lincan/src/proc.c

   1 /* proc.c
   2  * Linux CAN-bus device driver.
   3  * Written by Arnaud Westenberg email:arnaud@wanadoo.nl
   4  * Rewritten for new CAN queues by Pavel Pisa - OCERA team member
   5  * email:pisa@cmp.felk.cvut.cz
   6  * This software is released under the GPL-License.
   7  * Version lincan-0.3  17 Jun 2004
   8  */
   9
  10 #include "../include/can.h"
  11 #include "../include/can_sysdep.h"
  12 #include "../include/main.h"
  13 #include "../include/proc.h"
  14 #include "../include/setup.h"
  15
  16 #define __NO_VERSION__
  17 #include <linux/module.h>
  18
  19 int add_channel_to_procdir(struct candevice_t *candev);
  20 int remove_channel_from_procdir(void);
  21 int add_object_to_procdir(int chip_nr);
  22 int remove_object_from_procdir(int chip_nr);
  23
  24 #if (LINUX_VERSION_CODE <= KERNEL_VERSION(2,3,0))
  25 static int can_proc_readlink(struct proc_dir_entry *ent, char *page);
  26 #endif
  27
  28 static int cc=0; /* static counter for each CAN chip */
  29
  30 static struct canproc_t can_proc_base;
  31 static struct canproc_t *base=&can_proc_base;
  32
  33 /* The following functions are needed only for kernel version 2.2. Kernel
  34  * version 2.4 already defines them for us.
  35  */
  36 #if (LINUX_VERSION_CODE <= KERNEL_VERSION(2,3,0))
  37 static void can_fill_inode(struct inode *inode, int fill)
  38 {
  39         if (fill)
  40                 MOD_INC_USE_COUNT;
  41         else
  42                 MOD_DEC_USE_COUNT;
  43 }
  44
  45 static struct proc_dir_entry * can_create_proc_entry(const char *name, mode_t mode,
  46                                         struct proc_dir_entry *parent)
  47 {
  48         struct proc_dir_entry *new_entry = NULL;
  49         char *namestore;
  50         int namelen;
  51
  52         if(!name || !parent)
  53                 return NULL;
  54         namelen=strlen(name);
  55         if(!namelen)
  56                 return NULL;
  57
  58         new_entry = (struct proc_dir_entry *)
  59                         can_checked_malloc(sizeof(struct proc_dir_entry)+namelen+1);
  60
  61         if (new_entry == NULL)
  62                 return NULL;
  63
  64         memset(new_entry, 0, sizeof(struct proc_dir_entry));
  65
  66         /* Store copy of the proc entry name */
  67         namestore = ((char *) new_entry) + sizeof(struct proc_dir_entry);
  68         memcpy(namestore, name, namelen + 1);
  69
  70         new_entry->low_ino = 0;
  71         new_entry->namelen = namelen;
  72         new_entry->name = namestore;
  73         new_entry->mode = mode;
  74         new_entry->nlink = 0;
  75         new_entry->fill_inode = can_fill_inode;
  76         new_entry->parent = parent;
  77
  78         proc_register(parent, new_entry);
  79
  80         return new_entry;
  81 }
  82
  83 static int can_remove_proc_entry(struct proc_dir_entry *del, struct proc_dir_entry *parent)
  84 {
  85         if (del != NULL) {
  86                 proc_unregister(parent, del->low_ino);
  87                 can_checked_free(del);
  88                 return 0;
  89         }
  90         else return -ENODEV;
  91 }
  92
  93
  94 static int can_proc_readlink(struct proc_dir_entry *ent, char *page)
  95 {
  96         char *link_dest = (char*)ent->data;
  97
  98         strcpy(page, link_dest);
  99         return strlen(link_dest);
 100 }
 101
 102
 103
 104 /* This compatibility version of proc_symlink does not store local copy of destination */
 105 static inline struct proc_dir_entry *can_proc_symlink(const char *name,
 106                 struct proc_dir_entry *parent, const char *dest)
 107 {
 108         struct proc_dir_entry *entry;
 109
 110
 111         entry = can_create_proc_entry(name, S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO, parent);
 112         if (entry == NULL)
 113                 return NULL;
 114         entry->readlink_proc = can_proc_readlink;
 115         entry->data = dest;
 116         return entry;
 117 }
 118
 119 #else /* Functions forwarded for kernel 2.4 and above */
 120
 121 static inline struct proc_dir_entry * can_create_proc_entry(const char *name, mode_t mode,
 122                                         struct proc_dir_entry *parent)
 123 {
 124         return create_proc_entry(name, mode, parent);
 125 }
 126
 127
 128 /* This does not fully follow linux 2.4 and 2.6 prototype to simplify 2.2.x compatibility */
 129 /* The newer kernels use entry name instead of pointer to the entry */
 130 static int can_remove_proc_entry(struct proc_dir_entry *del, struct proc_dir_entry *parent)
 131 {
 132         if(!del) return -ENODEV;
 133         remove_proc_entry(del->name,parent);
 134         return 0;
 135 }
 136
 137 static inline struct proc_dir_entry *can_proc_symlink(const char *name,
 138                 struct proc_dir_entry *parent, const char *dest)
 139 {
 140         return proc_symlink(name, parent, dest);
 141 }
 142
 143 #endif /* Functions required for kernel 2.2 */
 144
 145 /* can_init_procdir registers the entire CAN directory tree recursively at
 146  * the proc system.
 147  */
 148 int can_init_procdir(void)
 149 {
 150         int board;
 151         struct candevice_t *candev;
 152         base->can_proc_entry = can_create_proc_entry("can", S_IFDIR | S_IRUGO |
 153                                         S_IXUGO, &proc_root);
 154         if (base->can_proc_entry == NULL)
 155                 return -ENODEV;
 156
 157         for (board=0; board<hardware_p->nr_boards; board++) {
 158                 candev=hardware_p->candevice[board];
 159                 if(candev) add_channel_to_procdir(candev);
 160         }
 161
 162         return 0;
 163 }
 164
 165 /* can_delete_procdir removes the entire CAN tree from the proc system */
 166 int can_delete_procdir(void)
 167 {
 168         if (remove_channel_from_procdir())
 169                 return -ENODEV;
 170         /* name: "can" */
 171         if (can_remove_proc_entry(base->can_proc_entry, &proc_root))
 172                 return -ENODEV;
 173
 174         return 0;
 175 }
 176
 177 int add_channel_to_procdir(struct candevice_t *candev)
 178 {
 179         int i=0;
 180
 181         for (i=0; i < candev->nr_all_chips; i++) {
 182
 183                 base->channel[cc] = (struct channelproc_t *)
 184                         can_checked_malloc(sizeof(struct channelproc_t));
 185                 if (base->channel[cc] == NULL)
 186                         return -ENOMEM;
 187
 188                 sprintf(base->channel[cc]->ch_name, "channel%d",cc);
 189
 190                 base->channel[cc]->ch_entry = can_create_proc_entry(
 191                                                 base->channel[cc]->ch_name,
 192                                                 S_IFDIR | S_IRUGO |S_IXUGO,
 193                                                 base->can_proc_entry);
 194
 195                 if (base->channel[cc]->ch_entry == NULL)
 196                         return -ENODEV;
 197
 198                 add_object_to_procdir(cc);
 199
 200                 cc++;
 201         }
 202
 203         return 0;
 204 }
 205
 206 int remove_channel_from_procdir(void)
 207 {
 208
 209         while (cc != 0) {
 210                 cc--;
 211
 212                 if(!base->channel[cc]) continue;
 213
 214                 if (remove_object_from_procdir(cc))
 215                         return -ENODEV;
 216
 217                 /* name: base->channel[cc]->ch_name */
 218                 if (can_remove_proc_entry(base->channel[cc]->ch_entry,
 219                                                         base->can_proc_entry))
 220                         return -ENODEV;
 221
 222                 can_checked_free(base->channel[cc]);
 223                 base->channel[cc] = NULL;
 224         }
 225
 226         return 0;
 227 }
 228
 229
 230 int add_object_to_procdir(int chip_nr)
 231 {
 232         int i, max_objects;
 233
 234         max_objects=chips_p[chip_nr]->max_objects;
 235
 236         for (i=0; i<max_objects; i++) {
 237                 base->channel[chip_nr]->object[i] = (struct objectproc_t *)
 238                         can_checked_malloc(sizeof(struct objectproc_t));
 239
 240                 if (base->channel[chip_nr]->object[i] == NULL)
 241                         return -ENOMEM;
 242
 243                 sprintf(base->channel[chip_nr]->object[i]->obj_name,"object%d",i);
 244                 sprintf(base->channel[chip_nr]->object[i]->lnk_name,"dev");
 245
 246                 base->channel[chip_nr]->object[i]->obj_entry = can_create_proc_entry(
 247                                 base->channel[chip_nr]->object[i]->obj_name,
 248                                 S_IFDIR | S_IRUGO | S_IXUGO,
 249                                 base->channel[chip_nr]->ch_entry);
 250                 if (base->channel[chip_nr]->object[i]->obj_entry == NULL)
 251                         return -ENODEV;
 252
 253                 sprintf(base->channel[chip_nr]->object[i]->lnk_dev,"/dev/can%d",
 254                         chips_p[chip_nr]->msgobj[i]->minor);
 255
 256                 base->channel[chip_nr]->object[i]->lnk = can_proc_symlink(
 257                                 base->channel[chip_nr]->object[i]->lnk_name,
 258                                 base->channel[chip_nr]->object[i]->obj_entry,
 259                                 base->channel[chip_nr]->object[i]->lnk_dev);
 260                 if (base->channel[chip_nr]->object[i]->lnk == NULL)
 261                         return -ENODEV;
 262
 263         }
 264         return 0;
 265 }
 266
 267 int remove_object_from_procdir(int chip_nr)
 268 {
 269         int i=0, obj=0;
 270
 271         obj=chips_p[chip_nr]->max_objects;
 272
 273         for (i=0; i<obj; i++) {
 274                 if(!base->channel[chip_nr]->object[i]) continue;
 275
 276                 /* name: base->channel[chip_nr]->object[i]->lnk_name */
 277                 if (can_remove_proc_entry( base->channel[chip_nr]->object[i]->lnk,
 278                                 base->channel[chip_nr]->object[i]->obj_entry))
 279                         return -ENODEV;
 280                 /* name: base->channel[chip_nr]->object[i]->obj_name */
 281                 if (can_remove_proc_entry(
 282                                 base->channel[chip_nr]->object[i]->obj_entry,
 283                                 base->channel[chip_nr]->ch_entry))
 284                         return -ENODEV;
 285
 286                 can_checked_free(base->channel[chip_nr]->object[i]);
 287
 288                 base->channel[chip_nr]->object[i]=NULL;
 289         }
 290         return 0;
 291 }
 292