Changes to i2c master and slave to handle large data buffers #322
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PR Overview
This PR updates the I2C master and slave implementations to support large DMA transfers by dividing data buffers into smaller, DMA-safe chunks. The changes include new chunking functions in both master and slave modules, an added constant for the maximum chunk size, and related updates to the Cargo configuration.
- Added write_chunks and read_chunks functions to I2C master to split large transfers.
- Updated the I2C slave’s response functions to process data in chunks.
- Introduced the MAX_I2C_CHUNK_SIZE constant and updated the Cargo config with a new executor arena size.
Reviewed Changes
| File | Description |
|---|---|
| src/i2c/master.rs | Introduces chunked write/read functions and updates I2C traits. |
| src/i2c/slave.rs | Implements chunking in slave response functions for write/read. |
| examples/rt685s-evk/.cargo/config.toml | Updates Cargo config with linker args and executor arena size. |
| src/i2c/mod.rs | Adds MAX_I2C_CHUNK_SIZE constant for DMA transfer size. |
Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.
| @@ -761,6 +761,30 @@ impl<'a> I2cMaster<'a, Async> { | |||
| ) | |||
| .await | |||
| } | |||
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| async fn write_chunks(&mut self, address: u16, write: &[u8]) -> Result<()> { | |||
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[nitpick] In write_chunks, when the write buffer is empty the function calls write_no_stop but does not return immediately. To improve clarity and control flow, consider returning immediately after handling the empty buffer.
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| @@ -502,6 +502,24 @@ impl I2cSlave<'_, Async> { | |||
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| /// Respond to write command from master | |||
| pub async fn respond_to_write(&mut self, buf: &mut [u8]) -> Result<Response> { | |||
| let mut xfer_count = 0; | |||
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[nitpick] In respond_to_write, the for loop returns as soon as a chunk yields a 'Complete' response, which may unintentionally skip processing remaining chunks. Review this behavior to ensure it meets the intended protocol for multi-chunk transactions.
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akshat2112
requested review from
felipebalbi,
JamesHuard,
madeleyneVaca,
tullom and
RobertZ2011
as code owners
Since DMA only handles a maximum of 1024 bytes of data, i2c master and slave need to handle larger buffers by dividing them into chunks of smaller buffers.
The example also demonstrates how to handle both read and write operations for a large buffer.
Closes #255