1 /*
2  * cpcihp_generic.c
3  *
4  * Generic port I/O CompactPCI driver
5  *
6  * Copyright 2002 SOMA Networks, Inc.
7  * Copyright 2001 Intel San Luis Obispo
8  * Copyright 2000,2001 MontaVista Software Inc.
9  *
10  * This program is free software; you can redistribute it and/or modify it
11  * under the terms of the GNU General Public License as published by the
12  * Free Software Foundation; either version 2 of the License, or (at your
13  * option) any later version.
14  *
15  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
16  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
17  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
18  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
22  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
23  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
24  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * You should have received a copy of the GNU General Public License along
27  * with this program; if not, write to the Free Software Foundation, Inc.,
28  * 675 Mass Ave, Cambridge, MA 02139, USA.
29  *
30  * This generic CompactPCI hotplug driver should allow using the PCI hotplug
31  * mechanism on any CompactPCI board that exposes the #ENUM signal as a bit
32  * in a system register that can be read through standard port I/O.
33  *
34  * Send feedback to <scottm@somanetworks.com>
35  */
36 
37 #include <linux/module.h>
38 #include <linux/init.h>
39 #include <linux/errno.h>
40 #include <linux/pci.h>
41 #include <linux/string.h>
42 #include "cpci_hotplug.h"
43 
44 #define DRIVER_VERSION	"0.1"
45 #define DRIVER_AUTHOR	"Scott Murray <scottm@somanetworks.com>"
46 #define DRIVER_DESC	"Generic port I/O CompactPCI Hot Plug Driver"
47 
48 #if !defined(MODULE)
49 #define MY_NAME	"cpcihp_generic"
50 #else
51 #define MY_NAME	THIS_MODULE->name
52 #endif
53 
54 #define dbg(format, arg...)					\
55 	do {							\
56 		if (debug)					\
57 			printk (KERN_DEBUG "%s: " format "\n",	\
58 				MY_NAME , ## arg);		\
59 	} while (0)
60 #define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME , ## arg)
61 #define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME , ## arg)
62 #define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME , ## arg)
63 
64 /* local variables */
65 static bool debug;
66 static char *bridge;
67 static u8 bridge_busnr;
68 static u8 bridge_slot;
69 static struct pci_bus *bus;
70 static u8 first_slot;
71 static u8 last_slot;
72 static u16 port;
73 static unsigned int enum_bit;
74 static u8 enum_mask;
75 
76 static struct cpci_hp_controller_ops generic_hpc_ops;
77 static struct cpci_hp_controller generic_hpc;
78 
79 static int __init validate_parameters(void)
80 {
81 	char *str;
82 	char *p;
83 	unsigned long tmp;
84 
85 	if (!bridge) {
86 		info("not configured, disabling.");
87 		return -EINVAL;
88 	}
89 	str = bridge;
90 	if (!*str)
91 		return -EINVAL;
92 
93 	tmp = simple_strtoul(str, &p, 16);
94 	if (p == str || tmp > 0xff) {
95 		err("Invalid hotplug bus bridge device bus number");
96 		return -EINVAL;
97 	}
98 	bridge_busnr = (u8) tmp;
99 	dbg("bridge_busnr = 0x%02x", bridge_busnr);
100 	if (*p != ':') {
101 		err("Invalid hotplug bus bridge device");
102 		return -EINVAL;
103 	}
104 	str = p + 1;
105 	tmp = simple_strtoul(str, &p, 16);
106 	if (p == str || tmp > 0x1f) {
107 		err("Invalid hotplug bus bridge device slot number");
108 		return -EINVAL;
109 	}
110 	bridge_slot = (u8) tmp;
111 	dbg("bridge_slot = 0x%02x", bridge_slot);
112 
113 	dbg("first_slot = 0x%02x", first_slot);
114 	dbg("last_slot = 0x%02x", last_slot);
115 	if (!(first_slot && last_slot)) {
116 		err("Need to specify first_slot and last_slot");
117 		return -EINVAL;
118 	}
119 	if (last_slot < first_slot) {
120 		err("first_slot must be less than last_slot");
121 		return -EINVAL;
122 	}
123 
124 	dbg("port = 0x%04x", port);
125 	dbg("enum_bit = 0x%02x", enum_bit);
126 	if (enum_bit > 7) {
127 		err("Invalid #ENUM bit");
128 		return -EINVAL;
129 	}
130 	enum_mask = 1 << enum_bit;
131 	return 0;
132 }
133 
134 static int query_enum(void)
135 {
136 	u8 value;
137 
138 	value = inb_p(port);
139 	return ((value & enum_mask) == enum_mask);
140 }
141 
142 static int __init cpcihp_generic_init(void)
143 {
144 	int status;
145 	struct resource *r;
146 	struct pci_dev *dev;
147 
148 	info(DRIVER_DESC " version: " DRIVER_VERSION);
149 	status = validate_parameters();
150 	if (status)
151 		return status;
152 
153 	r = request_region(port, 1, "#ENUM hotswap signal register");
154 	if (!r)
155 		return -EBUSY;
156 
157 	dev = pci_get_domain_bus_and_slot(0, bridge_busnr,
158 					  PCI_DEVFN(bridge_slot, 0));
159 	if (!dev || dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
160 		err("Invalid bridge device %s", bridge);
161 		pci_dev_put(dev);
162 		return -EINVAL;
163 	}
164 	bus = dev->subordinate;
165 	pci_dev_put(dev);
166 
167 	memset(&generic_hpc, 0, sizeof (struct cpci_hp_controller));
168 	generic_hpc_ops.query_enum = query_enum;
169 	generic_hpc.ops = &generic_hpc_ops;
170 
171 	status = cpci_hp_register_controller(&generic_hpc);
172 	if (status != 0) {
173 		err("Could not register cPCI hotplug controller");
174 		return -ENODEV;
175 	}
176 	dbg("registered controller");
177 
178 	status = cpci_hp_register_bus(bus, first_slot, last_slot);
179 	if (status != 0) {
180 		err("Could not register cPCI hotplug bus");
181 		goto init_bus_register_error;
182 	}
183 	dbg("registered bus");
184 
185 	status = cpci_hp_start();
186 	if (status != 0) {
187 		err("Could not started cPCI hotplug system");
188 		goto init_start_error;
189 	}
190 	dbg("started cpci hp system");
191 	return 0;
192 init_start_error:
193 	cpci_hp_unregister_bus(bus);
194 init_bus_register_error:
195 	cpci_hp_unregister_controller(&generic_hpc);
196 	err("status = %d", status);
197 	return status;
198 
199 }
200 
201 static void __exit cpcihp_generic_exit(void)
202 {
203 	cpci_hp_stop();
204 	cpci_hp_unregister_bus(bus);
205 	cpci_hp_unregister_controller(&generic_hpc);
206 	release_region(port, 1);
207 }
208 
209 module_init(cpcihp_generic_init);
210 module_exit(cpcihp_generic_exit);
211 
212 MODULE_AUTHOR(DRIVER_AUTHOR);
213 MODULE_DESCRIPTION(DRIVER_DESC);
214 MODULE_LICENSE("GPL");
215 module_param(debug, bool, S_IRUGO | S_IWUSR);
216 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
217 module_param(bridge, charp, 0);
218 MODULE_PARM_DESC(bridge, "Hotswap bus bridge device, <bus>:<slot> (bus and slot are in hexadecimal)");
219 module_param(first_slot, byte, 0);
220 MODULE_PARM_DESC(first_slot, "Hotswap bus first slot number");
221 module_param(last_slot, byte, 0);
222 MODULE_PARM_DESC(last_slot, "Hotswap bus last slot number");
223 module_param(port, ushort, 0);
224 MODULE_PARM_DESC(port, "#ENUM signal I/O port");
225 module_param(enum_bit, uint, 0);
226 MODULE_PARM_DESC(enum_bit, "#ENUM signal bit (0-7)");
227