SD ultra high speed configuration on custom board

ivanljubicic · ‎06-28-2016

Hi,

I need to configure ultra high speed sd card on custom board. Hardware for sd card is like sabre automotive sd card. So it has pin for switch 3V3 to 1V8. I tried with following configuration to enable ultra high speed for linux yocto kernel 3.14.28:

&usdhc4 {

pinctrl-names = "default";

pinctrl-0 = <&pinctrl_usdhc4_50mhz>;

pinctrl-1 = <&pinctrl_usdhc4_100mhz>;

pinctrl-2 = <&pinctrl_usdhc4_200mhz>;

cd-gpios = GP_USDHC4_CD;

vmmc-supply = <&reg_3p3v>;

vqmmc-supply = <&reg_sd_1p8v>;

vqmmc-1-8-v = <1>;

bus-width = <4>;

keep-power-in-suspend;

enable-sdio-wakeup;

status = "okay";

};

reg_sd_1p8v: regulator@4 {

compatible = "regulator-fixed";

reg = <0>;

pinctrl-names = "default";

pinctrl-0 = <&pinctrl_reg_sd_high>;

regulator-name = "sdhci_ultra_speed";

regulator-min-microvolt = <1800000>;

regulator-max-microvolt = <1800000>;

gpio = GP_USDHC4_REG;

regulator-always-on;

};

pinctrl_reg_sd_high: reg-sd-high {

fsl,pins = <

#define GP_USDHC4_REG <&gpio1 17 GPIO_ACTIVE_LOW>

MX6QDL_PAD_GPIO_17__GPIO7_IO12 0x030b0 //0x1b0b0

>;

};

where vqmmc-supply is configured for 1V8 regulator with pin that switch the voltage. I am able to get high speed for sd card but not ultra high speed.

What is the right way to switch to ultra high speed?

Thanks, regards, Ivan.

tomgao · ‎02-08-2017

After mount the SD on the system ,can you write anything into the SD ?

In my way ,it can not be writed .My command :

root@imx6qsabresd:~# mount -t vfat -wr /dev/mmcblk2p1 sd
root@imx6qsabresd:~# cd sd
root@imx6qsabresd:~/sd# mkdir wwww
mkdir: can't create directory 'wwww': Read-only file system

igorpadykov · ‎07-05-2016

Hi Ivan

could you try this card on Sabre AI board, to verify

if it works.

Best regards

igor

igorpadykov · ‎06-29-2016

Hi Ivan

according to SD specififcation host issues CMD11 to invoke voltage switch sequence.

By receiving CMD11, the card returns R1 response and start voltage switch sequence.

No response of CMD11 means that S18A (card indicates S18A=0, which means that

voltage switch is not allowed and the host needs to use current signalling level) was 0 and

therefore host should not have sent CMD11.

So that card does not support voltage switch or broken, one can try it once more on

Sabre AI board or use other card.

Best regards

igor

ivanljubicic · ‎07-04-2016

Hi Igor,

we have fixed all problems regarding voltage and pin for power switch.

What happens now is that high speed memory card is recognized OK, but

UHS-I sd card is getting error:

mmc0: error -110 whilst initialising SD card

On protocol analayzer after CMD11 is issued voltage is changed on low

CMD line and DAT0:3. Clock is still active. After 11 ms voltage is

changed on power switch from low to high and back to low for 2 ms.

DAT0:3 line stays low and clock and command are active and CMD55 is

issued and many CMD63 commands. Power switch is set for 3 more times

from low to high for 2 ms in this communication and fifth time is set to

high completely, but clock,cmd, and DAT0:3 line is low.

Clock voltage is 3V3 all the time. It is not switched as it should be to

1V8.

Is negotiation between UHS-I sd card and processor supposed to be done

this way or this is non regular behavior?

The hardware guys are stated that hardware is ok.

So there is problem with software.

We are using driver version from november 2015 on kernel 3.14.28-1.0.0.

Could this driver be problem?

Thanks, regards, Ivan.

igorpadykov · ‎07-04-2016

Hi Ivan

does card reply with R1 after CMD11?

According to SD specififcation host issues CMD11 to invoke voltage switch sequence.

By receiving CMD11, the card returns R1 response and start voltage switch sequence.

Regarding negotiation details suggest to check SD specifications.

There are no known UHS-I issues with nxp kernel 3.14.28.

Best regards

igor

ivanljubicic · ‎07-05-2016

Hi Igor,

we have found where the problem is but we do not know why is happening.

Protocol analyzer shows that after CMD 11 is issued card responses with

00 R1 and CMD and DAT3:0 are going to low. After 5 ms power switch

should go to high to switch voltage. But what happens is that power

switch is switched when CMD and clock are already high after ~15ms. So

after 2 ms power switch is going to low because driver detects that

failure condition on CMD and clock line. This behavior is repeted for 4

times and then power switch is going to high constantly. All the time

DAT3:0 are low, only cloack and CMD are active after power switch is set

to low.

I can not find description for such behavior in specification for sd card.

Can you help?

Thanks, regards, Ivan.

ivanljubicic · ‎06-30-2016

Hi Igor,

I had wrong gpio for power switch and that is the reason why voltage was

not changed. So we have fix that and now power pin is triggered and card

again is not working doe to following reasons:

Switch for SD card is implemented as sabre automotive switch. The

difference is that 1V8 voltage is connected on pmic output SW4 which is

used for LPDDR2 memory. When we switch on board we see that voltage is

stabilized on 1V8, but when we start boot voltage is become 2V1. Do you

have any idea why is this happening?

Thanks, regards, Ivan.

igorpadykov · ‎06-28-2016

Hi Ivan

support is already implemented in uboot with ENGR00139221

u-boot-acadia1.0-beta/0372-ENGR00139221-USDHC-Add-SDXC-UHS-I-support.patch at master · linksprite/u-...

also board should have such circuit.

One can try that sd card with Sabre AI board to verify

if it is not working due to signal integrity issues on custom board.

Best regards

igor

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ivanljubicic · ‎06-29-2016

Hi Igor,

I thing yocto jethro kernel 3.14.28 has implementation of ultra high

speed sd card in drivers, so I do not need to patch it. Problem is to

configure dts files to have ultra high speed sd card recognized and

operable. So what I asked was how to configure power switch from 3V3 to

1V8 and vice verse. I have looked dts file from sabre automotive also

and I see that this power switch has to be configured through regulator

configuration so I need help to configure dts files if possible.

Thanks, regards, Ivan.

igorpadykov · ‎06-29-2016

Hi Ivan

all necessary codes are implemented for Sabre AI configuration

http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/tree/?h=imx_3.14.28_1.0.0_ga

Best regards

igor

ivanljubicic · ‎06-29-2016

Hi Igor,

I have configuration as you described. There was hardware problem with

sd card that is fixed by hardware team, but I still can not get ultra

high speed.

I have following printout in dmesg:

sdhci_ultra_speed: 3300 mV

sdhci: Secure Digital Host Controller Interface driver

sdhci: Copyright(c) Pierre Ossman

sdhci-pltfm: SDHCI platform and OF driver helper

mmc0: no vqmmc regulator found

mmc0: SDHCI controller on 219c000.usdhc

using ADMA

mmc0: error -110 whilst initialising SD card

sdhci_ultra_speed: disabling

I have configured dts file like sabre automotive sd card configuration:

reg_sd_3p3v: regulator@4 {

compatible = "regulator-fixed";

reg = <4>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_reg_sd_high>;
regulator-name = "sdhci_ultra_speed";
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
gpio = GP_USDHC4_REG;
enable-active-high;
};

&usdhc4 {
pinctrl-names = "default", "state_100mhz", "state_200mhz";
pinctrl-0 = <&pinctrl_usdhc4_50mhz>;
pinctrl-1 = <&pinctrl_usdhc4_100mhz>;
pinctrl-2 = <&pinctrl_usdhc4_200mhz>;
cd-gpios = GP_USDHC4_CD;
vmmc-supply = <&reg_sd_3p3v>;

keep-power-in-suspend;

enable-sdio-wakeup;

status = "okay";

};

I still not sure what to do with code you have sent me in a link for

sabre al. To copy it to kernel-source directory, and compile bit bitbake

I have, or something else? I tried to copy mmc directory to my project

but I have errors compiling.

Thanks, regards, Ivan.

igorpadykov · ‎06-29-2016

Hi Ivan

these codes are implemented on later kernels.

error: mmc0: error -110 whilst initialising SD card

may mean that card is not even detected (due to wrong

kernel boot parameter root=/dev/mmcblkNp2) .

Also one can check with logic analyzer what

commands sent/answered to/from SD and using

oscilloscope check its tuning waveform (cmd19)

About adjust the timing by CMD19 in SDR104 mode.

Best regards

igor

ivanljubicic · ‎06-29-2016

Hi Igor,

I have connected protocol analyzer and measured commands toward SD card

and verse. Processor executes CMD11 to switch voltage from 3V3 to 1V8

but card does not response with R1 command and voltage is not switched

from 3V3 to 1V8. Clock stays on 3V3 and CMD also. Power switch is

defined as <&gpio1 17 GPIO_ACTIVE_HIGH> and stays always on 0. It should

probably switch to 3V3 but it does not happen. It seems that it is

configuration issue, but I am not able to figure out what. I have copied

configuration from sabre automotive board sd card, but it seems this

configuration fails. Is there example of configuration for sd card for

ultra high speed?

Thanks, regards, Ivan.

SD ultra high speed configuration on custom board

SD ultra high speed configuration on custom board

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