Merge #534

534: Non-Blocking I2C based on DMA r=burrbull a=SpeedCrash100

Adds method `use_dma` on I2c structure for creating a new structure `I2CMasterDma`. The new structure allows to use unsafe methods ended with `_dma` to send/receive data in non blocking mode and call specified `callback` at the end of transfer. The `I2CMasterDma` also have methods for blocking transfers but they returns `nb::Result` and `WouldBlock` if there are operation in progress. Clients must call `handle_dma_interrupt` in DMAx_STREAMy interrupt and `handle_error_interrupt` in I2Cx_ER interrupt for correct working of this structure.

At the current stage Start generation and Address sending is blocking anyway, so current implementation have benefits only with high amount of data to transfer. For example, sending image to display.

I've also prepared example of usage with SSD1306 display and LM75B temperature sensor in [separate repository](https://github.com/SpeedCrash100/stm32f4xx-dma-i2c-example)

Co-authored-by: SpeedCrash100 <[email protected]>

Author: bors[bot]

CHANGELOG.md

@@ -40,6 +40,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - `SysMonoTimerExt` helper trait, `Pwm::(get/set)_duty_time` [#497]
 - example of using i2s in out with rtic and interrupt.
 - example of using USB CDC with interrupts.
+- Added non-blocking I2C based on DMA [#534]
 
 [#481]: https://github.com/stm32-rs/stm32f4xx-hal/pull/481
 [#489]: https://github.com/stm32-rs/stm32f4xx-hal/pull/489
@@ -55,6 +56,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 [#519]: https://github.com/stm32-rs/stm32f4xx-hal/pull/519
 [#529]: https://github.com/stm32-rs/stm32f4xx-hal/pull/529
 [#536]: https://github.com/stm32-rs/stm32f4xx-hal/pull/536
+[#534]: https://github.com/stm32-rs/stm32f4xx-hal/pull/529
 
 ## [v0.13.2] - 2022-05-16
 

Cargo.toml

@@ -81,6 +81,7 @@ ist7920 = "0.1.1"
 smart-leds = "0.3.0"
 ws2812-spi = { version = "0.4.0", features = [] }
 hd44780-driver = "0.4.0"
+display-interface = "0.4"
 
 [dev-dependencies.time]
 version = "0.3"
@@ -403,6 +404,10 @@ required-features = ["device-selected"] # stm32f411
 name = "stopwatch-with-ssd1306-and-interrupts"
 required-features = ["tim2"] # stm32f411
 
+[[example]]
+name = "stopwatch-with-ssd1306-and-interrupts-and-dma-i2c"
+required-features = ["tim2", "stm32f411"] # stm32f411
+
 [[example]]
 name = "analog-stopwatch-with-spi-ssd1306"
 required-features = ["spi4", "tim2", "gpioe", "gpiog"] # stm32f429