Adding a matrix keypad to Verdin iMX8MM running Torizon

Technical Support
, , , ,
4

Does the matrix_keypad driver produce any error or messages in dmesg or anywhere? Otherwise I’m not sure how I can assume what the issue here is.

I’ve added pinctrl-names and pinctrl-0 properties to the matrix_keypad node, but I didn’t find their description as required/optional property, in gpio-matrix-keypad.txt

The pinctrl-0 wouldn’t be specified in the driver documentation. This is because pinctrl-0 is a detail of the iomuxc system that the SoC uses to pinmux the pins. Even in the example I provided with the backlight node. This property isn’t specified by the pwm-backlight driver but it’s still needed.

What I’m not sure is if the values I set on different GPIO inside the node pinctrl_gpio_matrix_keypad are correct/valid. I set 0x106 in all cases, I copied from the pinctrl_gpio1, 2,... of imx8mm-verdin.dtsi, assuming they were for GPIO configuration, but I didn’t find exactly what those values means in imx8mm reference manual. Do you know which are the register I have to look to know how to set this fileds?

These “magic numbers” are documented in the reference manual for the i.MX8M SoC. These tune things like drive strength and such. You’d need to consult the reference manual to figure out what exactly 0x106 means.

Best Regards,
Jeremias