How can I check status of pinmux of some AM335x pin?


You need to download AM335X Technical Reference Manual document spruh73e.pdf, loot at section 9.3, table 9.10. The offset is 800.
Then you can execute the following command.

root@arm:~# cat /sys/kernel/debug/pinctrl/44e10800.pinmux/pins |grep "884"
The output will be
pin 33 (44e10884.0) 00000032 pinctrl-single
root@arm:~# cat /sys/kernel/debug/pinctrl/44e10800.pinmux/pins |grep "884"
pin 33 (44e10884.0) 00000032 pinctrl-single
root@arm:~#

"884" in the table means "gpmc_csn2" and then compare to the pinmux tool.  The configuration for "gpmc_csn2" is 0×32.  0x32 means input/pullup/mode2 (mmc1_cmd).

To know what this setting means, we can look to the Technical Reference Manual again.

Section 9.3.50 describes what this value means. Table 9-60 shows us each bit:

 

Bit     1       0
5 Receive Enable   Receive disable
4 Pullup   Pulldown
3 Pullup/down Disabled   Pullup/down Enabled
2,1,0   Mode  
Tags: GPIO, Pinmux
Last update:
2014-08-25 18:04
Author:
Eric Lee
Revision:
1.1
Average rating: 4.17 (6 Votes)

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