Reference ALSA SoC codec drivers for the above mentioned devices are now available from gitorious.org. Please see this wiki article for more details. These device drivers have undergone limited testing on select OMAP3- and OMAP4-based platforms. While every attempt has been made to adhere to guidelines for the development of ALSA SoC codec drivers, use of these drivers on other application processor platforms may require significant additional plumbing.
Device variants that include the miniDSP also require a binary firmware to be made available to the driver by the system. The firmware may be built from PurePath™ Studio GDE process flows using firmware tools attached to this post. Additional information is available in this wiki article and in documents contained in the attached package.
These drivers are recommend for all use with Linux kernels 2.6.37 and newer.
UPDATE (19-Mar-2014):
For audio converter devices not mentioned in the subject line, chances are you can find a ready made driver in the open source kernel distribution (NOTE: The links below lead to a popular Linux source cross-reference site should you need to take a quick look at how the driver is implemented. You do not need to download from there; you will find the right copy for your kernel version under the path mentioned within the source tree you have)
AIC23: sound/soc/codecs/tlv320aic23.c
AIC33,AIC3101,AIC3104,AIC3107: sound/soc/codecs/tlv320aic3x.c
AIC3204: sound/soc/codecs/tlv320aic32x4.c
