Re: [PATCHv2] ARM: dts: use vmmc-supply of emmc/sd for exynos5422-odroidxu3

[Anand Moon]

hi Krzysztof,

On 22 October 2015 at 06:31, Krzysztof Kozlowski
<k.kozlowski@xxxxxxxxxxx> wrote:
> On 20.10.2015 21:56, Anand Moon wrote:
>> Changes need for host controller to detect UHS-I highspeed cards.
>> Changes in VDDQ_MMC2 voltage range help scale
>> the required voltage to detect and load the microSD cards.
>
> Thanks for updating description of commit.
>
>>
>> Signed-off-by: Anand Moon <linux.amoon@xxxxxxxxx>
>> ---
>> Changes based on git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung.git v4.4-next/dt-samsung branch
>>
>> Changes:
>> Drop the ranp_delay for LDO9.
>>
>> Thanks to : Krzysztof, Doug Anderson, Jaehoon Chung for helping
>> me out figure out the mmc core requirement.
>>
>> Also drop the previous changes:
>> use cd-gpio method to detect sd-card.
>> Added UHS-I bus speed support.
>>
>> [    4.713553] random: nonblocking pool is initialized
>> [    4.718423] 14530000.hdmi supply hdmi-en not found, using dummy regulator
>> [    4.726206] exynos-drm exynos-drm: bound 14400000.fimd (ops fimd_component_ops)
>> [    4.732555] exynos-drm exynos-drm: bound 14450000.mixer (ops mixer_component_ops)
>> [    4.740180] exynos-drm exynos-drm: bound 14530000.hdmi (ops hdmi_component_ops)
>> [    4.746936] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
>> [    4.753428] [drm] No driver support for vblank timestamp query.
>> [    4.940794] Console: switching to colour frame buffer device 274x77
>> [    4.995344] exynos-drm exynos-drm: fb0:  frame buffer device
>> [    5.024573] [drm] Initialized exynos 1.0.0 20110530 on minor 0
>> [    5.031164] exynos-dwc3 usb@12000000: no suspend clk specified
>> [    5.054571] usb 2-1: new full-speed USB device number 2 using exynos-ohci
>> [    5.159527] dwmmc_exynos 12220000.mmc: Busy; trying anyway
>> [    5.163705] mmc_host mmc1: Timeout sending command (cmd 0x202000 arg 0x0 status 0x0)
>> ---
>>  arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi b/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi
>> index 1af5bdc..a4be3e0 100644
>> --- a/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi
>> +++ b/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi
>> @@ -182,9 +182,10 @@
>>
>>                       ldo13_reg: LDO13 {
>>                               regulator-name = "vdd_ldo13";
>> -                             regulator-min-microvolt = <2800000>;
>> +                             regulator-min-microvolt = <1800000>;
>
> You did not convinced me in previous discussion about the change to
> 1.8V. I said that:
>> On the same diagram few lines below:
>> VDDQ_MMC2: 2.8V 250mA
>
> You responded:
>> You are correct.
>
> So I am confused. Are you sure that this SD card block can/should
> operate on 1.8V? Have you actually tried this?
>

Look like I missed this point. Here is the link I would like to share.

http://www.hjreggel.net/cardspeed/cs_sdxc.html
Section: Summary of SD modes

https://en.wikipedia.org/wiki/Secure_Digital
Section: Power consumption

Their different requirement for voltage requirement for UHS-I, the max
value is around 3.3V

>>                               regulator-max-microvolt = <2800000>;
>>                               regulator-always-on;
>> +                             regulator-ramp-delay = <12000>;
>
> NAK
>
> We've been talking about this. Sooo maaaanyyyy times.
>
> If you are going to send v3 please come up with detailed reasoning,
> which will convince my stubborn mind.
>

Look like I missed this point. my typo. Will drop this in next version.
No matter I try hard, it turn out I make silly and annoying mistake.

-Anand Moon

> Best regards,
> Krzysztof
>
>>                       };
>>
>>                       ldo15_reg: LDO15 {
>> @@ -213,6 +214,7 @@
>>                               regulator-min-microvolt = <2800000>;
>>                               regulator-max-microvolt = <2800000>;
>>                               regulator-always-on;
>> +                             regulator-ramp-delay = <12000>;
>>                       };
>>
>>                       ldo24_reg: LDO24 {
>> @@ -338,6 +340,7 @@
>>       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>;
>> @@ -355,6 +358,8 @@
>>       pinctrl-names = "default";
>>       pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_cd &sd2_bus1 &sd2_bus4>;
>>       bus-width = <4>;
>> +     vmmc-supply = <&ldo19_reg>;
>> +     vqmmc-supply = <&ldo13_reg>;
>>       cap-sd-highspeed;
>>  };
>>
>>
>
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