On Fri, 2015-01-09 at 18:21 +0100, Wolfram Sang wrote: > The number of I2C adapters which are not fully I2C compatible is rising, > sadly. Drivers usually do handle the flaws, still the user receives only > some errno for a transfer which normally can be expected to work. This > patch introduces a formal description of flaws. One advantage is that > the core can check before the actual transfer if the messages could be > transferred at all. This is done in the next patch. Another advantage is > that we can pass this information to the user so the restrictions are > exactly known and further actions can be based on that. This will be > done later after some stabilization period for this description. Hi Wolfram, This can describe the behavior of our current upstream driver[1], which only support combine write-then-read. After checking with Xudong & HW guys, it seems our HW can do more. On MT8135, it can support at most 2 messages, no matter read or write, with the limitation that the length of the second message must <= 31bytes. So this RFC is enough for our driver, but it would be better if we could also support other case. Joe.C [1]: http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/305468.html
