linguini1 commented on issue #16937: URL: https://github.com/apache/nuttx/issues/16937#issuecomment-3268340239
Have an implementation working for I2C reading, at least as far as the `i2c` tool bus scanner goes. I am able to scan the bus regularly and also using the `-z` flag for zero byte writes. Next I attempted to read the status register of the BMP280, but I am getting surprising results: ``` nsh> i2c get -a 77 -r f3 bcm2711_i2c_send: filltx: 1 bcm2711_i2c_filltxfifo: Wrote: f3 bcm2711_i2c_send: wrote: 1 bcm2711_i2c_send: Starting transfer of size 1... bcm2711_i2c_send: Dlen: 1 bcm2711_i2c_secondary_handler: TXW bcm2711_i2c_secondary_handler: Posted bcm2711_i2c_send: Transfer started... bcm2711_i2c_send: Transfer active?: 1 bcm2711_i2c_send: Dlen: 1 bcm2711_i2c_send: Waiting for interrupt bcm2711_i2c_send: Dlen (after wait): 1 bcm2711_i2c_send: filltx: 0 bcm2711_i2c_send: wrote: 0 bcm2711_i2c_send: Transfer active?: 1 bcm2711_i2c_send: Dlen: 1 bcm2711_i2c_send: Waiting for interrupt ``` I fill the FIFO with the single register byte that I want to send (0xf3) and set the transfer length to 1. It gets written to the FIFO properly, the transfer starts, I then get a TXW interrupt (FIFO needs write) although there are no more bytes to write and the FIFO contains the data already. I then hang waiting for a DONE interrupt that never comes. Changing the order hasn't made a difference. I tried this scenario where I pre-fill the FIFO before starting the transfer, and I've also tried the scenario where I start the transfer, wait for the TXW interrupt and then write the data to the FIFO. Neither of them work, they both hang waiting for a DONE interrupt. The last logs before hanging indicate an active transfer and that the DLEN hasn't been decremented. Investigating, but as far I can tell, this is the approach taken by other implementations. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@nuttx.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
