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