Pinmux - enabling SPI

In the process of digging through the details of how to enable some of the extra peripherals through devicetree and what pinmux settings are required I came across some things in the tables on p71 & 73 of the BBB_SRM that I couldn't get my head around or that didn't look quite right.

Unfortunately working out if the table was even correct was less than easy as you need to cross correlate a table in the am3359 datasheet with a horribly akwardly formatted table in the AM335x Technical ref manual that's spread out over nearly 30 pages and see if that matches what's in the BBB_SRM.

A lot of cut&pasting and processing with perl later I came up with my own version of the tables from the BBB_SRM, since I already did all the work, I thought I'd save anyone else the trouble and share them with you here.

The mapping of pins on P8 & P9 to pin numbers on the SoC come from the BBB_SRM, that was then used to map to the data from the am3359 datasheet and TRM. The functions marked with a * are the default for that pin after reset, but your kernel can obviously change those before you get access. You need the pinmux register offset to understand what the pinctrl settings in the devicetree files are doing.

Hope you find it useful..

looks like the forum is constraining the width of the tables, you should see the headings go out to a column for mode 7, but you need a fairly large monitor to see that, so I've attached a pdf version here

Attachments:

pinmux.pdf

Very useful, selsinork, many thanks!

If you can poke this and (separately) the pre-PDF text output into a flat file on Github or somewhere, that would be a great BBB resource!

And grep would thank you too.

PS. Or on eLinux.org if you prefer to maintain wiki tables.  I'd like to add it as a link under Resources at elinux.org/BeagleBone, that would be very useful.

I'm crap at getting tables into wiki's

https://github.com/selsinork/beaglebone-black-pinmux

The script, source data I used along with the output in text and as an ods spreadsheet are there too.

have a look in the commit message for some details on how to re-use it...  digging the big table out of the am3359 datasheet is painful and the format is all over the place, notes on various lines throw things out too. Rather than try to try to build a script that handled everything I manually edited the table data down just enough for the script to be able to pull the appropriate column data out.

Excellent, I linked your repo under http://elinux.org/BeagleBone#Home_page_and_Community .  Thankees!

I shall await the cries of "why not write it in python" or "you'll never win the perl obfuscation contest with code like that" with baited breath

I shall await the cries of "why not write it in python" or "you'll never win the perl obfuscation contest with code like that" with baited breath

LOL, don't worry about them.  (I'm sure you're not.)

The only response to give language fanboys is "Engineers have more than one tool in their toolkit".

And more than one OS on their computer

MK