Letux Kernel

Devices-Overview

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Table of Content

How to control Devices from user space (command line)

Introduction

This page lists the most important devices and drivers that are specific to this board. And how they can be accessed from user space.

Display

see Video

Audio

see Sound

Headset out / AUX in

The audio amplifier is controlled by (state=0: AUX IN, state=1: AUX OUT)

echo $state >/sys/devices/virtual/gpio/gpio55/value

If enabled, you can't use the AUX IN

Backlight

power (state=0: off, state=1: on)

echo $state >/sys/devices/virtual/gpio/gpio57/value

GPS

see GPS

AUX and Power button

button status can be read through

cat /sys/devices/virtual/gpio/gpio7/value  # 0=AUX pressed

The AUX button is available through the TPS driver as a key event. The power button is available through the TPS driver as a key event.

LEDs are switched through the TCA6507 driver

**** FIXME **** echo $state >/sys/devices/virtual/gpio/gpio70/value # AUX - red echo $state >/sys/devices/virtual/gpio/gpio71/value # AUX - green echo $state >/sys/devices/virtual/gpio/gpio78/value # POWER - red echo $state >/sys/devices/virtual/gpio/gpio79/value # POWER - green

I2C

Depending on the exact version of the board there may be I2C devices (besides the touch screen controller).

You should install http://packages.debian.org/de/lenny/i2c-tools resp. http://www.lm-sensors.org/wiki/I2CTools

Commands

There should be the following commands

  • i2cdetect
  • i2cdump
  • i2cget
  • i2cset

ADCs of the TPS65950

are available through /dev/twl4030-madc and the madc driver. See e.g. http://www.jumpnowtek.com/index.php?option=com_content&view=article&id=79&Itemid=91

ADC0: BATID (default: 0V) ADC1: BATTEMP (default: 1.8V) ADC2: ADC2IN (default: 0V) ADC7: MICSENSE (no headset / short / headset)