On 24/05/17 12:34, Heiko Stuebner wrote: > Am Mittwoch, 24. Mai 2017, 11:26:10 CEST schrieb Robin Murphy: >> On 24/05/17 09:17, Heiko Stuebner wrote: >>> Hi Eddie, >>> >>> Am Mittwoch, 24. Mai 2017, 15:33:41 CEST schrieb Eddie Cai: >>>> the previous setting of act8846 is just copy from firefly board. but >>>> the reload board is a little different from firefly board. let's correct >>>> it. >>>> >>>> Signed-off-by: Eddie Cai <eddie.cai.linux@xxxxxxxxx> >>>> --- >>>> arch/arm/boot/dts/rk3288-firefly-reload-core.dtsi | 21 +++++++++++---------- >>>> 1 file changed, 11 insertions(+), 10 deletions(-) >>>> >>>> diff --git a/arch/arm/boot/dts/rk3288-firefly-reload-core.dtsi b/arch/arm/boot/dts/rk3288-firefly-reload-core.dtsi >>>> index 8134966..4cfa109 100644 >>>> --- a/arch/arm/boot/dts/rk3288-firefly-reload-core.dtsi >>>> +++ b/arch/arm/boot/dts/rk3288-firefly-reload-core.dtsi >>>> @@ -179,6 +179,7 @@ >>>> regulator-name = "vccio_sd"; >>>> regulator-min-microvolt = <3300000>; >>>> regulator-max-microvolt = <3300000>; >>>> + regulator-always-on; >>> >>> the rest below looks pretty straight forward, but why does vccio_sd >>> need to be always on? >>> >>> I've checked the reload's schematics but did not find any further users >>> of vccio_sd that may warant this attribute. >> >> It looks like the card detect line is pulled up externally to vcc_sd, >> which isn't always-on either, so you probably do want this - on the >> (unrelated) rk3288 TV box I've been hacking on, I discovered that >> powering off the sdmmc-supply domain also kills the internal pull-up and >> leaves sdmmc_cd floating. The resulting stochastic card polling >> mechanism is amusing, but probably undesirable ;) > > Hmm, are you mixing up vcc_sd and vccio_sd? > > vccio_sd is the io supply (vqmmc in mmc-terms) to the mmc-host itself > while vcc_sd is the actual card supply (vmmc in mmc-terms). Yes, that is what I meant, although I was implicitly assuming the case where the MMC host driver has already turned off vcc_sd due to no card being present. I'll double-check, but I'm 99% certain that *unlike* Firefly, the Hotack board I've got (seemingly a straight implementation of the "Box" reference design based on what I've managed to reverse-engineer from scouring the internet) has no external pull-ups for anything on its microSD socket, so is entirely reliant on everything being pulled up internally to SDMMC0_VDD, i.e. vccio_sd. > After looking through some schematics, the pull-up to vcc_sd seems to be > the common pattern for rk3288 devices. So I guess this means the fixed > regulator vcc_sd should get an regulator-always-on instead to stabilize > the card-detect? That might make sense, especially where vcc_sd is just vcc_io behind a MOSFET switch, so turning it "off" when there's no card to draw power anyway probably doesn't achieve much. Plus if you can then rely on vcc_sd not going away it might be worth disabling the internal pull-ups which are still being set by all the sdmmc_* pinctrl configs as well. Robin. >>>> }; >>>> >>>> vdd10_lcd: REG6 { >>>> @@ -187,24 +188,23 @@ >>>> regulator-max-microvolt = <1000000>; >>>> }; >>>> >>>> - vcca_18: REG7 { >>>> - regulator-name = "vcca_18"; >>>> - regulator-min-microvolt = <1800000>; >>>> - regulator-max-microvolt = <1800000>; >>>> - regulator-always-on; >>>> + vcca_33: REG7 { >>>> + regulator-name = "vcca_33"; >>>> + regulator-min-microvolt = <3300000>; >>>> + regulator-max-microvolt = <3300000>; >>>> }; >>>> >>>> - vcca_33: REG8 { >>>> - regulator-name = "vcca_33"; >>>> + vcc_lan: REG8 { >>>> + regulator-name = "vcc_lan"; >>>> regulator-min-microvolt = <3300000>; >>>> regulator-max-microvolt = <3300000>; >>>> - regulator-always-on; >>>> }; >>>> >>>> - vcc_lan: REG9 { >>>> - regulator-name = "vcca_lan"; >>>> + vccio_pmu: REG9 { >>>> + regulator-name = "vccio_pmu"; >>>> regulator-min-microvolt = <3300000>; >>>> regulator-max-microvolt = <3300000>; >>>> + regulator-always-on; >>>> }; >>>> >>>> vdd_10: REG10 { >>>> @@ -218,6 +218,7 @@ >>>> regulator-name = "vcc_18"; >>>> regulator-min-microvolt = <1800000>; >>>> regulator-max-microvolt = <1800000>; >>>> + regulator-always-on; >>>> }; >>>> >>>> vcc18_lcd: REG12 { >>>> >>> >>> >>> >>> _______________________________________________ >>> linux-arm-kernel mailing list >>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx >>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >>> >> >> >> > > -- 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