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From: Dominik Brodowski <linux@brodo.de>
To: Edward Macfarlane Smith <snowfire@blueyonder.co.uk>
Cc: cpufreq@www.linux.org.uk
Subject: Re: How to control the speed?
Date: Mon, 23 Jun 2003 15:53:40 +0200	[thread overview]
Message-ID: <20030623135340.GG2330@brodo.de> (raw)
In-Reply-To: <200306230047.09481.snowfire@blueyonder.co.uk>

On Mon, Jun 23, 2003 at 12:47:09AM +0100, Edward Macfarlane Smith wrote:
> I'm writing a little graphical utility to allow you to specify the default 
> speed when switching between AC and battery, and also the screen brightness.
> At the moment it's specifically for my Sony Z1SP, so it will probably end
> up a mix of ACPI/cpufreq/sonypi.
>
> Currently I've got the screen brightness working as it can make some ioctl
> calls to /dev/sonypi. 
>
> I was wondering if there are any ioctls for setting the speed using cpufreq 
> or should I just open "/proc/cpufreq" and write a string to it?. I'd also
> like to know how to read the possible speeds, again in an ioctl.

In 2.5., this is easily possible [scaling_available_frequencies in the
corresponding sysfs directory], for 2.4., there is no such file but one of
the cpufreq daemons has some code in it to detect the speeds nonetheless.

All interfaces to cpufreq are either /proc files - sysctl's [sort of
deprecated] or sysfs files [2.5. only, though]

	Dominik

      reply	other threads:[~2003-06-23 13:53 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-06-22 23:47 How to control the speed? Edward Macfarlane Smith
2003-06-23 13:53 ` Dominik Brodowski [this message]

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