Xingxing.li: Created page with " === Configuration/Test === ==== Configuration ==== The RK3288 bank/bit notation for GPIOs must be formed as "GPIO_" The numeric value..."

2024-01-16T02:24:37Z

Created page with " === Configuration/Test === ==== Configuration ==== The RK3288 bank/bit notation for GPIOs must be formed as "GPIO<GPIO_bank>_<gpio_bit>" The numeric value..."

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=== Configuration/Test ===

==== Configuration ====

The RK3288 bank/bit notation for GPIOs must be formed as "GPIO<GPIO_bank>_<gpio_bit>" 

The numeric value of GPIO is calculated as follows:
<pre>32 x (gpio_bank) + gpio_bit - 8
</pre>

Group GPIO0 only 24 gpios,So each GPIO Num subtracts 8.

gpio_bit : A0～A7 0-7 B0～B7 8-15 C0～C7 16-23 D0～D7 24-31

E.g. GPIO2_A4 becomes 60

RSB-4680

{| border="1" cellpadding="1" cellspacing="1"
|-
| GPIO Number
| GPIO formed
| Numeric Representation
|-
| GPIO0
| GPIO7_A3
| 219
|-
| GPIO1
| GPIO7_A4
| 220
|-
| GPIO2
| GPIO7_A5
| 221
|-
| GPIO3
| GPIO7_C5
| 237
|-
| GPIO4
| GPIO8_A2
| 250
|-
| GPIO5
| GPIO8_A3
| 251
|-
| GPIO6
| GPIO8_A0
| 248
|-
| GPIO7
| GPIO8_A1
| 249
|}

Test

Export GPIO then you can use control GPIO from userr space through sysfs

Export GPIO0
<pre># echo 219 > /sys/class/gpio/export
</pre>

Set GPIO direction to in/out
<pre># echo "out" > /sys/class/gpio/gpio219/direction
</pre>

Set GPIO value 0/1 if GPIO pin define is output
<pre># echo 1 > /sys/class/gpio/gpio219/value
</pre>

Used as IRQ signal

Note:You have to configure GPIO to input
<pre># echo "rising" > /sys/class/gpio/gpio219/edge
</pre>

*rising: Trigger on rising edge
*falling: Trigger on falling edge
*both: Trigger on both edges
*none: Disable interrupt on both edges

Unexport GPIO0
<pre># echo 219 > /sys/class/gpio/unexport
</pre>

==== Test ====

GPIO 219 and GPIO 220 are taken as an example:

*Connect GPIO 219 and GPIO 220
*Export GPIO 219 and GPIO 220
<pre># echo 219 > /sys/class/gpio/export
# echo 220 > /sys/class/gpio/export
</pre>

*Set GPIO 219 to output
<pre># echo "out" > /sys/class/gpio/gpio219/direction
</pre>

*Set GPIO 220 to input
<pre># echo "in" > /sys/class/gpio/gpio220/direction
</pre>

*Change GPIO 219 to 1 and read GPIO 220 value
<pre># echo 1 > /sys/class/gpio/gpio219/value
# cat /sys/class/gpio/gpio220/value
1
</pre>

*Change GPIO 219 to 0 and read GPIO 220 value
<pre># echo 0 > /sys/class/gpio/gpio219/value
# cat /sys/class/gpio/gpio220/value
0</pre>

RSB-4680 How to use GPIO. - Revision history

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