On 2018-01-30 13:38, Ladislav Michl wrote: > On Tue, Jan 30, 2018 at 11:35:38AM +0100, Pavel Machek wrote: >> On Tue 2018-01-30 11:10:46, Ladislav Michl wrote: >>> On Tue, Jan 30, 2018 at 11:00:23AM +0100, Pavel Machek wrote: >>>> On Tue 2018-01-30 10:38:38, Ladislav Michl wrote: >>>>> On Tue, Jan 30, 2018 at 10:11:02AM +0100, Filip Matijević wrote: >>>>>> Hi, >>>>>> >>>> >>>>>>> Well, notice I'm converting existing driver to device tree. And that >>>>>>> one already has GPIO dependency. It is possible that more work needs >>>>>>> to be done there, but that should not be a reason to delay this. Feel >>>>>>> free to help. >>>>> >>>>> Adding DT properties that need to be maintained for compatibility reasons >>>>> is a bad idea and very good reason to delay merging unfinished stuff. >>>>> And meanwhile it turned out it is not power-gpio :) >>>> >>>> I believe reset-gpios and power-gpios are commonly used like >>>> this... and that's what the old code does. >>> >>> Why do you care about old code when introducing new DT property? >>> Either it is reset, then lets call it reset-gpios or it is power supply >>> and then voltage regulator should be used (VAUX4.OUT is such a regulator >>> although it is unclear to me how it is controlled (*)). >> >> power gpio = !reset gpio. Difference is only in polarity. > > Quick grep: > Documentation/devicetree/bindings/net/smsc-lan91c111.txt > - power-gpios: GPIO to control the PWRDWN pin > - reset-gpios: GPIO to control the RESET pin > Documentation/devicetree/bindings/net/wireless/ti,wl1251.txt > - ti,power-gpio : GPIO connected to chip's PMEN pin > Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt > - power-gpios : Specification for the pin connected to the gsl1680's > shutdown input. This needs to be driven high to take the > gsl1680 out of its low power state > Documentation/devicetree/bindings/input/touchscreen/ektf2127.txt > - power-gpios : GPIO specification for the pin connected to the > ektf2127's wake input. This needs to be driven high > to take ektf2127 out of it's low power state > > As you can see others are using it to drive pins different from nRESET. As > stated in datasheet: > "The TLV320DAC32 requires a hardware reset after power-up for proper operation. > After all power supplies are at their specified values, the nRESET pin must be > driven low for at least 10ns. If this reset sequence is not performed, the DAC32 > may not respond properly to register reads/writes". That does not sound like > anything to do with power. > > (It seems the only difference between TLV320DAC33 and TLV320DAC32 is uses a ball > grid array package vs QFN32) Note that tlv320dac32 != tlv320dac33, they are not even register compatible devices... dac33 was created _for_ Nokia back in the days and as far as I know there is no publicly available documentation for dac33. And yes, my pick to use power_gpio in the code was wrong, it should have been named as reset_gpio. > >>>> You are not helping. >>> >>> The only way I can help here is to resend your patch with "reset-gpios" >>> used, which I'm pretty sure you can handle yourself. >> >> Well, you can do that, and then you can argue with the next person who >> feels one of the properties has to get his preferred color. Hard part >> is not changing code :-(. > > Indeed, hard part is not to break DT compatibility later. Consider someone > will have to add regulator support later, which you omitted to do - having > both power supply and power gpio is a bit confusing, don't you think? > > Anyway, time to stop arguing, feel free to do what you think is right, I do > not have anything important to add :) > > ladis > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@xxxxxxxxxxxxxxxx > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel > - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
