Can someone clear this GPIO thing?

[Sp0T]

Hello Everyone,

 

I would like to play with my A20 board a bit and would like to use the GPIOs. I checked the forum but it's still not clear what to do and how. Can someone explain to me how to get for example pin 16 on the board?

 

This is the fex:

Spoiler

[gpio_para]
gpio_used = 1
gpio_num = 88
gpio_pin_1 = port:PB20<1><default><default><default>
gpio_pin_2 = port:PB21<1><default><default><default>
gpio_pin_3 = port:PB20<1><default><default><default>
gpio_pin_4 = port:PI03<1><default><default><default>
gpio_pin_5 = port:PB22<1><default><default><default>
gpio_pin_6 = port:PB23<1><default><default><default>
gpio_pin_7 = port:PI14<1><default><default><default>
gpio_pin_8 = port:PI10<1><default><default><default>
gpio_pin_9 = port:PI13<1><default><default><default>
gpio_pin_10 = port:PI12<1><default><default><default>
gpio_pin_11 = port:PI11<1><default><default><default>
gpio_pin_12 = port:PH05<1><default><default><default>
gpio_pin_13 = port:PH03<1><default><default><default>
gpio_pin_14 = port:PH00<1><default><default><default>
gpio_pin_15 = port:PH01<1><default><default><default>
gpio_pin_16 = port:PH01<1><default><default><default>
gpio_pin_17 = port:PI19<1><default><default><default>
gpio_pin_18 = port:PH02<1><default><default><default>
gpio_pin_19 = port:PH02<1><default><default><default>
gpio_pin_20 = port:PI20<1><default><default><default>
gpio_pin_21 = port:PI21<1><default><default><default>
gpio_pin_22 = port:PI17<1><default><default><default>
gpio_pin_23 = port:PH20<1><default><default><default>
gpio_pin_24 = port:PH21<1><default><default><default>
gpio_pin_25 = port:PI16<1><default><default><default>
gpio_pin_26 = port:PI16<1><default><default><default>
gpio_pin_27 = port:PI18<1><default><default><default>
gpio_pin_28 = port:PH05<1><default><default><default>
gpio_pin_29 = port:PI21<1><default><default><default>
gpio_pin_30 = port:PH03<1><default><default><default>
gpio_pin_31 = port:PI20<1><default><default><default>
gpio_pin_32 = port:PH17<1><default><default><default>
gpio_pin_33 = port:PB19<1><default><default><default>
gpio_pin_34 = port:PB18<1><default><default><default>
gpio_pin_35 = port:PH19<1><default><default><default>
gpio_pin_36 = port:PE00<1><default><default><default>
gpio_pin_37 = port:PH16<1><default><default><default>
gpio_pin_38 = port:PE01<1><default><default><default>
gpio_pin_39 = port:PH14<1><default><default><default>
gpio_pin_40 = port:PE03<1><default><default><default>
gpio_pin_41 = port:PE02<1><default><default><default>
gpio_pin_42 = port:PH18<1><default><default><default>
gpio_pin_43 = port:PH11<1><default><default><default>
gpio_pin_44 = port:PE04<1><default><default><default>
gpio_pin_45 = port:PE05<1><default><default><default>
gpio_pin_46 = port:PE06<1><default><default><default>
gpio_pin_47 = port:PE07<1><default><default><default>
gpio_pin_48 = port:PE08<1><default><default><default>
gpio_pin_49 = port:PE09<1><default><default><default>
gpio_pin_50 = port:PE10<1><default><default><default>
gpio_pin_51 = port:PE11<1><default><default><default>
gpio_pin_52 = port:PH13<1><default><default><default>
gpio_pin_53 = port:PI01<1><default><default><default>
gpio_pin_54 = port:PI00<1><default><default><default>
gpio_pin_55 = port:PH07<1><default><default><default>
gpio_pin_56 = port:PH08<1><default><default><default>
gpio_pin_57 = port:PB02<1><default><default><default>
gpio_pin_58 = port:PH09<1><default><default><default>
gpio_pin_59 = port:PD25<1><default><default><default>
gpio_pin_60 = port:PD27<1><default><default><default>
gpio_pin_61 = port:PD26<1><default><default><default>
gpio_pin_62 = port:PH06<1><default><default><default>
gpio_pin_63 = port:PD24<1><default><default><default>
gpio_pin_64 = port:PD23<1><default><default><default>
gpio_pin_65 = port:PD22<1><default><default><default>
gpio_pin_66 = port:PD21<1><default><default><default>
gpio_pin_67 = port:PD20<1><default><default><default>
gpio_pin_68 = port:PD19<1><default><default><default>
gpio_pin_69 = port:PD18<1><default><default><default>
gpio_pin_70 = port:PD17<1><default><default><default>
gpio_pin_71 = port:PD16<1><default><default><default>
gpio_pin_72 = port:PH12<1><default><default><default>
gpio_pin_73 = port:PD00<1><default><default><default>
gpio_pin_74 = port:PD01<1><default><default><default>
gpio_pin_75 = port:PD02<1><default><default><default>
gpio_pin_76 = port:PD03<1><default><default><default>
gpio_pin_77 = port:PD04<1><default><default><default>
gpio_pin_78 = port:PD05<1><default><default><default>
gpio_pin_79 = port:PD06<1><default><default><default>
gpio_pin_80 = port:PD07<1><default><default><default>
gpio_pin_81 = port:PD08<1><default><default><default>
gpio_pin_82 = port:PD09<1><default><default><default>
gpio_pin_83 = port:PD10<1><default><default><default>
gpio_pin_84 = port:PD11<1><default><default><default>
gpio_pin_85 = port:PD12<1><default><default><default>
gpio_pin_86 = port:PD13<1><default><default><default>
gpio_pin_87 = port:PD14<1><default><default><default>
gpio_pin_88 = port:PD15<1><default><default><default>

 

 

Thanks,

Sty

[Sp0T]

Some future more information, my board is an Orange PI mini A20.

 

I tried to use the formla by xunxi :

(position of letter in alphabet - 1) * 32 + pin number

 

But all the numbers are over 88 and i'm not able to export them at all.

 

I try to calculate out 

gpio_pin_16 = port:PH01 but i don't really know it this port 1 or port 16 or none of them. 

it was (8 - 1) * 32 + 1 which is 225 but there are no 225 the max is 88

 

If anyone can help i would thanks that.

 

Regards,

Spot

 

[martinayotte]

From where this 88 number comes from ?

 

Did you tried to do the following commands directly into a shell ?

 

echo 225 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio225/direction
echo 1 > /sys/class/gpio/gpio225/value

 

[Sp0T]

Hello,

 

From the script.bin file(linked in the first post)

 

[gpio_para]
gpio_used = 1
gpio_num = 88

 

Yes, i tried and i got error because there are only 88 ports declared into the script.bin file.

 

Regards,

Sp0T

[martinayotte]

Ok ! but thing 88 means the count of gpio definition lines, not the gpio number. This means, like you've shown in your first post, gpio_pin_1 to gpio_pin_88.

 

Did you try the commands I've provided above ?

 

 

[zador.blood.stained]

AFAIK A10/A20 legacy kernel doesn't use mainline pin numbering, so legacy section in the wiki should apply: https://linux-sunxi.org/GPIO#Accessing_the_GPIO_pins_through_sysfs_on_sunxi-3.4

[Sp0T]

The result:

 

root@orange:~# echo 225 > /sys/class/gpio/export
-bash: echo: write error: Invalid argument
root@orange:~#

[martinayotte]

I'm not using Legacy, but always Mainline, so my previous post was wrong.

 

Zador was right, Legacy image still using the old numbering scheme.

 

So the commands would be more likely be for PH1 :

echo 16 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio16_ph1/direction
echo 1 > /sys/class/gpio/gpio16_ph1/value

 

[Sp0T]

This one worked:

 

echo 16 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio16/direction
echo 1 > /sys/class/gpio/gpio16/value

 

But i still don't know which physical port is this?

[martinayotte]

According to FEX that you provided in first post, it is PH1.

 

[Sp0T]

So gpio_pin_10 = port:PI12 is physically the 12nd pin on the header?

[zador.blood.stained]

9 minutes ago, Sp0T said:

So gpio_pin_10 = port:PI12 is physically the 12nd pin on the header?

No, you have to use the schematic or Wiki to map header pins to SoC pins.

[Sp0T]

Thank you everyone. Based on your hints, i was able to controll a port. And at last i understand it

 

Thank you,

Sp0T