1 /*
2 * PCI Hot Plug Controller Skeleton Driver - 0.3
3 *
4 * Copyright (C) 2001,2003 Greg Kroah-Hartman (greg@kroah.com)
5 * Copyright (C) 2001,2003 IBM Corp.
6 *
7 * All rights reserved.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or (at
12 * your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
17 * NON INFRINGEMENT. See the GNU General Public License for more
18 * details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 *
24 * This driver is to be used as a skeleton driver to show how to interface
25 * with the pci hotplug core easily.
26 *
27 * Send feedback to <greg@kroah.com>
28 *
29 */
30
31 #include <linux/module.h>
32 #include <linux/moduleparam.h>
33 #include <linux/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/pci.h>
36 #include <linux/pci_hotplug.h>
37 #include <linux/init.h>
38
39 #define SLOT_NAME_SIZE 10
40 struct slot {
41 u8 number;
42 struct hotplug_slot *hotplug_slot;
43 struct list_head slot_list;
44 char name[SLOT_NAME_SIZE];
45 };
46
47 static LIST_HEAD(slot_list);
48
49 #define MY_NAME "pcihp_skeleton"
50
51 #define dbg(format, arg...) \
52 do { \
53 if (debug) \
54 printk(KERN_DEBUG "%s: " format "\n", \
55 MY_NAME, ## arg); \
56 } while (0)
57 #define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg)
58 #define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg)
59 #define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg)
60
61 /* local variables */
62 static bool debug;
63 static int num_slots;
64
65 #define DRIVER_VERSION "0.3"
66 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>"
67 #define DRIVER_DESC "Hot Plug PCI Controller Skeleton Driver"
68
69 MODULE_AUTHOR(DRIVER_AUTHOR);
70 MODULE_DESCRIPTION(DRIVER_DESC);
71 MODULE_LICENSE("GPL");
72 module_param(debug, bool, 0644);
73 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
74
75 static int enable_slot(struct hotplug_slot *slot);
76 static int disable_slot(struct hotplug_slot *slot);
77 static int set_attention_status(struct hotplug_slot *slot, u8 value);
78 static int hardware_test(struct hotplug_slot *slot, u32 value);
79 static int get_power_status(struct hotplug_slot *slot, u8 *value);
80 static int get_attention_status(struct hotplug_slot *slot, u8 *value);
81 static int get_latch_status(struct hotplug_slot *slot, u8 *value);
82 static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
83
84 static struct hotplug_slot_ops skel_hotplug_slot_ops = {
85 .enable_slot = enable_slot,
86 .disable_slot = disable_slot,
87 .set_attention_status = set_attention_status,
88 .hardware_test = hardware_test,
89 .get_power_status = get_power_status,
90 .get_attention_status = get_attention_status,
91 .get_latch_status = get_latch_status,
92 .get_adapter_status = get_adapter_status,
93 };
94
enable_slot(struct hotplug_slot * hotplug_slot)95 static int enable_slot(struct hotplug_slot *hotplug_slot)
96 {
97 struct slot *slot = hotplug_slot->private;
98 int retval = 0;
99
100 dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
101
102 /*
103 * Fill in code here to enable the specified slot
104 */
105
106 return retval;
107 }
108
disable_slot(struct hotplug_slot * hotplug_slot)109 static int disable_slot(struct hotplug_slot *hotplug_slot)
110 {
111 struct slot *slot = hotplug_slot->private;
112 int retval = 0;
113
114 dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
115
116 /*
117 * Fill in code here to disable the specified slot
118 */
119
120 return retval;
121 }
122
set_attention_status(struct hotplug_slot * hotplug_slot,u8 status)123 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
124 {
125 struct slot *slot = hotplug_slot->private;
126 int retval = 0;
127
128 dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
129
130 switch (status) {
131 case 0:
132 /*
133 * Fill in code here to turn light off
134 */
135 break;
136
137 case 1:
138 default:
139 /*
140 * Fill in code here to turn light on
141 */
142 break;
143 }
144
145 return retval;
146 }
147
hardware_test(struct hotplug_slot * hotplug_slot,u32 value)148 static int hardware_test(struct hotplug_slot *hotplug_slot, u32 value)
149 {
150 struct slot *slot = hotplug_slot->private;
151 int retval = 0;
152
153 dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
154
155 switch (value) {
156 case 0:
157 /* Specify a test here */
158 break;
159 case 1:
160 /* Specify another test here */
161 break;
162 }
163
164 return retval;
165 }
166
get_power_status(struct hotplug_slot * hotplug_slot,u8 * value)167 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
168 {
169 struct slot *slot = hotplug_slot->private;
170 int retval = 0;
171
172 dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
173
174 /*
175 * Fill in logic to get the current power status of the specific
176 * slot and store it in the *value location.
177 */
178
179 return retval;
180 }
181
get_attention_status(struct hotplug_slot * hotplug_slot,u8 * value)182 static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
183 {
184 struct slot *slot = hotplug_slot->private;
185 int retval = 0;
186
187 dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
188
189 /*
190 * Fill in logic to get the current attention status of the specific
191 * slot and store it in the *value location.
192 */
193
194 return retval;
195 }
196
get_latch_status(struct hotplug_slot * hotplug_slot,u8 * value)197 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
198 {
199 struct slot *slot = hotplug_slot->private;
200 int retval = 0;
201
202 dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
203
204 /*
205 * Fill in logic to get the current latch status of the specific
206 * slot and store it in the *value location.
207 */
208
209 return retval;
210 }
211
get_adapter_status(struct hotplug_slot * hotplug_slot,u8 * value)212 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
213 {
214 struct slot *slot = hotplug_slot->private;
215 int retval = 0;
216
217 dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
218
219 /*
220 * Fill in logic to get the current adapter status of the specific
221 * slot and store it in the *value location.
222 */
223
224 return retval;
225 }
226
release_slot(struct hotplug_slot * hotplug_slot)227 static void release_slot(struct hotplug_slot *hotplug_slot)
228 {
229 struct slot *slot = hotplug_slot->private;
230
231 dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
232 kfree(slot->hotplug_slot->info);
233 kfree(slot->hotplug_slot);
234 kfree(slot);
235 }
236
make_slot_name(struct slot * slot)237 static void make_slot_name(struct slot *slot)
238 {
239 /*
240 * Stupid way to make a filename out of the slot name.
241 * replace this if your hardware provides a better way to name slots.
242 */
243 snprintf(slot->hotplug_slot->name, SLOT_NAME_SIZE, "%d", slot->number);
244 }
245
246 /**
247 * init_slots - initialize 'struct slot' structures for each slot
248 *
249 */
init_slots(void)250 static int __init init_slots(void)
251 {
252 struct slot *slot;
253 struct hotplug_slot *hotplug_slot;
254 struct hotplug_slot_info *info;
255 int retval;
256 int i;
257
258 /*
259 * Create a structure for each slot, and register that slot
260 * with the pci_hotplug subsystem.
261 */
262 for (i = 0; i < num_slots; ++i) {
263 slot = kzalloc(sizeof(*slot), GFP_KERNEL);
264 if (!slot) {
265 retval = -ENOMEM;
266 goto error;
267 }
268
269 hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
270 if (!hotplug_slot) {
271 retval = -ENOMEM;
272 goto error_slot;
273 }
274 slot->hotplug_slot = hotplug_slot;
275
276 info = kzalloc(sizeof(*info), GFP_KERNEL);
277 if (!info) {
278 retval = -ENOMEM;
279 goto error_hpslot;
280 }
281 hotplug_slot->info = info;
282
283 slot->number = i;
284
285 hotplug_slot->name = slot->name;
286 hotplug_slot->private = slot;
287 hotplug_slot->release = &release_slot;
288 make_slot_name(slot);
289 hotplug_slot->ops = &skel_hotplug_slot_ops;
290
291 /*
292 * Initialize the slot info structure with some known
293 * good values.
294 */
295 get_power_status(hotplug_slot, &info->power_status);
296 get_attention_status(hotplug_slot, &info->attention_status);
297 get_latch_status(hotplug_slot, &info->latch_status);
298 get_adapter_status(hotplug_slot, &info->adapter_status);
299
300 dbg("registering slot %d\n", i);
301 retval = pci_hp_register(slot->hotplug_slot);
302 if (retval) {
303 err("pci_hp_register failed with error %d\n", retval);
304 goto error_info;
305 }
306
307 /* add slot to our internal list */
308 list_add(&slot->slot_list, &slot_list);
309 }
310
311 return 0;
312 error_info:
313 kfree(info);
314 error_hpslot:
315 kfree(hotplug_slot);
316 error_slot:
317 kfree(slot);
318 error:
319 return retval;
320 }
321
cleanup_slots(void)322 static void __exit cleanup_slots(void)
323 {
324 struct slot *slot, *next;
325
326 /*
327 * Unregister all of our slots with the pci_hotplug subsystem.
328 * Memory will be freed in release_slot() callback after slot's
329 * lifespan is finished.
330 */
331 list_for_each_entry_safe(slot, next, &slot_list, slot_list) {
332 list_del(&slot->slot_list);
333 pci_hp_deregister(slot->hotplug_slot);
334 }
335 }
336
pcihp_skel_init(void)337 static int __init pcihp_skel_init(void)
338 {
339 int retval;
340
341 info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
342 /*
343 * Do specific initialization stuff for your driver here
344 * like initializing your controller hardware (if any) and
345 * determining the number of slots you have in the system
346 * right now.
347 */
348 num_slots = 5;
349
350 return init_slots();
351 }
352
pcihp_skel_exit(void)353 static void __exit pcihp_skel_exit(void)
354 {
355 /*
356 * Clean everything up.
357 */
358 cleanup_slots();
359 }
360
361 module_init(pcihp_skel_init);
362 module_exit(pcihp_skel_exit);
363