refactor(rust): improve time module

[no changelog]

core/embed/rust/build.rs

@@ -394,6 +394,7 @@ fn generate_trezorhal_bindings() {
         // systick
         .allowlist_function("systick_delay_ms")
         .allowlist_function("systick_ms")
+        .allowlist_function("systick_us")
         // toif
         .allowlist_type("toif_format_t")
         //usb

core/embed/rust/src/micropython/mod.rs

@@ -16,7 +16,6 @@ pub mod print;
 pub mod qstr;
 pub mod runtime;
 pub mod simple_type;
-pub mod time;
 pub mod typ;
 pub mod util;
 

core/embed/rust/src/micropython/time.rs

@@ -1,11 +0,0 @@
-use crate::time::Duration;
-
-use super::ffi;
-
-pub fn ticks_ms() -> u32 {
-    unsafe { ffi::mp_hal_ticks_ms() as _ }
-}
-
-pub fn sleep(delay: Duration) {
-    unsafe { ffi::mp_hal_delay_ms(delay.to_millis() as _) }
-}

core/embed/rust/src/trezorhal/mod.rs

@@ -30,8 +30,4 @@ pub mod wordlist;
 
 pub mod secbool;
 
-#[cfg(not(feature = "micropython"))]
 pub mod time;
-
-#[cfg(feature = "micropython")]
-pub use crate::micropython::time;

core/embed/rust/src/trezorhal/time.rs

@@ -2,12 +2,28 @@ use crate::time::Duration;
 
 use super::ffi;
 
+/// Returns the current time in milliseconds since the device was reset.
+/// Time is represented as a 32-bit number that wraps around every 49.7 days.
 pub fn ticks_ms() -> u32 {
     unsafe { ffi::systick_ms() as _ }
 }
 
+/// Returns the current time in microseconds since the device was reset.
+/// Time is represented as a 64-bit number and never wraps around.
+pub fn ticks_us() -> u64 {
+    unsafe { ffi::systick_us() as _ }
+}
+
+/// Sleeps for the specified duration.
 pub fn sleep(delay: Duration) {
     unsafe {
         ffi::systick_delay_ms(delay.to_millis() as _);
     }
 }
+
+/// Measures the time it takes to execute a closure in microseconds.
+pub fn measure_us(f: impl FnOnce()) -> u64 {
+    let start = ticks_us();
+    f();
+    ticks_us() - start
+}