1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Virtual EISA root driver.
4 * Acts as a placeholder if we don't have a proper EISA bridge.
5 *
6 * (C) 2003 Marc Zyngier <maz@wild-wind.fr.eu.org>
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/platform_device.h>
11 #include <linux/eisa.h>
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/init.h>
15
16 #if defined(CONFIG_ALPHA_JENSEN) || defined(CONFIG_EISA_VLB_PRIMING)
17 #define EISA_FORCE_PROBE_DEFAULT 1
18 #else
19 #define EISA_FORCE_PROBE_DEFAULT 0
20 #endif
21
22 static int force_probe = EISA_FORCE_PROBE_DEFAULT;
23 static void virtual_eisa_release (struct device *);
24
25 /* The default EISA device parent (virtual root device).
26 * Now use a platform device, since that's the obvious choice. */
27
28 static struct platform_device eisa_root_dev = {
29 .name = "eisa",
30 .id = 0,
31 .dev = {
32 .release = virtual_eisa_release,
33 },
34 };
35
36 static struct eisa_root_device eisa_bus_root = {
37 .dev = &eisa_root_dev.dev,
38 .bus_base_addr = 0,
39 .res = &ioport_resource,
40 .slots = EISA_MAX_SLOTS,
41 .dma_mask = 0xffffffff,
42 };
43
virtual_eisa_release(struct device * dev)44 static void virtual_eisa_release (struct device *dev)
45 {
46 /* nothing really to do here */
47 }
48
virtual_eisa_root_init(void)49 static int __init virtual_eisa_root_init (void)
50 {
51 int r;
52
53 if ((r = platform_device_register (&eisa_root_dev)))
54 return r;
55
56 eisa_bus_root.force_probe = force_probe;
57
58 dev_set_drvdata(&eisa_root_dev.dev, &eisa_bus_root);
59
60 if (eisa_root_register (&eisa_bus_root)) {
61 /* A real bridge may have been registered before
62 * us. So quietly unregister. */
63 platform_device_unregister (&eisa_root_dev);
64 return -1;
65 }
66
67 return 0;
68 }
69
70 module_param (force_probe, int, 0444);
71
72 device_initcall (virtual_eisa_root_init);
73