drivers/pci/hotplug/pcihp_skeleton.c

   1 /*
   2  * PCI Hot Plug Controller Skeleton Driver - 0.2
   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 be 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/init.h>
  37 #include "pci_hotplug.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
  62
  63 /* local variables */
  64 static int debug;
  65 static int num_slots;
  66
  67 #define DRIVER_VERSION  "0.3"
  68 #define DRIVER_AUTHOR   "Greg Kroah-Hartman <greg@kroah.com>"
  69 #define DRIVER_DESC     "Hot Plug PCI Controller Skeleton Driver"
  70
  71 MODULE_AUTHOR(DRIVER_AUTHOR);
  72 MODULE_DESCRIPTION(DRIVER_DESC);
  73 MODULE_LICENSE("GPL");
  74 module_param(debug, bool, 0644);
  75 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
  76
  77 static int enable_slot          (struct hotplug_slot *slot);
  78 static int disable_slot         (struct hotplug_slot *slot);
  79 static int set_attention_status (struct hotplug_slot *slot, u8 value);
  80 static int hardware_test        (struct hotplug_slot *slot, u32 value);
  81 static int get_power_status     (struct hotplug_slot *slot, u8 *value);
  82 static int get_attention_status (struct hotplug_slot *slot, u8 *value);
  83 static int get_latch_status     (struct hotplug_slot *slot, u8 *value);
  84 static int get_adapter_status   (struct hotplug_slot *slot, u8 *value);
  85
  86 static struct hotplug_slot_ops skel_hotplug_slot_ops = {
  87         .owner =                THIS_MODULE,
  88         .enable_slot =          enable_slot,
  89         .disable_slot =         disable_slot,
  90         .set_attention_status = set_attention_status,
  91         .hardware_test =        hardware_test,
  92         .get_power_status =     get_power_status,
  93         .get_attention_status = get_attention_status,
  94         .get_latch_status =     get_latch_status,
  95         .get_adapter_status =   get_adapter_status,
  96 };
  97
  98 static int enable_slot(struct hotplug_slot *hotplug_slot)
  99 {
 100         struct slot *slot = hotplug_slot->private;
 101         int retval = 0;
 102
 103         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 104
 105         /*
 106          * Fill in code here to enable the specified slot
 107          */
 108
 109         return retval;
 110 }
 111
 112
 113 static int disable_slot(struct hotplug_slot *hotplug_slot)
 114 {
 115         struct slot *slot = hotplug_slot->private;
 116         int retval = 0;
 117
 118         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 119
 120         /*
 121          * Fill in code here to disable the specified slot
 122          */
 123
 124         return retval;
 125 }
 126
 127 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
 128 {
 129         struct slot *slot = hotplug_slot->private;
 130         int retval = 0;
 131
 132         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 133
 134         switch (status) {
 135                 case 0:
 136                         /*
 137                          * Fill in code here to turn light off
 138                          */
 139                         break;
 140
 141                 case 1:
 142                 default:
 143                         /*
 144                          * Fill in code here to turn light on
 145                          */
 146                         break;
 147         }
 148
 149         return retval;
 150 }
 151
 152 static int hardware_test(struct hotplug_slot *hotplug_slot, u32 value)
 153 {
 154         struct slot *slot = hotplug_slot->private;
 155         int retval = 0;
 156
 157         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 158
 159         switch (value) {
 160                 case 0:
 161                         /* Specify a test here */
 162                         break;
 163                 case 1:
 164                         /* Specify another test here */
 165                         break;
 166         }
 167
 168         return retval;
 169 }
 170
 171 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 172 {
 173         struct slot *slot = hotplug_slot->private;
 174         int retval = 0;
 175
 176         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 177
 178         /*
 179          * Fill in logic to get the current power status of the specific
 180          * slot and store it in the *value location.
 181          */
 182
 183         return retval;
 184 }
 185
 186 static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
 187 {
 188         struct slot *slot = hotplug_slot->private;
 189         int retval = 0;
 190
 191         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 192
 193         /*
 194          * Fill in logic to get the current attention status of the specific
 195          * slot and store it in the *value location.
 196          */
 197
 198         return retval;
 199 }
 200
 201 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
 202 {
 203         struct slot *slot = hotplug_slot->private;
 204         int retval = 0;
 205
 206         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 207
 208         /*
 209          * Fill in logic to get the current latch status of the specific
 210          * slot and store it in the *value location.
 211          */
 212
 213         return retval;
 214 }
 215
 216 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 217 {
 218         struct slot *slot = hotplug_slot->private;
 219         int retval = 0;
 220
 221         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 222
 223         /*
 224          * Fill in logic to get the current adapter status of the specific
 225          * slot and store it in the *value location.
 226          */
 227
 228         return retval;
 229 }
 230
 231 static void release_slot(struct hotplug_slot *hotplug_slot)
 232 {
 233         struct slot *slot = hotplug_slot->private;
 234
 235         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 236         kfree(slot->hotplug_slot->info);
 237         kfree(slot->hotplug_slot);
 238         kfree(slot);
 239 }
 240
 241 static void make_slot_name(struct slot *slot)
 242 {
 243         /*
 244          * Stupid way to make a filename out of the slot name.
 245          * replace this if your hardware provides a better way to name slots.
 246          */
 247         snprintf(slot->hotplug_slot->name, SLOT_NAME_SIZE, "%d", slot->number);
 248 }
 249
 250 /**
 251  * init_slots - initialize 'struct slot' structures for each slot
 252  *
 253  */
 254 static int __init init_slots(void)
 255 {
 256         struct slot *slot;
 257         struct hotplug_slot *hotplug_slot;
 258         struct hotplug_slot_info *info;
 259         int retval = -ENOMEM;
 260         int i;
 261
 262         /*
 263          * Create a structure for each slot, and register that slot
 264          * with the pci_hotplug subsystem.
 265          */
 266         for (i = 0; i < num_slots; ++i) {
 267                 slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 268                 if (!slot)
 269                         goto error;
 270
 271                 hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
 272                 if (!hotplug_slot)
 273                         goto error_slot;
 274                 slot->hotplug_slot = hotplug_slot;
 275
 276                 info = kzalloc(sizeof(*info), GFP_KERNEL);
 277                 if (!info)
 278                         goto error_hpslot;
 279                 hotplug_slot->info = info;
 280
 281                 slot->number = i;
 282
 283                 hotplug_slot->name = slot->name;
 284                 hotplug_slot->private = slot;
 285                 hotplug_slot->release = &release_slot;
 286                 make_slot_name(slot);
 287                 hotplug_slot->ops = &skel_hotplug_slot_ops;
 288
 289                 /*
 290                  * Initialize the slot info structure with some known
 291                  * good values.
 292                  */
 293                 get_power_status(hotplug_slot, &info->power_status);
 294                 get_attention_status(hotplug_slot, &info->attention_status);
 295                 get_latch_status(hotplug_slot, &info->latch_status);
 296                 get_adapter_status(hotplug_slot, &info->adapter_status);
 297
 298                 dbg("registering slot %d\n", i);
 299                 retval = pci_hp_register(slot->hotplug_slot);
 300                 if (retval) {
 301                         err("pci_hp_register failed with error %d\n", retval);
 302                         goto error_info;
 303                 }
 304
 305                 /* add slot to our internal list */
 306                 list_add(&slot->slot_list, &slot_list);
 307         }
 308
 309         return 0;
 310 error_info:
 311         kfree(info);
 312 error_hpslot:
 313         kfree(hotplug_slot);
 314 error_slot:
 315         kfree(slot);
 316 error:
 317         return retval;
 318 }
 319
 320 static void __exit cleanup_slots(void)
 321 {
 322         struct list_head *tmp;
 323         struct list_head *next;
 324         struct slot *slot;
 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_safe(tmp, next, &slot_list) {
 332                 slot = list_entry(tmp, struct slot, slot_list);
 333                 list_del(&slot->slot_list);
 334                 pci_hp_deregister(slot->hotplug_slot);
 335         }
 336 }
 337
 338 static int __init pcihp_skel_init(void)
 339 {
 340         int retval;
 341
 342         info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
 343         /*
 344          * Do specific initialization stuff for your driver here
 345          * Like initializing your controller hardware (if any) and
 346          * determining the number of slots you have in the system
 347          * right now.
 348          */
 349         num_slots = 5;
 350
 351         return init_slots();
 352 }
 353
 354 static void __exit pcihp_skel_exit(void)
 355 {
 356         /*
 357          * Clean everything up.
 358          */
 359         cleanup_slots();
 360 }
 361
 362 module_init(pcihp_skel_init);
 363 module_exit(pcihp_skel_exit);