i2c: buffer mode support when mode changes through bus restart#417
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- Rename variables used in buffer mode communication to follow the driver naming style and improve clarity. Signed-off-by: Shreehari HK <shreehari.hk@alifsemi.com>
- Remove the buf_pos reset in the dw_transfer() API, as this function is not intended to be used for I2C target mode. Signed-off-by: Shreehari HK <shreehari.hk@alifsemi.com>
- Replace the shared buf_pos variable with separate rx_pos and tx_pos variables to independently track RX and TX buffer progress. - Previously, a single variable was used for both RX and TX buffer tracking, which could lead to incorrect behavior when switching communication modes if the expected number of bytes was not transferred. Signed-off-by: Shreehari HK <shreehari.hk@alifsemi.com>
- Reset buffer mode variables when configuring the controller for slave mode. Signed-off-by: Shreehari HK <shreehari.hk@alifsemi.com>
- In slave mode, there is no interrupt generated for a RESTART condition. The buffer mode communication logic currently assumes that the transfer terminates only when a STOP condition is detected. - When the bus issues a RESTART instead of STOP, the buffer mode state is not handled correctly, which can lead to data mismatch or communication errors when the transfer direction changes. - Handle this case by detecting a START condition and resetting the buffer mode state accordingly. Signed-off-by: Shreehari HK <shreehari.hk@alifsemi.com>
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| ret = i2c_dw_set_slave_mode(dev, cfg->address, cfg->flags); | ||
| write_intr_mask(DW_INTR_MASK_RX_FULL | DW_INTR_MASK_RD_REQ | DW_INTR_MASK_TX_ABRT | | ||
| DW_INTR_MASK_STOP_DET, | ||
| DW_INTR_MASK_START_DET | DW_INTR_MASK_STOP_DET, |
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Should we have this flag enabled only for the buffer mode?
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The PR performs the following:
Rename variables used in buffer mode communication to follow the driver naming style and improve clarity.
Remove the buf_pos reset in the dw_transfer() API, as this function is not intended to be used for I2C target mode.
Replace the shared buf_pos variable with separate rx_pos and tx_pos variables to independently track RX and TX buffer progress.
Reset buffer mode variables when configuring the controller for slave mode.
Add buffer mode support during communication direction change through RESTART:
In slave mode, there is no interrupt generated for a RESTART condition.
The buffer mode communication logic currently assumes that the transfer
terminates only when a STOP condition is detected.
When the bus issues a RESTART instead of STOP, the buffer mode state
is not handled correctly, which can lead to data mismatch or
communication errors when the transfer direction changes.
Handle this case by detecting a START condition and resetting
the buffer mode state accordingly.