Hello Arnd, [adding Rob Herring to Cc] On Wed, Jul 06, 2016 at 10:09:39PM +0200, Arnd Bergmann wrote: > On Wednesday, July 6, 2016 7:30:57 PM CEST Uwe Kleine-König wrote: > > On Wed, Jul 06, 2016 at 05:22:40PM +0200, Arnd Bergmann wrote: > > > On Monday, July 4, 2016 5:50:09 PM CEST Uwe Kleine-König wrote: > > > > On Mon, Jul 04, 2016 at 05:43:03PM +0200, Arnd Bergmann wrote: > > > > > On Monday, July 4, 2016 5:34:12 PM CEST Uwe Kleine-König wrote: > > > > > > Add support for two led triggers per UART instance that blink on > > > > > > transmission and reception of data respectively. > > > > > > > > > If this is something we may want to do on other platforms as well, > > > we should perhaps not hardwire the name of the imx tty device in > > > the led trigger name. > > > > I cannot follow. If we have several serial lines and a trigger for each > > of them, they must get different names. Using the device's name to > > distinguish them seems like a good and obvious idea. > > The main problem I see is if someone puts the name of the trigger into > a dtb file, as this hardcodes the connection between the Linux driver > name and numbering system with the device tree binding, which are normally > separate. > > If we could derive the trigger name from the "/aliases/serial%d" property > in DT instead, it would get a little more portable. Alternatively we could invent a more dtish way as aliases seem to be frowned upon [1], something like: led#0 { label = "userled"; linux,default-trigger = &uart1, "tx"; }; uart1: serial@43f90000 { ... #trigger-cells = <1>; }; Having said that, I don't think it's a big problem if the value of "linux,default-trigger" is Linux-specific. Moreover, is a default trigger considered a hardware description? Best regards Uwe [1] http://mid.gmane.org/20160705140546.GA10601@rob-hp-laptop Not sure this is a general objection to aliases, though. -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html