early_get_count(void)
+{
+	return readq((void __iomem *)MTIME_REG(RISCV_MMODE_TIMERBASE));
+}
+#endif
+
 static const struct timer_ops sifive_clint_ops = {
 	.get_count = sifive_clint_get_count,
 };