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
22static int force_probe = EISA_FORCE_PROBE_DEFAULT;
23static 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
28static struct platform_device eisa_root_dev = {
29 .name = "eisa",
30 .id = 0,
31 .dev = {
32 .release = virtual_eisa_release,
33 },
34};
35
36static 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
44static void virtual_eisa_release (struct device *dev)
45{
46 /* nothing really to do here */
47}
48
49static 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(dev: &eisa_root_dev.dev, data: &eisa_bus_root);
59
60 if (eisa_root_register (root: &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
70module_param (force_probe, int, 0444);
71
72device_initcall (virtual_eisa_root_init);
73

source code of linux/drivers/eisa/virtual_root.c