Messages in this thread | | | From | Parshuram Raju Thombare <> | Subject | RE: [PATCH v1 0/3] I3C mastership handover support | Date | Wed, 8 Apr 2020 15:06:22 +0000 |
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Hi Boris,
>It's definitely not the first version (as implied in the subject), and >I'd like a proper changelog detailing what has changed since the last >version (the one sent by Przemek).
Sure, I will resend patches with updated version and change log.
But just to summarize, main changes are 1. Secondary master deferring initialization i.e. registering devices representing other device as well as master itself, until bus ownership is achieved. 2. Moved bus request from slave and bus handover from current Master to separate state machines. This is to assist any further changes in mastership request/handover procedures. e.g. MIPI v1.1 specify additional features likes bus yield at the will of current master to sec master selected by current master, group address functionality, multi lane support etc which requires additional steps in handover procedure. This structure will help to extend the functionality further. 3. We don't really need secondary master to be aware other devices on the bus through mechanism like device tree, since main master broadcast this information through DEFSLVS. And receiving this information does not require sec. master driver to be loaded, at least in case of CDNS I3C controller .DEFSLVS information is stored by HW inside a table which is later accessed by controller driver, to be passed to I3C master subsystem. Sec master initialization state machine make sure it has active dynamic address (this may seems repetitive, but it is to handle case of RSTDAA CCC), and DEFSLVS is received at least once. And IMO we don't really need to process DEFSLVS for a sec master until it want to become current master. 4. Another important change is setting main master and sec master In pure bus mode during enumeration (DAA), this is to avoid need of sec. master having device information through device tree, and at the same time allowing enumeration to happened successfully. Both main master and sec master change bus mode once enumeration is done.
Regards, Parshuram Thombare
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