2008-02-05 10:12:13     SPI driver and GPIO CS control

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2008-02-05 10:12:13     SPI driver and GPIO CS control

daniel amor (SPAIN)

Message: 50697    Hello,

 

I am developing a driver used to control a set of chips connected to the SPI bus. To generate the CSs I have a 3 o 8 decoder, so I can control up to 8 chips in the bus. I am using BF537 and dist R1.1-RC3.

 

My driver will control the 3 GPIO signals to generate the right CS, but when configuring the driver, which are the right values for bus_num and chip_select?

 

I have tried looking at the sources of the master controller but it only seems to be prepared for hardware controlled CS.

 

Thanks,

 

  Daniel Amor,

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2008-02-05 10:38:43     Re: SPI driver and GPIO CS control

Mike Frysinger (UNITED STATES)

Message: 50699    you are correct ... currently, only hardware chip selects work with the Blackfin SPI bus driver

 

your options are:

- use the GPIO SPI bus driver (but all SPI lines are GPIO driven)

- add support for GPIO CS's to the SPI bus driver

- open a tracker and wait for a developer to add support for it

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2008-02-05 11:18:52     Re: SPI driver and GPIO CS control

daniel amor (SPAIN)

Message: 50706    Ok, thanks.

 

I have one of the hardware controlled CS not conected to anything so I think I could use it as a fake CS, but I'll have a look at the master driver to include some kind of GPIO support.

 

I'll check bfin datasheet and the driver to see where to look at.

 

Thanks for your help,

 

Daniel Amor,

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