drivers/staging/ozwpan/ozcdev.c

   1 /* -----------------------------------------------------------------------------
   2  * Copyright (c) 2011 Ozmo Inc
   3  * Released under the GNU General Public License Version 2 (GPLv2).
   4  * -----------------------------------------------------------------------------
   5  */
   6 #include <linux/module.h>
   7 #include <linux/fs.h>
   8 #include <linux/cdev.h>
   9 #include <linux/uaccess.h>
  10 #include <linux/netdevice.h>
  11 #include <linux/etherdevice.h>
  12 #include <linux/poll.h>
  13 #include <linux/sched.h>
  14 #include "ozconfig.h"
  15 #include "ozprotocol.h"
  16 #include "oztrace.h"
  17 #include "ozappif.h"
  18 #include "ozeltbuf.h"
  19 #include "ozpd.h"
  20 #include "ozproto.h"
  21 #include "ozevent.h"
  22 /*------------------------------------------------------------------------------
  23  */
  24 #define OZ_RD_BUF_SZ    256
  25 struct oz_cdev {
  26         dev_t devnum;
  27         struct cdev cdev;
  28         wait_queue_head_t rdq;
  29         spinlock_t lock;
  30         u8 active_addr[ETH_ALEN];
  31         struct oz_pd *active_pd;
  32 };
  33
  34 /* Per PD context for the serial service stored in the PD. */
  35 struct oz_serial_ctx {
  36         atomic_t ref_count;
  37         u8 tx_seq_num;
  38         u8 rx_seq_num;
  39         u8 rd_buf[OZ_RD_BUF_SZ];
  40         int rd_in;
  41         int rd_out;
  42 };
  43 /*------------------------------------------------------------------------------
  44  */
  45 static struct oz_cdev g_cdev;
  46 struct class *g_oz_class;
  47 /*------------------------------------------------------------------------------
  48  * Context: process and softirq
  49  */
  50 static struct oz_serial_ctx *oz_cdev_claim_ctx(struct oz_pd *pd)
  51 {
  52         struct oz_serial_ctx *ctx;
  53         spin_lock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
  54         ctx = (struct oz_serial_ctx *)pd->app_ctx[OZ_APPID_SERIAL-1];
  55         if (ctx)
  56                 atomic_inc(&ctx->ref_count);
  57         spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
  58         return ctx;
  59 }
  60 /*------------------------------------------------------------------------------
  61  * Context: softirq or process
  62  */
  63 static void oz_cdev_release_ctx(struct oz_serial_ctx *ctx)
  64 {
  65         if (atomic_dec_and_test(&ctx->ref_count)) {
  66                 oz_trace("Dealloc serial context.\n");
  67                 kfree(ctx);
  68         }
  69 }
  70 /*------------------------------------------------------------------------------
  71  * Context: process
  72  */
  73 int oz_cdev_open(struct inode *inode, struct file *filp)
  74 {
  75         struct oz_cdev *dev;
  76         oz_trace("oz_cdev_open()\n");
  77         oz_trace("major = %d minor = %d\n", imajor(inode), iminor(inode));
  78         dev = container_of(inode->i_cdev, struct oz_cdev, cdev);
  79         filp->private_data = dev;
  80         return 0;
  81 }
  82 /*------------------------------------------------------------------------------
  83  * Context: process
  84  */
  85 int oz_cdev_release(struct inode *inode, struct file *filp)
  86 {
  87         oz_trace("oz_cdev_release()\n");
  88         return 0;
  89 }
  90 /*------------------------------------------------------------------------------
  91  * Context: process
  92  */
  93 ssize_t oz_cdev_read(struct file *filp, char __user *buf, size_t count,
  94                 loff_t *fpos)
  95 {
  96         int n;
  97         int ix;
  98
  99         struct oz_pd *pd;
 100         struct oz_serial_ctx *ctx = 0;
 101
 102         spin_lock_bh(&g_cdev.lock);
 103         pd = g_cdev.active_pd;
 104         if (pd)
 105                 oz_pd_get(pd);
 106         spin_unlock_bh(&g_cdev.lock);
 107         if (pd == NULL)
 108                 return -1;
 109         ctx = oz_cdev_claim_ctx(pd);
 110         if (ctx == NULL)
 111                 goto out2;
 112         n = ctx->rd_in - ctx->rd_out;
 113         if (n < 0)
 114                 n += OZ_RD_BUF_SZ;
 115         if (count > n)
 116                 count = n;
 117         ix = ctx->rd_out;
 118         n = OZ_RD_BUF_SZ - ix;
 119         if (n > count)
 120                 n = count;
 121         if (copy_to_user(buf, &ctx->rd_buf[ix], n)) {
 122                 count = 0;
 123                 goto out1;
 124         }
 125         ix += n;
 126         if (ix == OZ_RD_BUF_SZ)
 127                 ix = 0;
 128         if (n < count) {
 129                 if (copy_to_user(&buf[n], ctx->rd_buf, count-n)) {
 130                         count = 0;
 131                         goto out1;
 132                 }
 133                 ix = count-n;
 134         }
 135         ctx->rd_out = ix;
 136 out1:
 137         oz_cdev_release_ctx(ctx);
 138 out2:
 139         oz_pd_put(pd);
 140         return count;
 141 }
 142 /*------------------------------------------------------------------------------
 143  * Context: process
 144  */
 145 ssize_t oz_cdev_write(struct file *filp, const char __user *buf, size_t count,
 146                 loff_t *fpos)
 147 {
 148         struct oz_pd *pd;
 149         struct oz_elt_buf *eb;
 150         struct oz_elt_info *ei = 0;
 151         struct oz_elt *elt;
 152         struct oz_app_hdr *app_hdr;
 153         struct oz_serial_ctx *ctx;
 154
 155         spin_lock_bh(&g_cdev.lock);
 156         pd = g_cdev.active_pd;
 157         if (pd)
 158                 oz_pd_get(pd);
 159         spin_unlock_bh(&g_cdev.lock);
 160         if (pd == NULL)
 161                 return -1;
 162         eb = &pd->elt_buff;
 163         ei = oz_elt_info_alloc(eb);
 164         if (ei == NULL) {
 165                 count = 0;
 166                 goto out;
 167         }
 168         elt = (struct oz_elt *)ei->data;
 169         app_hdr = (struct oz_app_hdr *)(elt+1);
 170         elt->length = sizeof(struct oz_app_hdr) + count;
 171         elt->type = OZ_ELT_APP_DATA;
 172         ei->app_id = OZ_APPID_SERIAL;
 173         ei->length = elt->length + sizeof(struct oz_elt);
 174         app_hdr->app_id = OZ_APPID_SERIAL;
 175         if (copy_from_user(app_hdr+1, buf, count))
 176                 goto out;
 177         spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
 178         ctx = (struct oz_serial_ctx *)pd->app_ctx[OZ_APPID_SERIAL-1];
 179         if (ctx) {
 180                 app_hdr->elt_seq_num = ctx->tx_seq_num++;
 181                 if (ctx->tx_seq_num == 0)
 182                         ctx->tx_seq_num = 1;
 183                 spin_lock(&eb->lock);
 184                 if (oz_queue_elt_info(eb, 0, 0, ei) == 0)
 185                         ei = 0;
 186                 spin_unlock(&eb->lock);
 187         }
 188         spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
 189 out:
 190         if (ei) {
 191                 count = 0;
 192                 spin_lock_bh(&eb->lock);
 193                 oz_elt_info_free(eb, ei);
 194                 spin_unlock_bh(&eb->lock);
 195         }
 196         oz_pd_put(pd);
 197         return count;
 198 }
 199 /*------------------------------------------------------------------------------
 200  * Context: process
 201  */
 202 static int oz_set_active_pd(u8 *addr)
 203 {
 204         int rc = 0;
 205         struct oz_pd *pd;
 206         struct oz_pd *old_pd;
 207         pd = oz_pd_find(addr);
 208         if (pd) {
 209                 spin_lock_bh(&g_cdev.lock);
 210                 memcpy(g_cdev.active_addr, addr, ETH_ALEN);
 211                 old_pd = g_cdev.active_pd;
 212                 g_cdev.active_pd = pd;
 213                 spin_unlock_bh(&g_cdev.lock);
 214                 if (old_pd)
 215                         oz_pd_put(old_pd);
 216         } else {
 217                 if (is_zero_ether_addr(addr)) {
 218                         spin_lock_bh(&g_cdev.lock);
 219                         pd = g_cdev.active_pd;
 220                         g_cdev.active_pd = 0;
 221                         memset(g_cdev.active_addr, 0,
 222                                 sizeof(g_cdev.active_addr));
 223                         spin_unlock_bh(&g_cdev.lock);
 224                         if (pd)
 225                                 oz_pd_put(pd);
 226                 } else {
 227                         rc = -1;
 228                 }
 229         }
 230         return rc;
 231 }
 232 /*------------------------------------------------------------------------------
 233  * Context: process
 234  */
 235 long oz_cdev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 236 {
 237         int rc = 0;
 238         if (_IOC_TYPE(cmd) != OZ_IOCTL_MAGIC)
 239                 return -ENOTTY;
 240         if (_IOC_NR(cmd) > OZ_IOCTL_MAX)
 241                 return -ENOTTY;
 242         if (_IOC_DIR(cmd) & _IOC_READ)
 243                 rc = !access_ok(VERIFY_WRITE, (void __user *)arg,
 244                         _IOC_SIZE(cmd));
 245         else if (_IOC_DIR(cmd) & _IOC_WRITE)
 246                 rc = !access_ok(VERIFY_READ, (void __user *)arg,
 247                         _IOC_SIZE(cmd));
 248         if (rc)
 249                 return -EFAULT;
 250         switch (cmd) {
 251         case OZ_IOCTL_GET_PD_LIST: {
 252                         struct oz_pd_list list;
 253                         oz_trace("OZ_IOCTL_GET_PD_LIST\n");
 254                         list.count = oz_get_pd_list(list.addr, OZ_MAX_PDS);
 255                         if (copy_to_user((void __user *)arg, &list,
 256                                 sizeof(list)))
 257                                 return -EFAULT;
 258                 }
 259                 break;
 260         case OZ_IOCTL_SET_ACTIVE_PD: {
 261                         u8 addr[ETH_ALEN];
 262                         oz_trace("OZ_IOCTL_SET_ACTIVE_PD\n");
 263                         if (copy_from_user(addr, (void __user *)arg, ETH_ALEN))
 264                                 return -EFAULT;
 265                         rc = oz_set_active_pd(addr);
 266                 }
 267                 break;
 268         case OZ_IOCTL_GET_ACTIVE_PD: {
 269                         u8 addr[ETH_ALEN];
 270                         oz_trace("OZ_IOCTL_GET_ACTIVE_PD\n");
 271                         spin_lock_bh(&g_cdev.lock);
 272                         memcpy(addr, g_cdev.active_addr, ETH_ALEN);
 273                         spin_unlock_bh(&g_cdev.lock);
 274                         if (copy_to_user((void __user *)arg, addr, ETH_ALEN))
 275                                 return -EFAULT;
 276                 }
 277                 break;
 278         case OZ_IOCTL_ADD_BINDING:
 279         case OZ_IOCTL_REMOVE_BINDING: {
 280                         struct oz_binding_info b;
 281                         if (copy_from_user(&b, (void __user *)arg,
 282                                 sizeof(struct oz_binding_info))) {
 283                                 return -EFAULT;
 284                         }
 285                         /* Make sure name is null terminated. */
 286                         b.name[OZ_MAX_BINDING_LEN-1] = 0;
 287                         if (cmd == OZ_IOCTL_ADD_BINDING)
 288                                 oz_binding_add(b.name);
 289                         else
 290                                 oz_binding_remove(b.name);
 291                 }
 292                 break;
 293         }
 294         return rc;
 295 }
 296 /*------------------------------------------------------------------------------
 297  * Context: process
 298  */
 299 unsigned int oz_cdev_poll(struct file *filp, poll_table *wait)
 300 {
 301         unsigned int ret = 0;
 302         struct oz_cdev *dev = filp->private_data;
 303         oz_trace("Poll called wait = %p\n", wait);
 304         spin_lock_bh(&dev->lock);
 305         if (dev->active_pd) {
 306                 struct oz_serial_ctx *ctx = oz_cdev_claim_ctx(dev->active_pd);
 307                 if (ctx) {
 308                         if (ctx->rd_in != ctx->rd_out)
 309                                 ret |= POLLIN | POLLRDNORM;
 310                         oz_cdev_release_ctx(ctx);
 311                 }
 312         }
 313         spin_unlock_bh(&dev->lock);
 314         if (wait)
 315                 poll_wait(filp, &dev->rdq, wait);
 316         return ret;
 317 }
 318 /*------------------------------------------------------------------------------
 319  */
 320 const struct file_operations oz_fops = {
 321         .owner =        THIS_MODULE,
 322         .open =         oz_cdev_open,
 323         .release =      oz_cdev_release,
 324         .read =         oz_cdev_read,
 325         .write =        oz_cdev_write,
 326         .unlocked_ioctl = oz_cdev_ioctl,
 327         .poll =         oz_cdev_poll
 328 };
 329 /*------------------------------------------------------------------------------
 330  * Context: process
 331  */
 332 int oz_cdev_register(void)
 333 {
 334         int err;
 335         struct device *dev;
 336         memset(&g_cdev, 0, sizeof(g_cdev));
 337         err = alloc_chrdev_region(&g_cdev.devnum, 0, 1, "ozwpan");
 338         if (err < 0)
 339                 goto out3;
 340         oz_trace("Alloc dev number %d:%d\n", MAJOR(g_cdev.devnum),
 341                         MINOR(g_cdev.devnum));
 342         cdev_init(&g_cdev.cdev, &oz_fops);
 343         g_cdev.cdev.owner = THIS_MODULE;
 344         g_cdev.cdev.ops = &oz_fops;
 345         spin_lock_init(&g_cdev.lock);
 346         init_waitqueue_head(&g_cdev.rdq);
 347         err = cdev_add(&g_cdev.cdev, g_cdev.devnum, 1);
 348         if (err < 0) {
 349                 oz_trace("Failed to add cdev\n");
 350                 goto out2;
 351         }
 352         g_oz_class = class_create(THIS_MODULE, "ozmo_wpan");
 353         if (IS_ERR(g_oz_class)) {
 354                 oz_trace("Failed to register ozmo_wpan class\n");
 355                 goto out1;
 356         }
 357         dev = device_create(g_oz_class, NULL, g_cdev.devnum, NULL, "ozwpan");
 358         if (IS_ERR(dev)) {
 359                 oz_trace("Failed to create sysfs entry for cdev\n");
 360                 goto out1;
 361         }
 362         return 0;
 363 out1:
 364         cdev_del(&g_cdev.cdev);
 365 out2:
 366         unregister_chrdev_region(g_cdev.devnum, 1);
 367 out3:
 368         return err;
 369 }
 370 /*------------------------------------------------------------------------------
 371  * Context: process
 372  */
 373 int oz_cdev_deregister(void)
 374 {
 375         cdev_del(&g_cdev.cdev);
 376         unregister_chrdev_region(g_cdev.devnum, 1);
 377         if (g_oz_class) {
 378                 device_destroy(g_oz_class, g_cdev.devnum);
 379                 class_destroy(g_oz_class);
 380         }
 381         return 0;
 382 }
 383 /*------------------------------------------------------------------------------
 384  * Context: process
 385  */
 386 int oz_cdev_init(void)
 387 {
 388         oz_event_log(OZ_EVT_SERVICE, 1, OZ_APPID_SERIAL, 0, 0);
 389         oz_app_enable(OZ_APPID_SERIAL, 1);
 390         return 0;
 391 }
 392 /*------------------------------------------------------------------------------
 393  * Context: process
 394  */
 395 void oz_cdev_term(void)
 396 {
 397         oz_event_log(OZ_EVT_SERVICE, 2, OZ_APPID_SERIAL, 0, 0);
 398         oz_app_enable(OZ_APPID_SERIAL, 0);
 399 }
 400 /*------------------------------------------------------------------------------
 401  * Context: softirq-serialized
 402  */
 403 int oz_cdev_start(struct oz_pd *pd, int resume)
 404 {
 405         struct oz_serial_ctx *ctx;
 406         struct oz_serial_ctx *old_ctx = 0;
 407         oz_event_log(OZ_EVT_SERVICE, 3, OZ_APPID_SERIAL, 0, resume);
 408         if (resume) {
 409                 oz_trace("Serial service resumed.\n");
 410                 return 0;
 411         }
 412         ctx = kzalloc(sizeof(struct oz_serial_ctx), GFP_ATOMIC);
 413         if (ctx == NULL)
 414                 return -ENOMEM;
 415         atomic_set(&ctx->ref_count, 1);
 416         ctx->tx_seq_num = 1;
 417         spin_lock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
 418         old_ctx = pd->app_ctx[OZ_APPID_SERIAL-1];
 419         if (old_ctx) {
 420                 spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
 421                 kfree(ctx);
 422         } else {
 423                 pd->app_ctx[OZ_APPID_SERIAL-1] = ctx;
 424                 spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
 425         }
 426         spin_lock(&g_cdev.lock);
 427         if ((g_cdev.active_pd == NULL) &&
 428                 (memcmp(pd->mac_addr, g_cdev.active_addr, ETH_ALEN) == 0)) {
 429                 oz_pd_get(pd);
 430                 g_cdev.active_pd = pd;
 431                 oz_trace("Active PD arrived.\n");
 432         }
 433         spin_unlock(&g_cdev.lock);
 434         oz_trace("Serial service started.\n");
 435         return 0;
 436 }
 437 /*------------------------------------------------------------------------------
 438  * Context: softirq or process
 439  */
 440 void oz_cdev_stop(struct oz_pd *pd, int pause)
 441 {
 442         struct oz_serial_ctx *ctx;
 443         oz_event_log(OZ_EVT_SERVICE, 4, OZ_APPID_SERIAL, 0, pause);
 444         if (pause) {
 445                 oz_trace("Serial service paused.\n");
 446                 return;
 447         }
 448         spin_lock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
 449         ctx = (struct oz_serial_ctx *)pd->app_ctx[OZ_APPID_SERIAL-1];
 450         pd->app_ctx[OZ_APPID_SERIAL-1] = 0;
 451         spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
 452         if (ctx)
 453                 oz_cdev_release_ctx(ctx);
 454         spin_lock(&g_cdev.lock);
 455         if (pd == g_cdev.active_pd)
 456                 g_cdev.active_pd = 0;
 457         else
 458                 pd = 0;
 459         spin_unlock(&g_cdev.lock);
 460         if (pd) {
 461                 oz_pd_put(pd);
 462                 oz_trace("Active PD departed.\n");
 463         }
 464         oz_trace("Serial service stopped.\n");
 465 }
 466 /*------------------------------------------------------------------------------
 467  * Context: softirq-serialized
 468  */
 469 void oz_cdev_rx(struct oz_pd *pd, struct oz_elt *elt)
 470 {
 471         struct oz_serial_ctx *ctx;
 472         struct oz_app_hdr *app_hdr;
 473         u8 *data;
 474         int len;
 475         int space;
 476         int copy_sz;
 477         int ix;
 478
 479         ctx = oz_cdev_claim_ctx(pd);
 480         if (ctx == NULL) {
 481                 oz_trace("Cannot claim serial context.\n");
 482                 return;
 483         }
 484
 485         app_hdr = (struct oz_app_hdr *)(elt+1);
 486         /* If sequence number is non-zero then check it is not a duplicate.
 487          */
 488         if (app_hdr->elt_seq_num != 0) {
 489                 if (((ctx->rx_seq_num - app_hdr->elt_seq_num) & 0x80) == 0) {
 490                         /* Reject duplicate element. */
 491                         oz_trace("Duplicate element:%02x %02x\n",
 492                                 app_hdr->elt_seq_num, ctx->rx_seq_num);
 493                         goto out;
 494                 }
 495         }
 496         ctx->rx_seq_num = app_hdr->elt_seq_num;
 497         len = elt->length - sizeof(struct oz_app_hdr);
 498         data = ((u8 *)(elt+1)) + sizeof(struct oz_app_hdr);
 499         if (len <= 0)
 500                 goto out;
 501         space = ctx->rd_out - ctx->rd_in - 1;
 502         if (space < 0)
 503                 space += OZ_RD_BUF_SZ;
 504         if (len > space) {
 505                 oz_trace("Not enough space:%d %d\n", len, space);
 506                 len = space;
 507         }
 508         ix = ctx->rd_in;
 509         copy_sz = OZ_RD_BUF_SZ - ix;
 510         if (copy_sz > len)
 511                 copy_sz = len;
 512         memcpy(&ctx->rd_buf[ix], data, copy_sz);
 513         len -= copy_sz;
 514         ix += copy_sz;
 515         if (ix == OZ_RD_BUF_SZ)
 516                 ix = 0;
 517         if (len) {
 518                 memcpy(ctx->rd_buf, data+copy_sz, len);
 519                 ix = len;
 520         }
 521         ctx->rd_in = ix;
 522         wake_up(&g_cdev.rdq);
 523 out:
 524         oz_cdev_release_ctx(ctx);
 525 }
 526 /*------------------------------------------------------------------------------
 527  * Context: softirq
 528  */
 529 void oz_cdev_heartbeat(struct oz_pd *pd)
 530 {
 531 }