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 */
46 static bool debug;
47 static char *bridge;
48 static u8 bridge_busnr;
49 static u8 bridge_slot;
50 static struct pci_bus *bus;
51 static u8 first_slot;
52 static u8 last_slot;
53 static u16 port;
54 static unsigned int enum_bit;
55 static u8 enum_mask;
56
57 static struct cpci_hp_controller_ops generic_hpc_ops;
58 static struct cpci_hp_controller generic_hpc;
59
validate_parameters(void)60 static 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
query_enum(void)115 static int query_enum(void)
116 {
117 u8 value;
118
119 value = inb_p(port);
120 return ((value & enum_mask) == enum_mask);
121 }
122
cpcihp_generic_init(void)123 static 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;
173 init_start_error:
174 cpci_hp_unregister_bus(bus);
175 init_bus_register_error:
176 cpci_hp_unregister_controller(&generic_hpc);
177 err("status = %d", status);
178 return status;
179
180 }
181
cpcihp_generic_exit(void)182 static 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
190 module_init(cpcihp_generic_init);
191 module_exit(cpcihp_generic_exit);
192
193 MODULE_AUTHOR(DRIVER_AUTHOR);
194 MODULE_DESCRIPTION(DRIVER_DESC);
195 MODULE_LICENSE("GPL");
196 module_param(debug, bool, S_IRUGO | S_IWUSR);
197 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
198 module_param(bridge, charp, 0);
199 MODULE_PARM_DESC(bridge, "Hotswap bus bridge device, <bus>:<slot> (bus and slot are in hexadecimal)");
200 module_param(first_slot, byte, 0);
201 MODULE_PARM_DESC(first_slot, "Hotswap bus first slot number");
202 module_param(last_slot, byte, 0);
203 MODULE_PARM_DESC(last_slot, "Hotswap bus last slot number");
204 module_param_hw(port, ushort, ioport, 0);
205 MODULE_PARM_DESC(port, "#ENUM signal I/O port");
206 module_param(enum_bit, uint, 0);
207 MODULE_PARM_DESC(enum_bit, "#ENUM signal bit (0-7)");
208