Difference between revisions of "How to use GPIO"

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−
=== Configuration/Test ===
 
  
−
==== Configuration ====
+
= Configuration =
  
−
The general-purpose interface combines eight general-purpose input/output (GPIO) banks.
+
The RK3399 bank/bit notation for GPIOs must be formed&nbsp;as&nbsp;"GPIO<GPIO_bank>_<gpio_bit>"&nbsp;
  
−
Each GPIO module provides 32 dedicated general-purpose pins with input and output capabilities; thus, the general-purpose interface supports up to 256 (8 × 32) pins.
+
The numeric value of GPIO&nbsp;is calculated as follows:
 +
<pre>32 x (gpio_bank) + gpio_bit
 +
</pre>
 +
 
 +
gpio_bit&nbsp;: A0～A7 0-7 B0～B7 8-15 C0～C7 16-23 D0～D7 24-31
 +
 
 +
E.g. GPIO2_B0&nbsp;becomes 72
 +
 
 +
== ROM-5780 ==
 +
 
 +
{| border="1" cellpadding="0" cellspacing="1" width="500"
 +
|-
 +
|
 +
GPIO Number
 +
 
 +
|
 +
GPIO formed
 +
 
 +
|
 +
Numeric Representation
 +
 
 +
|-
 +
|
 +
GPIO0
 +
 
 +
|
 +
GPIO1_A2
 +
 
 +
|
 +
34
 +
 
 +
|-
 +
|
 +
GPIO1
 +
 
 +
|
 +
GPIO1_A3
 +
 
 +
|
 +
35
 +
 
 +
|-
 +
|
 +
GPIO2
  
−
The numeric value of GPIO&nbsp;is calculated as follows:
+
|
−
<pre>32 x (gpio_bank - 1) + gpio_bit</pre>
+
GPIO1_B1
  
−
ROM-7510
+
|
 +
41
  
−
{| cellpadding="1" cellspacing="1" border="1" style="width: 500px;"
 
 
|-
 
|-
−
| GPIO Number
+
|  
−
| Linux OS(/sys/class/gpio/)
+
GPIO3
−
| Default direction
+
 
 +
|  
 +
GPIO1_B2
 +
 
 +
|  
 +
42
 +
 
 
|-
 
|-
−
| GPIO0
+
|  
−
| gpio97<br/>
+
GPIO4
−
| in<br/>
+
 
 +
|  
 +
GPIO1_B5
 +
 
 +
|  
 +
45
 +
 
 
|-
 
|-
−
| GPIO1<br/>
+
|  
−
| gpio218<br/>
+
GPIO5
−
| in<br/>
+
 
 +
|  
 +
GPIO1_C2
 +
 
 +
|  
 +
50
 +
 
 
|-
 
|-
−
| GPIO2<br/>
+
|  
−
| gpio98<br/>
+
GPIO6
−
| in<br/>
+
 
 +
|  
 +
GPIO1_C4
 +
 
 +
|  
 +
52
 +
 
 
|-
 
|-
−
| GPIO3<br/>
+
|  
−
| gpio219<br/>
+
GPIO7
−
| in<br/>
+
 
 +
|  
 +
GPIO1_C6
 +
 
 +
|  
 +
54
 +
 
 
|-
 
|-
−
| GPIO4<br/>
+
|  
−
| gpio100<br/>
+
GPIO8
−
| in<br/>
+
 
 +
|  
 +
GPIO1_C7
 +
 
 +
|  
 +
55
 +
 
 
|-
 
|-
−
| GPIO5<br/>
+
|  
−
| gpio68<br/>
+
GPIO9
−
| in<br/>
+
 
 +
|  
 +
GPIO2_A2
 +
 
 +
|  
 +
66
 +
 
 
|-
 
|-
−
| GPIO6<br/>
+
|  
−
| gpio101<br/>
+
GPIO10
−
| in<br/>
+
 
 +
|  
 +
GPIO2_A3
 +
 
 +
|  
 +
67
 +
 
 
|-
 
|-
−
| GPIO7<br/>
+
|  
−
| gpio69<br/>
+
GPIO11
−
| in
+
 
 +
|  
 +
GPIO4_C5
 +
 
 +
|  
 +
149
 +
 
 
|}
 
|}
  
−
Test
 
  
−
Export GPIO then you can use control GPIO from userr space through sysfs
+
= Test =
 +
 
 +
'''Export GPIO then you can use control GPIO from user space through sysfs.'''
  
 
Export GPIO0
 
Export GPIO0
−
<pre># echo 97 > /sys/class/gpio/export
+
<pre># echo 34 > /sys/class/gpio/export
 
</pre>
 
</pre>
  
 
Set GPIO direction to in/out
 
Set GPIO direction to in/out
−
<pre># echo "out" > /sys/class/gpio/gpio97/direction
+
<pre># echo "out" > /sys/class/gpio/gpio34/direction
 
</pre>
 
</pre>
  
 
Set GPIO value 0/1 if GPIO pin define is output
 
Set GPIO value 0/1 if GPIO pin define is output
−
<pre>#  echo 1 > /sys/class/gpio/gpio97/value
+
<pre>#  echo 1 > /sys/class/gpio/gpio34/value
 
</pre>
 
</pre>
  
Line 70: Line 167:
  
 
Note:You have to configure GPIO to input
 
Note:You have to configure GPIO to input
−
<pre>#  echo "rising" > /sys/class/gpio/gpio97/edge
+
<pre>#  echo "rising" > /sys/class/gpio/gpio34/edge
 
</pre>
 
</pre>
  
−
*rising: Trigger on rising edge
+
*rising: Trigger on rising edge  
−
*falling: Trigger on falling edge
+
*falling: Trigger on falling edge  
−
*both: Trigger on both edges
+
*both: Trigger on both edges  
−
*none: Disable interrupt on both edges
+
*none: Disable interrupt on both edges  
  
 
Unexport GPIO0
 
Unexport GPIO0
−
<pre># echo 97 > /sys/class/gpio/unexport
+
<pre># echo 34 > /sys/class/gpio/unexport
 
</pre>
 
</pre>
  
−
==== Test ====
+
'''Test'''
  
−
GPIO&nbsp;97 and GPIO&nbsp;218 are taken as an example:
+
GPIO0 and GPIO1 are taken as an example:
  
−
*Connect GPIO&nbsp;97 and GPIO 218
+
*Connect GPIO0 and GPIO1
−
*Export GPIO&nbsp;97 and GPIO 218
+
*Export GPIO0 and GPIO1
−
<pre># echo 97 > /sys/class/gpio/export
+
<pre># echo 34 > /sys/class/gpio/export
−
# echo 218 > /sys/class/gpio/export
+
# echo 35 > /sys/class/gpio/export
 
</pre>
 
</pre>
  
−
*Set GPIO&nbsp;97 to output
+
*Set GPIO 1 to output  
−
<pre># echo "out" > /sys/class/gpio/gpio97/direction
+
<pre># echo "out" > /sys/class/gpio/gpio34/direction
 
</pre>
 
</pre>
  
−
*Set GPIO 218 to input
+
*Set GPIO 2 to input  
−
<pre># echo "in" > /sys/class/gpio/gpio218/direction
+
<pre># echo "in" > /sys/class/gpio/gpio35/direction
 
</pre>
 
</pre>
  
−
*Change GPIO&nbsp;97 to 1 and read GPIO&nbsp;218 value
+
*Change GPIO 0 to 1 and read GPIO 2 value  
−
<pre># echo 1 > /sys/class/gpio/gpio97/value
+
<pre># echo 1 > /sys/class/gpio/gpio34/value
−
# cat /sys/class/gpio/gpio218/value
+
# cat /sys/class/gpio/gpio35/value  
 
1
 
1
 
</pre>
 
</pre>
  
−
*Change GPIO&nbsp;97 to 0 and read GPIO 218 value
+
*Change GPIO 0&nbsp;to 0 and read GPIO 2&nbsp;value  
−
<pre># echo 0 > /sys/class/gpio/gpio97/value
+
<pre># echo 0 > /sys/class/gpio/gpio34/value
−
# cat /sys/class/gpio/gpio218/value
+
# cat /sys/class/gpio/gpio35/value  
 
0
 
0
 
</pre>
 
</pre>

Latest revision as of 02:50, 6 June 2023

Configuration

The RK3399 bank/bit notation for GPIOs must be formed as "GPIO<GPIO_bank>_<gpio_bit>" 

The numeric value of GPIO is calculated as follows: 

32 x (gpio_bank) + gpio_bit

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

E.g. GPIO2_B0 becomes 72

ROM-5780

GPIO Number

GPIO formed

Numeric Representation

GPIO0

GPIO1_A2

34

GPIO1

GPIO1_A3

35

GPIO2

GPIO1_B1

41

GPIO3

GPIO1_B2

42

GPIO4

GPIO1_B5

45

GPIO5

GPIO1_C2

50

GPIO6

GPIO1_C4

52

GPIO7

GPIO1_C6

54

GPIO8

GPIO1_C7

55

GPIO9

GPIO2_A2

66

GPIO10

GPIO2_A3

67

GPIO11

GPIO4_C5

149


Test

Export GPIO then you can use control GPIO from user space through sysfs.

Export GPIO0 

# echo 34 > /sys/class/gpio/export

Set GPIO direction to in/out 

# echo "out" > /sys/class/gpio/gpio34/direction

Set GPIO value 0/1 if GPIO pin define is output 

#  echo 1 > /sys/class/gpio/gpio34/value

Used as IRQ signal

Note:You have to configure GPIO to input 

#  echo "rising" > /sys/class/gpio/gpio34/edge
  • rising: Trigger on rising edge
  • falling: Trigger on falling edge
  • both: Trigger on both edges
  • none: Disable interrupt on both edges

Unexport GPIO0 

# echo 34 > /sys/class/gpio/unexport

Test

GPIO0 and GPIO1 are taken as an example:

  • Connect GPIO0 and GPIO1
  • Export GPIO0 and GPIO1 
# echo 34 > /sys/class/gpio/export
# echo 35 > /sys/class/gpio/export
  • Set GPIO 1 to output 
# echo "out" > /sys/class/gpio/gpio34/direction
  • Set GPIO 2 to input 
# echo "in" > /sys/class/gpio/gpio35/direction
  • Change GPIO 0 to 1 and read GPIO 2 value 
# echo 1 > /sys/class/gpio/gpio34/value
# cat /sys/class/gpio/gpio35/value 
1
  • Change GPIO 0 to 0 and read GPIO 2 value 
# echo 0 > /sys/class/gpio/gpio34/value
# cat /sys/class/gpio/gpio35/value 
0
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