Matrix Keypad

Peter Steinberg

Expert 1640 points

Other Parts Discussed in Thread: AM3352

I'm trying to interface a custom matrix keypad to an AM3352.

The Linux image is very slightly modified from the code in am335x SDK version 01.00.00.00.

I verified the GPIO lines by manually setting and reading them through the standard /sys/class/gpio interface.

I then created and loaded a DTB that defined the GPIO pins and key mapping.

The keypad driver shows up during the boot process:

input: matrix-keypad.8 as /devices/matrix-keypad.8/input/input0

The GPIO pins are mapped correctly when I look at /sys/kernel/debug/gpio.

The keys appear mapped correctly when I run "input-kbd 0" or "evtest /dev/input/event0", but when running evtest I never get any response when I press one of the buttons.

I'm missing something, but I have no idea what.

Thanks,

Peter Steinberg

over 10 years ago

0 Titusrathinaraj Stalin over 10 years ago

TI__Guru** 116100 points

Hi,
I would like you to suggest to put some printk in ISR of matrix driver to confirm that you are getting interrupt event when you press any key.

0 Peter Steinberg over 10 years ago in reply to Titusrathinaraj Stalin

Expert 1640 points

matrix_keypad_interrupt is never called.

I see calls the following calls during the boot process, then no other calls to the matrix keypad module.

matrix_keypad_probe
matrix_keypad_platform_data
matrix_keypad_init_gpio
matrix_keypad_start
matrix_keypad_scan

0 Titusrathinaraj Stalin over 10 years ago in reply to Peter Steinberg

TI__Guru** 116100 points

Hi,
Please make sure that you have done proper pinmuxing for GPIO and configured the GPIO for matrix properly.

I have done matrix keypad driver and not with dts support but board file changes.

0 Peter Steinberg over 10 years ago in reply to Titusrathinaraj Stalin

Expert 1640 points

Thanks.

I knew it had to be something simple; I had the rows and columns reversed in 1 spot in the DTS.

Peter

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Matrix Keypad