On 04/11/2013 02:19:37 PM, Marek Vasut wrote:
Dear Mike Dunn,
This patch adds a driver for the diskonchip G4 nand flash device.
It is
based on the driver from the linux kernel.
This also includes a separate SPL driver. A separate SPL driver is
used
because the device operates in a different mode (reliable mode) when loading a boot image, and also because the storage format of the
boot
image is different from normal data (pages are stored
redundantly). The
SPL driver basically mimics how a typical IPL reads data from the
device.
The special operating mode and storage format are used to
compensate for
the fact that the IPL does not contain the BCH ecc decoding
algorithm (due
to size constraints). Although the u-boot SPL *could* use ecc, it operates like an IPL for the sake of simplicity and uniformity,
since the
IPL and SPL share the task of loading the u-boot image. As a side
benefit,
the SPL driver is very small.
[port from linux kernel 3.4 commit 570469f3bde7f71cc1ece07a18d54a05b6a8775d]
Scott, this really is your turf.
I already acked it (it's up to Mike what he wants to do with dbg). Feel free to pick it up as part of the larger patchset -- it's a dependency for patch 7/7 that adds the board support.
-Scott