On Sun, 2014-12-07 at 06:26 +0100, Marek Vasut wrote: > On Sunday, December 07, 2014 at 02:50:25 AM, Scott Wood wrote: > > On Sun, 2014-12-07 at 02:32 +0100, Marek Vasut wrote: > > > On Sunday, December 07, 2014 at 12:45:30 AM, Scott Wood wrote: > > > > On Sat, 2014-12-06 at 14:07 +0100, Marek Vasut wrote: > > > > > On Tuesday, December 02, 2014 at 02:26:14 PM, Stefan Roese wrote: > > > > > > This patch adds support for multiple NAND chips connected to the > > > > > > i.MX6. Linux already supports this configuration. So lets port > > > > > > the missing features to the U-Boot driver to support more than > > > > > > one NAND chip here as well. > > > > > > > > > > > > The necessary changes in detail are: > > > > > > > > > > > > - Only use DMA channel 0 for all NAND chips: > > > > > > Linux: a7c12d01 (mtd: gpmi: use DMA channel 0 for all the > > > > > > > > > > > > nand chips) > > > > > > > > > > > > d159d8b7 (mtd: gpmi: decouple the chip select from > > > > > > > > > > > > the DMA channel) > > > > > > > > > > > > - On i.MX6 only use ready/busy pin for CS0: > > > > > > Linux: 7caa4fd2 (mtd: gpmi: imx6: fix the wrong method for > > > > > > > > > > > > checking ready/busy) > > > > > > > > > > > > To enable this feature the board needs to configure > > > > > > CONFIG_SYS_NAND_MAX_CHIPS to 2 (or more). > > > > > > > > > > > > With these changes I'm able to detect and acces 2 NAND chips: > > > > > > > > > > > > => nand device > > > > > > > > > > > > Device 0: 2x nand0, sector size 128 KiB > > > > > > > > > > > > Page size 2048 b > > > > > > OOB size 64 b > > > > > > Erase size 131072 b > > > > > > > > > > Shouldn't you see "Device 0" and "Device 1" ? > > > > > > > > The "2x" indicates that there are two identical chips being treated as > > > > a single device (chip->numchips). > > > > > > Is that correct ? What if I have two different NAND chips on this > > > controller? > > > > Then they need to be represented as separate NAND devices, rather than > > multiple chips on one device. > > Gee, I wouldn't have though of that, really ;-)
Well, you asked a vague question... > So is this patch correct or not ? In all its details? I don't know, as I'm not familiar with the hardware. With regards to the question about non-identical devices, this patch doesn't add support for that. So it's a question of what the requirements are, and whether it's being used in the right circumstances. If you have non-identical NAND chips, make sure CONFIG_SYS_NAND_MAX_CHIPS is 1. A better question might be, does this approach make sense, versus implementing support for multiple devices? What does Linux support? -Scott _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
