xref: /openbmc/u-boot/doc/README.mxc_ocotp (revision 112fd2ec6c1a96c6ff51490c28eb971795a2dd95)
1*112fd2ecSBenoît ThébaudeauDriver implementing the fuse API for Freescale's On-Chip OTP Controller (OCOTP)
2*112fd2ecSBenoît Thébaudeauon MXC
3*112fd2ecSBenoît Thébaudeau
4*112fd2ecSBenoît ThébaudeauThis IP can be found on the following SoCs:
5*112fd2ecSBenoît Thébaudeau - i.MX6.
6*112fd2ecSBenoît Thébaudeau
7*112fd2ecSBenoît ThébaudeauNote that this IP is different from albeit similar to the IPs of the same name
8*112fd2ecSBenoît Thébaudeauthat can be found on the following SoCs:
9*112fd2ecSBenoît Thébaudeau - i.MX23,
10*112fd2ecSBenoît Thébaudeau - i.MX28,
11*112fd2ecSBenoît Thébaudeau - i.MX50.
12*112fd2ecSBenoît Thébaudeau
13*112fd2ecSBenoît ThébaudeauThe section numbers in this file refer to the i.MX6 Reference Manual.
14*112fd2ecSBenoît Thébaudeau
15*112fd2ecSBenoît ThébaudeauA fuse word contains 32 fuse bit slots, as explained in 46.2.1.
16*112fd2ecSBenoît Thébaudeau
17*112fd2ecSBenoît ThébaudeauA bank contains 8 fuse word slots, as explained in 46.2.1 and shown by the
18*112fd2ecSBenoît Thébaudeaumemory map in 46.4.
19*112fd2ecSBenoît Thébaudeau
20*112fd2ecSBenoît ThébaudeauSome fuse bit or word slots may not have the corresponding fuses actually
21*112fd2ecSBenoît Thébaudeauimplemented in the fusebox.
22*112fd2ecSBenoît Thébaudeau
23*112fd2ecSBenoît ThébaudeauSee the README files of the SoCs using this driver in order to know the
24*112fd2ecSBenoît Thébaudeauconventions used by U-Boot to store some specific data in the fuses, e.g. MAC
25*112fd2ecSBenoît Thébaudeauaddresses.
26*112fd2ecSBenoît Thébaudeau
27*112fd2ecSBenoît ThébaudeauFuse operations:
28*112fd2ecSBenoît Thébaudeau
29*112fd2ecSBenoît Thébaudeau   Read
30*112fd2ecSBenoît Thébaudeau      Read operations are implemented as read accesses to the shadow registers,
31*112fd2ecSBenoît Thébaudeau      using "Bankx Wordy" from the memory map in 46.4. This is explained in
32*112fd2ecSBenoît Thébaudeau      detail by the first two paragraphs in 46.2.1.2.
33*112fd2ecSBenoît Thébaudeau
34*112fd2ecSBenoît Thébaudeau   Sense
35*112fd2ecSBenoît Thébaudeau      Sense operations are implemented as the direct fusebox read explained by
36*112fd2ecSBenoît Thébaudeau      the steps in 46.2.1.2.
37*112fd2ecSBenoît Thébaudeau
38*112fd2ecSBenoît Thébaudeau   Program
39*112fd2ecSBenoît Thébaudeau      Program operations are implemented as explained by the steps in 46.2.1.3.
40*112fd2ecSBenoît Thébaudeau      Following this operation, the shadow registers are not reloaded by the
41*112fd2ecSBenoît Thébaudeau      hardware.
42*112fd2ecSBenoît Thébaudeau
43*112fd2ecSBenoît Thébaudeau   Override
44*112fd2ecSBenoît Thébaudeau      Override operations are implemented as write accesses to the shadow
45*112fd2ecSBenoît Thébaudeau      registers, as explained by the first paragraph in 46.2.1.3.
46*112fd2ecSBenoît Thébaudeau
47*112fd2ecSBenoît ThébaudeauConfiguration:
48*112fd2ecSBenoît Thébaudeau
49*112fd2ecSBenoît Thébaudeau   CONFIG_MXC_OCOTP
50*112fd2ecSBenoît Thébaudeau      Define this to enable the mxc_ocotp driver.
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