xref: /openbmc/u-boot/doc/README.mxc_ocotp (revision 8a00061e)
1Driver implementing the fuse API for Freescale's On-Chip OTP Controller (OCOTP)
2on MXC
3
4This IP can be found on the following SoCs:
5 - i.MX6.
6
7Note that this IP is different from albeit similar to the IPs of the same name
8that can be found on the following SoCs:
9 - i.MX23,
10 - i.MX28,
11 - i.MX50.
12
13The section numbers in this file refer to the i.MX6 Reference Manual.
14
15A fuse word contains 32 fuse bit slots, as explained in 46.2.1.
16
17A bank contains 8 fuse word slots, as explained in 46.2.1 and shown by the
18memory map in 46.4.
19
20Some fuse bit or word slots may not have the corresponding fuses actually
21implemented in the fusebox.
22
23See the README files of the SoCs using this driver in order to know the
24conventions used by U-Boot to store some specific data in the fuses, e.g. MAC
25addresses.
26
27Fuse operations:
28
29   Read
30      Read operations are implemented as read accesses to the shadow registers,
31      using "Bankx Wordy" from the memory map in 46.4. This is explained in
32      detail by the first two paragraphs in 46.2.1.2.
33
34   Sense
35      Sense operations are implemented as the direct fusebox read explained by
36      the steps in 46.2.1.2.
37
38   Program
39      Program operations are implemented as explained by the steps in 46.2.1.3.
40      Following this operation, the shadow registers are not reloaded by the
41      hardware.
42
43   Override
44      Override operations are implemented as write accesses to the shadow
45      registers, as explained by the first paragraph in 46.2.1.3.
46
47Configuration:
48
49   CONFIG_MXC_OCOTP
50      Define this to enable the mxc_ocotp driver.
51