drivers/eisa/virtual_root.c

   1 /*
   2  * Virtual EISA root driver.
   3  * Acts as a placeholder if we don't have a proper EISA bridge.
   4  *
   5  * (C) 2003 Marc Zyngier <maz@wild-wind.fr.eu.org>
   6  *
   7  * This code is released under the GPL version 2.
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/eisa.h>
  13 #include <linux/module.h>
  14 #include <linux/moduleparam.h>
  15 #include <linux/init.h>
  16
  17 #if defined(CONFIG_ALPHA_JENSEN) || defined(CONFIG_EISA_VLB_PRIMING)
  18 #define EISA_FORCE_PROBE_DEFAULT 1
  19 #else
  20 #define EISA_FORCE_PROBE_DEFAULT 0
  21 #endif
  22
  23 static int force_probe = EISA_FORCE_PROBE_DEFAULT;
  24 static void virtual_eisa_release (struct device *);
  25
  26 /* The default EISA device parent (virtual root device).
  27  * Now use a platform device, since that's the obvious choice. */
  28
  29 static struct platform_device eisa_root_dev = {
  30         .name = "eisa",
  31         .id   = 0,
  32         .dev  = {
  33                 .release = virtual_eisa_release,
  34         },
  35 };
  36
  37 static struct eisa_root_device eisa_bus_root = {
  38         .dev            = &eisa_root_dev.dev,
  39         .bus_base_addr  = 0,
  40         .res            = &ioport_resource,
  41         .slots          = EISA_MAX_SLOTS,
  42         .dma_mask       = 0xffffffff,
  43 };
  44
  45 static void virtual_eisa_release (struct device *dev)
  46 {
  47         /* nothing really to do here */
  48 }
  49
  50 static int __init virtual_eisa_root_init (void)
  51 {
  52         int r;
  53
  54         if ((r = platform_device_register (&eisa_root_dev)))
  55                 return r;
  56
  57         eisa_bus_root.force_probe = force_probe;
  58
  59         dev_set_drvdata(&eisa_root_dev.dev, &eisa_bus_root);
  60
  61         if (eisa_root_register (&eisa_bus_root)) {
  62                 /* A real bridge may have been registered before
  63                  * us. So quietly unregister. */
  64                 platform_device_unregister (&eisa_root_dev);
  65                 return -1;
  66         }
  67
  68         return 0;
  69 }
  70
  71 module_param (force_probe, int, 0444);
  72
  73 device_initcall (virtual_eisa_root_init);