u-boot/doc/README.mxc_ocotp

Driver implementing the fuse API for Freescale's On-Chip OTP Controller (OCOTP)
on MXC

This IP can be found on the following SoCs:
 - Vybrid VF610,
 - i.MX6.

Note that this IP is different from albeit similar to the IPs of the same name
that can be found on the following SoCs:
 - i.MX23,
 - i.MX28,
 - i.MX50.

The section numbers in this file refer to the i.MX6 Reference Manual.

A fuse word contains 32 fuse bit slots, as explained in 46.2.1.

A bank contains 8 fuse word slots, as explained in 46.2.1 and shown by the
memory map in 46.4.

Some fuse bit or word slots may not have the corresponding fuses actually
implemented in the fusebox.

See the README files of the SoCs using this driver in order to know the
conventions used by U-Boot to store some specific data in the fuses, e.g. MAC
addresses.

Fuse operations:

   Read
      Read operations are implemented as read accesses to the shadow registers,
      using "Bankx Wordy" from the memory map in 46.4. This is explained in
      detail by the first two paragraphs in 46.2.1.2.

   Sense
      Sense operations are implemented as the direct fusebox read explained by
      the steps in 46.2.1.2.

   Program
      Program operations are implemented as explained by the steps in 46.2.1.3.
      Following this operation, the shadow registers are not reloaded by the
      hardware.

   Override
      Override operations are implemented as write accesses to the shadow
      registers, as explained by the first paragraph in 46.2.1.3.

Configuration:

   CONFIG_MXC_OCOTP
      Define this to enable the mxc_ocotp driver.