Accessing MMC2 in PSP-SDK_02.01.01.08

ler

Expert 1070 points

Hello,

Our board is utilizing the mmc2 interface. I'm wanting to activate this device in Linux. From what I can

tell, I only have mmcblk0p1 device available. How do I go about getting mmcblk0p2? Is there a better way

of accessing this device?

over 16 years ago

0 Steve Kipisz over 16 years ago

TI__Genius 15510 points

Acutally, MMC1 is mmcblk0 and each partitions would be mmcblk0p1, mmcblk0p2, etc. MMC2 then becomes mmcblk1 with the partitions being mmcblk1p1, mmcblk1p2, etc.

I would start with u-boot. Modify the pin muxing in there to support MMC2. Then in your Linux kernel, look at your arch/arm/mach-omap2/board- file. For example, the OMAP3 EVM file is named board-omap3evm.c. You'll find a table with MMC interfaces:

static struct twl4030_hsmmc_info mmc[] __initdata = {
        {
                .mmc            = 1,
                .wires          = 4,
                .gpio_cd        = -EINVAL,
                .gpio_wp        = 63,
        },
        {}      /* Terminator */
};

You would add an entry for your MMC2.

There might be more work, but this is a start.

Steve K.

0 ler over 16 years ago in reply to Steve Kipisz

Expert 1070 points

In reading the Technical Reference Manual, it states that ...

The second controller (MMC/SD/SDIO2) allows connecting MMC/SD/SDIO cards (only 1.8V cards) or

and external device that uses the MMC/SD/SDIO interface (WLAN device for example).

When I run the PSP-SDK_02.01.01.08 kernel, it seems to be setting VMMC2 to about 3V. Is this OK? Can

I run standard SD cards in MMC2, or must I use a 1.8V part? I guess the same goes for MMC3?

Thanks.

0 Rishi47239 over 15 years ago in reply to ler

Prodigy 60 points

I have been trying to get MMC2 to work with a Marvell 8686 SDIO card, this card does not have any write protect or chip detect. It is being externally powered and can be assumed to always be there. I was able to get the card to work on MMC1 but it needs to be on MMC2. I probably need to add voltage translators to go from the 1.8 V to 3.0 V but I cannot ever see a MMC2 clock ever come out of the OMAP3EVM board.

I am using the OMAP3EVM with 2.6.29-rc3 kernel, I have made the following modifications but I am unable to see a MMC2 clock. I would think during linux initialization it would probe the MMC2 to see if anything is there. Is this not true?

/*Wireless LAN */\
MUX_VAL(CP(MMC2_CLK),          (IEN | PTD | DIS | M0)) /*MMC2_CLK*/\
MUX_VAL(CP(MMC2_CMD),          (IEN | PTU | EN | M0)) /*MMC2_CMD*/\
MUX_VAL(CP(MMC2_DAT0),         (IEN | PTU | EN | M0)) /*MMC2_DAT0*/\
MUX_VAL(CP(MMC2_DAT1),         (IEN | PTU | EN | M0)) /*MMC2_DAT1*/\
MUX_VAL(CP(MMC2_DAT2),         (IEN | PTU | EN | M0)) /*MMC2_DAT2*/\
MUX_VAL(CP(MMC2_DAT3),         (IEN | PTU | EN | M0)) /*MMC2_DAT3*/\
MUX_VAL(CP(MMC2_DAT4),         (IDIS | PTD | DIS | M0)) /*MMC2_DAT4*/\
MUX_VAL(CP(MMC2_DAT5),         (IDIS | PTD | DIS | M0)) /*MMC2_DAT5*/\
MUX_VAL(CP(MMC2_DAT6),         (IDIS | PTD | DIS | M0)) /*MMC2_DAT6 */\
MUX_VAL(CP(MMC2_DAT7),         (IEN | PTU | EN | M0)) /*MMC2_DAT7*/\

And then in my board file I changed the mmc structure to:

static struct twl4030_hsmmc_info mmc[] __initdata = {
    {
        .mmc        = 1,
        .wires        = 4,
        .gpio_cd    = -EINVAL,
        .gpio_wp    = 63,
    },
    {
        .mmc        = 2,
        .wires        = 4,
        .gpio_wp    = -EINVAL
    },
    {}    /* Terminator */
};

Anyone have any success getting MMC2 to work with a fixed attached device?

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Accessing MMC2 in PSP-SDK_02.01.01.08