Add MG

esp-hal/MIGRATING-0.21.md

@@ -356,7 +356,9 @@ refer to the `Config` struct as `uart::Config`.
 +)
 ```
 
-## I8080 driver split `set_byte_order()` into `set_8bits_order()` and `set_byte_order()`.
+## I8080 changes
+
+### I8080 driver split `set_byte_order()` into `set_8bits_order()` and `set_byte_order()`.
 
 If you were using an 8-bit bus.
 ```diff
@@ -368,3 +370,45 @@ If you were using an 16-bit bus, you don't need to change anything, `set_byte_or
 
 If you were sharing the bus between an 8-bit and 16-bit device, you will have to call the corresponding method when
 you switch between devices. Be sure to read the documentation of the new methods.
+
+### Mixed mode constructor
+
+It is no longer possible to construct an `I8080` driver using a blocking-mode `Lcd` and an async-mode
+DMA channel. Convert the DMA channel into blocking, or set up an async `LcdCam` first.
+
+```diff
+ let lcd_cam = LcdCam::new(peripherals.LCD_CAM);
+ let channel = ctx
+     .dma
+     .channel0
+-    .configure(false, DmaPriority::Priority0)
+-    .into_async();
++    .configure(false, DmaPriority::Priority0);
+
+ let i8080 = I8080::new(
+     lcd_cam.lcd,
+     channel.tx,
+     pins,
+     20.MHz(),
+     Config::default(),
+ );
+```
+
+Or:
+
+```diff
+-let lcd_cam = LcdCam::new(peripherals.LCD_CAM);
++let lcd_cam = LcdCam::new(peripherals.LCD_CAM).into_async();
+ let channel = ctx
+     .dma
+     .channel0
+     .into_async();
+
+ let i8080 = I8080::new(
+     lcd_cam.lcd,
+     channel.tx,
+     pins,
+     20.MHz(),
+     Config::default(),
+ );
+```