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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 = -ENOMEM;
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 			goto error;
266 
267 		hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
268 		if (!hotplug_slot)
269 			goto error_slot;
270 		slot->hotplug_slot = hotplug_slot;
271 
272 		info = kzalloc(sizeof(*info), GFP_KERNEL);
273 		if (!info)
274 			goto error_hpslot;
275 		hotplug_slot->info = info;
276 
277 		slot->number = i;
278 
279 		hotplug_slot->name = slot->name;
280 		hotplug_slot->private = slot;
281 		hotplug_slot->release = &release_slot;
282 		make_slot_name(slot);
283 		hotplug_slot->ops = &skel_hotplug_slot_ops;
284 
285 		/*
286 		 * Initialize the slot info structure with some known
287 		 * good values.
288 		 */
289 		get_power_status(hotplug_slot, &info->power_status);
290 		get_attention_status(hotplug_slot, &info->attention_status);
291 		get_latch_status(hotplug_slot, &info->latch_status);
292 		get_adapter_status(hotplug_slot, &info->adapter_status);
293 
294 		dbg("registering slot %d\n", i);
295 		retval = pci_hp_register(slot->hotplug_slot);
296 		if (retval) {
297 			err("pci_hp_register failed with error %d\n", retval);
298 			goto error_info;
299 		}
300 
301 		/* add slot to our internal list */
302 		list_add(&slot->slot_list, &slot_list);
303 	}
304 
305 	return 0;
306 error_info:
307 	kfree(info);
308 error_hpslot:
309 	kfree(hotplug_slot);
310 error_slot:
311 	kfree(slot);
312 error:
313 	return retval;
314 }
315 
cleanup_slots(void)316 static void __exit cleanup_slots(void)
317 {
318 	struct list_head *tmp;
319 	struct list_head *next;
320 	struct slot *slot;
321 
322 	/*
323 	 * Unregister all of our slots with the pci_hotplug subsystem.
324 	 * Memory will be freed in release_slot() callback after slot's
325 	 * lifespan is finished.
326 	 */
327 	list_for_each_safe(tmp, next, &slot_list) {
328 		slot = list_entry(tmp, struct slot, slot_list);
329 		list_del(&slot->slot_list);
330 		pci_hp_deregister(slot->hotplug_slot);
331 	}
332 }
333 
pcihp_skel_init(void)334 static int __init pcihp_skel_init(void)
335 {
336 	int retval;
337 
338 	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
339 	/*
340 	 * Do specific initialization stuff for your driver here
341 	 * like initializing your controller hardware (if any) and
342 	 * determining the number of slots you have in the system
343 	 * right now.
344 	 */
345 	num_slots = 5;
346 
347 	return init_slots();
348 }
349 
pcihp_skel_exit(void)350 static void __exit pcihp_skel_exit(void)
351 {
352 	/*
353 	 * Clean everything up.
354 	 */
355 	cleanup_slots();
356 }
357 
358 module_init(pcihp_skel_init);
359 module_exit(pcihp_skel_exit);
360