Add SYSTIMER based ESP32-C3 monotonic (#972)

* add esp32c3 monotonic

* fix tests

7 files changed, 153 insertions, 9 deletions

diff --git a/examples/esp32c3/.cargo/config.toml b/examples/esp32c3/.cargo/config.toml
index 9ea4ecb..05f0a29 100644
--- a/examples/esp32c3/.cargo/config.toml
+++ b/examples/esp32c3/.cargo/config.toml
@@ -1,6 +1,6 @@
 [target.riscv32imc-unknown-none-elf]
 # Real hardware
-#runner = "espflash flash --monitor"
+# runner = "espflash flash --monitor"
 
 # QEMU emulator
 runner = "./runner.sh"
@@ -14,6 +14,3 @@ rustflags = [
 ]
 
 target = "riscv32imc-unknown-none-elf"
-
-[unstable]
-build-std = ["core"]
diff --git a/examples/esp32c3/Cargo.lock b/examples/esp32c3/Cargo.lock
index 35d467e..5aaf0e1 100644
--- a/examples/esp32c3/Cargo.lock
+++ b/examples/esp32c3/Cargo.lock
@@ -145,6 +145,15 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "361a90feb7004eca4019fb28352a9465666b24f840f5c3cddf0ff13920590b89"
 
 [[package]]
+name = "embedded-hal-async"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c4c685bbef7fe13c3c6dd4da26841ed3980ef33e841cddfa15ce8a8fb3f1884"
+dependencies = [
+ "embedded-hal 1.0.0",
+]
+
+[[package]]
 name = "enum-as-inner"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -285,6 +294,7 @@ dependencies = [
  "esp-println",
  "esp32c3 0.22.0",
  "rtic",
+ "rtic-monotonics",
 ]
 
 [[package]]
@@ -385,6 +395,30 @@ dependencies = [
 ]
 
 [[package]]
+name = "futures-core"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dfc6580bb841c5a68e9ef15c77ccc837b40a7504914d52e47b8b0e9bbda25a1d"
+
+[[package]]
+name = "futures-task"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "38d84fa142264698cdce1a9f9172cf383a0c82de1bddcf3092901442c4097004"
+
+[[package]]
+name = "futures-util"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d6401deb83407ab3da39eba7e33987a73c3df0c82b4bb5813ee871c19c41d48"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "pin-project-lite",
+ "pin-utils",
+]
+
+[[package]]
 name = "gcd"
 version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -480,6 +514,18 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "de3145af08024dea9fa9914f381a17b8fc6034dfb00f3a84013f7ff43f29ed4c"
 
 [[package]]
+name = "pin-project-lite"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bda66fc9667c18cb2758a2ac84d1167245054bcf85d5d1aaa6923f45801bdd02"
+
+[[package]]
+name = "pin-utils"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
+
+[[package]]
 name = "portable-atomic"
 version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -612,6 +658,14 @@ dependencies = [
 ]
 
 [[package]]
+name = "rtic-common"
+version = "1.0.1"
+dependencies = [
+ "critical-section",
+ "portable-atomic",
+]
+
+[[package]]
 name = "rtic-core"
 version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -629,6 +683,30 @@ dependencies = [
 ]
 
 [[package]]
+name = "rtic-monotonics"
+version = "2.0.2"
+dependencies = [
+ "cfg-if",
+ "esp32c3 0.22.0",
+ "fugit",
+ "portable-atomic",
+ "riscv",
+ "rtic-time",
+]
+
+[[package]]
+name = "rtic-time"
+version = "2.0.0"
+dependencies = [
+ "critical-section",
+ "embedded-hal 1.0.0",
+ "embedded-hal-async",
+ "fugit",
+ "futures-util",
+ "rtic-common",
+]
+
+[[package]]
 name = "rustversion"
 version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/examples/esp32c3/Cargo.toml b/examples/esp32c3/Cargo.toml
index fa2a4e0..adb0ece 100644
--- a/examples/esp32c3/Cargo.toml
+++ b/examples/esp32c3/Cargo.toml
@@ -8,6 +8,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 rtic = {path = "../../rtic/"}
+rtic-monotonics = {path = "../../rtic-monotonics/"}
 esp-hal = { version = "0.16.1", features = ["esp32c3", "direct-vectoring", "interrupt-preemption"] }
 esp-backtrace = { version = "0.11.0", features = [
     "esp32c3",
@@ -21,4 +22,4 @@ esp-println = { version = "0.9.0", features = ["esp32c3", "uart"] }
 
 [features]
 test-critical-section = []
-riscv-esp32c3-backend = ["rtic/riscv-esp32c3-backend"]
+riscv-esp32c3-backend = ["rtic/riscv-esp32c3-backend", "rtic-monotonics/esp32c3-systimer"]
diff --git a/examples/esp32c3/README.md b/examples/esp32c3/README.md
index 37d0167..fa382c6 100644
--- a/examples/esp32c3/README.md
+++ b/examples/esp32c3/README.md
@@ -15,12 +15,24 @@ This crate uses the most convenient option in ``cargo-espflash`` and ``espflash`
 
 ## Running the crate
 
+Uncomment the 
+
+```runner = "espflash flash --monitor"```
+
+line in ``.cargo/config.toml``
+
+and comment out (or remove) 
+
+```runner = "./runner.sh"```
+
+Now, running
+
 ```cargo run --example sw_and_hw --features=riscv-esp32c3-backend (--release)```
 
-should do the trick.
+in the root of this crate should do the trick.
 
 # Expected behavior
-The program
+The example ``sw_and_hw``
 - Prints ``init``
 - Enters a high prio task
 - During the execution of the high prio task, the button should be non-functional
@@ -31,3 +43,9 @@ The program
 - Exits the low prio task
 - Prints ``idle``
 
+The example ``monotonic``
+- Prints ``init``
+- Spawns the ``foo``, ``bar``, ``baz`` tasks (because of hardware interrupt latency dispatch, the order here may vary).
+- Each task prints ``hello from $TASK`` on entry
+- The tasks wait for 1, 2, 3 seconds respectively
+- Once the wait period is over, each task exits printing ``bye from $TASK`` (now in the proper order).
diff --git a/examples/esp32c3/examples/monotonic.rs b/examples/esp32c3/examples/monotonic.rs
new file mode 100644
index 0000000..1c0bd77
--- /dev/null
+++ b/examples/esp32c3/examples/monotonic.rs
@@ -0,0 +1,51 @@
+#![no_main]
+#![no_std]
+use esp_backtrace as _;
+#[rtic::app(device = esp32c3, dispatchers = [])]
+mod app {
+    use rtic_monotonics::esp32c3::prelude::*;
+    esp32c3_systimer_monotonic!(Mono);
+    use esp_hal as _;
+    use esp_println::println;
+
+    #[shared]
+    struct Shared {}
+
+    #[local]
+    struct Local {}
+
+    #[init]
+    fn init(cx: init::Context) -> (Shared, Local) {
+        println!("init");
+        let timer = cx.device.SYSTIMER;
+
+        Mono::start(timer);
+
+        foo::spawn().unwrap();
+        bar::spawn().unwrap();
+        baz::spawn().unwrap();
+
+        (Shared {}, Local {})
+    }
+
+    #[task]
+    async fn foo(_cx: foo::Context) {
+        println!("hello from foo");
+        Mono::delay(2_u64.secs()).await;
+        println!("bye from foo");
+    }
+
+    #[task]
+    async fn bar(_cx: bar::Context) {
+        println!("hello from bar");
+        Mono::delay(3_u64.secs()).await;
+        println!("bye from bar");
+    }
+
+    #[task]
+    async fn baz(_cx: baz::Context) {
+        println!("hello from baz");
+        Mono::delay(4_u64.secs()).await;
+        println!("bye from baz");
+    }
+}
diff --git a/examples/esp32c3/examples/sw_and_hw.rs b/examples/esp32c3/examples/sw_and_hw.rs
index 413df92..42dd0ec 100644
--- a/examples/esp32c3/examples/sw_and_hw.rs
+++ b/examples/esp32c3/examples/sw_and_hw.rs
@@ -1,6 +1,5 @@
 #![no_main]
 #![no_std]
-
 #[rtic::app(device = esp32c3, dispatchers=[FROM_CPU_INTR0, FROM_CPU_INTR1])]
 mod app {
     use esp_backtrace as _;
diff --git a/examples/esp32c3/rust-toolchain.toml b/examples/esp32c3/rust-toolchain.toml
index 446d6fe..e6c6255 100644
--- a/examples/esp32c3/rust-toolchain.toml
+++ b/examples/esp32c3/rust-toolchain.toml
@@ -1,4 +1,4 @@
 [toolchain]
-channel = "nightly-2023-11-14"
+channel = "stable"
 components = ["rust-src"]
 targets = ["riscv32imc-unknown-none-elf"]