[alsa-devel] CS4270 supported?

Liam Girdwood lg at opensource.wolfsonmicro.com
Wed Apr 18 11:45:04 CEST 2007

Hi Timur,

On Tue, 2007-04-17 at 16:01 -0500, Timur Tabi wrote:
> I've never worked with ALSA before, but I'm about to start developing on an ALSA driver 
> for our hardware, which has a CS4270 on it attached via an I2S interface.  After scanning 
> the source code and mailing lists, I see no mention of the CS4270.  So does that mean I 
> would need to write an ASoC codec driver for the CS4270? 

You will need to write a codec driver for the CS4270 and a small machine
driver for your board (there are lots of examples in my git tree). The
codec driver will export mixers, configure the digital audio interface,
setup any codec PLL's etc. The machine driver glues the codec to your
platform and does any machine specific configuration e.g. gpio, clocks,
audio mux (on i.MXxx)  

I assume your either targeting the i.MX21/27 or i.MX31 ?

Fwiw, I've made a start to i.MX31 ASoC DMA (based on the Freescale BSP)
and I'm actively working on this atm. dev branch is here :-


However, I don't have any bandwidth atm to work on i.MX21. 

>  If so, does the data sheet 
> (http://www.cirrus.com/en/pubs/proDatasheet/CS4270_PP1.pdf) contain enough information?

I've had a quick look and I think you have all the information that will
be required for your driver.

More docs can be found here (must add to new ALSA Wiki) :-



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