Re: [RFC/PATCH] NAND bus-width detection extreme makeover

[Alexander Shiyan]

Hello.

> Here's my proposal, based in Pekon's latest work.
> 
> This patch removes the flash device bus-width configuration, prior to
> the device detection. With this modification, a NAND driver is no longer
> able to "force" the device width, and instead can only obtain the detected
> bus-width after the call to nand_scan_ident().
...
> Alexander: Could you try this patch and see if it's suitable for your needs?
> I think you should be able to use it to set the bus-width, without any need for
> a new DT property. You will have to split your nand_scan() call in an initial
> call to nand_scan_ident() and a final call to nand_scan_tail().

16-bit ONFI:

ONFI param page 0 valid
ONFI flash detected
NAND device: Manufacturer ID: 0x2c, Chip ID: 0xca (Micron MT29F2G16ABAEAWP), 256MiB, page size: 2048, OOB size: 64
Scanning device for bad blocks
1 ofpart partitions found on MTD device MT29F2G16ABAEAWP
Creating 1 MTD partitions on "MT29F2G16ABAEAWP":
0x000000000000-0x000010000000 : "nand-gpio"

8-bit non-ONFI:
NAND device: Manufacturer ID: 0xec, Chip ID: 0x76 (Samsung NAND 64MiB 3,3V 8-bit), 64MiB, page size: 512, OOB size: 16
Scanning device for bad blocks
1 ofpart partitions found on MTD device NAND 64MiB 3,3V 8-bit
Creating 1 MTD partitions on "NAND 64MiB 3,3V 8-bit":
0x000000000000-0x000004000000 : "nand-gpio"

Cannot test 8-bit ONFI, since have not such chip.

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