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IMX6SL-EVK-PL reading/writing GPIO/kpp

Question asked by moranmoran on Jun 14, 2017
Latest reply on Jun 26, 2017 by moranmoran



I'm working on the IMX6SL EVB.

using Kernel 3.10.53 and imx6sl-evk-pl.dtb.


I've several questions regarding read/write GPIO/KPP ( from user space ) :



1) After setting (export,direction ...) all needed in order to write / read from GPIO there are few that works and some that doesn't.

for example all the LCD_DATX works (read/write) while other like LED_DEBUG (HSIC_STROBE) that doesn't.

Where is the place that i can see the diffrent between them and how to enable the ones that dowsn't works.


2) Probably same question as above , just fucus on KPP.

i can see kernel prints of evbug while press on the push buttons , but i can't read them from user space.


3) what is the diffrent between Device tree pinctrl setting to the setting register in the imx6sl-pinfunc.h

for example (for the KEY_ROW0) in the device tree the setting is : 0x1b0b0

while in the header the setting is :  0x18C 0x494 0x754 0x0 0x0

what each configure ? 


Thanks in advance