On Jan 11, 2008 6:05 PM, Pierre Ossman <[EMAIL PROTECTED]> wrote: > On Fri, 11 Jan 2008 04:47:44 -0500 > "Mike Frysinger" <[EMAIL PROTECTED]> wrote: > > > Cliff should be able to enumerate the cards he has tested and the > > issues he's run into. i'll see if i cant get more in depth > > information from the hardware guys beyond the documentation on the sdh > > already available in the hardware manual (which i'm guessing has not > > been enough to appease you). > > > > Great. And you're right in that the spec did not give any indication that MMC > shouldn't work. >
Our tester will reopen a tracker of this issue. When it's fired, you will be updated with this information. > I did notice one thing though. The pull-ups and pull-downs seem to be > controllable. If I remember correctly, DAT3 needs to have a controller-side > pull-up for MMC cards. And the docs said the default was not to provide that > (in order to use the internal pull-up that most, but not all, SD cards have > for detection). Might be something to look at if you haven't already. > I guess it is for MMC/SD card insert detection. Is it related with the 4-bit MMC and 4-bit SD? Actually, there are some issues about the card insert detection on BF54x SDH. Following is some comments of our bfin-sdh driver which is in the development. --- /* In term of ADSP_BF54x_Blackfin_Processor_Peripheral_Hardware_Reference, * the SDH allows software to detect a card when it is inserted into its slot. * The SD_DATA3 pin powers up low due to a special pull-down resistor. When an * SD Card is inserted in its slot, the resistance increases and a rising edge * is detected by the SDH module. * But this doesn't work sometimes. When a MMC/SD card is inserted, the voltage * doesn't rise on SD_DATA3. In term of The MultiMediaCard System Specification, * SD_DATA3 is used as CS pin in SPI mode. The MultiMediaCard wakes up in the * MultiMediaCard mode. During the scan procedure, host will send CMD0 to reset * MMC card, if CS pin is low, MMC card will enter SPI mode. Of course Secure * Digital Host controller is not a SPI controller. So the Card detect function * has to be disabled. After card is inserted run "echo 0 > /proc/driver/sdh" * to trigger card scanning */ --- Thanks -Bryan Wu -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
