Dear Daniel, Scott, On Thu, Aug 2, 2012 at 03:55:51 PM, Benoît Thébaudeau wrote: > On Thu, Aug 2, 2012 at 01:28:08 PM, Benoît Thébaudeau wrote: > > On Thu, Aug 2, 2012 at 01:17:07 PM, Daniel Gachet wrote: > > > The mxc_nand driver uses the symmetric mode to access the NAND > > > Flash, > > > but the > > > devices populated on the KARO TX25 only support ann asymmetic > > > mode > > > (MX25: bit 8 within NAND_FLAHS_CONFIG1 register cleared). > > > > > > This patch enables to selected the NAND Flash access mode with > > > the > > > configuration flag CONFIG_SYS_NAND_MXC_NFC_TWO_CYCLES. > [snip] > > Why don't you simply add a factor of two to the CCM NFC divider in > > lowlevel_init.S? > > To be more specific, I also have hardware based on the i.MX25 that > does not use > the NAND Flash from the reference design. It works fine with the > symmetric mode > as long as the NFC prescaler is set up appropriately in the MMC. I > don't think > that it is possible that a NAND Flash device does not support > symmetric mode. So > there should not be any need for a CONFIG_SYS_NAND_MXC_NFC_TWO_CYCLES > config > option. > > All you have to do is to set the appropriate value in PER8 DIV in > PCDR2 (address > 0x53f80020). This can easily be added as a single line to the > init_clocks macro > in board/karo/tx25/lowlevel_init.S. Since the TX25 board does not set > this > register, it is left at its reset value, which is 0x01010101, so the > line to add > would be (dividing the NFC clock twice more): > write32 0x53f80020, 0x01010103 > > This patch is interfering with a patch series that I'd like to post > today or > tomorrow, so please make a quick decision about this, so that I can > know if I > should take this patch into account for my series or if I should > ignore it.
Did you have a chance to test my suggestion on Karo TX25? Do you want me to send a patch for it? Except if adding this config option to the driver adds a real benefit compared to my suggestion, it is probably better to tune the board files first. Best regards, Benoît _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
