drivers/pci/hotplug/pcihp_skeleton.c

   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
  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
 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
 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
 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
 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
 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
 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
 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
 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
 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  */
 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
 322 static void __exit cleanup_slots(void)
 323 {
 324         struct list_head *tmp;
 325         struct list_head *next;
 326         struct slot *slot;
 327
 328         /*
 329          * Unregister all of our slots with the pci_hotplug subsystem.
 330          * Memory will be freed in release_slot() callback after slot's
 331          * lifespan is finished.
 332          */
 333         list_for_each_safe(tmp, next, &slot_list) {
 334                 slot = list_entry(tmp, struct slot, slot_list);
 335                 list_del(&slot->slot_list);
 336                 pci_hp_deregister(slot->hotplug_slot);
 337         }
 338 }
 339
 340 static int __init pcihp_skel_init(void)
 341 {
 342         int retval;
 343
 344         info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
 345         /*
 346          * Do specific initialization stuff for your driver here
 347          * like initializing your controller hardware (if any) and
 348          * determining the number of slots you have in the system
 349          * right now.
 350          */
 351         num_slots = 5;
 352
 353         return init_slots();
 354 }
 355
 356 static void __exit pcihp_skel_exit(void)
 357 {
 358         /*
 359          * Clean everything up.
 360          */
 361         cleanup_slots();
 362 }
 363
 364 module_init(pcihp_skel_init);
 365 module_exit(pcihp_skel_exit);