Set pins mode for kernel 3.8

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1

Hello all,

I’m using BBB with latest Angtrom image.

I want to set pins mode for kernel 3.8, I’ve already googled and find this page: http://robotic-controls.com/node/68 but it’s for older kernel.

I want to change some pins to PWM mode. For example, I want to set P8_34 and P8_36 to PWM mode. How to do?

Anyones know how to set mode for these pin please tell me.

Many thanks!

2

http://circuitco.com/support/index.php?title=BeagleBone_Black_FAQ#Can_someone_please_explain_the_Device_Tree_to_me.3F

Gerald

3

I have read device tree, and I did like the document show but I’m still getting only 8 devices, this is the result:

`

sh-4.2# cat /sys/kernel/debug/pwm
platform/48304100.ecap, 1 PWM device
pwm-0 ((null) ):

platform/48304200.ehrpwm, 2 PWM devices
pwm-0 ((null) ):
pwm-1 ((null) ):

platform/48302200.ehrpwm, 2 PWM devices
pwm-0 ((null) ):
pwm-1 ((null) ):

platform/48300100.ecap, 1 PWM device
pwm-0 ((null) ):

platform/48300200.ehrpwm, 2 PWM devices
pwm-0 ((null) ):
pwm-1 ((null) ):

`

4

I want to enable P8_34 PWM pin.

This is content of file: bone_pwm_P8_34-00A0.dts

`

/*

  • Copyright © 2013 CircuitCo
  • Copyright © 2013 Texas Instruments
5

`

cat /sys/devices/bone_capemgr*/slots

0: 54:PF—
1: 55:PF—
2: 56:PF—
3: 57:PF—
4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G
5: ff:P-O-L Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI
7: ff:P-O-L Override Board Name,00A0,Override Manuf,am33xx_pwm

8: ff:P-O-L Override Board Name,00A0,Override Manuf,bone_pwm_P8_13
9: ff:P-O-L Override Board Name,00A0,Override Manuf,bone_pwm_P9_21
10: ff:P-O-L Override Board Name,00A0,Override Manuf,bone_pwm_P9_42
11: ff:P-O-L Override Board Name,00A0,Override Manuf,bone_pwm_P9_14

`

I can enable P8_13, P8_21, P9_42, P9_14 but I can’t enable P8_34 and others else…

My problem is I want to enable 8 pins.

6

Ok man, I’ve disabled HDMI by modidying uEnv.txt

`

optargs=quiet drm.debug=7 capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN

`

and it’s working now. That’s what I need.

Thank you.