Re: [PATCH 2/3] ARM: dts: use vmmc-supply of emmc/sd for exynos5422-odroidxu3

[Anand Moon <linux.amoon@gmail.com>]

Hi Krzysztof,

On 12 October 2015 at 11:19, Krzysztof Kozlowski
<k.kozlowski@samsung.com> wrote:
> On 12.10.2015 13:42, Krzysztof Kozlowski wrote:
>> On 12.10.2015 00:46, Anand Moon wrote:
>>> Added support for vmmc/vqmmc-supply for emmc/sd cards.
>>> Fixed the min values for regulator ldo13_reg (VDDQ_MMC2).
>>
>> I can't see the description of a problem which is fixed. If you fix
>> something, then please describe what is wrong.
>>
>>> Added ramp-delay for LDO9(VDD33_USB3_0).
>>> Added ramp-delay for LDO13(VDDQ_MMC2).
>>> Added ramp-delay for LDO15(ETH_P3V3).
>>>
>>> Signed-off-by: Anand Moon <linux.amoon@gmail.com>
>>>
>>> ---
>>> Changes based on git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung.git v4.4-next/dt-samsung branch
>>>
>>> Note:
>>> Changes need for support of UHS-I highspeed cards.
>>> changes for vqmmc-supply for emmc is not supported.
>>>
>>> [    1.831136] vdd_ldo9: ramp_delay not set
>>> [    1.843049] vdd_ldo13: ramp_delay not set
>>> [    1.850975] vdd_ldo15: ramp_delay not set
>>> [    1.862816] vdd_sd: ramp_delay not set
>>> ---
>>>  arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi | 8 +++++++-
>>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi b/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi
>>> index 26decbd..58c06d3 100644
>>> --- a/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi
>>> +++ b/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi
>>> @@ -157,6 +157,7 @@
>>>                              regulator-min-microvolt = <3000000>;
>>>                              regulator-max-microvolt = <3000000>;
>>>                              regulator-always-on;
>>> +                            regulator-ramp-delay = <12000>;
>>>                      };
>>>
>>>                      ldo10_reg: LDO10 {
>>> @@ -182,9 +183,10 @@
>>>
>>>                      ldo13_reg: LDO13 {
>>>                              regulator-name = "vdd_ldo13";
>>> -                            regulator-min-microvolt = <2800000>;
>>> +                            regulator-min-microvolt = <1800000>;
>>>                              regulator-max-microvolt = <2800000>;
>>>                              regulator-always-on;
>>> +                            regulator-ramp-delay = <12000>;
>>>                      };
>>>
>>>                      ldo15_reg: LDO15 {
>>> @@ -213,6 +215,7 @@
>>>                              regulator-min-microvolt = <2800000>;
>>>                              regulator-max-microvolt = <2800000>;
>>>                              regulator-always-on;
>>> +                            regulator-ramp-delay = <12000>;
>>
>> Where did you get this value from? It looks wrong... My datasheet does
>> not have 12000 uV/uS.
>

> Anand,
>
> We have actually been here:
> http://lists.infradead.org/pipermail/linux-arm-kernel/2015-June/351601.html
>
> That time you used 8000. I asked the same question - how did you figure
> out the exact value.
>
> Now we have the same question - why 12000?
>
> It is completely fine to make a mistake (I do a lot of them) but please
> try not to make the same mistake again.
>
> BR,
> Krzysztof

I will focus more in the future to clamp down my mistakes to minimal.

>
>>
>>>                      };
>>>
>>>                      ldo24_reg: LDO24 {
>>> @@ -338,6 +341,7 @@
>>>      samsung,dw-mshc-ddr-timing = <0 2>;
>>>      samsung,dw-mshc-hs400-timing = <0 2>;
>>>      samsung,read-strobe-delay = <90>;
>>> +    vmmc-supply = <&ldo3_reg>;
>>>      pinctrl-names = "default";
>>>      pinctrl-0 = <&sd0_clk &sd0_cmd &sd0_bus1 &sd0_bus4 &sd0_bus8 &sd0_cd &sd0_rclk>;
>>>      bus-width = <8>;
>>> @@ -352,6 +356,8 @@
>>>      samsung,dw-mshc-ciu-div = <3>;
>>>      samsung,dw-mshc-sdr-timing = <0 4>;
>>>      samsung,dw-mshc-ddr-timing = <0 2>;
>>> +    vmmc-supply = <&ldo19_reg>;
>>> +    vqmmc-supply = <&ldo13_reg>;
>>
>> It looks wrong. LDO13 is used in one place as VQMMC and in other as
>> VMMC. How did you figure out which regulator supplies which power domain?
>>

I refer Schematics diagram to XU4_MAIN_REV0.1.pdf

>From the PWR_PMCI_S2MPS11_LDO_CTRL document it LDO13 point to VDDQ_MMC2.

>> Best regards,
>> Krzysztof
>>
>>>      cd-gpios = <&gpc2 2 GPIO_ACTIVE_HIGH>;
>>>      cd-inverted;
>>>      pinctrl-names = "default";
>>>
>>
>>
>

-Anand Moon