[U-Boot] [EXT] Re: [PATCH 1/6] spi: fsl_qspi: Fix DDR mode setting for latest iMX platforms

[Ashish Kumar]

> -----Original Message-----
> From: Stefan Roese <sr at denx.de>
> Sent: Wednesday, September 11, 2019 11:17 AM
> To: Schrempf Frieder <frieder.schrempf at kontron.de>; Ashish Kumar
> <ashish.kumar at nxp.com>; Ye Li <ye.li at nxp.com>;
> jagan at amarulasolutions.com
> Cc: Fabio Estevam <fabio.estevam at nxp.com>; u-boot at lists.denx.de; dl-
> uboot-imx <uboot-imx at nxp.com>
> Subject: Re: [U-Boot] [EXT] Re: [PATCH 1/6] spi: fsl_qspi: Fix DDR mode
> setting for latest iMX platforms
> 
> Caution: EXT Email
> 
> Hi Ashish,
> Hi Frieder,
> 
> On 09.09.19 10:10, Schrempf Frieder wrote:
> > Hi Ashish,
> >
> > On 27.08.19 11:56, Ashish Kumar wrote:
> >>
> >>
> >>> -----Original Message-----
> >>> From: Schrempf Frieder <frieder.schrempf at kontron.de>
> >>> Sent: Wednesday, August 14, 2019 5:41 PM
> >>> To: Ashish Kumar <ashish.kumar at nxp.com>; Ye Li <ye.li at nxp.com>;
> >>> jagan at amarulasolutions.com
> >>> Cc: Fabio Estevam <fabio.estevam at nxp.com>; u-boot at lists.denx.de;
> dl-
> >>> uboot-imx <uboot-imx at nxp.com>
> >>> Subject: Re: [EXT] Re: [U-Boot] [PATCH 1/6] spi: fsl_qspi: Fix DDR
> >>> mode setting for latest iMX platforms
> >>>
> >>> Caution: EXT Email
> >>>
> >>> Sorry, I hit the "Send" button too early ;)
> >>>
> >>> On 14.08.19 14:07, Frieder Schrempf wrote:
> >>>> Hi Ashish,
> >>>>
> >>>> On 14.08.19 14:02, Ashish Kumar wrote:
> >>>>>
> >>>>>
> >>>>>> -----Original Message-----
> >>>>>> From: U-Boot <u-boot-bounces at lists.denx.de> On Behalf Of
> Schrempf
> >>>>>> Frieder
> >>>>>> Sent: Wednesday, August 14, 2019 5:07 PM
> >>>>>> To: Ye Li <ye.li at nxp.com>; jagan at amarulasolutions.com
> >>>>>> Cc: Fabio Estevam <fabio.estevam at nxp.com>; u-
> boot at lists.denx.de;
> >>> dl-
> >>>>>> uboot-imx <uboot-imx at nxp.com>
> >>>>>> Subject: [EXT] Re: [U-Boot] [PATCH 1/6] spi: fsl_qspi: Fix DDR
> >>>>>> mode setting for latest iMX platforms
> >>>>>>
> >>>>>> Caution: EXT Email
> >>>>>>
> >>>>>> Hi Ye,
> >>>>>>
> >>>>>> On 14.08.19 12:08, Ye Li wrote:
> >>>>>>> On latest iMX platforms like iMX7D/iMX6UL/iMX8MQ, the QSPI
> >>>>>>> controller is updated to have TDH field in FLSHCR register.
> >>>>>>> According to reference manual, this TDH must be set to 1 when
> >>> DDR_EN is set.
> >>>>>>> Otherwise, the TX DDR delay logic won't be enabled.
> >>>>>>
> >>>>>> This is actually an issue I have experienced myself. But in our
> >>>>>> case this behavior only happened on i.MX6ULL not on i.MX6UL.
> >>>>>> Either the QSPI controller hardware or the BootROM code changed
> >>>>>> when moving from UL to ULL. For details see: [1].
> >>>>>>
> >>>>>>>
> >>>>>>> Another issue in DDR mode is the MCR register will be
> >>>>>>> overwritten in every read/write/erase operation. This causes
> >>>>>>> DDR_EN been cleared while TDH=1, then no clk2x output for TX
> >>>>>>> data shift and all operations will fail.
> >>>>>>
> >>>>>> The best way to fix all of these things (also the ones in the
> >>>>>> other
> >>>>>> patches) would be to fix them in Linux and port the driver from
> >>>>>> Linux to U- Boot. Actually I've already done most of the porting
> >>>>>> [2],
> >>>>> Hello Frieder,
> >>>>>
> >>>>> I had tested your porting and it was not functional on u-boot.
> >>>>> I found that only erase, read up to TX/RX buf size is working or
> >>>>> something like that.
> >>>>> Also ip and AHB mode cannot be used at time in code. Previously
> >>>>> only IP mode was used in u-boot, Since endianness across different
> >>>>> QSPI-IP(ls1012, ls1043, ls1021 big endian), (ls1088,ls2088 little
> >>>>> endian) is not consistent on various silicon's. I am not sure if
> >>>>> Yogesh who worked with you on Linux porting gave you this
> >>>>> information about endianness inconsistency.
> >>>>
> >>>> Ok, thanks for your feedback. The endianness for the different SoCs
> >>>> can be handled by the device data.
> >>>
> >>> Does this work correctly in Linux, or does the Linux driver need fixes?
> >>>
> >>>>
> >>>>> Please suggest way forward. How to correct this issue?
> >>>
> >>> The first thigh would be to make sure the Linux driver works for all
> >>> platforms and then do the porting to U-Boot. I will be out of office
> >>> for
> >>> 10 days. After that I can try to work on this, but I need support
> >>> and testing for other platforms. I only have i.MX6UL/ULL.
> >>
> >> Hi Frieder,
> >>
> >> I have found some break though after porting to 2019.10 and few
> modification in driver code, I will update in a weeks' time. Please  do not
> invest time on this.
> >> If I need some help I will update.
> >
> > Thanks for your work. Do you already have some news? Can you share
> > your results?
> 
> I'm most likely currently running in similar issues on tests with the i.MX6ULL
> EVK. QSPI does not work reliably. So before digging deeper into the QSPI
> driver, I wanted to check on the status of any updates in the driver. Is there
> anything available that I could use for testing already?
Hi Stefan,  Frieder,

The spi-mem version is still under debug, I could make it working for ls1088rdb, ls1046rdb, but it is failing for 
ls1012ardb and ls2088ardb and untested for i.mx and other Layerscape silicon/boards . It is derived from work done by Frieder earlier. This version can be found here:
https://github.com/erashish007/u-boot-spi-mem/tree/spi-mem-port

There is completely working version of fsl_qspi.c based on old xfer method, which was not accepted  in upstream, 
considering it is recommended to migrate to spi-mem frame. This version is located here:
https://github.com/erashish007/u-boot-spi-mem/tree/xfer_wrking

Regards
Ashish 


I have push the working version of these on github.


> 
> Thanks,
> Stefan