Difference between revisions of "How to use GPIO"
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==== Configuration ==== | ==== Configuration ==== | ||
| − | The | + | 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 | |
| − | {| | + | {| cellspacing="1" cellpadding="1" border="1" |
|- | |- | ||
| GPIO Number | | GPIO Number | ||
| − | | | + | | GPIO formed |
| − | | | + | | Numeric Representation |
|- | |- | ||
| GPIO0 | | GPIO0 | ||
| − | | | + | | GPIO7_A3<br/> |
| − | | | + | | 219<br/> |
|- | |- | ||
| GPIO1<br/> | | GPIO1<br/> | ||
| − | | | + | | GPIO7_A4<br/> |
| − | | | + | | 220<br/> |
|- | |- | ||
| GPIO2<br/> | | GPIO2<br/> | ||
| − | | | + | | GPIO7_A5<br/> |
| − | | | + | | 221<br/> |
|- | |- | ||
| GPIO3<br/> | | GPIO3<br/> | ||
| − | | | + | | GPIO7_C5<br/> |
| − | | | + | | 237<br/> |
|- | |- | ||
| GPIO4<br/> | | GPIO4<br/> | ||
| − | | | + | | GPIO8_A2<br/> |
| − | | | + | | 250<br/> |
|- | |- | ||
| GPIO5<br/> | | GPIO5<br/> | ||
| − | | | + | | GPIO8_A3<br/> |
| − | | | + | | 251<br/> |
|- | |- | ||
| GPIO6<br/> | | GPIO6<br/> | ||
| − | | | + | | GPIO8_A0<br/> |
| − | | | + | | 248<br/> |
|- | |- | ||
| GPIO7<br/> | | GPIO7<br/> | ||
| − | | | + | | GPIO8_A1<br/> |
| − | | | + | | 249 |
|} | |} | ||
| Line 56: | Line 61: | ||
Export GPIO0 | Export GPIO0 | ||
| − | <pre># echo | + | <pre># echo 219 > /sys/class/gpio/export |
</pre> | </pre> | ||
Set GPIO direction to in/out | Set GPIO direction to in/out | ||
| − | <pre># echo "out" > /sys/class/gpio/ | + | <pre># echo "out" > /sys/class/gpio/gpio219/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/ | + | <pre># echo 1 > /sys/class/gpio/gpio219/value |
</pre> | </pre> | ||
| Line 70: | Line 75: | ||
Note:You have to configure GPIO to input | Note:You have to configure GPIO to input | ||
| − | <pre># echo "rising" > /sys/class/gpio/ | + | <pre># echo "rising" > /sys/class/gpio/gpio219/edge |
</pre> | </pre> | ||
| Line 79: | Line 84: | ||
Unexport GPIO0 | Unexport GPIO0 | ||
| − | <pre># echo | + | <pre># echo 219 > /sys/class/gpio/unexport |
</pre> | </pre> | ||
==== Test ==== | ==== Test ==== | ||
| − | GPIO | + | GPIO 219 and GPIO 220 are taken as an example: |
| − | *Connect GPIO | + | *Connect GPIO 219 and GPIO 220 |
| − | *Export GPIO | + | *Export GPIO 219 and GPIO 220 |
| − | <pre># echo | + | <pre># echo 219 > /sys/class/gpio/export |
| − | # echo | + | # echo 220 > /sys/class/gpio/export |
</pre> | </pre> | ||
| − | *Set GPIO | + | *Set GPIO 219 to output |
| − | <pre># echo "out" > /sys/class/gpio/ | + | <pre># echo "out" > /sys/class/gpio/gpio219/direction |
</pre> | </pre> | ||
| − | *Set GPIO | + | *Set GPIO 220 to input |
| − | <pre># echo "in" > /sys/class/gpio/ | + | <pre># echo "in" > /sys/class/gpio/gpio220/direction |
</pre> | </pre> | ||
| − | *Change GPIO | + | *Change GPIO 219 to 1 and read GPIO 220 value |
| − | <pre># echo 1 > /sys/class/gpio/ | + | <pre># echo 1 > /sys/class/gpio/gpio219/value |
| − | # cat /sys/class/gpio/ | + | # cat /sys/class/gpio/gpio220/value |
1 | 1 | ||
</pre> | </pre> | ||
| − | *Change GPIO | + | *Change GPIO 219 to 0 and read GPIO 220 value |
| − | <pre># echo 0 > /sys/class/gpio/ | + | <pre># echo 0 > /sys/class/gpio/gpio219/value |
| − | # cat /sys/class/gpio/ | + | # cat /sys/class/gpio/gpio220/value |
| − | 0 | + | 0</pre> |
| − | </pre> | ||
Revision as of 03:59, 22 October 2021
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:
32 x (gpio_bank) + gpio_bit - 8
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
| 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
# echo 219 > /sys/class/gpio/export
Set GPIO direction to in/out
# echo "out" > /sys/class/gpio/gpio219/direction
Set GPIO value 0/1 if GPIO pin define is output
# echo 1 > /sys/class/gpio/gpio219/value
Used as IRQ signal
Note:You have to configure GPIO to input
# echo "rising" > /sys/class/gpio/gpio219/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 219 > /sys/class/gpio/unexport
Test
GPIO 219 and GPIO 220 are taken as an example:
- Connect GPIO 219 and GPIO 220
- Export GPIO 219 and GPIO 220
# echo 219 > /sys/class/gpio/export # echo 220 > /sys/class/gpio/export
- Set GPIO 219 to output
# echo "out" > /sys/class/gpio/gpio219/direction
- Set GPIO 220 to input
# echo "in" > /sys/class/gpio/gpio220/direction
- Change GPIO 219 to 1 and read GPIO 220 value
# echo 1 > /sys/class/gpio/gpio219/value # cat /sys/class/gpio/gpio220/value 1
- Change GPIO 219 to 0 and read GPIO 220 value
# echo 0 > /sys/class/gpio/gpio219/value # cat /sys/class/gpio/gpio220/value 0