change cpu_freq

change cpu_freq

[Martin Margraf]

hi,

how can i change the cpu frequency of my osk5912 using the 
scale_cpu_freq feature of the 2.6.16 kernel? how is the syntax of this? 
is there a documentation available (except the ones in the documentation 
folder of my linux directory)?

my next question is, how can i read/write to the regs of the omap5912? 
during using 2.4 kernel i was able to access the regs directly with a 
module. but now with 2.6 kernel i get a segmentation fault. maybe 
someone can help me?

regards

martin

Re: change cpu_freq

[Juha Yrjölä]

Martin Margraf wrote:

> my next question is, how can i read/write to the regs of the omap5912? 
> during using 2.4 kernel i was able to access the regs directly with a 
> module. but now with 2.6 kernel i get a segmentation fault. maybe 
> someone can help me?

Nowadays there isn't 1-to-1 mapping between physical and virtual I/O 
addresses.  If you're operating on a physical address, you can use the 
omap_{read,write} helper macros to access the registers.  Alternatively, 
you can convert the physical address to a virtual one first by io_p2v(), 
  after which the memory accesses can be done directly.

Cheers,
Juha

RE: change cpu_freq

[Minjie Lin]

Hi Martin,

You can select userspace governor for cpu_freq and change
/sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed value
to change the cpu frequency.

Regards,

Minjie
 

-----Original Message-----
From:
linux-omap-open-source-bounces+mlin=empowertechnologies.com@linux.omap.c
om
[mailto:linux-omap-open-source-bounces+mlin=empowertechnologies.com@linu
x.omap.com] On Behalf Of Martin Margraf
Sent: June 14, 2006 5:34 AM
To: linux-omap-open-source@linux.omap.com
Subject: change cpu_freq

hi,

how can i change the cpu frequency of my osk5912 using the
scale_cpu_freq feature of the 2.6.16 kernel? how is the syntax of this? 
is there a documentation available (except the ones in the documentation
folder of my linux directory)?

my next question is, how can i read/write to the regs of the omap5912? 
during using 2.4 kernel i was able to access the regs directly with a
module. but now with 2.6 kernel i get a segmentation fault. maybe
someone can help me?

regards

martin
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Linux-omap-open-source@linux.omap.com
http://linux.omap.com/mailman/listinfo/linux-omap-open-source

RE: change cpu_freq

[Martin Margraf]

hi minjie,

thanks for the answer.
how is the syntax of this? like "echo scaling_setspeed=value > /sys/devices...." ?

martin

> -----Ursprüngliche Nachricht-----
> Von: "Minjie Lin" <MLin@EmpowerTechnologies.com>
> Gesendet: 15.06.06 20:19:01
> An:  <linux-omap-open-source@linux.omap.com>
> Betreff: RE: change cpu_freq


> Hi Martin,
> 
> You can select userspace governor for cpu_freq and change
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed value
> to change the cpu frequency.
> 
> Regards,
> 
> Minjie
>  
> 
> -----Original Message-----
> From:
> linux-omap-open-source-bounces+mlin=empowertechnologies.com@linux.omap.c
> om
> [mailto:linux-omap-open-source-bounces+mlin=empowertechnologies.com@linu
> x.omap.com] On Behalf Of Martin Margraf
> Sent: June 14, 2006 5:34 AM
> To: linux-omap-open-source@linux.omap.com
> Subject: change cpu_freq
> 
> hi,
> 
> how can i change the cpu frequency of my osk5912 using the
> scale_cpu_freq feature of the 2.6.16 kernel? how is the syntax of this? 
> is there a documentation available (except the ones in the documentation
> folder of my linux directory)?
> 
> my next question is, how can i read/write to the regs of the omap5912? 
> during using 2.4 kernel i was able to access the regs directly with a
> module. but now with 2.6 kernel i get a segmentation fault. maybe
> someone can help me?
> 
> regards
> 
> martin
> _______________________________________________
> Linux-omap-open-source mailing list
> Linux-omap-open-source@linux.omap.com
> http://linux.omap.com/mailman/listinfo/linux-omap-open-source


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RE: change cpu_freq

[Minjie Lin]

 Hi Martin,

 just use "echo value > /sys/devices..../scaling_setspeed"

 Minjie


-----Original Message-----
From: Martin Margraf [mailto:m_margraf@web.de] 
Sent: June 15, 2006 11:41 PM
To: Minjie Lin
Cc: linux-omap-open-source@linux.omap.com
Subject: RE: change cpu_freq

hi minjie,

thanks for the answer.
how is the syntax of this? like "echo scaling_setspeed=value > /sys/devices...." ?

martin

> -----Ursprüngliche Nachricht-----
> Von: "Minjie Lin" <MLin@EmpowerTechnologies.com>
> Gesendet: 15.06.06 20:19:01
> An:  <linux-omap-open-source@linux.omap.com>
> Betreff: RE: change cpu_freq


> Hi Martin,
> 
> You can select userspace governor for cpu_freq and change 
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed value to change 
> the cpu frequency.
> 
> Regards,
> 
> Minjie
>  
> 
> -----Original Message-----
> From:
> linux-omap-open-source-bounces+mlin=empowertechnologies.com@linux.omap
> linux-omap-open-source-bounces+.c
> om
> [mailto:linux-omap-open-source-bounces+mlin=empowertechnologies.com@li
> nu x.omap.com] On Behalf Of Martin Margraf
> Sent: June 14, 2006 5:34 AM
> To: linux-omap-open-source@linux.omap.com
> Subject: change cpu_freq
> 
> hi,
> 
> how can i change the cpu frequency of my osk5912 using the 
> scale_cpu_freq feature of the 2.6.16 kernel? how is the syntax of this?
> is there a documentation available (except the ones in the 
> documentation folder of my linux directory)?
> 
> my next question is, how can i read/write to the regs of the omap5912? 
> during using 2.4 kernel i was able to access the regs directly with a 
> module. but now with 2.6 kernel i get a segmentation fault. maybe 
> someone can help me?
> 
> regards
> 
> martin
> _______________________________________________
> Linux-omap-open-source mailing list
> Linux-omap-open-source@linux.omap.com
> http://linux.omap.com/mailman/listinfo/linux-omap-open-source


_____________________________________________________________________
Der WEB.DE SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen!
http://smartsurfer.web.de/?mc=100071&distributionid=000000000071