Is there support for 32bit wide NAND Flash ?
No. The generic NAND driver supports 8/16 bit wide NAND Flash only. 32 bit NAND Flash can be built by using 2 or 4 chips and connect them to D0-7, D8-D15, D16-D23 and D24-D31 on the data bus. You can tie all corresponding control signals together. But you have to build a new nand16 or nand32 driver, which can be derived from the existing nand.c. Be aware, that the writebuffer size is 2 or 4 times as big as on 8 bit NAND. This mean’s, if you flush the buffer to ensure, that your data are on disk, you may waste much more memory space than on 8 bit NAND. Another point is bad block handling. When a block on 1 chip is bad, the corresponding blocks on the other chips are lost too, as you present them as one big block to the filesystem driver. The JFFS2 code, which handles the writebuffer and the out of band (spare) area of NAND doesn’t support 32 bit neither.
