>Hi, I'm having trouble with this patch using a Cadence QSPI controller and >Micron n25q00 part.
>I can use quad commands in Extended SPI mode, but I can't make this EVCR Quad >mode work. Yes,but if you use quad commands in Extended spi mode,only for Quad commands,the command line is DQ0, Address/data line is DQ0,DQ1,DQ2 and DQ3(1-x-4). But if in Quad I/O mode,for all the commands,the command/address/data line will be 4,they are DQ0,DQ1,DQ2 and DQ3(4-x-4). >The Cadence QSPI Controller has fields to configure the quad transfer, and can >support quad opcode, >quad address, and quad data, or some combination. There is a chart in the >docs which shows the combinations for various read commands. >Problem is, I've tried all of the combinations and all I get is FF with this >EVCR patch. This maybe your spi controller is still extended mode, Once EVCR bit 7 is set to 0, the spi nor device will operate in quad I/O.Command-address-data line is 4-x-4. So after send WRITE EVCR command , spi controller also must transfer to quad I/O Mode,and set its Command-address-data line also Should be 4-x-4 . >If I don't set the quad mode in the EVCR, then I can use quad read commands no >problem. Yes,you don't set the quad mode in the EVCR,you can use quad read commands,but this patch is for enable Micron SPI nor Quad I/O mode, If you want to enable it ,you must set EVCR. >Bottom line, with the Cadence QSPI controller, if I use quad commands in >Extended SPI mode, then all good. If I use this EVCR quad mode, then all bad. >Anybody else have a Cadence QSPI controller and using EVCR quad mode >successfully? >Thanks, >Graham Moore Hi,Brian Whether this patch can be merged?thanks. -- 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/
