a4749bbeee
So here's the current greybus audio driver, which I wanted to send out for more serious review and consideration for merging. I've tried to integrate much of the feedback from the last round and most of the hotplug issues that I've found have been resolved. I've tested this via gbsim, and the Android ARA HAL layer seems to work with it. Mark has also successfully played audio with this driver, adding a few hacks to get the codec's i2c connection to probe. Current issues: * Hotplug problem - When gbsim is killed, or the module removed, the greybus driver gets stuck since the android mediaserver process is holding the audio device open. Killing the mediaserver allows things to clean up and allows greybus to accept new gbsim connections. I have a workaround patch to the soc-core.c logic which converts the snd_card_free() call to snd_card_free_when_closed() which allows the greybus connection cleanup to finish. Remaining todos: * Probably need to break apart the mgmt_setup function to integrate better with the constraint logic. I took a really basic stab at this, but more is probably needed. * Figure out how to properly find and tie in the codec's I2C bus-id to the driver. This code requires that the kernel support the following config options, which I've enabled in a separate kernel patch: CONFIG_SND_SIMPLE_CARD CONFIG_SND_SOC_SPDIF CONFIG_SND_SOC_RT5645 I really can't calim to be the sole author of this, since many many fixes and tweaks that have been folded in have come from Mark Greer. His analsysis and debugging is really what has made this dummy-framework driver evolve into an actual audio driver. So much credit and thanks to Mark! Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>