On 08/08/2012 15:55, Benoît Thébaudeau wrote: > The NAND Flash of the KARO TX25 board is a Samsung K9F1G08U0B with 25-ns R/W > cycle times. However, the NFC clock for this board was set to 66.5 MHz, so > using > the NFC driver in symmetric mode (i.e. 1 NFC clock cycle = 1 NF R/W cycle) > resulted in NF R/W cycle times of 15 ns, hence corrupted NF accesses. > > This patch fixes this issue by setting the NFC clock to the highest frequency > complying to the 25-ns NF R/W cycle times specification, i.e. 33.25 MHz. > > Signed-off-by: Benoît Thébaudeau <benoit.thebaud...@advansee.com> > Cc: John Rigby <jcri...@gmail.com> > Cc: Scott Wood <scottw...@freescale.com> > Cc: Stefano Babic <sba...@denx.de> > Cc: Daniel Gachet <daniel.gac...@hefr.ch> > --- > This patch is a replacement solution that I suggest instead of > http://patchwork.ozlabs.org/patch/174735/ since there is no need for a > CONFIG_SYS_NAND_MXC_NFC_TWO_CYCLES config option in the NFC driver. > > It still has to be tested by someone having this board, but I'm very confident > that it works since I have another PCB design based on the i.MX25 with a NAND > Flash with the same timings that works fine using these clock settings. > > .../board/karo/tx25/lowlevel_init.S | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git u-boot-2012.07.orig/board/karo/tx25/lowlevel_init.S > u-boot-2012.07/board/karo/tx25/lowlevel_init.S > index 823df10..eb3f187 100644 > --- u-boot-2012.07.orig/board/karo/tx25/lowlevel_init.S > +++ u-boot-2012.07/board/karo/tx25/lowlevel_init.S > @@ -67,6 +67,14 @@ > write32 0x53f80008, 0x20034000 > > /* > + * PCDR2: NFC = 33.25 MHz > + * This is required for the NAND Flash of this board, which is a Samsung > + * K9F1G08U0B with 25-ns R/W cycle times, in order to make it work with > + * the NFC driver in symmetric (i.e. one-cycle) mode. > + */ > + write32 0x53f80020, 0x01010103 > + > + /*
This is a very local change, only for the Karo-TX25. I see no problem with it. Acked-by: Stefano Babic <sba...@denx.de> Best regards, Stefano Babic -- ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sba...@denx.de ===================================================================== _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
