On Thu, 2007-02-08 at 07:58 -0800, Brad Beveridge wrote: > On 08/02/07, Liam Girdwood <lg@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > On Wed, 2007-02-07 at 13:23 -0800, Brad Beveridge wrote: > > > > > On the codec side I've started with the AK4535, and pulled out almost > > > everything interesting. The AK4550 has two input pins which control a > > > de-emphasis filter for when the codec does ADC conversions, but I > > > don't really know what to do with them. > > > > > > > I would suggest contacting AKM for information on the input pins. > > > > > On to the questions: > > > 1) Is the AK4550 codec really without registers like I think it is? > > > 2) What is the best way to hook up the de-emphasis pins and expose > > > them? I feel like I need generic functions in the codec to control > > > them, and those generics should somehow hook to machine-specific > > > functions. I don't know how to do this. > > > 3) Am I basically on the right track here? > > > > Please check 1,2 and 3 with AKM. > Hi, and thanks for the quick reply. > I think I spoke imprecisely with regard to #2. I know how the > de-emphasis pins are physically hooked up to the SA2410, they are just > GPIOs. What I am unsure about is exactly how to expose control of > these GPIOs. I see now, I thought you were asking what they should be routed to in the schematics. > My thoughts are that control of these pins is somewhat > analogous to reading/writing registers on a codec, and so therefore > the codec driver should expose an interface to the outside world that > lets you turn on/off the de-emphasis input filter. To actually > configure the pins, the codec needs to call out to functions in the > machine-specific driver - analogous to the hw_read/hw_write functions. > Hmm, using these functions may actually be the correct thing to do in > this case. If they are the correct way to access machine specific > stuff, do I just setup the hw_read/write pointers in my > machine_codec_init function? (ie the function smdk2440_uda1341_init > in smdk2440.c). > I would probably create a mixer kcontrol in your machine driver for the deemphasis. I know it's technically codec specific, but the hardware control method is very machine specific. I would also probably stick a comment in you codec driver stating this. Anyone then creating a new machine driver for this codec can then copy and modify your original kcontrol. 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 _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-devel
