xref: /OK3568_Linux_fs/u-boot/doc/README.mxc_ocotp (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunDriver implementing the fuse API for Freescale's On-Chip OTP Controller (OCOTP)
2*4882a593Smuzhiyunon MXC
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunThis IP can be found on the following SoCs:
5*4882a593Smuzhiyun - Vybrid VF610,
6*4882a593Smuzhiyun - i.MX6.
7*4882a593Smuzhiyun
8*4882a593SmuzhiyunNote that this IP is different from albeit similar to the IPs of the same name
9*4882a593Smuzhiyunthat can be found on the following SoCs:
10*4882a593Smuzhiyun - i.MX23,
11*4882a593Smuzhiyun - i.MX28,
12*4882a593Smuzhiyun - i.MX50.
13*4882a593Smuzhiyun
14*4882a593SmuzhiyunThe section numbers in this file refer to the i.MX6 Reference Manual.
15*4882a593Smuzhiyun
16*4882a593SmuzhiyunA fuse word contains 32 fuse bit slots, as explained in 46.2.1.
17*4882a593Smuzhiyun
18*4882a593SmuzhiyunA bank contains 8 fuse word slots, as explained in 46.2.1 and shown by the
19*4882a593Smuzhiyunmemory map in 46.4.
20*4882a593Smuzhiyun
21*4882a593SmuzhiyunSome fuse bit or word slots may not have the corresponding fuses actually
22*4882a593Smuzhiyunimplemented in the fusebox.
23*4882a593Smuzhiyun
24*4882a593SmuzhiyunSee the README files of the SoCs using this driver in order to know the
25*4882a593Smuzhiyunconventions used by U-Boot to store some specific data in the fuses, e.g. MAC
26*4882a593Smuzhiyunaddresses.
27*4882a593Smuzhiyun
28*4882a593SmuzhiyunFuse operations:
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun   Read
31*4882a593Smuzhiyun      Read operations are implemented as read accesses to the shadow registers,
32*4882a593Smuzhiyun      using "Bankx Wordy" from the memory map in 46.4. This is explained in
33*4882a593Smuzhiyun      detail by the first two paragraphs in 46.2.1.2.
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun   Sense
36*4882a593Smuzhiyun      Sense operations are implemented as the direct fusebox read explained by
37*4882a593Smuzhiyun      the steps in 46.2.1.2.
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun   Program
40*4882a593Smuzhiyun      Program operations are implemented as explained by the steps in 46.2.1.3.
41*4882a593Smuzhiyun      Following this operation, the shadow registers are not reloaded by the
42*4882a593Smuzhiyun      hardware.
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun   Override
45*4882a593Smuzhiyun      Override operations are implemented as write accesses to the shadow
46*4882a593Smuzhiyun      registers, as explained by the first paragraph in 46.2.1.3.
47*4882a593Smuzhiyun
48*4882a593SmuzhiyunConfiguration:
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun   CONFIG_MXC_OCOTP
51*4882a593Smuzhiyun      Define this to enable the mxc_ocotp driver.
52