mach-mxs pwm implementation question

Arnd Bergmann arnd at
Tue Jun 21 10:31:53 EDT 2011

On Tuesday 21 June 2011, Andreas Mueller wrote:
> For a karo tx28 (freescale imx28 or mach-mxs) I try to build a kernel 
> with LCD backlight enabled and get
> | drivers/built-in.o: In function `pwm_backlight_suspend':
> | clkdev.c:(.text+0xfe38): undefined reference to `pwm_config'
> | clkdev.c:(.text+0xfe40): undefined reference to `pwm_disable'
> | drivers/built-in.o: In function `pwm_backlight_remove':
> | clkdev.c:(.text+0xfe84): undefined reference to `pwm_config'
> | clkdev.c:(.text+0xfe8c): undefined reference to `pwm_disable'
> | clkdev.c:(.text+0xfe94): undefined reference to `pwm_free'
> | drivers/built-in.o: In function `pwm_backlight_update_status':
> | clkdev.c:(.text+0xff14): undefined reference to `pwm_config'
> | clkdev.c:(.text+0xff1c): undefined reference to `pwm_disable'
> | clkdev.c:(.text+0xff48): undefined reference to `pwm_config'
> | clkdev.c:(.text+0xff50): undefined reference to `pwm_enable'
> | drivers/built-in.o: In function `pwm_backlight_probe':
> | clkdev.c:(.text+0x10020): undefined reference to `pwm_request'
> | clkdev.c:(.text+0x100a0): undefined reference to `pwm_free'
> I saw in [1] that there was an attempt to create a pwm-framework with mxs 
> implementation as example but it did not find its way to mainline because of a 
> better pwm framework already available ( rejected implemetation still can be 
> downloaded at karo website ). Before trying to do myself: Is anybody working on 
> a implementation fitting linux/pwm.h?

I think that Sascha still plans to submit that driver again. Viresh
already posted another driver to go into the drivers/pwm/ directory
with the intention of converting that once the common code coes in.


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