On 07/29/2016 02:30 AM, Takashi Sakamoto wrote: > Lars, > > On Jul 29 2016 05:33, Lars-Peter Clausen wrote: >> Hotplug is something that always pops up sooner or later. E.g. if someone >> puts a ASoC supported CODEC on a hot-pluggable device (maybe USB) we >> don't want to duplicate the code, but be able to reuse. > > (A bit to sidetrack) > > To me, it's unclear for devices on USB. When ALSA SoC part supports these > devices, what is the scenario you assumed? In short, assuming we put codes > to ALSA SoC part, what is the shape of the corresponding devices and links > of pairs of endpoints? Additionally, in this case, what codes are able to be > reused? Lets say you have USB stick with a small micro controller or FPGA which has a USB interface on one side and a I2S and I2C interface on the other side. The I2S and I2C are connected to a CODEC. I2S for data, I2C for control. If the interface is implemented in a way so that it is just a simple USB to I2C bridge, this means the raw I2C commands are send over the USB interface you can implement a I2C adapter driver for this bridge. If you have that you can instantiate the existing ASoC CODEC driver, which is a I2C device driver, on the bus registered by the adapter. - Lars
