ChibiOS Free Embedded RTOS

Dear all,

these days I am trying to read an embedded MMC device, using the SDIO interface.

After getting to BLK_ACTIVE state, I try to sdcConnect(), and the result is CH_FAILED.

Precisely, the place where fail happens is file sdc.c:

00236 #if SDC_MMC_SUPPORT
00237 if ((sdcp->cardmode & SDC_MODE_CARDTYPE_MASK) == SDC_MODE_CARDTYPE_MMC) {
00238 /* TODO: MMC initialization.*/
00239 goto failed;
00240 }
00241 else
00242 #endif /* SDC_MMC_SUPPORT */

So, is it possible my embedded MMC card is not supported?
It's a common eMMC from Micron.

Regards.
-g

Hi,

It is not yet supported, there is a missing portion of code in the driver. MMC devices are way less common than SD devices so it has never been an high priority.

Giovanni

Dear Giovanni, when you say "missing portion" of code, you mean small, medium or large
i need this feature working for my project, so i could spend some time developing and fixing this issue.

where do i start? what is needed in order to make it working? do somebody try this at home?

thanks.
-g

Hi,

It is just missing the MMC initialization part, it could be as small as 10 lines of code. There is a remark in the code.

I don't have pure MMC devices so cannot write nor test it.

Giovanni

my eMMC does not support SPI mode at all: do the sdc driver use SPI mode only?
-g

The SDC driver uses SDIO, the MMC_SPI driver uses SPI, both drivers have a common interface.

Giovanni