Yest another pinmux question

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1

This may be a stupid question, but I have spent the best part of today attempting to figure it out myself.

On the BBB, I see the node:

/sys/kernel/debug/pinctrl/44e10800.pinmux/pins

which contains entries such as:

…
pin 119 (44e109dc) 00000030 pinctrl-single
pin 120 (44e109e0) 00000020 pinctrl-single
pin 121 (44e109e4) 00000030 pinctrl-single
pin 122 (44e109e8) 00000030 pinctrl-single
pin 123 (44e109ec) 00000028 pinctrl-single
pin 124 (44e109f0) 00000028 pinctrl-single
pin 125 (44e109f4) 00000028 pinctrl-single
pin 126 (44e109f8) 00000030 pinctrl-single
…

My question is where do I find the mappings between the decimal pin numbers and the physical terminals? The README in:

https://github.com/jadonk/validation-scripts/tree/master/test-capemgr

shows:
“0x164 0x07 /* P9_42 muxRegOffset, OUTPUT | MODE7 */”,

which in turn refers to pin 89:

pin 89 (44e10964) 00000027 pinctrl-single

Where do I find the rest of the mappings?

Help please,

Dave.

2

Hi Dave,
Table 9-10 in the TRM for the AM335X has the list of CONTROL_MODULE Registers, section 9.3. The pins start at 800h so in the “0x164” you have in your email, the 0x164 is the offset from 0x800, or pin 0x44e10964.

The layout of those registers is in section:
9.3.50 conf__ Register (offset = 800h–A34h)

The TRM can be downloaded from here:
http://www.ti.com/litv/pdf/spruh73h

Nick

3

Thanks Nick. I had seen that, but I still do not see how one gets from Pin 89 to P9_42. The SRM Table 11 indicates processor pin C18 is connected to P9_42 with no mention of pin 89. Obviously I am missing something very simple, just stuck :-[

Dave.