# WP7702 Pin Mapping for Kernel

**URL:** <https://forum.sierrawireless.com/t/wp7702-pin-mapping-for-kernel/22521>\
**Category:** IoT Modules\
**Created:** [January 8, 2021, 12:58am UTC](https://forum.sierrawireless.com/t/wp7702-pin-mapping-for-kernel/22521 "2021-01-08T00:58:53Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![dbeckwith](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/dbeckwith/32/4479_2.png) [@dbeckwith](https://forum.sierrawireless.com/u/dbeckwith)\
**Post date:** [January 8, 2021, 12:58am UTC](https://forum.sierrawireless.com/t/wp7702-pin-mapping-for-kernel/22521/1 "2021-01-08T00:58:53Z")

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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](https://forum.mangoh.io/t/gpio-interrupts-on-wp7702-module/1616/2?u=dbeckwith) 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

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**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\
**Post date:** [January 8, 2021, 1:46am UTC](https://forum.sierrawireless.com/t/wp7702-pin-mapping-for-kernel/22521/2 "2021-01-08T01:46:48Z")

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

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<div class="post-metadata">

**Author:** ![dbeckwith](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/dbeckwith/32/4479_2.png) [@dbeckwith](https://forum.sierrawireless.com/u/dbeckwith)\
**Post date:** [January 8, 2021, 6:07pm UTC](https://forum.sierrawireless.com/t/wp7702-pin-mapping-for-kernel/22521/3 "2021-01-08T18:07:53Z")

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@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,

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<div class="post-metadata">

**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\
**Post date:** [January 9, 2021, 1:06am UTC](https://forum.sierrawireless.com/t/wp7702-pin-mapping-for-kernel/22521/4 "2021-01-09T01:06:04Z")

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

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<div class="post-metadata">

**Author:** ![dbeckwith](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/dbeckwith/32/4479_2.png) [@dbeckwith](https://forum.sierrawireless.com/u/dbeckwith)\
**Post date:** [January 12, 2021, 7:42pm UTC](https://forum.sierrawireless.com/t/wp7702-pin-mapping-for-kernel/22521/5 "2021-01-12T19:42:31Z")

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