From 4c5f5f71693600d133d3416634169acdf0042ff7 Mon Sep 17 00:00:00 2001
From: Daniel Franklin <daniel@danielzfranklin.org>
Date: Fri, 11 Feb 2022 18:45:23 -0700
Subject: [PATCH 1/2] Add feature defmt-timestamp-uptime

Enabling it adds a timestamp of the number of seconds since startup next
to defmt log messages using `Instant::now`.
---
 embassy/Cargo.toml | 4 ++++
 embassy/src/fmt.rs | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/embassy/Cargo.toml b/embassy/Cargo.toml
index d10a8874e..9a5467c6f 100644
--- a/embassy/Cargo.toml
+++ b/embassy/Cargo.toml
@@ -17,6 +17,10 @@ nightly = ["embedded-hal-async"]
 # Implement embedded-hal-async traits if `nightly` is set as well.
 unstable-traits = ["embedded-hal-1"]
 
+# Display a timestamp of the number of seconds since startup next to defmt log messages
+# To use this you must have a time driver provided.
+defmt-timestamp-uptime = ["defmt"]
+
 # Enable `embassy::time` module. 
 # NOTE: This feature is only intended to be enabled by crates providing the time driver implementation.
 # Enabling it directly without supplying a time driver will fail to link.
diff --git a/embassy/src/fmt.rs b/embassy/src/fmt.rs
index 066970813..115febb58 100644
--- a/embassy/src/fmt.rs
+++ b/embassy/src/fmt.rs
@@ -195,6 +195,10 @@ macro_rules! unwrap {
     }
 }
 
+#[cfg(feature = "defmt-timestamp-uptime")]
+// defmt offers a disply hint for microseconds so we convert from millis
+defmt::timestamp! {"{=u64:us}", crate::time::Instant::now().as_millis() * 1_000 }
+
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub struct NoneError;
 

From 04ac4883196c25990964968b5d52b4125986d1be Mon Sep 17 00:00:00 2001
From: Daniel Franklin <daniel@danielzfranklin.org>
Date: Fri, 11 Feb 2022 19:01:43 -0700
Subject: [PATCH 2/2] Add {from_as}_micros to Instant

---
 embassy/src/fmt.rs          |  3 +--
 embassy/src/time/instant.rs | 12 ++++++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/embassy/src/fmt.rs b/embassy/src/fmt.rs
index 115febb58..f8bb0a035 100644
--- a/embassy/src/fmt.rs
+++ b/embassy/src/fmt.rs
@@ -196,8 +196,7 @@ macro_rules! unwrap {
 }
 
 #[cfg(feature = "defmt-timestamp-uptime")]
-// defmt offers a disply hint for microseconds so we convert from millis
-defmt::timestamp! {"{=u64:us}", crate::time::Instant::now().as_millis() * 1_000 }
+defmt::timestamp! {"{=u64:us}", crate::time::Instant::now().as_micros() }
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub struct NoneError;
diff --git a/embassy/src/time/instant.rs b/embassy/src/time/instant.rs
index 36c2b2dc2..aff83be20 100644
--- a/embassy/src/time/instant.rs
+++ b/embassy/src/time/instant.rs
@@ -28,6 +28,13 @@ impl Instant {
         Self { ticks }
     }
 
+    /// Create an Instant from a microsecond count since system boot.
+    pub const fn from_micros(micros: u64) -> Self {
+        Self {
+            ticks: micros * TICKS_PER_SECOND / 1_000_000,
+        }
+    }
+
     /// Create an Instant from a millisecond count since system boot.
     pub const fn from_millis(millis: u64) -> Self {
         Self {
@@ -57,6 +64,11 @@ impl Instant {
         self.ticks * 1000 / TICKS_PER_SECOND
     }
 
+    /// Microseconds since system boot.
+    pub const fn as_micros(&self) -> u64 {
+        self.ticks * 1_000_000 / TICKS_PER_SECOND
+    }
+
     /// Duration between this Instant and another Instant
     /// Panics on over/underflow.
     pub fn duration_since(&self, earlier: Instant) -> Duration {