2008-10-16 17:17:34     SPI_MMC and AD1836

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2008-10-16 17:17:34     SPI_MMC and AD1836

Guillaume Duteil (FRANCE)

Message: 63811   


Good evening,


I am working on a sound gateway based on BF533, AD1836 and MMC/SD card on SPI.


I am facing a problem using MMC and AD1836 in the same time. When I mount the MMC, the AD1836 driver doesn't load, and if I load the AD1836 before mounting the MMC, I can't mount the partition.


Is there a way to make both work in the same time ?


Are there other "easy" ways to access MMC cards and free the SPI bus for the AD1836 ?




Thank you un advance




Guillaume Duteil






2008-10-16 22:24:59     Re: SPI_MMC and AD1836


Message: 63815   




There may be two aspects for your issue:


1. Does you spi_mmc use the same SPI_CS pin as the AD1836?


2. Currently, spi_mmc cannot share SPI bus with other SPI devices (otherwise spi_mmc cannot work properly). We are still working to solve this issue from software side. (Some people suggest emulate SPI using SPORT but we don't support this currently. Also you may think of using GPIO to emulate SPI (please refer to linux/drivers/spi/spi_bitbang.c), for AD1836, I think this could work).






2008-10-17 00:29:37     Re: SPI_MMC and AD1836

Mike Frysinger (UNITED STATES)

Message: 63823   


post the actual errors you're seeing instead of vague high level terms




2008-10-17 04:26:58     Re: SPI_MMC and AD1836

Guillaume Duteil (FRANCE)

Message: 63847   


Thank you I will look at spi_bitbang




2008-10-22 10:18:24     Re: SPI_MMC and AD1836

Steve Strobel (UNITED STATES)

Message: 64046   


I have spi_bitbang working on the AD1938, for which I adapted the AD1836 driver (they are somewhat similar).  I think you can find the SPI driver in the file https://blackfin.uclinux.org/gf/download/forummessage/60926/5184/ad1938codecdriverandnotes.zip.