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