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

[Krzysztof Kozlowski <k.kozlowski@samsung.com>]

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

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