api/api_storage.c

   1 /*
   2  * (C) Copyright 2007 Semihalf
   3  *
   4  * Written by: Rafal Jaworowski <raj@semihalf.com>
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation; either version 2 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22  * MA 02111-1307 USA
  23  *
  24  */
  25
  26 #include <config.h>
  27
  28 #if defined(CONFIG_API)
  29
  30 #include <common.h>
  31 #include <api_public.h>
  32
  33 #define DEBUG
  34 #undef DEBUG
  35
  36 #ifdef DEBUG
  37 #define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt, ##args); } while (0)
  38 #else
  39 #define debugf(fmt, args...)
  40 #endif
  41
  42 #define errf(fmt, args...) do { printf("ERROR @ %s(): ", __func__); printf(fmt, ##args); } while (0)
  43
  44
  45 #define ENUM_IDE        0
  46 #define ENUM_USB        1
  47 #define ENUM_SCSI       2
  48 #define ENUM_MMC        3
  49 #define ENUM_MAX        4
  50
  51 struct stor_spec {
  52         int             max_dev;
  53         int             enum_started;
  54         int             enum_ended;
  55         int             type;           /* "external" type: DT_STOR_{IDE,USB,etc} */
  56         char            name[4];
  57 };
  58
  59 static struct stor_spec specs[ENUM_MAX] = { { 0, 0, 0, 0, "" }, };
  60
  61
  62 void dev_stor_init(void)
  63 {
  64 #if defined(CONFIG_CMD_IDE)
  65         specs[ENUM_IDE].max_dev = CFG_IDE_MAXDEVICE;
  66         specs[ENUM_IDE].enum_started = 0;
  67         specs[ENUM_IDE].enum_ended = 0;
  68         specs[ENUM_IDE].type = DEV_TYP_STOR | DT_STOR_IDE;
  69         specs[ENUM_IDE].name = "ide";
  70 #endif
  71 #if defined(CONFIG_CMD_USB)
  72         specs[ENUM_USB].max_dev = USB_MAX_STOR_DEV;
  73         specs[ENUM_USB].enum_started = 0;
  74         specs[ENUM_USB].enum_ended = 0;
  75         specs[ENUM_USB].type = DEV_TYP_STOR | DT_STOR_USB;
  76         specs[ENUM_USB].name = "usb";
  77 #endif
  78 #if defined(CONFIG_CMD_SCSI)
  79         specs[ENUM_SCSI].max_dev = CFG_SCSI_MAX_DEVICE;
  80         specs[ENUM_SCSI].enum_started = 0;
  81         specs[ENUM_SCSI].enum_ended = 0;
  82         specs[ENUM_SCSI].type = DEV_TYP_STOR | DT_STOR_SCSI;
  83         specs[ENUM_SCSI].name = "scsi";
  84 #endif
  85 }
  86
  87 /*
  88  * Finds next available device in the storage group
  89  *
  90  * type:        storage group type - ENUM_IDE, ENUM_SCSI etc.
  91  *
  92  * first:       if 1 the first device in the storage group is returned (if
  93  *              exists), if 0 the next available device is searched
  94  *
  95  * more:        returns 0/1 depending if there are more devices in this group
  96  *              available (for future iterations)
  97  *
  98  * returns:     0/1 depending if device found in this iteration
  99  */
 100 static int dev_stor_get(int type, int first, int *more, struct device_info *di)
 101 {
 102         int found = 0;
 103         *more = 0;
 104
 105         int i;
 106
 107         block_dev_desc_t *dd;
 108
 109         if (first) {
 110                 di->cookie = (void *)get_dev(specs[type].name, 0);
 111                 found = 1;
 112
 113         } else {
 114                 for (i = 0; i < specs[type].max_dev; i++)
 115                         if (di->cookie == (void *)get_dev(specs[type].name, i)) {
 116                                 /* previous cookie found -- advance to the
 117                                  * next device, if possible */
 118
 119                                 if (++i >= specs[type].max_dev) {
 120                                         /* out of range, no more to enum */
 121                                         di->cookie = NULL;
 122                                         break;
 123                                 }
 124
 125                                 di->cookie = (void *)get_dev(specs[type].name, i);
 126                                 found = 1;
 127
 128                                 /* provide hint if there are more devices in
 129                                  * this group to enumerate */
 130                                 if ((i + 1) < specs[type].max_dev)
 131                                         *more = 1;
 132
 133                                 break;
 134                         }
 135         }
 136
 137         if (found) {
 138                 di->type = specs[type].type;
 139
 140                 if (di->cookie != NULL) {
 141                         dd = (block_dev_desc_t *)di->cookie;
 142                         if (dd->type == DEV_TYPE_UNKNOWN) {
 143                                 debugf("device instance exists, but is not active..");
 144                                 found = 0;
 145                         } else {
 146                                 di->di_stor.block_count = dd->lba;
 147                                 di->di_stor.block_size = dd->blksz;
 148                         }
 149                 }
 150
 151         } else
 152                 di->cookie = NULL;
 153
 154         return found;
 155 }
 156
 157
 158 /*
 159  * returns:     ENUM_IDE, ENUM_USB etc. based on block_dev_desc_t
 160  */
 161 static int dev_stor_type(block_dev_desc_t *dd)
 162 {
 163         int i, j;
 164
 165         for (i = ENUM_IDE; i < ENUM_MAX; i++)
 166                 for (j = 0; j < specs[i].max_dev; j++)
 167                         if (dd == get_dev(specs[i].name, j))
 168                                 return i;
 169
 170         return ENUM_MAX;
 171 }
 172
 173
 174 /*
 175  * returns:     0/1 whether cookie points to some device in this group
 176  */
 177 static int dev_is_stor(int type, struct device_info *di)
 178 {
 179         return (dev_stor_type(di->cookie) == type) ? 1 : 0;
 180 }
 181
 182
 183 static int dev_enum_stor(int type, struct device_info *di)
 184 {
 185         int found = 0, more = 0;
 186
 187         debugf("called, type %d\n", type);
 188
 189         /*
 190          * Formulae for enumerating storage devices:
 191          * 1. if cookie (hint from previous enum call) is NULL we start again
 192          *    with enumeration, so return the first available device, done.
 193          *
 194          * 2. if cookie is not NULL, check if it identifies some device in
 195          *    this group:
 196          *
 197          * 2a. if cookie is a storage device from our group (IDE, USB etc.),
 198          *     return next available (if exists) in this group
 199          *
 200          * 2b. if it isn't device from our group, check if such devices were
 201          *     ever enumerated before:
 202          *     - if not, return the first available device from this group
 203          *     - else return 0
 204          */
 205
 206         if (di->cookie == NULL) {
 207
 208                 debugf("group%d - enum restart\n", type);
 209
 210                 /*
 211                  * 1. Enumeration (re-)started: take the first available
 212                  * device, if exists
 213                  */
 214                 found = dev_stor_get(type, 1, &more, di);
 215                 specs[type].enum_started = 1;
 216
 217         } else if (dev_is_stor(type, di)) {
 218
 219                 debugf("group%d - enum continued for the next device\n", type);
 220
 221                 if (specs[type].enum_ended) {
 222                         debugf("group%d - nothing more to enum!\n", type);
 223                         return 0;
 224                 }
 225
 226                 /* 2a. Attempt to take a next available device in the group */
 227                 found = dev_stor_get(type, 0, &more, di);
 228
 229         } else {
 230
 231                 if (specs[type].enum_ended) {
 232                         debugf("group %d - already enumerated, skipping\n", type);
 233                         return 0;
 234                 }
 235
 236                 debugf("group%d - first time enum\n", type);
 237
 238                 if (specs[type].enum_started == 0) {
 239                         /*
 240                          * 2b.  If enumerating devices in this group did not
 241                          * happen before, it means the cookie pointed to a
 242                          * device frome some other group (another storage
 243                          * group, or network); in this case try to take the
 244                          * first available device from our group
 245                          */
 246                         specs[type].enum_started = 1;
 247
 248                         /*
 249                          * Attempt to take the first device in this group:
 250                          *'first element' flag is set
 251                          */
 252                         found = dev_stor_get(type, 1, &more, di);
 253
 254                 } else {
 255                         errf("group%d - out of order iteration\n", type);
 256                         found = 0;
 257                         more = 0;
 258                 }
 259         }
 260
 261         /*
 262          * If there are no more devices in this group, consider its
 263          * enumeration finished
 264          */
 265         specs[type].enum_ended = (!more) ? 1 : 0;
 266
 267         if (found)
 268                 debugf("device found, returning cookie 0x%08x\n",
 269                         (u_int32_t)di->cookie);
 270         else
 271                 debugf("no device found\n");
 272
 273         return found;
 274 }
 275
 276 void dev_enum_reset(void)
 277 {
 278         int i;
 279
 280         for (i = 0; i < ENUM_MAX; i ++) {
 281                 specs[i].enum_started = 0;
 282                 specs[i].enum_ended = 0;
 283         }
 284 }
 285
 286 int dev_enum_storage(struct device_info *di)
 287 {
 288         int i;
 289
 290         /*
 291          * check: ide, usb, scsi, mmc
 292          */
 293         for (i = ENUM_IDE; i < ENUM_MAX; i ++) {
 294                 if (dev_enum_stor(i, di))
 295                         return 1;
 296         }
 297
 298         return 0;
 299 }
 300
 301 static int dev_stor_is_valid(int type, block_dev_desc_t *dd)
 302 {
 303         int i;
 304
 305         for (i = 0; i < specs[type].max_dev; i++)
 306                 if (dd == get_dev(specs[type].name, i))
 307                         if (dd->type != DEV_TYPE_UNKNOWN)
 308                                 return 1;
 309
 310         return 0;
 311 }
 312
 313
 314 int dev_open_stor(void *cookie)
 315 {
 316         int type = dev_stor_type(cookie);
 317
 318         if (type == ENUM_MAX)
 319                 return API_ENODEV;
 320
 321         if (dev_stor_is_valid(type, (block_dev_desc_t *)cookie))
 322                 return 0;
 323
 324         return API_ENODEV;
 325 }
 326
 327
 328 int dev_close_stor(void *cookie)
 329 {
 330         /*
 331          * Not much to do as we actually do not alter storage devices upon
 332          * close
 333          */
 334         return 0;
 335 }
 336
 337
 338 static int dev_stor_index(block_dev_desc_t *dd)
 339 {
 340         int i, type;
 341
 342         type = dev_stor_type(dd);
 343         for (i = 0; i < specs[type].max_dev; i++)
 344                 if (dd == get_dev(specs[type].name, i))
 345                         return i;
 346
 347         return (specs[type].max_dev);
 348 }
 349
 350
 351 lbasize_t dev_read_stor(void *cookie, void *buf, lbasize_t len, lbastart_t start)
 352 {
 353         int type;
 354         block_dev_desc_t *dd = (block_dev_desc_t *)cookie;
 355
 356         if ((type = dev_stor_type(dd)) == ENUM_MAX)
 357                 return 0;
 358
 359         if (!dev_stor_is_valid(type, dd))
 360                 return 0;
 361
 362         if ((dd->block_read) == NULL) {
 363                 debugf("no block_read() for device 0x%08x\n");
 364                 return 0;
 365         }
 366
 367         return (dd->block_read(dev_stor_index(dd), start, len, buf));
 368 }
 369
 370 #endif /* CONFIG_API */