On Fri, 2009-04-24 at 19:17 +0530, Kapil Pendse wrote: > Hello, > > I have a very basic questions to clear up the confusion that has built > up in my head. I hope someone here will help me out. > > I have a DM355 EVM board, and a daughter board is to be connected to > it. The daughter board will have a voice processor and it will > exchange PCM data with DM355 over McBSP interface. This voice > processor chip has a UART interface which needs to be connected to > UART1 of DM355. The voice processor's configuration registers will be > controlled over this UART1 interface. > > Now, I want to write a driver for this voice processor - say voiceproc.c. > My confusion is this: > > Do I have to use the tty layer in order to establish the connection > with the voice processor? I don't want to give user space applications > direct access to UART1, so I don't want to create /dev/tty* node. > > Instead, I want to create something more like /dev/voiceproc1 (just an > example) with its own set of IOCTLs which expose the voice processor's > functionality to the user applications. These applications will > read/write the PCM data to this device by calling open(), close(), > read() and write() on /dev/voiceproc1.
If you are using ALSA, this is probably not what you want to do. I did some work on DA830/OMAP-l137 which has a daughter card that used SPI to configure the CODEC registers. The code is based on MVL pro 5.0 (2.6.18 kernel). It won't give you all the answers, but it should give you some example code of configuring codec with an interface other than i2c. I'm not in the position to provide the code, but you can probably get it from TI. Regards, Steve > > So again, my question is do I need to use the tty layer to get through > to UART1 or is there any other direct way? > > This device isn't really a terminal so I'm guessing I don't need to go > through the tty layer? > > Please help me out here. Maybe you can direct me to some examples: > some driver of a device which uses the UART interface for > configuration and another interface for actual work (data processing > and transfer). Or maybe some flash chip driver which uses UART > interface for configuration of the flash chip? > > Kindly help. > > Warm regards, > Kapil Pendse > > _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
