Under what conditions will / sys / kernel / debug / gpio be empty?

Summary

My goal is to manage the GPIO contacts in Peppermint 4 Linux (Kernel version 3.8.0) on an Intel motherboard (NM70 chipset with a C1037U processor).

Am I debugging sysfs interface problems and trying to understand the conditions under which / sys / kernel / debug / gpio will be empty?

When you try to export contacts 0 to 255 using

echo XX > /sys/class/gpio/export

for XX from 0 to 255, the following error message appears

echo: write error: No such device

Under what conditions would / sys / kernel / debug / gpio be empty?

Background

  • Motherboard: Intel with NM70 Chipset
  • Processor: C1037U processor
  • OS: Peppermint 4 Linux
  • Kernel Version: 3.8.0
  • GPIO Interface: sysfs

I am trying to use the sysfs interface, which allows me to get GPIO contacts from user space through the file system.

Ive " : Debian" https://help.ubuntu.com/community/Kernel/Compile, ​​ GPIO GPIO:

​​ , GPIO /sys/class/gpio. , , / GPIO . http://falsinsoft.blogspot.co.uk/2012/11/access-gpio-from-linux-user-space.html.

0 255

echo XX > /sys/class/gpio/export

XX 0 255,

echo: write error: No such device

0 255

echo XX > /sys/class/gpio/export

echo: write error: Invalid argument

, , GPIO , , (/sys/kernel/debug/gpio) , .

,/sys/kernel/debug/gpio .

GPIO BIOS ( HIGH/LOW).

/sys/class/gpio/export

pullup GPIO

+4
1

/sys/kernel/debug/gpio , GPIO (: GPIO, , ).

, GPIO GPIO.

, GPIO , GPIO.

, ​​ PCI GPIO, / PCI. GPIO GPIO.

, GPIO - , GPIO, /sys/kernel/debug/gpio.

" " Linux. , [1].

, GPIO NM70. , - "Panther Point-M" [2]. lpc_ich . ​​ CONFIG_LPC_ICH = y.

, GPIO PCI, lspci , grep .

[1] http://www.oreilly.com/openbook/linuxdrive3/book/ch14.pdf

[2] https://en.wikipedia.org/wiki/List_of_Intel_chipsets

+1

Source: https://habr.com/ru/post/1543601/


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