On Thu, Dec 12, 2013 at 10:38:34AM +0200, Tomi Valkeinen wrote: > On 2013-12-12 01:44, Laurent Pinchart wrote: > > So, are they independent? I don't know =). I think they lean on the > independent side. dss_core is always needed for the submodules to work, > but for example DSI could be used without DISPC, using system DMA to > transfer data from memory to DSI. Not a very useful thing to do, but > still, there are dedicated DMA channels for that. If they have separate hwmod entries, they should be considered separate independent devices for sure. To summarize, here are few reasons why they need to be treated as separate devices: 1. The modules maybe clocked/powered/idled separately and can have their own idle configuration so they can do the hardware based idling separately. 2. Doing a readback after a write to one module will not flush the write to the other modules on the (bus depending on the SoC version AFAIK). That can lead to nasty bugs caused by the ordering. 3. If the devices are described in a different way in the .dts files from the hwmod data, we will not have 1-to-1 mapping and will never be able to replace ti,hwmods with just the compatible string. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
