Messages in this thread | | | Date | Fri, 12 Mar 2021 22:30:02 +0530 | From | Pratyush Yadav <> | Subject | Re: [RFC PATCH 0/6] spi: Add OSPI PHY calibration support for spi-cadence-quadspi |
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On 12/03/21 02:32PM, Michael Walle wrote: > Am 2021-03-11 20:12, schrieb Pratyush Yadav: > > The main problem here is telling the controller where to find the > > pattern and how to read it. This RFC uses nvmem cells which point to a > > fixed partition containing the data to do the reads. It depends on [0] > > and [1]. > > > > The obvious problem with this is it won't work when the partitions are > > defined via command line. I don't see any good way to add nvmem cells to > > command line partitions. I would like some help or ideas here. We don't > > necessarily have to use nvmem either. Any way that can cleanly and > > consistently let the controller find out where the pattern is stored is > > good. > > The NXP LS1028A SoC has a similar calibration (although there its done > in hardware it seems) and there the datasheet mentions there are flash > devices which supports a preamble before a read function. The preamble > is then some kind of learning pattern. Did you see a flash which actually > supports that in the wild? I can't find any publicly available datasheets > of 8bit I/O SPI NOR flashes.
I haven't seen any such flash but it looks like Tudor has.
> > -michael
-- Regards, Pratyush Yadav Texas Instruments Inc.
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