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