On 03/15/2013 12:42 PM, Laxman Dewangan wrote:OK, so I see that Tegra30 has an enhancement over Tegra20. However,
Simple uart driver use the uart clock divider and it is fine here.
High speed uart driver uses the car register driver for better
flexibility and better resolution.
given your description, that enhancement is optional; a driver could
simply continue to use /just/ the in-UART divider, and ignore the CAR
divider, and still work just fine, albeit with (entirely
backwards-compatible) less accuracy than it might achieve if it used the
new feature.
As such, I think it's correct to mark the device as actually being
compatible with all 3: 114 (precise HW model), 30 (base model w/ extra
divider), 20 (base model that's compatible, albeit ignoring extra features).
That might be a bit excessive though, so I guess I'll just go with the
values in your patch. It'd be a good idea if you could post a follow-on
patch that updates the DT binding to explain this, and then removes the
comments from *.dtsi since this really should be explained in the
binding document not the .dtsi files, I think.
At most, I'd expect to see the following in the .dtsi files:
These nodes can either be compatible with nvidia,tegra114-uart, or
nvidia,tegra114-hsuart. See the bindings for details of the difference.