xref: /openbmc/u-boot/doc/README.fsl_iim (revision d66ff4ba)
1Driver implementing the fuse API for Freescale's IC Identification Module (IIM)
2
3This IP can be found on the following SoCs:
4 - MPC512x,
5 - i.MX25,
6 - i.MX27,
7 - i.MX31,
8 - i.MX35,
9 - i.MX51,
10 - i.MX53.
11
12The section numbers in this file refer to the i.MX25 Reference Manual.
13
14A fuse word contains 8 fuse bit slots, as explained in 30.4.2.2.1.
15
16A bank contains 256 fuse word slots, as shown by the memory map in 30.3.1.
17
18Some fuse bit or word slots may not have the corresponding fuses actually
19implemented in the fusebox.
20
21See the README files of the SoCs using this driver in order to know the
22conventions used by U-Boot to store some specific data in the fuses, e.g. MAC
23addresses.
24
25Fuse operations:
26
27   Read
28      Read operations are implemented as read accesses to the shadow registers,
29      using "Word y of Bank x" from the register summary in 30.3.2. This is
30      explained in detail in 30.4.5.1.
31
32   Sense
33      Sense operations are implemented as explained in 30.4.5.2.
34
35   Program
36      Program operations are implemented as explained in 30.4.5.3. Following
37      this operation, the shadow registers are reloaded by the hardware (not
38      immediately, but this does not make any difference for a user reading
39      these registers).
40
41   Override
42      Override operations are implemented as write accesses to the shadow
43      registers, as explained in 30.4.5.4.
44
45Configuration:
46
47   CONFIG_FSL_IIM
48      Define this to enable the fsl_iim driver.
49