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