extmod/machine_i2c: Extend I2C transfer func to support write then read. #8682
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Signed-off-by: Damien George <damien@micropython.org>
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That looks like a good extension. Do I have to adapt the mimxrt port, or is that handled in extmod/machine_i2c.c by calling machine_i2c_transfer_single() as often as needed? |
No need to change mimxrt, it's handled by transfer single. All ports should be working with this PR (but I didn't yet test any...). |
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This increases code size by: Which is a fair bit for a feature that only esp32 makes use of. The other ports don't need and don't benefit from this change. So I will close this in favour of #8718. |
This leaves internal memory for FreeRTOS and other IDF buffers. Fixes micropython#8682
We used to default to `malloc()` using SPIRAM but it disables dynamic WiFi TX buffers. The increased static buffer allocation prevents MBEDTLS from allocating everything it needs. So, switch the IDF to SPIRAM through caps_alloc only. This is pretty much what we do in CP8 except we no longer need to explicitly give the IDF SPIRAM memory to use. Fixes micropython#8682 (again)
This PR aims to fix #8135, and optimise I2C as per #7134.
The general I2C transfer function has changed from:
to:
That means it supports 0 or more writes followed by 0 or more reads, in one "transaction".