2014-09-24 19:42 GMT+08:00 Mark Brown broonie@kernel.org:
On Wed, Sep 24, 2014 at 06:02:40PM +0800, Scott Jiang wrote:
2014-09-24 16:26 GMT+08:00 Mark Brown broonie@kernel.org:
Can you go into a bit more detail on the differences - clearly there's some similarlities since the drivers got merged, can we really not share any code?
First, sport2 only supports i2s and left justified mode, while sport3 adds i2s packed and right justified mode. Second, in tdm mode for sport2, tx and rx are dependent and have a window granularity of 8 channel. While sport3 doesn't have these limits. What's more, sport3 is not only used on blackfin. That means many patches can only apply to this driver.
These sound more like extended functionality and tweaks rather than massive updates which need a completely separate driver - new modes and so on.
Yes, it looks similar in i2s mode. But in tdm mode, because we don't need to copy 2 channels user buffer to 8 channels dma buffer, it might looks very different. If you think this patch is not good, I'd send a new one after I merged tdm driver. By the way, if the channel order of hardware is different from what is expected by alsa, the copy work is left to plugin or driver?
Scott