From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liam Girdwood Subject: Re: Re: Re: How to access vendor specific AC97 codecregister? Date: Thu, 20 Apr 2006 17:57:52 +0100 Message-ID: <1145552273.25762.22.camel@localhost.localdomain> References: <1145546855.3008.0.camel@mindpipe> <1145549628.25762.4.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: alsa-devel-admin@lists.sourceforge.net Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: alasinski Cc: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org On Thu, 2006-04-20 at 12:37 -0400, alasinski wrote: > Thx Liam, > > > You will only be able to access these functions from an ad-hoc AC97 > > driver. Please see the UCB14xx touch driver for implementation details. > - where I can find it ? Please use Google. > > > Alternatively, you could always export the vendor specific registers > > using sysfs. That way your user space program could read and write to > > the codec registers exported. I've done this with the codec GPIO status > > register (0x54) for the WM97xx touch drivers. As Takashi said this is really not a standard way to do this. Your probably better of writing your own driver to handle your codec GPIO needs. > How to go about using sysfs() to access to registers ? It provides info on > file system equivalent to /proc/filesystems content I'm told. I know of one > way to do it: I can map registers into user space with open("/dev/mem",...) > followed by mmap (...). Then I'm a king and can read/write to any of them. This wont work for AC97 codec registers as they are not part of the host memory map and are accessed via the hosts AC97 controller. > > I've done this with the codec GPIO status register (0x54) for the WM97xx > > touch drivers. > Did you handled AC97 initialization yourself, or you relied on other driver > (exp: ALSA) ? > I used the standard Alsa AC97 codec driver and every thing works fine for me. Liam ------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642