Standard driver call to enable/disable PCI ROM

[Jon Smirl <jonsmirl@yahoo.com>]

I needed to enable a PCI ROM and read a few things
from it, and then disable it again. It might be worth
adding a standard PCI API in 2.6 for this.

Here's the code I used...

static void * __init aty128_map_ROM(struct pci_dev
                   *dev, const struct aty128fb_par
*par)
{
   void *rom;
   struct resource *r =
      &dev->resource[PCI_ROM_RESOURCE];
                                                      
   /* assign address if it doesn't have one */
   if (r->start == 0)
      pci_assign_resource(dev,
                                    PCI_ROM_RESOURCE);
                                                      
   /* enable if needed */
   if (!(r->flags & PCI_ROM_ADDRESS_ENABLE)) {
      pci_write_config_dword(dev,
                     dev->rom_base_reg, r->start | 
                     PCI_ROM_ADDRESS_ENABLE);
      r->flags |= PCI_ROM_ADDRESS_ENABLE;
   }
   rom = ioremap(r->start, r->end - r->start + 1);
   if (!rom) {
     printk(KERN_ERR "aty128fb: ROM failed to map\n");
     return NULL;
   }
   /* Very simple test to make sure it appeared */
   if (readb(rom) != 0x55) {
      printk(KERN_ERR "aty128fb: Invalid ROM
            signature %x should be 0x55\n",
readb(rom));          
      aty128_unmap_ROM(dev, rom);
      return NULL;
   }
   return rom;
}
                                            
static void __init aty128_unmap_ROM(struct pci_dev
                                             *dev,
void * rom)
{
   /* leave it disabled and unassigned */
   struct resource *r =
         &dev->resource[PCI_ROM_RESOURCE];
                                            
   iounmap(rom);
                                            
   r->flags &= ~PCI_ROM_ADDRESS_ENABLE;
   r->end -= r->start;
   r->start = 0;
   /* This will disable and set address to unassigned
*/
   pci_write_config_dword(dev, dev->rom_base_reg, 0);
   release_resource(r);
}


=====
Jon Smirl
jonsmirl@yahoo.com

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