> > > > Again, doesn't matter, since it's the DTB that provides the default > > > > state. So, back when it was authored, the default state was HW > > > > flow-control disabled. And in a newer DTB (again, until I follow-up > > > > with more changes), the defaults for UART 1 and UART 2 are HW > > > > flow-control disabled. > > > > > > > > Your issue seems to be that you've assumed since we now provide the > > > > possibility of a "manual-rts" state, then the "default" state should > > > > *only* be HW flow-control capable, which is not the case. > > > > > > No my feedback was that it would be clearer & simpler to make manual-rts the > > > 'default' state, and 'hw-flow-control' the optional state. > > > > Absolutely not. The use of "manual-rts" is the corner-case here and > > is not normally required. > > See below. > > > The "default" state should normally be > > populated with whatever pins are available i.e. all 4 pins (including > > "rts, cts") if they are wired up and only 2 pins (just "tx, rx") if > > they are not. > > Yep OK, I agree :) \o/ > > The submission of "manual-rts" is only required if the > > RTS pin is required for some other purpose e.g. resetting a uC on a > > draughtboard. > > All UARTs the SoC have the same st-asc IP, which suffers from the same > hw flow control limitation. Also all instances on the SoC have rts/cts > pins, the only limitation is board wiring. > > So I can't see why would you ever *not* want to deploy this dynamic pin > switching solution if rts/cts is wired up at board level now the facility > exists? Mainly because it's surplus to requirement, in that there is very seldom any point in manually toggling the RTS line (at least to my knowledge). I figure we'd add >1 Pinctrl states only when the need arises, thus keeping the DTS' as simple as possible. > Also regarding the naming of the second pin group, 'manual-rts' seems like > a bad name as a logical extension of this set is to also offer the same > dynamic switching for the CTS line. > > Maybe a better name would be 'tx-rx-only' or 'no-rts-cts'. Works for me. Will fix. > > > > It's the > > > > 'uart-has-rtscts' property which determines this *not* whether the > > > > second state has been provided. > > > > > > Yep, which is why IMO it makes more sense for the optional pin group to be the hw > > > flow control pins which are obtained if the uart-has-rtscts property is present. > > > > There would normally only be one pin group. Your method would insist > > we always provided 2, which would be surplus to requirement. > > Yep OK, agree with your point. \o/ > Yep OK, I agree. \o/ > Yep OK, I agree. \o/ -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
