Re: [PATCH 4/5] dt-bindings: i2c: Add Mediatek MT8183 i2c binding

Qii Wang
2018-12-13T09:32:27Z

On Tue, 2018-12-11 at 21:29 +0100, Wolfram Sang wrote:
> > + - ch-offset: base reg offset for multi-user.
>
> What is "multi-user"? Why can't you add this offset to the reg-property
> directly?
>

Thanks for your comment.
There are 3 channel in one MT8183 I3C controller, and every channel can
be used as an I2C controller.
Take the following diagram as example:
If use I3C channels as I2C bus,
1. CH-A/B/C offset are different;
2. If use CH-B or CH-A as I2C, they must config registers which's
address are in CH-A.
____________________________________
| ________ |
| | |<--- offset:0x00 |
| | CH-A | |
| |________| |
| | |<--- offset:0x100 |
| | CH-B | |
| |________| |
| | |<--- offset:0x200 |
| | CH-C | |
| |________| |
|____________________________________|
one I3C controller

Because of CH-B/CH-C depend on CH-A's register, it can't add offset to
reg-property directly.

MT8183 doesn't need to support muti-user according to the latest project
information, and I'll remove this feature from patches.

> > + - mediatek,share-i3c: i3c controller can share i2c function.
>
> Please explain in more detail? Is this an I3C controller?
>

Yes, it is a i3c controller, and it is compatible with i2c. I only use
the feature of i2c, so I need a flag to do some extra settings.