i2c: aspeed: Add multi-master use case support
In multi-master environment, this driver's master cannot know exactly when a peer master sends data to this driver's slave so cases can be happened that this master tries sending data through the master_xfer function but slave data from a peer master is still being processed or slave xfer is started by a peer immediately after it queues a master command. To support multi-master use cases properly, this H/W provides arbitration in physical level and it provides priority based command handling too to avoid conflicts in multi-master environment, means that if a master and a slave events happen at the same time, H/W will handle a higher priority event first and a pending event will be handled when bus comes back to the idle state. To support this H/W feature properly, this patch adds the 'pending' state of master and its handling code so that the pending master xfer can be continued after slave operation properly. Signed-off-by:Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> Reviewed-by:
Brendan Higgins <brendanhiggins@google.com> Signed-off-by:
Wolfram Sang <wsa@the-dreams.de>
parent
bceb26bf