There is some note regarding the devmem2 approach for kernel
versions > 2.6.39
NOTE: The devmem2 procedure won't work with kernel
2.6.39 or greater. The source clocks for PWM are now disabled by
default and have to be explicitly enabled before the timer
registers can be accessed. The devmem2 steps below do not do this.
Refer to the omap3-pwm
driver and look for pwm_enable_clock() in pwm.c to see how to
enable the clocks in a driver.
Hope that helps.
Btw.: the omap3-pwm driver works like a charm!
-------- Original Message --------
Subject: [Gumstix-users] Overo devmem2 bus error
From: Robin Moss [hidden email]
To: [hidden email]
Date: 08/28/2012 11:34 PM
looking around and fiddling but haven’t been able to fix
this issue. I’m trying to get PWM working, I have some code
that worked before on an Overo-Air but with my new one it
0x48088024 w 0x00000000
Gives me a Bus
I have google
quite a few things and have tried the following:
CONFIG_OMAP_RESET_CLOCKS – Disabling this in the kernel
config (via menuconfig)
ARCH_HAS_HOLES_MEMORYMODEL – This is enabled in the config
Just to make
sure I'm actually compiling the kernel right (with new