Cherry PUMA SOM-RK3399-Q7 User Manual page 19

The GPIO numbers printed on the board refer to numbers used in the Qseven specification. They are different
than the ones used in Linux via /sys/class/gpio.
The mapping is shown in the following table:
To calculate the Linux GPIO # for CPU pins that are not listed in this table, use the following formula:
n = (block_number * 32)
Where:
• block_number: index of the block number
• sub_block_number: the alphabetical index of the block name, minus 1
• index: the pin number within the block
Example:
GPIO4_D4 -> (4 * 32) +
To enable a GPIO, write the Linux GPIO # to the special export file:
echo 156 > /sys/class/gpio/export
ls /sys/class/gpio/gpio156
cat /sys/class/gpio/gpio156/direction
in
cat /sys/class/gpio/gpio156/value
0
To set the direction to output, write out in the GPIO's direction file:
echo out > /sys/class/gpio/gpio156/direction
echo 1 > /sys/class/gpio/gpio156/value
RK3399-Q7 User Manual
© Cherry Embedded Solutions GmbH
Fig. 3.15: GPIO header
Qseven signal
GPIO0
GPIO1
GPIO2
GPIO3
GPIO4
GPIO5
GPIO6
GPIO7
+ (sub_block_number *
(3 * 8) + 4 = 156
CPU pin Linux GPIO #
GPIO4_D4 156
GPIO4_D1 153
GPIO4_D0 152
GPIO4_D5 157
GPIO4_D2 154
GPIO4_C4 148
GPIO4_C3 147
GPIO4_D3 155
8) + index
v1.6
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