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OMAP 3530 GPMC driver problem

Peter Lohmer
Prodigy 20 points

High all,

i'm trying to create a kernel driver for fpga access connected to GPMC. I work with openembedded and gumstix board and the fpga ist connected to cs1. I use the driver functions supplied with the kernel to configure the gpmc. I configure for 16bit devicesize, devicetype nor. Additionally i exported kernel function for timing settings and set new timings. When i try to write 1 32bit word with iowrite32(..) i would expect 2 accesses with 16bit width, but on logic analyzer i see 4 byte accesses. Adress/Data multiplexing and timing settings works like expected.  Does anyone have an idea what mistake i have done or what goes wrong here?

Thank you very much

Peter

  • 0
    Prodigy 20 points

    Hallo,

    i could solve my problem, but i think that there is a mistake in the OMAP35xx reference manual. If i don't set device size expicitly, means using the default setting for cs1 then everything works fine. But the code in gpmc.c sets the bit 12 for 16bit like described in reference manual and this causes 8bit accesses. So bit 12 must be 0 for 16 bit access and this is the default setting after reset. 

    Peter

  • 0 in reply to Peter Lohmer
    Prodigy 165 points

    Hi,

    Can you be more specific as to which GPMC register you are referring to of a possible mistake in the TRM?

    Thank you.

    James Ang.