Hi Jagan,
On Fri, 11 May 2018 11:30:43 +0530 Jagan Teki jagannadh.teki@gmail.com wrote:
On Fri, May 11, 2018 at 11:08 AM, Prabhakar Kushwaha prabhakar.kushwaha@nxp.com wrote:
Dear Jagan,
NXP is coming up with new FlexSPI controller. It is similar to existing QSPI with enhanced feature-set. We have the driver ready as per existing framework i.e. driver/spi.
From recend discussion, we go to know about framework change. Migration of qspi drivers in u-boot-spi/drivers/mtd/spi-nor/ git://git.denx.de/u-boot-spi.git branch mtd-spinor-working.
We are in dilemma for sending FlexSPI driver upstream. Do we follow existing framework i.e. driver/spi or new proposed framework i.e. u-boot-spi/drivers/mtd/spi-nor/
Also, do we have any timeline of u-boot-spi/drivers/mtd/spi-nor/ to become default.
Idea is to move spi-nor, mtd-spinor-working is paused because of non-dm drivers accessing. We are clear that we can't create another legacy layer to access spi-nor for the sake of non-dm driver to work which eventually ended-up another mess and also no one take care of non-dm conversion to dm if we give such feasibility. So we exported a deadline for full SPI/SPI_FLASH DM conversion till v2018.09. Once all these relevant conversion done, will try to move.
Just for the record, the spi-mem interface has been accepted in Linux [1] (should be there in 4.18). From now on, I'll try to encourage people move existing spi-nor controller drivers to the SPI subsystem, and I'll definitely ask new QPSI drivers to use this interface (and extend it if needed).
So, I'm not sure creating this spi-nor subsystem in uboot is a good idea anymore. Of course, it's up to you to decide, but if you take this path you'll run into the same problem we had in Linux:
- how to support SPI NANDs in a clean and efficient way - how to support both memory-like operations and regular SPI transfers with the same driver
Regards,
Boris
[1]https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git/commit/?h=fo...