Hi, > > > Analyze and rework the PIO mode operation. The PIO mode operation > > was unreliable on MX28, by analyzing the bus with LA, the checks for > > when data were available or were to be sent were wrong. > > > > The PIO WRITE has to be completely reworked as it multiple problems. > > The MX23 datasheet helped here, see comments in the code for > > details. > > The problems boil down to: > > - RUN bit in CTRL0 must be set after DATA register was written - The > > PIO transfer must be 4 bytes long tops, otherwise use > > clock stretching. > > Both of these fixes are implemented. > > > > The PIO READ operation can only be done for up to four bytes as we > > are unable to read out the data from the DATA register fast enough. > > > > This patch also tries to document the investigation within the code. > > > > Signed-off-by: Marek Vasut <marex@xxxxxxx> > > Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx> > > Cc: Fabio Estevam <r49496@xxxxxxxxxxxxx> > > Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx> > > Cc: Shawn Guo <shawn.guo@xxxxxxxxxx> > > Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx> > > Cc: <to-fleischer@xxxxxxxxxxx> > > > > I so far got confirmation from ALexandre this patch works. Can someone > else test it please? I'd like to roll out a final version to close > this issue. > sorry, I couldn't test the patch until today on my iMX283 board. It works when reading the registers from the temperature sensor TCN75A. But it fails when writing less than 7 bytes to the EEPROM (24LC32). Then I always get a 'Connection timed out' error in the user space. Best regards Torsten Fleischer -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
