Hi, On 10/07/2014 01:51 AM, Doug Anderson wrote: > Bartlomiej, > > On Thu, Oct 2, 2014 at 10:24 AM, Bartlomiej Zolnierkiewicz > <b.zolnierkie@xxxxxxxxxxx> wrote: >> >> Hi, >> >> On Thursday, October 02, 2014 09:45:41 AM Doug Anderson wrote: >>> Bartiomiej >>> >>> On Thu, Oct 2, 2014 at 9:39 AM, Bartlomiej Zolnierkiewicz >>> <b.zolnierkie@xxxxxxxxxxx> wrote: >>>> On Thursday, October 02, 2014 09:19:08 AM Doug Anderson wrote: >>>>> Bartiomiej, >>>>> >>>>> On Thu, Oct 2, 2014 at 9:10 AM, Bartlomiej Zolnierkiewicz >>>>> <b.zolnierkie@xxxxxxxxxxx> wrote: >>>>>> Regulators for MMC2 (SD card) are PVDD_TFLASH_2V8 (LDO19) for vmmc >>>>>> and PVDD_APIO_MMCOFF_2V8 (LDO13) for vqmmc. Currently the device >>>>>> tree entry for MMC2 uses PVDD_PRE_1V8 (LDO10) for vmmc and vqmmc is >>>>>> not specified. Fix it. >>>>>> >>>>>> Without this patch: >>>>>> - "mmc: dw_mmc: use mmc_regulator_get_supply to handle regulators" >>>>>> patch causes a SD card detection to fail >>>>>> - "mmc: dw_mmc: Support voltage changes" patch causes a boot hang >>>>>> >>>>>> This patch fixes both above problems. >>>>>> >>>>>> Suggested-by: Doug Anderson <dianders@xxxxxxxxxx> >>>>>> Cc: Yuvaraj Kumar C D <yuvaraj.cd@xxxxxxxxxxx> >>>>>> Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx> >>>>>> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> >>>>>> Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> >>>>>> --- >>>>>> arch/arm/boot/dts/exynos5420-arndale-octa.dts | 3 ++- >>>>>> 1 file changed, 2 insertions(+), 1 deletion(-) >>>>>> >>>>>> Index: b/arch/arm/boot/dts/exynos5420-arndale-octa.dts >>>>>> =================================================================== >>>>>> --- a/arch/arm/boot/dts/exynos5420-arndale-octa.dts 2014-10-02 15:44:53.014826886 +0200 >>>>>> +++ b/arch/arm/boot/dts/exynos5420-arndale-octa.dts 2014-10-02 17:35:24.110600398 +0200 >>>>>> @@ -74,7 +74,8 @@ >>>>>> samsung,dw-mshc-ddr-timing = <1 2>; >>>>>> pinctrl-names = "default"; >>>>>> pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_cd &sd2_bus4>; >>>>>> - vmmc-supply = <&ldo10_reg>; >>>>>> + vmmc-supply = <&ldo19_reg>; >>>>>> + vqmmc-supply = <&ldo13_reg>; >>>>> >>>>> This looks right to me. ...but I notice that ldo13 and ldo19 are not >>>>> "always-on" in the DTS. Are you sure card detect works for you if you >>>>> eject your card and try to put it back in? >>>>> >>>>> ...eventually the "always-on" won't be needed, but for now I think it is... >>>> >>>> Card detection works fine without "always-on". >>> >>> That's weird. >>> >>> 1. In the schematics I see XMMC2CDN has an external pullup to PVDD_TFLASH_2V8. >>> >>> 2. The internal pullup should (I think) be to VDDQ_MMC2 which is >>> PVDD_APIO_MMCOFF_2V8. >>> >>> 3. In (51da224 mmc: dw_mmc: use mmc_regulator_get_supply to handle >>> regulators) we should be turning off both regulators in >>> "MMC_POWER_OFF". >>> >>> 4. If I understand correctly MMC_POWER_OFF is called when the card is >>> ejected, which means that both regulators should be off when the card >>> is ejected. >>> >>> 5. I don't think card detect can work if neither regulator is powered. >>> >>> >>> One of the above points must be wrong. Any idea which one? Can you >>> check to see if MMC_POWER_OFF is called for you when the card is >>> ejected? Can you check to see if these regulators are off? >> >> MMC_POWER_OFF is called on card removal and both regulators get disabled >> (I have verified that they are really off with regulator_is_enabled() which >> returns 1 before and 0 after disabling regulator). It seems that 5. is >> wrong? > > This really doesn't make a lot of sense to me, so I'm still kinda > confused. If you want to call it good then that's your (and Ulf's) > decision, but it's the kind of thing that would keep me up at night. > How can this pin be high if all the regulators pulling it up are off? > Is there a current leak somewhere and that's why it's working? > > How this is supposed to work (as I understand it): > > 1. When no card is inserted then this pin is supposed to be pulled up > to VDDQ_MMC2. That could be either an internal or an external pullup. > It should be pulled up to VDDQ_MMC2 (as opposed to any other voltage) > since the exynos manual documents that this pin lives in the VDDQ_MMC2 > io domain. Note that it could be pulled up externally to a different > supply than the one going to VDDQ_MMC2, but for correctness it should > be the same voltage. > > 2. When a card is inserted, the pin will be grounded (AKA this is an > open drain pin). > > > With your patch, can you probe the pin and see if card detect is high > when all the regulators are off? Any idea how it gets high? If you > turn off the internal pullup is it still high? I remembered that I and Doug were discussed for this problem with exynos5420-peach board(?), right? Is arndale-octa board the same circuit with peach? If it's same, I think Doug's comment is right. But if card-detect pis is used with other power, we don't need to consider the VDDQ_MMC2 power domain. It needs more information and checks its schematic. Best Regards, Jaehoon Chung > > > -Doug > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
