2010-11-19 08:01:55     Question related with MMC_SPI driver.

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2010-11-19 08:01:55     Question related with MMC_SPI driver.

Dimitar Penev (BULGARIA)

Message: 96008   

 

Hello Guys,

 

 

I am trying to run mmc_spi driver on one of our BF537 Blackfin boards.

And I got an issue which probably will be obvious for some of you.

 

Let me copy the log:

 

*******The SD card is inserted and I switch on the board. After I get linux up I do:

 

root@dpn:~> modprobe mmc_spi

mmc_spi spi0.4: ASSUMING 3.2-3.4 V slot power

mmc_spi spi0.4: SD/MMC host mmc0, no DMA, no WP, no poweroff

mmc_spi spi0.4: requested mode not fully supported

mmc_spi spi0.4: can't change chip-select polarity

root@dpn:~> mmc0: error -84 whilst initialising SD card

 

***** Unplug and plug the SD card again

 

root@dpn:~> rmmod mmc_spi

root@dpn:~> modprobe mmc_spi

mmc_spi spi0.4: ASSUMING 3.2-3.4 V slot power

mmc_spi spi0.4: SD/MMC host mmc0, no DMA, no WP, no poweroff

mmc_spi spi0.4: requested mode not fully supported

mmc_spi spi0.4: can't change chip-select polarity

root@dpn:~> mmc0: host does not support reading read-only switch. assuming write-enable.

mmc0: new SD card on SPI

root@dpn:~>

root@dpn:~> modprobe mmc_block

mmcblk0: mmc0:0000 SD01G 982 MiB

mmcblk0:

root@dpn:~>

root@dpn:~> ls /dev/mmc*

/dev/mmc   /dev/mmc1  /dev/mmc2  /dev/mmc3

 

So I don't see the SD card partitions which I can mount.

 

The card I am using is 1GB Mini Kongston.

 

I am using uclinux-dist 2009R1.1-RC4 release

 

Thank you in advance!

Dimitar Penev

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2010-11-19 09:55:28     Re: Question related with MMC_SPI driver.

Dimitar Penev (BULGARIA)

Message: 96012   

 

Hi Guys,

 

I've noticed that this behaviour is card dependent.

Another card 2GB Kinkston I can detect and mount withot need to eject re-insert

And alos the partitions are detected properly.

 

Should I expect improved SD card support of the SVN trunk in respect to 2009R1.1-RC4?

 

Thanks

Dimitar

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2010-11-19 18:22:11     Re: Question related with MMC_SPI driver.

Mike Frysinger (UNITED STATES)

Message: 96020   

 

what sort of pull ups/downs do you have on the SPI lines ?

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2010-11-23 10:30:42     Re: Question related with MMC_SPI driver.

Dimitar Penev (BULGARIA)

Message: 96138   

 

Hi Mike,

 

All the SPI signals are pooled up only CLK is pulled down.

I am using SPI_MODE0 in my board definition.

 

Best Regards

Dimitar

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2010-11-23 12:04:14     Re: Question related with MMC_SPI driver.

Frank Van Hooft (CANADA)

Message: 96141   

 

On our board all SD Card signals are pulled up, including the unused SD card signals, and including the SPI CLK. Our board has the option to pull SPI CLK either up or down, but we only pull it up. I'd suggest you try doing the same.

 

Also, what speed are you running the SPI port at?

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2010-11-23 15:41:04     Re: Question related with MMC_SPI driver.

Dimitar Penev (BULGARIA)

Message: 96143   

 

Hi Frank,

 

Thank you for the reply.

 

In my board definition file i have

 

max_speed_hz = 20000000

 

Best Regards

Dimitar

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