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/config.h>
  11 #include <linux/kernel.h>
  12 #include <linux/device.h>
  13 #include <linux/eisa.h>
  14 #include <linux/module.h>
  15 #include <linux/moduleparam.h>
  16 #include <linux/init.h>
  17
  18 #if defined(CONFIG_ALPHA_JENSEN) || defined(CONFIG_EISA_VLB_PRIMING)
  19 #define EISA_FORCE_PROBE_DEFAULT 1
  20 #else
  21 #define EISA_FORCE_PROBE_DEFAULT 0
  22 #endif
  23
  24 static int force_probe = EISA_FORCE_PROBE_DEFAULT;
  25 static void virtual_eisa_release (struct device *);
  26
  27 /* The default EISA device parent (virtual root device).
  28  * Now use a platform device, since that's the obvious choice. */
  29
  30 static struct platform_device eisa_root_dev = {
  31         .name = "eisa",
  32         .id   = 0,
  33         .dev  = {
  34                 .release = virtual_eisa_release,
  35         },
  36 };
  37
  38 static struct eisa_root_device eisa_bus_root = {
  39         .dev           = &eisa_root_dev.dev,
  40         .bus_base_addr = 0,
  41         .res           = &ioport_resource,
  42         .slots         = EISA_MAX_SLOTS,
  43         .dma_mask      = 0xffffffff,
  44 };
  45
  46 static void virtual_eisa_release (struct device *dev)
  47 {
  48         /* nothing really to do here */
  49 }
  50
  51 static int virtual_eisa_root_init (void)
  52 {
  53         int r;
  54
  55         if ((r = platform_device_register (&eisa_root_dev))) {
  56                 return r;
  57         }
  58
  59         eisa_bus_root.force_probe = force_probe;
  60
  61         eisa_root_dev.dev.driver_data = &eisa_bus_root;
  62
  63         if (eisa_root_register (&eisa_bus_root)) {
  64                 /* A real bridge may have been registered before
  65                  * us. So quietly unregister. */
  66                 platform_device_unregister (&eisa_root_dev);
  67                 return -1;
  68         }
  69
  70         return 0;
  71 }
  72
  73 module_param (force_probe, int, 0444);
  74
  75 device_initcall (virtual_eisa_root_init);