2008-04-22 22:27:18     Can spi/mmc work when spi/wifi at working?

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2008-04-22 22:27:18     Can spi/mmc work when spi/wifi at working?

浩 何 (CHINA)

Message: 54745   

 

hello:

 

my board is bf537_stamp, and i use the spi port as a wlan interface,

 

now i found when my wlan at work, my spi/mmc can't work at all,

 

can  the spi device support wlan/mmc work at the same time?

 

my hardware  HOST   MOSI ----------------------------->wlan and spi/mmc miso

 

                                        MISo ----------------------------->wlan and spi/mmc mosi

 

                                      SPISSEL1---------------------------->SPI/MMC SSEL

 

                                      SPISSEL2------------------------------>WLAN   SSEL

 

 

 

 

 

thanks!!!

 

 

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2008-04-23 00:33:34     Re: Can spi/mmc work when spi/wifi at working?

Frank Van Hooft (CANADA)

Message: 54747    I'm also using an SD/MMC card on the BF537-STAMP. My understanding is that the SD/MMC has to be the only device on the SPI bus for it to work.

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2008-04-23 00:41:07     Re: Can spi/mmc work when spi/wifi at working?

Mike Frysinger (UNITED STATES)

Message: 54748    it isnt so much "only on the bus" as "only one in use at one time"

 

most likely concurrent use of SPI/SD/MMC storage and SPI/WIFI usage will currently get tripped up ... if you manage the time slices in software however, you could probably work around the issue

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2008-04-23 16:06:26     Re: Can spi/mmc work when spi/wifi at working?

Robin Getz (UNITED STATES)

Message: 54803    Mike:

 

If both drivers are using the SPI framework properly - it should be OK - but as you indicated - it is likely that they are not using it properly, and don't work.

 

-Robin

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2008-04-23 16:51:55     Re: Can spi/mmc work when spi/wifi at working?

Mike Frysinger (UNITED STATES)

Message: 54804    SPI/MMC already has a known deficiency where it needs to lock the bus for more than one message in order to communicate properly.  the SPI framework currently does not provide for this.

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2008-04-24 21:36:37     Re: Can spi/mmc work when spi/wifi at working?

Wei Jiang (CHINA)

Message: 54914    Dear Mike,

   In 08-R1, I saw there are two choices in the "MMC/SD card support" menuconfig:

    ( ) SPI framework master             

    (X) Blackfin SPI bus directly

   Did you means the driver will not work if I choose "SPI framework master"?

   Or both of them should be OK?

   Thanks..

       Wei Jiang

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2008-04-24 21:53:54     Re: Can spi/mmc work when spi/wifi at working?

Mike Frysinger (UNITED STATES)

Message: 54917    it isnt a mmc driver issue, it's a design/framework issue.

 

read the configuration help for the options.  the latter should work properly, but obviously you cant use any other SPI device.  but if you arent using any other SPI device, then the issue in question wont be present anyways, so it's sort of a moot point.

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