1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * cpcihp_generic.c
4 *
5 * Generic port I/O CompactPCI driver
6 *
7 * Copyright 2002 SOMA Networks, Inc.
8 * Copyright 2001 Intel San Luis Obispo
9 * Copyright 2000,2001 MontaVista Software Inc.
10 *
11 * This generic CompactPCI hotplug driver should allow using the PCI hotplug
12 * mechanism on any CompactPCI board that exposes the #ENUM signal as a bit
13 * in a system register that can be read through standard port I/O.
14 *
15 * Send feedback to <scottm@somanetworks.com>
16 */
17
18#include <linux/module.h>
19#include <linux/init.h>
20#include <linux/errno.h>
21#include <linux/pci.h>
22#include <linux/string.h>
23#include "cpci_hotplug.h"
24
25#define DRIVER_VERSION	"0.1"
26#define DRIVER_AUTHOR	"Scott Murray <scottm@somanetworks.com>"
27#define DRIVER_DESC	"Generic port I/O CompactPCI Hot Plug Driver"
28
29#if !defined(MODULE)
30#define MY_NAME	"cpcihp_generic"
31#else
32#define MY_NAME	THIS_MODULE->name
33#endif
34
35#define dbg(format, arg...)					\
36	do {							\
37		if (debug)					\
38			printk(KERN_DEBUG "%s: " format "\n",	\
39				MY_NAME, ## arg);		\
40	} while (0)
41#define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg)
42#define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg)
43#define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg)
44
45/* local variables */
46static bool debug;
47static char *bridge;
48static u8 bridge_busnr;
49static u8 bridge_slot;
50static struct pci_bus *bus;
51static u8 first_slot;
52static u8 last_slot;
53static u16 port;
54static unsigned int enum_bit;
55static u8 enum_mask;
56
57static struct cpci_hp_controller_ops generic_hpc_ops;
58static struct cpci_hp_controller generic_hpc;
59
60static int __init validate_parameters(void)
61{
62	char *str;
63	char *p;
64	unsigned long tmp;
65
66	if (!bridge) {
67		info("not configured, disabling.");
68		return -EINVAL;
69	}
70	str = bridge;
71	if (!*str)
72		return -EINVAL;
73
74	tmp = simple_strtoul(str, &p, 16);
75	if (p == str || tmp > 0xff) {
76		err("Invalid hotplug bus bridge device bus number");
77		return -EINVAL;
78	}
79	bridge_busnr = (u8) tmp;
80	dbg("bridge_busnr = 0x%02x", bridge_busnr);
81	if (*p != ':') {
82		err("Invalid hotplug bus bridge device");
83		return -EINVAL;
84	}
85	str = p + 1;
86	tmp = simple_strtoul(str, &p, 16);
87	if (p == str || tmp > 0x1f) {
88		err("Invalid hotplug bus bridge device slot number");
89		return -EINVAL;
90	}
91	bridge_slot = (u8) tmp;
92	dbg("bridge_slot = 0x%02x", bridge_slot);
93
94	dbg("first_slot = 0x%02x", first_slot);
95	dbg("last_slot = 0x%02x", last_slot);
96	if (!(first_slot && last_slot)) {
97		err("Need to specify first_slot and last_slot");
98		return -EINVAL;
99	}
100	if (last_slot < first_slot) {
101		err("first_slot must be less than last_slot");
102		return -EINVAL;
103	}
104
105	dbg("port = 0x%04x", port);
106	dbg("enum_bit = 0x%02x", enum_bit);
107	if (enum_bit > 7) {
108		err("Invalid #ENUM bit");
109		return -EINVAL;
110	}
111	enum_mask = 1 << enum_bit;
112	return 0;
113}
114
115static int query_enum(void)
116{
117	u8 value;
118
119	value = inb_p(port);
120	return ((value & enum_mask) == enum_mask);
121}
122
123static int __init cpcihp_generic_init(void)
124{
125	int status;
126	struct resource *r;
127	struct pci_dev *dev;
128
129	info(DRIVER_DESC " version: " DRIVER_VERSION);
130	status = validate_parameters();
131	if (status)
132		return status;
133
134	r = request_region(port, 1, "#ENUM hotswap signal register");
135	if (!r)
136		return -EBUSY;
137
138	dev = pci_get_domain_bus_and_slot(0, bridge_busnr,
139					  PCI_DEVFN(bridge_slot, 0));
140	if (!dev || dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
141		err("Invalid bridge device %s", bridge);
142		pci_dev_put(dev);
143		return -EINVAL;
144	}
145	bus = dev->subordinate;
146	pci_dev_put(dev);
147
148	memset(&generic_hpc, 0, sizeof(struct cpci_hp_controller));
149	generic_hpc_ops.query_enum = query_enum;
150	generic_hpc.ops = &generic_hpc_ops;
151
152	status = cpci_hp_register_controller(&generic_hpc);
153	if (status != 0) {
154		err("Could not register cPCI hotplug controller");
155		return -ENODEV;
156	}
157	dbg("registered controller");
158
159	status = cpci_hp_register_bus(bus, first_slot, last_slot);
160	if (status != 0) {
161		err("Could not register cPCI hotplug bus");
162		goto init_bus_register_error;
163	}
164	dbg("registered bus");
165
166	status = cpci_hp_start();
167	if (status != 0) {
168		err("Could not started cPCI hotplug system");
169		goto init_start_error;
170	}
171	dbg("started cpci hp system");
172	return 0;
173init_start_error:
174	cpci_hp_unregister_bus(bus);
175init_bus_register_error:
176	cpci_hp_unregister_controller(&generic_hpc);
177	err("status = %d", status);
178	return status;
179
180}
181
182static void __exit cpcihp_generic_exit(void)
183{
184	cpci_hp_stop();
185	cpci_hp_unregister_bus(bus);
186	cpci_hp_unregister_controller(&generic_hpc);
187	release_region(port, 1);
188}
189
190module_init(cpcihp_generic_init);
191module_exit(cpcihp_generic_exit);
192
193MODULE_AUTHOR(DRIVER_AUTHOR);
194MODULE_DESCRIPTION(DRIVER_DESC);
195MODULE_LICENSE("GPL");
196module_param(debug, bool, S_IRUGO | S_IWUSR);
197MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
198module_param(bridge, charp, 0);
199MODULE_PARM_DESC(bridge, "Hotswap bus bridge device, <bus>:<slot> (bus and slot are in hexadecimal)");
200module_param(first_slot, byte, 0);
201MODULE_PARM_DESC(first_slot, "Hotswap bus first slot number");
202module_param(last_slot, byte, 0);
203MODULE_PARM_DESC(last_slot, "Hotswap bus last slot number");
204module_param_hw(port, ushort, ioport, 0);
205MODULE_PARM_DESC(port, "#ENUM signal I/O port");
206module_param(enum_bit, uint, 0);
207MODULE_PARM_DESC(enum_bit, "#ENUM signal bit (0-7)");
208