On Fri, Aug 10, 2012 at 08:46:20AM +0200, Marc Pignat wrote: > Hi John, > > (You asked me in private, but I prefer to respond on the mailing list). > > This driver was working, I wrote (and tested it) in 2008 ;) > The hardware it was running on was a custom at91rm9200 based board with > a adc084s051. > The last time a checked it, it was on 2.6.28, and it was still working fine. > > I just had a look to the adc128s052 datasheet, and it looks compatible > with this driver. > > Guenter, the spi_write_then_read() function is really the good one. > In brief, the write selects the channel, then the read reads the data. > Yes, I noticed that this must be the idea. I _think_ it assumes that the first access initiates the conversion, and the second access reads the data (while providing a dummy ADC index). The data sheet seems to confirm that. In other words, the read data obtained with the first write is the ADC result from the _previous_ conversion. The data sheet seems to confirm that: "The first conversion result after power-up will be that of IN0". I think I am going to order a couple of those chips and check what is happening on the bus with a Logic Analyzer. Thanks, Guenter _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
