[ECOS] eCos VME Bus Device Driver.

Jason Thomas jason@cosmic.utah.edu
Thu Mar 4 21:19:00 GMT 2004

   I'm trying to write a Universe Bridge VME Bus Device Driver for eCos. I
used "cyg_pci_find_device((CYG_PCI_VENDOR_ID_TUNDRA,
PCI_DEVICE_ID_TUNDRA_CA91C042, &devid);" to begin with, it it always
returned false. So, instead I used cyg_pci_find_device in a loop, and
compared the device registers to these two in order to find the device.
After finding the device I can read and write to the configuration
registers, but now I want to map the configuration space hardware
address from a register variable on the Universe chip to a virtual
memory space.

//Tell the chip I want to read CONFIG_REG_SPACE address.
cyg_pci_write_config_uint32(uni_pci_dev, PCI_BS, CONFIG_REG_SPACE);
//Read it.
cyg_pci_read_config_uint32(uni_pci_dev, PCI_BS, &ba);
//Map it to a virtual memory address space.
baseaddr = (char *)ioremap(ba,4096);

Except, ioremap doesn't exist... From reading the documentation on device
drivers it seems like "cyg_pci_allocate_io" probably is the equivolent
call. I'm not exactly clear on how to use this.

Does the "cyg_pci_configure_device" call do this memory mapping
automagicaly for you? The cyg_pci_dev structure seems to have an array of
the base addresses inside of it. Are these already the virtual memory
mapped base addresses for the PCI device??

It would be nice to look at other eCos driver example implementations, I
just can't find where they're located in the build tree. All I can find
are the binaries for these drivers under the <target>_build directory

-Jason Thomas.

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