drivers/uwb/reset.c

   1 /*
   2  * Ultra Wide Band
   3  * UWB basic command support and radio reset
   4  *
   5  * Copyright (C) 2005-2006 Intel Corporation
   6  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License version
  10  * 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20  * 02110-1301, USA.
  21  *
  22  *
  23  * FIXME:
  24  *
  25  *  - docs
  26  *
  27  *  - Now we are serializing (using the uwb_dev->mutex) the command
  28  *    execution; it should be parallelized as much as possible some
  29  *    day.
  30  */
  31 #include <linux/kernel.h>
  32 #include <linux/err.h>
  33 #include <linux/slab.h>
  34 #include <linux/delay.h>
  35
  36 #include "uwb-internal.h"
  37
  38 /**
  39  * Command result codes (WUSB1.0[T8-69])
  40  */
  41 static
  42 const char *__strerror[] = {
  43         "success",
  44         "failure",
  45         "hardware failure",
  46         "no more slots",
  47         "beacon is too large",
  48         "invalid parameter",
  49         "unsupported power level",
  50         "time out (wa) or invalid ie data (whci)",
  51         "beacon size exceeded",
  52         "cancelled",
  53         "invalid state",
  54         "invalid size",
  55         "ack not received",
  56         "no more asie notification",
  57 };
  58
  59
  60 /** Return a string matching the given error code */
  61 const char *uwb_rc_strerror(unsigned code)
  62 {
  63         if (code == 255)
  64                 return "time out";
  65         if (code >= ARRAY_SIZE(__strerror))
  66                 return "unknown error";
  67         return __strerror[code];
  68 }
  69
  70 int uwb_rc_cmd_async(struct uwb_rc *rc, const char *cmd_name,
  71                      struct uwb_rccb *cmd, size_t cmd_size,
  72                      u8 expected_type, u16 expected_event,
  73                      uwb_rc_cmd_cb_f cb, void *arg)
  74 {
  75         struct device *dev = &rc->uwb_dev.dev;
  76         struct uwb_rc_neh *neh;
  77         int needtofree = 0;
  78         int result;
  79
  80         uwb_dev_lock(&rc->uwb_dev);     /* Protect against rc->priv being removed */
  81         if (rc->priv == NULL) {
  82                 uwb_dev_unlock(&rc->uwb_dev);
  83                 return -ESHUTDOWN;
  84         }
  85
  86         if (rc->filter_cmd) {
  87                 needtofree = rc->filter_cmd(rc, &cmd, &cmd_size);
  88                 if (needtofree < 0 && needtofree != -ENOANO) {
  89                         dev_err(dev, "%s: filter error: %d\n",
  90                                 cmd_name, needtofree);
  91                         uwb_dev_unlock(&rc->uwb_dev);
  92                         return needtofree;
  93                 }
  94         }
  95
  96         neh = uwb_rc_neh_add(rc, cmd, expected_type, expected_event, cb, arg);
  97         if (IS_ERR(neh)) {
  98                 result = PTR_ERR(neh);
  99                 goto out;
 100         }
 101
 102         result = rc->cmd(rc, cmd, cmd_size);
 103         uwb_dev_unlock(&rc->uwb_dev);
 104         if (result < 0)
 105                 uwb_rc_neh_rm(rc, neh);
 106         else
 107                 uwb_rc_neh_arm(rc, neh);
 108         uwb_rc_neh_put(neh);
 109 out:
 110         if (needtofree == 1)
 111                 kfree(cmd);
 112         return result < 0 ? result : 0;
 113 }
 114 EXPORT_SYMBOL_GPL(uwb_rc_cmd_async);
 115
 116 struct uwb_rc_cmd_done_params {
 117         struct completion completion;
 118         struct uwb_rceb *reply;
 119         ssize_t reply_size;
 120 };
 121
 122 static void uwb_rc_cmd_done(struct uwb_rc *rc, void *arg,
 123                             struct uwb_rceb *reply, ssize_t reply_size)
 124 {
 125         struct uwb_rc_cmd_done_params *p = (struct uwb_rc_cmd_done_params *)arg;
 126
 127         if (reply_size > 0) {
 128                 if (p->reply)
 129                         reply_size = min(p->reply_size, reply_size);
 130                 else
 131                         p->reply = kmalloc(reply_size, GFP_ATOMIC);
 132
 133                 if (p->reply)
 134                         memcpy(p->reply, reply, reply_size);
 135                 else
 136                         reply_size = -ENOMEM;
 137         }
 138         p->reply_size = reply_size;
 139         complete(&p->completion);
 140 }
 141
 142
 143 /**
 144  * Generic function for issuing commands to the Radio Control Interface
 145  *
 146  * @rc:       UWB Radio Control descriptor
 147  * @cmd_name: Name of the command being issued (for error messages)
 148  * @cmd:      Pointer to rccb structure containing the command;
 149  *            normally you embed this structure as the first member of
 150  *            the full command structure.
 151  * @cmd_size: Size of the whole command buffer pointed to by @cmd.
 152  * @reply:    Pointer to where to store the reply
 153  * @reply_size: @reply's size
 154  * @expected_type: Expected type in the return event
 155  * @expected_event: Expected event code in the return event
 156  * @preply:   Here a pointer to where the event data is received will
 157  *            be stored. Once done with the data, free with kfree().
 158  *
 159  * This function is generic; it works for commands that return a fixed
 160  * and known size or for commands that return a variable amount of data.
 161  *
 162  * If a buffer is provided, that is used, although it could be chopped
 163  * to the maximum size of the buffer. If the buffer is NULL, then one
 164  * be allocated in *preply with the whole contents of the reply.
 165  *
 166  * @rc needs to be referenced
 167  */
 168 static
 169 ssize_t __uwb_rc_cmd(struct uwb_rc *rc, const char *cmd_name,
 170                      struct uwb_rccb *cmd, size_t cmd_size,
 171                      struct uwb_rceb *reply, size_t reply_size,
 172                      u8 expected_type, u16 expected_event,
 173                      struct uwb_rceb **preply)
 174 {
 175         ssize_t result = 0;
 176         struct device *dev = &rc->uwb_dev.dev;
 177         struct uwb_rc_cmd_done_params params;
 178
 179         init_completion(&params.completion);
 180         params.reply = reply;
 181         params.reply_size = reply_size;
 182
 183         result = uwb_rc_cmd_async(rc, cmd_name, cmd, cmd_size,
 184                                   expected_type, expected_event,
 185                                   uwb_rc_cmd_done, &params);
 186         if (result)
 187                 return result;
 188
 189         wait_for_completion(&params.completion);
 190
 191         if (preply)
 192                 *preply = params.reply;
 193
 194         if (params.reply_size < 0)
 195                 dev_err(dev, "%s: confirmation event 0x%02x/%04x/%02x "
 196                         "reception failed: %d\n", cmd_name,
 197                         expected_type, expected_event, cmd->bCommandContext,
 198                         (int)params.reply_size);
 199         return params.reply_size;
 200 }
 201
 202
 203 /**
 204  * Generic function for issuing commands to the Radio Control Interface
 205  *
 206  * @rc:       UWB Radio Control descriptor
 207  * @cmd_name: Name of the command being issued (for error messages)
 208  * @cmd:      Pointer to rccb structure containing the command;
 209  *            normally you embed this structure as the first member of
 210  *            the full command structure.
 211  * @cmd_size: Size of the whole command buffer pointed to by @cmd.
 212  * @reply:    Pointer to the beginning of the confirmation event
 213  *            buffer. Normally bigger than an 'struct hwarc_rceb'.
 214  *            You need to fill out reply->bEventType and reply->wEvent (in
 215  *            cpu order) as the function will use them to verify the
 216  *            confirmation event.
 217  * @reply_size: Size of the reply buffer
 218  *
 219  * The function checks that the length returned in the reply is at
 220  * least as big as @reply_size; if not, it will be deemed an error and
 221  * -EIO returned.
 222  *
 223  * @rc needs to be referenced
 224  */
 225 ssize_t uwb_rc_cmd(struct uwb_rc *rc, const char *cmd_name,
 226                    struct uwb_rccb *cmd, size_t cmd_size,
 227                    struct uwb_rceb *reply, size_t reply_size)
 228 {
 229         struct device *dev = &rc->uwb_dev.dev;
 230         ssize_t result;
 231
 232         result = __uwb_rc_cmd(rc, cmd_name,
 233                               cmd, cmd_size, reply, reply_size,
 234                               reply->bEventType, reply->wEvent, NULL);
 235
 236         if (result > 0 && result < reply_size) {
 237                 dev_err(dev, "%s: not enough data returned for decoding reply "
 238                         "(%zu bytes received vs at least %zu needed)\n",
 239                         cmd_name, result, reply_size);
 240                 result = -EIO;
 241         }
 242         return result;
 243 }
 244 EXPORT_SYMBOL_GPL(uwb_rc_cmd);
 245
 246
 247 /**
 248  * Generic function for issuing commands to the Radio Control
 249  * Interface that return an unknown amount of data
 250  *
 251  * @rc:       UWB Radio Control descriptor
 252  * @cmd_name: Name of the command being issued (for error messages)
 253  * @cmd:      Pointer to rccb structure containing the command;
 254  *            normally you embed this structure as the first member of
 255  *            the full command structure.
 256  * @cmd_size: Size of the whole command buffer pointed to by @cmd.
 257  * @expected_type: Expected type in the return event
 258  * @expected_event: Expected event code in the return event
 259  * @preply:   Here a pointer to where the event data is received will
 260  *            be stored. Once done with the data, free with kfree().
 261  *
 262  * The function checks that the length returned in the reply is at
 263  * least as big as a 'struct uwb_rceb *'; if not, it will be deemed an
 264  * error and -EIO returned.
 265  *
 266  * @rc needs to be referenced
 267  */
 268 ssize_t uwb_rc_vcmd(struct uwb_rc *rc, const char *cmd_name,
 269                     struct uwb_rccb *cmd, size_t cmd_size,
 270                     u8 expected_type, u16 expected_event,
 271                     struct uwb_rceb **preply)
 272 {
 273         return __uwb_rc_cmd(rc, cmd_name, cmd, cmd_size, NULL, 0,
 274                             expected_type, expected_event, preply);
 275 }
 276 EXPORT_SYMBOL_GPL(uwb_rc_vcmd);
 277
 278
 279 /**
 280  * Reset a UWB Host Controller (and all radio settings)
 281  *
 282  * @rc:      Host Controller descriptor
 283  * @returns: 0 if ok, < 0 errno code on error
 284  *
 285  * We put the command on kmalloc'ed memory as some arches cannot do
 286  * USB from the stack. The reply event is copied from an stage buffer,
 287  * so it can be in the stack. See WUSB1.0[8.6.2.4] for more details.
 288  */
 289 int uwb_rc_reset(struct uwb_rc *rc)
 290 {
 291         int result = -ENOMEM;
 292         struct uwb_rc_evt_confirm reply;
 293         struct uwb_rccb *cmd;
 294         size_t cmd_size = sizeof(*cmd);
 295
 296         mutex_lock(&rc->uwb_dev.mutex);
 297         cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
 298         if (cmd == NULL)
 299                 goto error_kzalloc;
 300         cmd->bCommandType = UWB_RC_CET_GENERAL;
 301         cmd->wCommand = cpu_to_le16(UWB_RC_CMD_RESET);
 302         reply.rceb.bEventType = UWB_RC_CET_GENERAL;
 303         reply.rceb.wEvent = UWB_RC_CMD_RESET;
 304         result = uwb_rc_cmd(rc, "RESET", cmd, cmd_size,
 305                             &reply.rceb, sizeof(reply));
 306         if (result < 0)
 307                 goto error_cmd;
 308         if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
 309                 dev_err(&rc->uwb_dev.dev,
 310                         "RESET: command execution failed: %s (%d)\n",
 311                         uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
 312                 result = -EIO;
 313         }
 314 error_cmd:
 315         kfree(cmd);
 316 error_kzalloc:
 317         mutex_unlock(&rc->uwb_dev.mutex);
 318         return result;
 319 }
 320
 321 int uwbd_msg_handle_reset(struct uwb_event *evt)
 322 {
 323         struct uwb_rc *rc = evt->rc;
 324         int ret;
 325
 326         dev_info(&rc->uwb_dev.dev, "resetting radio controller\n");
 327         ret = rc->reset(rc);
 328         if (ret < 0) {
 329                 dev_err(&rc->uwb_dev.dev, "failed to reset hardware: %d\n", ret);
 330                 goto error;
 331         }
 332         return 0;
 333 error:
 334         /* Nothing can be done except try the reset again. Wait a bit
 335            to avoid reset loops during probe() or remove(). */
 336         msleep(1000);
 337         uwb_rc_reset_all(rc);
 338         return ret;
 339 }
 340
 341 /**
 342  * uwb_rc_reset_all - request a reset of the radio controller and PALs
 343  * @rc: the radio controller of the hardware device to be reset.
 344  *
 345  * The full hardware reset of the radio controller and all the PALs
 346  * will be scheduled.
 347  */
 348 void uwb_rc_reset_all(struct uwb_rc *rc)
 349 {
 350         struct uwb_event *evt;
 351
 352         evt = kzalloc(sizeof(struct uwb_event), GFP_ATOMIC);
 353         if (unlikely(evt == NULL))
 354                 return;
 355
 356         evt->rc = __uwb_rc_get(rc);     /* will be put by uwbd's uwbd_event_handle() */
 357         evt->ts_jiffies = jiffies;
 358         evt->type = UWB_EVT_TYPE_MSG;
 359         evt->message = UWB_EVT_MSG_RESET;
 360
 361         uwbd_event_queue(evt);
 362 }
 363 EXPORT_SYMBOL_GPL(uwb_rc_reset_all);
 364
 365 void uwb_rc_pre_reset(struct uwb_rc *rc)
 366 {
 367         rc->stop(rc);
 368         uwbd_flush(rc);
 369
 370         uwb_radio_reset_state(rc);
 371         uwb_rsv_remove_all(rc);
 372 }
 373 EXPORT_SYMBOL_GPL(uwb_rc_pre_reset);
 374
 375 int uwb_rc_post_reset(struct uwb_rc *rc)
 376 {
 377         int ret;
 378
 379         ret = rc->start(rc);
 380         if (ret)
 381                 goto out;
 382         ret = uwb_rc_mac_addr_set(rc, &rc->uwb_dev.mac_addr);
 383         if (ret)
 384                 goto out;
 385         ret = uwb_rc_dev_addr_set(rc, &rc->uwb_dev.dev_addr);
 386         if (ret)
 387                 goto out;
 388 out:
 389         return ret;
 390 }
 391 EXPORT_SYMBOL_GPL(uwb_rc_post_reset);