Initial TWAI Driver Implementation (#192)

* wip: initial implementation of transmission only.

* Moved TWAI to its own directory and added initial reception of packets.

* Added extended id transmit and receive.

* Added maybe better code for making packet filters.

* Fixed bug with ids and improved methods of copying data to the peripheral.

* Added some guards against Bus Off

* Added reception of remote frames.

* Clean up of comments, etc

* Updated TWAI naming and cleaned up example a bit.

* Updated bitselector to include better unpacking methods.

* Add embedded-can and limit initial TWAI implementation to esp32c3.

* Added embedded-can to esp32c3 twai example.

* Switched twai filter to using bytestrings.

Co-authored-by: dimi <dimi.polonski@gmail.com>

* Implemented new() for twai filters.

* Clean up TWAI docs and example.

* Fix filter constructors and add examples.

* pre driver PeripheralRef update.

* PeripheralRef/twai

* Format comments with nightly rustfmt.

* Add gpio PeripheralRef and use volatile for direct register access.

Co-authored-by: dimi <dimi.polonski@gmail.com>

esp-hal-common/Cargo.toml

@@ -17,6 +17,7 @@ critical-section     = "1.1.1"
 embedded-hal         = { version = "0.2.7", features = ["unproven"] }
 embedded-hal-1       = { version = "=1.0.0-alpha.9", optional = true, package = "embedded-hal" }
 embedded-hal-nb      = { version = "=1.0.0-alpha.1", optional = true }
+embedded-can         = { version = "0.4.1", optional = true }
 fugit                = "0.3.6"
 lock_api             = { version = "0.4.9", optional = true }
 nb                   = "1.0.0"
@@ -67,7 +68,7 @@ esp32c2_40mhz = []
 esp32c2_26mhz = []
 
 # Implement the `embedded-hal==1.0.0-alpha.x` traits
-eh1 = ["embedded-hal-1", "embedded-hal-nb"]
+eh1 = ["embedded-hal-1", "embedded-hal-nb", "embedded-can"]
 
 # To use the external `smart_led` crate
 smartled = ["smart-leds-trait"]

esp-hal-common/src/lib.rs

@@ -73,6 +73,8 @@ pub mod system;
 #[cfg(systimer)]
 pub mod systimer;
 pub mod timer;
+#[cfg(any(esp32c3))]
+pub mod twai;
 pub mod uart;
 #[cfg(usb_serial_jtag)]
 pub mod usb_serial_jtag;

esp-hal-common/src/peripherals/esp32c3.rs

@@ -67,5 +67,6 @@ mod peripherals {
         TIMG0,
         TIMG1,
         APB_SARADC,
+        TWAI,
     }
 }

esp-hal-common/src/system.rs

@@ -42,6 +42,8 @@ pub enum Peripheral {
     I2s1,
     #[cfg(usb_otg)]
     Usb,
+    #[cfg(any(esp32c3))]
+    Twai,
 }
 
 /// Controls the enablement of peripheral clocks.
@@ -149,6 +151,11 @@ impl PeripheralClockControl {
                 perip_clk_en0.modify(|_, w| w.usb_clk_en().set_bit());
                 perip_rst_en0.modify(|_, w| w.usb_rst().clear_bit());
             }
+            #[cfg(any(esp32c3))]
+            Peripheral::Twai => {
+                perip_clk_en0.modify(|_, w| w.can_clk_en().set_bit());
+                perip_rst_en0.modify(|_, w| w.can_rst().clear_bit());
+            }
         }
     }
 }