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/config.h>
  32 #include <linux/module.h>
  33 #include <linux/moduleparam.h>
  34 #include <linux/kernel.h>
  35 #include <linux/slab.h>
  36 #include <linux/pci.h>
  37 #include <linux/init.h>
  38 #include "pci_hotplug.h"
  39
  40 struct slot {
  41         u8 number;
  42         struct hotplug_slot *hotplug_slot;
  43         struct list_head slot_list;
  44 };
  45
  46 static LIST_HEAD(slot_list);
  47
  48 #define MY_NAME "pcihp_skeleton"
  49
  50 #define dbg(format, arg...)                                     \
  51         do {                                                    \
  52                 if (debug)                                      \
  53                         printk (KERN_DEBUG "%s: " format "\n",  \
  54                                 MY_NAME , ## arg);              \
  55         } while (0)
  56 #define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME , ## arg)
  57 #define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME , ## arg)
  58 #define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME , ## arg)
  59
  60
  61
  62 /* local variables */
  63 static int debug;
  64 static int num_slots;
  65
  66 #define DRIVER_VERSION  "0.3"
  67 #define DRIVER_AUTHOR   "Greg Kroah-Hartman <greg@kroah.com>"
  68 #define DRIVER_DESC     "Hot Plug PCI Controller Skeleton Driver"
  69
  70 MODULE_AUTHOR(DRIVER_AUTHOR);
  71 MODULE_DESCRIPTION(DRIVER_DESC);
  72 MODULE_LICENSE("GPL");
  73 module_param(debug, bool, 0644);
  74 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
  75
  76 static int enable_slot          (struct hotplug_slot *slot);
  77 static int disable_slot         (struct hotplug_slot *slot);
  78 static int set_attention_status (struct hotplug_slot *slot, u8 value);
  79 static int hardware_test        (struct hotplug_slot *slot, u32 value);
  80 static int get_power_status     (struct hotplug_slot *slot, u8 *value);
  81 static int get_attention_status (struct hotplug_slot *slot, u8 *value);
  82 static int get_latch_status     (struct hotplug_slot *slot, u8 *value);
  83 static int get_adapter_status   (struct hotplug_slot *slot, u8 *value);
  84
  85 static struct hotplug_slot_ops skel_hotplug_slot_ops = {
  86         .owner =                THIS_MODULE,
  87         .enable_slot =          enable_slot,
  88         .disable_slot =         disable_slot,
  89         .set_attention_status = set_attention_status,
  90         .hardware_test =        hardware_test,
  91         .get_power_status =     get_power_status,
  92         .get_attention_status = get_attention_status,
  93         .get_latch_status =     get_latch_status,
  94         .get_adapter_status =   get_adapter_status,
  95 };
  96
  97 static int enable_slot(struct hotplug_slot *hotplug_slot)
  98 {
  99         struct slot *slot = hotplug_slot->private;
 100         int retval = 0;
 101
 102         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 103
 104         /*
 105          * Fill in code here to enable the specified slot
 106          */
 107
 108         return retval;
 109 }
 110
 111
 112 static int disable_slot(struct hotplug_slot *hotplug_slot)
 113 {
 114         struct slot *slot = hotplug_slot->private;
 115         int retval = 0;
 116
 117         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 118
 119         /*
 120          * Fill in code here to disable the specified slot
 121          */
 122
 123         return retval;
 124 }
 125
 126 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
 127 {
 128         struct slot *slot = hotplug_slot->private;
 129         int retval = 0;
 130
 131         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 132
 133         switch (status) {
 134                 case 0:
 135                         /*
 136                          * Fill in code here to turn light off
 137                          */
 138                         break;
 139
 140                 case 1:
 141                 default:
 142                         /*
 143                          * Fill in code here to turn light on
 144                          */
 145                         break;
 146         }
 147
 148         return retval;
 149 }
 150
 151 static int hardware_test(struct hotplug_slot *hotplug_slot, u32 value)
 152 {
 153         struct slot *slot = hotplug_slot->private;
 154         int retval = 0;
 155
 156         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 157
 158         switch (value) {
 159                 case 0:
 160                         /* Specify a test here */
 161                         break;
 162                 case 1:
 163                         /* Specify another test here */
 164                         break;
 165         }
 166
 167         return retval;
 168 }
 169
 170 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 171 {
 172         struct slot *slot = hotplug_slot->private;
 173         int retval = 0;
 174
 175         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 176
 177         /*
 178          * Fill in logic to get the current power status of the specific
 179          * slot and store it in the *value location.
 180          */
 181
 182         return retval;
 183 }
 184
 185 static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
 186 {
 187         struct slot *slot = hotplug_slot->private;
 188         int retval = 0;
 189
 190         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 191
 192         /*
 193          * Fill in logic to get the current attention status of the specific
 194          * slot and store it in the *value location.
 195          */
 196
 197         return retval;
 198 }
 199
 200 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
 201 {
 202         struct slot *slot = hotplug_slot->private;
 203         int retval = 0;
 204
 205         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 206
 207         /*
 208          * Fill in logic to get the current latch status of the specific
 209          * slot and store it in the *value location.
 210          */
 211
 212         return retval;
 213 }
 214
 215 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 216 {
 217         struct slot *slot = hotplug_slot->private;
 218         int retval = 0;
 219
 220         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 221
 222         /*
 223          * Fill in logic to get the current adapter status of the specific
 224          * slot and store it in the *value location.
 225          */
 226
 227         return retval;
 228 }
 229
 230 static void release_slot(struct hotplug_slot *hotplug_slot)
 231 {
 232         struct slot *slot = hotplug_slot->private;
 233
 234         dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 235         kfree(slot->hotplug_slot->info);
 236         kfree(slot->hotplug_slot->name);
 237         kfree(slot->hotplug_slot);
 238         kfree(slot);
 239 }
 240
 241 #define SLOT_NAME_SIZE  10
 242 static void make_slot_name(struct slot *slot)
 243 {
 244         /*
 245          * Stupid way to make a filename out of the slot name.
 246          * replace this if your hardware provides a better way to name slots.
 247          */
 248         snprintf(slot->hotplug_slot->name, SLOT_NAME_SIZE, "%d", slot->number);
 249 }
 250
 251 /**
 252  * init_slots - initialize 'struct slot' structures for each slot
 253  *
 254  */
 255 static int __init init_slots(void)
 256 {
 257         struct slot *slot;
 258         struct hotplug_slot *hotplug_slot;
 259         struct hotplug_slot_info *info;
 260         char *name;
 261         int retval = -ENOMEM;
 262         int i;
 263
 264         /*
 265          * Create a structure for each slot, and register that slot
 266          * with the pci_hotplug subsystem.
 267          */
 268         for (i = 0; i < num_slots; ++i) {
 269                 slot = kmalloc(sizeof(struct slot), GFP_KERNEL);
 270                 if (!slot)
 271                         goto error;
 272                 memset(slot, 0, sizeof(struct slot));
 273
 274                 hotplug_slot = kmalloc(sizeof(struct hotplug_slot),
 275                                         GFP_KERNEL);
 276                 if (!hotplug_slot)
 277                         goto error_slot;
 278                 memset(hotplug_slot, 0, sizeof (struct hotplug_slot));
 279                 slot->hotplug_slot = hotplug_slot;
 280
 281                 info = kmalloc(sizeof(struct hotplug_slot_info), GFP_KERNEL);
 282                 if (!info)
 283                         goto error_hpslot;
 284                 memset(info, 0, sizeof (struct hotplug_slot_info));
 285                 hotplug_slot->info = info;
 286
 287                 name = kmalloc(SLOT_NAME_SIZE, GFP_KERNEL);
 288                 if (!name)
 289                         goto error_info;
 290                 hotplug_slot->name = name;
 291
 292                 slot->number = i;
 293
 294                 hotplug_slot->private = slot;
 295                 hotplug_slot->release = &release_slot;
 296                 make_slot_name(slot);
 297                 hotplug_slot->ops = &skel_hotplug_slot_ops;
 298
 299                 /*
 300                  * Initialize the slot info structure with some known
 301                  * good values.
 302                  */
 303                 info->power_status = get_power_status(slot);
 304                 info->attention_status = get_attention_status(slot);
 305                 info->latch_status = get_latch_status(slot);
 306                 info->adapter_status = get_adapter_status(slot);
 307
 308                 dbg("registering slot %d\n", i);
 309                 retval = pci_hp_register(slot->hotplug_slot);
 310                 if (retval) {
 311                         err("pci_hp_register failed with error %d\n", retval);
 312                         goto error_name;
 313                 }
 314
 315                 /* add slot to our internal list */
 316                 list_add(&slot->slot_list, &slot_list);
 317         }
 318
 319         return 0;
 320 error_name:
 321         kfree(name);
 322 error_info:
 323         kfree(info);
 324 error_hpslot:
 325         kfree(hotplug_slot);
 326 error_slot:
 327         kfree(slot);
 328 error:
 329         return retval;
 330 }
 331
 332 static void __exit cleanup_slots(void)
 333 {
 334         struct list_head *tmp;
 335         struct list_head *next;
 336         struct slot *slot;
 337
 338         /*
 339          * Unregister all of our slots with the pci_hotplug subsystem.
 340          * Memory will be freed in release_slot() callback after slot's
 341          * lifespan is finished.
 342          */
 343         list_for_each_safe(tmp, next, &slot_list) {
 344                 slot = list_entry(tmp, struct slot, slot_list);
 345                 list_del(&slot->slot_list);
 346                 pci_hp_deregister(slot->hotplug_slot);
 347         }
 348 }
 349
 350 static int __init pcihp_skel_init(void)
 351 {
 352         int retval;
 353
 354         info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
 355         /*
 356          * Do specific initialization stuff for your driver here
 357          * Like initializing your controller hardware (if any) and
 358          * determining the number of slots you have in the system
 359          * right now.
 360          */
 361         num_slots = 5;
 362
 363         return init_slots();
 364 }
 365
 366 static void __exit pcihp_skel_exit(void)
 367 {
 368         /*
 369          * Clean everything up.
 370          */
 371         cleanup_slots();
 372 }
 373
 374 module_init(pcihp_skel_init);
 375 module_exit(pcihp_skel_exit);