AM335x and MMC2

Sergey Manucharian

Prodigy 40 points

Dear team,

I've followed all suggestions and advices from:

https://e2e.ti.com/support/arm/sitara_arm/f/791/p/259004/1242116

and got u-boot to list the MMC2. However, it's not usable: there is no clock on the corresponding clock pin.

With commands:
mmc dev 0
mmc dev 1

I see clock signal on oscilloscope, but not with

mmc dev 2

Thank you for directions!

Sergey

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

Hi,

Please check your pinmux settings for the MMC2 pins you use.

0 Sergey Manucharian over 7 years ago in reply to Biser Gatchev-XID

Prodigy 40 points

Thanks, Biser, here are my pinmux settings, there is only one mmc2_clk available on my Beaglebone Black board:

static struct module_pin_mux mmc2_pin_mux[] = {

{OFFSET(gpmc_ad12), (MODE(3) | RXACTIVE | PULLUP_EN)}, /* mmc2_dat0 */

{OFFSET(gpmc_ad13), (MODE(3) | RXACTIVE | PULLUP_EN)}, /* mmc2_dat1 */

{OFFSET(gpmc_ad14), (MODE(3) | RXACTIVE | PULLUP_EN)}, /* mmc2_dat2 */

{OFFSET(gpmc_ad15), (MODE(3) | RXACTIVE | PULLUP_EN)}, /* mmc2_dat3 */

{OFFSET(gpmc_clk), (MODE(3) | RXACTIVE | PULLUP_EN)}, /* mmc2_clk */

{OFFSET(gpmc_csn3), (MODE(1) | RXACTIVE | PULLUP_EN)}, /* mmc2_cmd */

{OFFSET(uart1_txd), (MODE(1) | RXACTIVE | PULLUP_EN)}, /* mmc2_wp */

{OFFSET(mcasp0_axr0),(MODE(4) | RXACTIVE | PULLUP_EN)}, /* mmc2_sdcd */

{-1},

};

0 Yordan Kovachev over 7 years ago in reply to Sergey Manucharian

TI__Guru**** 161600 points

Hi,

Have you tried a direct __raw_writel() to CM_PER_MMC2_CLKCTRL[1:0]MODULEMODE bit field in the mmc2 init function in board.c?

Best Regards,
Yordan

0 Sergey Manucharian over 7 years ago in reply to Yordan Kovachev

Prodigy 40 points

Thanks, Yordan!
I was thinking about it, but found that in the latest u-boot sources CM_PER_MMC2_CLKCTRL is not defined anymore.

I use build scripts from:
https://github.com/RobertCNelson/Bootloader-Builder.git

and I stick with v2016.05-r3 at the moment.

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AM335x and MMC2