Hi Marek, Le 16/07/2015 19:44, Marek Vasut a écrit : > On Thursday, July 16, 2015 at 05:27:51 PM, Cyrille Pitchen wrote: > > Hi! > >> Both the SPI controller and the NOR flash memory need to agree on the >> number of dummy cycles to use for Fast Read commands. For Spansion >> memories, this number of dummy cycles is not given directly but through a >> so called "latency code". >> The latency code can be found into the memory datasheet and depends on the >> SPI clock frequency, the Fast Read op code and the Single/Dual Data Rate >> mode. > > Shouldn't you be able to derive the latency code from the above information, > which you already know then ? Yes I agree with you; this could have been done adding static tables inside the driver instead of creating a new DT property dedicated to Spansion memories.
When I wrote this patch, I had a close look at the s25fl512s datasheet but only overviewed few datasheets for other Spansion QSPI flash memories. So I don't know whether a single latency code table could be shared among all Spansion memories or many tables should be added to support different memory models. That's why I've chosen to add a dedicated DT property to support Spansion memories as it avoids to add tables to guess the proper latency code to be used. I thought it would be more flexible. Maybe I will remove the support of Spansion QSPI memories from this series for now. Their support can still be implemented later. Anyway, thanks for your review :) > > Best regards, > Marek Vasut > Best Regards, Cyrille -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
