On Tue, 29 Jun 2021 07:02:06 -0700 (PDT), in
gmane.comp.hardware.beagleboard.user Radovan Chovan
<
rado991-Re5JQEe...@public.gmane.org> wrote:
>Thanks for all your comments.
>
>Is there any mapping between /sys/class/gpio and schematic diagram of
>Beaglebone Black board?
>
Does
https://vadl.github.io/beagleboneblack/2016/07/29/setting-up-bbb-gpio
provide any help.
P9_24 equates to GPIO15, but in raw pin numbering appears to be 97. As
I recall, there are 32 GPIOs per "CHIP", so that might be the 4th CHIP
(counting from 0), and the second GPIO (again, counting from 0)
>>> divmod(97, 32)
(3, 1)
P9_26 -> GPIO14, raw 96...
>>> divmod(96, 32)
(3, 0)
>>>
HOWEVER,
debian@beaglebone:~$ gpioinfo
gpiochip0 - 32 lines:
line 0: "MDIO_DATA" unused input active-high
<SNIP>
line 12: "UART1_CTSN" "P9_20" input active-high [used]
line 13: "UART1_RTSN" "P9_19" input active-high [used]
line 14: "UART1_RXD" "P9_26" input active-high [used]
line 15: "UART1_TXD" "P9_24" input active-high [used]
line 16: "GMII1_TXD3" unused input active-high
indicates that it is CHIP0, and the "line" 14/15 map to the GPIOxx (so for,
say, GPIO45 it becomes chip 1, line 13)
The gpioinfo command is provided by installing the gpiod package.
debian@beaglebone:~$
/opt/source/bb.org-overlays/tools/beaglebone-universal-io/config-pin -i
p9_26
Pin name: P9_26
Function if no cape loaded: gpio
Function if cape loaded: default gpio gpio_pu gpio_pd gpio_input uart can
i2c pru_uart pruin
Function information: gpio0_14 default gpio0_14 gpio0_14 gpio0_14 gpio0_14
uart1_rxd dcan1_tx i2c1_sda pru_uart pru1_in16
Kernel GPIO id: 14
PRU GPIO id: 46
debian@beaglebone:~$
/opt/source/bb.org-overlays/tools/beaglebone-universal-io/config-pin -i
p9_24
Pin name: P9_24
Function if no cape loaded: gpio
Function if cape loaded: default gpio gpio_pu gpio_pd gpio_input uart can
i2c pru_uart pruin
Function information: gpio0_15 default gpio0_15 gpio0_15 gpio0_15 gpio0_15
uart1_txd dcan1_rx i2c1_scl pru_uart pru0_in16
Kernel GPIO id: 15
PRU GPIO id: 47
debian@beaglebone:~$
(Unfortunately, that script doesn't tell one what "default" mode IS for the
pin, but does have more capability than the compiled config-pin that
replaces it)
--
Dennis L Bieber