WP7702 Pin Mapping for Kernel

IoT Modules
1

Hi all,

I’m migrating from WP8548 modules to WP7702 modules on our customer circuit board. One of our kernel drivers requires CF3_GPIO21 to be used in order to set up the I2C hub.

I understand from these this post that actual GPIO numbers for used but the kernel are different than the actual GPIO numbers. I have followed these posts and tried to build from the Yocto source but I am not having much luck finding the ext_gpio_wp gpiolib-sysfs.c.

Can someone please post the pin mapping or the WP7702 or help me locate it?

Thanks,
Darren

2

The GPIO21 of WP8548 and WP77xx are both on pin 147.
To check what is the internal mapping to the MDM chipset, you can see the following example on checking GPIO23: (of course you need to change it to GPIO21 for your case)

  1. typing “echo 23 > /sys/class/gpio/export” in console
  2. see the MDM_GPIO in dmesg kernel log which is GPIO 10.
    [ 172.509405] gpio_sync_ri: RI owner is Modem
    [ 172.509432] gpio_map_name_to_num: find GPIO 10
    [ 172.509442] export_store: Export GPIO: 10

BTW, do you find the the ext_gpio_wp gpiolib-sysfs.c in R12?

https://source.sierrawireless.com/resources/airprime/software/wp77xx/wp77xx-firmware-release-12-components/#sthash.isosBRm7.dpbs

3

@jyijyi

Thank you for your quick response and the tip about the /sys/class/gpio/export. I was able to find the pin number of the module.

I tried looking in R13 for ext_gpio_wp in gpiolib-sysfs.c but it was in the source that I downloaded. I’d like to know how to find it.

Thanks,

4

I don’t find it in r13, but i remember it was in r9

5

@jyijyi Thank you for your help. I will try downloading R9.