New PCI Device Driver
Is your driver GPL?
Cheers, Dean.
On 07 Oct 2002 20:58:26 +0100 Alan Cox <[email protected]> wrote:
Quoted 6 lines · Patrick Jennings
I have been tasked with writing a driver for my companies digital radio. The card has 16K of PCI space at BAR0. I need to memory map this into user space, and provide DMA and isr handling. First things first i want to get
the mapping working. When i run the code below after inserting the module
i seg. fault. I know this is what happens when engineers have to write code, but can someone point me in the right direction?
First things I'd pick on are the obvious ones - we have headers defining KERN_ERR etc as <1> so use them 8)
Second you probably want to use the pci_module_init api then multiple cards will basically just work, cardbus will just work and even hotplug should come for free.
Beyond that you get the pci resources correctly, you enable the device first as you should. You then ruin it all by poking around directly into I/O space you have not mapped.
The kernel isn't running in physical space, and on other platforms it gets even more exciting as to what goes on. Its all abstracted do
addr = ioremap(io_base_start, len);
databuf = read(addr + 0x590);Finally note that we have a radio interface layer as part of video4linux. Other than some basic tuning ioctls it probably has little in common with digital radio (assuming you mean something like Eureka-147 (aka DAB) rather than digital tuner/mixer for analogue radio.It would nice to make use of that API and extend it logically if you want to get a driver into the base kernel eventually.
Alan
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