xref: /openbmc/linux/drivers/eisa/virtual_root.c (revision 4a1ccb5b)
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 
58 	eisa_bus_root.force_probe = force_probe;
59 
60 	eisa_root_dev.dev.driver_data = &eisa_bus_root;
61 
62 	if (eisa_root_register (&eisa_bus_root)) {
63 		/* A real bridge may have been registered before
64 		 * us. So quietly unregister. */
65 		platform_device_unregister (&eisa_root_dev);
66 		return -1;
67 	}
68 
69 	return 0;
70 }
71 
72 module_param (force_probe, int, 0444);
73 
74 device_initcall (virtual_eisa_root_init);
75