TMDSEVM437X: How to enable eMMC in u-boot

HCRajan GopalSamy

Intellectual 465 points

Part Number: TMDSEVM437X

Hello,

I am trying to access eMMC on this EVK in u-boot and followed instructions as per the thread

$/support/processors/f/791/t/518624?AM437x-eMMC-support-in-U-boot

Modified mux.c, am43xx_evm_defconfig, am437x-gp-evm.dts, am437x-gp-evm-u-boot.dtsi files.

However, it is reporting an error that "Card did not respond to voltage select".

=> mmc rescan
=> mmc list
OMAP SD/MMC: 0 (SD)
OMAP SD/MMC: 1
=> mmc dev 1
Card did not respond to voltage select!

mux.c has the following settings,

static struct module_pin_mux emmc_pin_mux[] = {
{OFFSET(gpmc_ad0), (MODE(1) | PULLUP_EN | RXACTIVE)}, /* AD0 */
{OFFSET(gpmc_ad1), (MODE(1) | PULLUP_EN | RXACTIVE)}, /* AD1 */
{OFFSET(gpmc_ad2), (MODE(1) | PULLUP_EN | RXACTIVE)}, /* AD2 */
{OFFSET(gpmc_ad3), (MODE(1) | PULLUP_EN | RXACTIVE)}, /* AD3 */
{OFFSET(gpmc_ad4), (MODE(1) | PULLUP_EN | RXACTIVE)}, /* AD4 */
{OFFSET(gpmc_ad5), (MODE(1) | PULLUP_EN | RXACTIVE)}, /* AD5 */
{OFFSET(gpmc_ad6), (MODE(1) | PULLUP_EN | RXACTIVE)}, /* AD6 */
{OFFSET(gpmc_ad7), (MODE(1) | PULLUP_EN | RXACTIVE)}, /* AD7 */

{OFFSET(gpmc_csn1), (MODE(2) | PULLUP_EN)}, /* gpmc_csn1.mmc1_clk */
{OFFSET(gpmc_csn2), (MODE(2) | PULLUP_EN)}, /* gpmc_csn2.mmc1_cmd */

{OFFSET(spi2_cs0), (MODE(7) | PULLUP_EN)}, /* spi2_cs0.gpio0_23 SEL_eMMCorNANDn */
{-1},
};

Similar changes to kernel is working fine and able to see the eMMC after the kernel boots.

Is there any other changes needed on the u-boot side to properly enable eMMC?

Looking forward for your support,

Thanks

over 6 years ago

0 Kemal R. Shakir over 6 years ago

TI__Guru 55345 points

Hello HCRajan,

Can you attach the changes you made with git diff command?

cd <Processor SDK>/board-support/u-boot-<version>/
git diff > 0001-AM437x-eMMC-in-U-Boot.patch

Best regards,
Kemal

0 HCRajan GopalSamy over 6 years ago in reply to Kemal R. Shakir

Intellectual 465 points

Hello Kemal,

Thank you for your reply.
I have used diff -u command to manually generate the patch file.

When I tried to insert that file, it is reporting an error, when I click "Reply".

Pardon my ignorance,
Using this web interface, how to attach the file?

Thanks

0 Kemal R. Shakir over 6 years ago in reply to HCRajan GopalSamy

TI__Guru 55345 points

Can you compress it and attach in that way?

0 HCRajan GopalSamy over 6 years ago in reply to Kemal R. Shakir

Intellectual 465 points

0001-u-boot-emmc-enable.zip

0 Kemal R. Shakir over 6 years ago in reply to HCRajan GopalSamy

TI__Guru 55345 points

Hello HCRajan,

Please, change the pinmuxes in <Processor SDK>/board-support/u-boot-<version>board/ti/am43xx/mux.c

from
{OFFSET(gpmc_csn1), (MODE(2) | PULLUP_EN)}, /* gpmc_csn1.mmc1_clk */
{OFFSET(gpmc_csn2), (MODE(2) | PULLUP_EN)}, /* gpmc_csn2.mmc1_cmd */
to
{OFFSET(gpmc_csn1), (MODE(2) | PULLUDDIS | RXACTIVE)}, /* gpmc_csn1.mmc1_clk */
{OFFSET(gpmc_csn2), (MODE(2) | PULLUP_EN | RXACTIVE)}, /* gpmc_csn2.mmc1_cmd */

append EMMC to CONFIG_SYS_EXTRA_OPTIONS in <Processor SDK>/board-support/u-boot-<version>/configs/am43xx_evm_defconfig and add CONFIG_EMMC in <Processor SDK>/board-support/u-boot-<version>/scripts/config_whitelist.txt to fix this issue.

Best regards,
Kemal

0 HCRajan GopalSamy over 6 years ago in reply to Kemal R. Shakir

Intellectual 465 points

Hello Kemal,

Thank you for your efforts.
There is some progress, but eMMC is still not recognized.

With the suggested modifications, I find the following errors,
{
=> mmc dev 1
mmc_read_data: timedout waiting for status!
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
=> mmc rescan
}

Tried with other MUX settings as well without luck.

Do you have any working patch file that I could try?

I am using Yocto build environment. Is it mandatory to switch to linux dev environment?

What is the recommended way to try the code changes?
I am a bit afraid to remove and reinsert uSD card for every changes that I try.

Can this EVK boot from USB or network (TFTP) ?
Any tips to speed up the analysis could help a lot.

Looking forward for your reply,

Thanks

0 Kemal R. Shakir over 6 years ago in reply to HCRajan GopalSamy

TI__Guru 55345 points

You need to put a jumper on J89 between pin 1 and 2.

0 HCRajan GopalSamy over 6 years ago in reply to Kemal R. Shakir

Intellectual 465 points

Yes.

It worked.

Could you please explain the need for the external pullup over the internal one?

By the way, there is no jumper called J89 on my EVK Rev 1.5.
I tried this on jumper J2. FYI.

Looking forward for your reply,

Thanks

0 Kemal R. Shakir over 6 years ago in reply to HCRajan GopalSamy

TI__Guru 55345 points

Yes, it is J2 on Rev 1.5 and J89 on Rev 1.2. You need the external pullup because the internal pullup can drive the pin up to 0.9V due to the mounted external pulldown (R176).

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TMDSEVM437X: How to enable eMMC in u-boot