linux/drivers/uwb/reset.c
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   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#include <linux/export.h>
  36
  37#include "uwb-internal.h"
  38
  39/**
  40 * Command result codes (WUSB1.0[T8-69])
  41 */
  42static
  43const char *__strerror[] = {
  44        "success",
  45        "failure",
  46        "hardware failure",
  47        "no more slots",
  48        "beacon is too large",
  49        "invalid parameter",
  50        "unsupported power level",
  51        "time out (wa) or invalid ie data (whci)",
  52        "beacon size exceeded",
  53        "cancelled",
  54        "invalid state",
  55        "invalid size",
  56        "ack not received",
  57        "no more asie notification",
  58};
  59
  60
  61/** Return a string matching the given error code */
  62const char *uwb_rc_strerror(unsigned code)
  63{
  64        if (code == 255)
  65                return "time out";
  66        if (code >= ARRAY_SIZE(__strerror))
  67                return "unknown error";
  68        return __strerror[code];
  69}
  70
  71int uwb_rc_cmd_async(struct uwb_rc *rc, const char *cmd_name,
  72                     struct uwb_rccb *cmd, size_t cmd_size,
  73                     u8 expected_type, u16 expected_event,
  74                     uwb_rc_cmd_cb_f cb, void *arg)
  75{
  76        struct device *dev = &rc->uwb_dev.dev;
  77        struct uwb_rc_neh *neh;
  78        int needtofree = 0;
  79        int result;
  80
  81        uwb_dev_lock(&rc->uwb_dev);     /* Protect against rc->priv being removed */
  82        if (rc->priv == NULL) {
  83                uwb_dev_unlock(&rc->uwb_dev);
  84                return -ESHUTDOWN;
  85        }
  86
  87        if (rc->filter_cmd) {
  88                needtofree = rc->filter_cmd(rc, &cmd, &cmd_size);
  89                if (needtofree < 0 && needtofree != -ENOANO) {
  90                        dev_err(dev, "%s: filter error: %d\n",
  91                                cmd_name, needtofree);
  92                        uwb_dev_unlock(&rc->uwb_dev);
  93                        return needtofree;
  94                }
  95        }
  96
  97        neh = uwb_rc_neh_add(rc, cmd, expected_type, expected_event, cb, arg);
  98        if (IS_ERR(neh)) {
  99                result = PTR_ERR(neh);
 100                goto out;
 101        }
 102
 103        result = rc->cmd(rc, cmd, cmd_size);
 104        uwb_dev_unlock(&rc->uwb_dev);
 105        if (result < 0)
 106                uwb_rc_neh_rm(rc, neh);
 107        else
 108                uwb_rc_neh_arm(rc, neh);
 109        uwb_rc_neh_put(neh);
 110out:
 111        if (needtofree == 1)
 112                kfree(cmd);
 113        return result < 0 ? result : 0;
 114}
 115EXPORT_SYMBOL_GPL(uwb_rc_cmd_async);
 116
 117struct uwb_rc_cmd_done_params {
 118        struct completion completion;
 119        struct uwb_rceb *reply;
 120        ssize_t reply_size;
 121};
 122
 123static void uwb_rc_cmd_done(struct uwb_rc *rc, void *arg,
 124                            struct uwb_rceb *reply, ssize_t reply_size)
 125{
 126        struct uwb_rc_cmd_done_params *p = (struct uwb_rc_cmd_done_params *)arg;
 127
 128        if (reply_size > 0) {
 129                if (p->reply)
 130                        reply_size = min(p->reply_size, reply_size);
 131                else
 132                        p->reply = kmalloc(reply_size, GFP_ATOMIC);
 133
 134                if (p->reply)
 135                        memcpy(p->reply, reply, reply_size);
 136                else
 137                        reply_size = -ENOMEM;
 138        }
 139        p->reply_size = reply_size;
 140        complete(&p->completion);
 141}
 142
 143
 144/**
 145 * Generic function for issuing commands to the Radio Control Interface
 146 *
 147 * @rc:       UWB Radio Control descriptor
 148 * @cmd_name: Name of the command being issued (for error messages)
 149 * @cmd:      Pointer to rccb structure containing the command;
 150 *            normally you embed this structure as the first member of
 151 *            the full command structure.
 152 * @cmd_size: Size of the whole command buffer pointed to by @cmd.
 153 * @reply:    Pointer to where to store the reply
 154 * @reply_size: @reply's size
 155 * @expected_type: Expected type in the return event
 156 * @expected_event: Expected event code in the return event
 157 * @preply:   Here a pointer to where the event data is received will
 158 *            be stored. Once done with the data, free with kfree().
 159 *
 160 * This function is generic; it works for commands that return a fixed
 161 * and known size or for commands that return a variable amount of data.
 162 *
 163 * If a buffer is provided, that is used, although it could be chopped
 164 * to the maximum size of the buffer. If the buffer is NULL, then one
 165 * be allocated in *preply with the whole contents of the reply.
 166 *
 167 * @rc needs to be referenced
 168 */
 169static
 170ssize_t __uwb_rc_cmd(struct uwb_rc *rc, const char *cmd_name,
 171                     struct uwb_rccb *cmd, size_t cmd_size,
 172                     struct uwb_rceb *reply, size_t reply_size,
 173                     u8 expected_type, u16 expected_event,
 174                     struct uwb_rceb **preply)
 175{
 176        ssize_t result = 0;
 177        struct device *dev = &rc->uwb_dev.dev;
 178        struct uwb_rc_cmd_done_params params;
 179
 180        init_completion(&params.completion);
 181        params.reply = reply;
 182        params.reply_size = reply_size;
 183
 184        result = uwb_rc_cmd_async(rc, cmd_name, cmd, cmd_size,
 185                                  expected_type, expected_event,
 186                                  uwb_rc_cmd_done, &params);
 187        if (result)
 188                return result;
 189
 190        wait_for_completion(&params.completion);
 191
 192        if (preply)
 193                *preply = params.reply;
 194
 195        if (params.reply_size < 0)
 196                dev_err(dev, "%s: confirmation event 0x%02x/%04x/%02x "
 197                        "reception failed: %d\n", cmd_name,
 198                        expected_type, expected_event, cmd->bCommandContext,
 199                        (int)params.reply_size);
 200        return params.reply_size;
 201}
 202
 203
 204/**
 205 * Generic function for issuing commands to the Radio Control Interface
 206 *
 207 * @rc:       UWB Radio Control descriptor
 208 * @cmd_name: Name of the command being issued (for error messages)
 209 * @cmd:      Pointer to rccb structure containing the command;
 210 *            normally you embed this structure as the first member of
 211 *            the full command structure.
 212 * @cmd_size: Size of the whole command buffer pointed to by @cmd.
 213 * @reply:    Pointer to the beginning of the confirmation event
 214 *            buffer. Normally bigger than an 'struct hwarc_rceb'.
 215 *            You need to fill out reply->bEventType and reply->wEvent (in
 216 *            cpu order) as the function will use them to verify the
 217 *            confirmation event.
 218 * @reply_size: Size of the reply buffer
 219 *
 220 * The function checks that the length returned in the reply is at
 221 * least as big as @reply_size; if not, it will be deemed an error and
 222 * -EIO returned.
 223 *
 224 * @rc needs to be referenced
 225 */
 226ssize_t uwb_rc_cmd(struct uwb_rc *rc, const char *cmd_name,
 227                   struct uwb_rccb *cmd, size_t cmd_size,
 228                   struct uwb_rceb *reply, size_t reply_size)
 229{
 230        struct device *dev = &rc->uwb_dev.dev;
 231        ssize_t result;
 232
 233        result = __uwb_rc_cmd(rc, cmd_name,
 234                              cmd, cmd_size, reply, reply_size,
 235                              reply->bEventType, reply->wEvent, NULL);
 236
 237        if (result > 0 && result < reply_size) {
 238                dev_err(dev, "%s: not enough data returned for decoding reply "
 239                        "(%zu bytes received vs at least %zu needed)\n",
 240                        cmd_name, result, reply_size);
 241                result = -EIO;
 242        }
 243        return result;
 244}
 245EXPORT_SYMBOL_GPL(uwb_rc_cmd);
 246
 247
 248/**
 249 * Generic function for issuing commands to the Radio Control
 250 * Interface that return an unknown amount of data
 251 *
 252 * @rc:       UWB Radio Control descriptor
 253 * @cmd_name: Name of the command being issued (for error messages)
 254 * @cmd:      Pointer to rccb structure containing the command;
 255 *            normally you embed this structure as the first member of
 256 *            the full command structure.
 257 * @cmd_size: Size of the whole command buffer pointed to by @cmd.
 258 * @expected_type: Expected type in the return event
 259 * @expected_event: Expected event code in the return event
 260 * @preply:   Here a pointer to where the event data is received will
 261 *            be stored. Once done with the data, free with kfree().
 262 *
 263 * The function checks that the length returned in the reply is at
 264 * least as big as a 'struct uwb_rceb *'; if not, it will be deemed an
 265 * error and -EIO returned.
 266 *
 267 * @rc needs to be referenced
 268 */
 269ssize_t uwb_rc_vcmd(struct uwb_rc *rc, const char *cmd_name,
 270                    struct uwb_rccb *cmd, size_t cmd_size,
 271                    u8 expected_type, u16 expected_event,
 272                    struct uwb_rceb **preply)
 273{
 274        return __uwb_rc_cmd(rc, cmd_name, cmd, cmd_size, NULL, 0,
 275                            expected_type, expected_event, preply);
 276}
 277EXPORT_SYMBOL_GPL(uwb_rc_vcmd);
 278
 279
 280/**
 281 * Reset a UWB Host Controller (and all radio settings)
 282 *
 283 * @rc:      Host Controller descriptor
 284 * @returns: 0 if ok, < 0 errno code on error
 285 *
 286 * We put the command on kmalloc'ed memory as some arches cannot do
 287 * USB from the stack. The reply event is copied from an stage buffer,
 288 * so it can be in the stack. See WUSB1.0[8.6.2.4] for more details.
 289 */
 290int uwb_rc_reset(struct uwb_rc *rc)
 291{
 292        int result = -ENOMEM;
 293        struct uwb_rc_evt_confirm reply;
 294        struct uwb_rccb *cmd;
 295        size_t cmd_size = sizeof(*cmd);
 296
 297        mutex_lock(&rc->uwb_dev.mutex);
 298        cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
 299        if (cmd == NULL)
 300                goto error_kzalloc;
 301        cmd->bCommandType = UWB_RC_CET_GENERAL;
 302        cmd->wCommand = cpu_to_le16(UWB_RC_CMD_RESET);
 303        reply.rceb.bEventType = UWB_RC_CET_GENERAL;
 304        reply.rceb.wEvent = UWB_RC_CMD_RESET;
 305        result = uwb_rc_cmd(rc, "RESET", cmd, cmd_size,
 306                            &reply.rceb, sizeof(reply));
 307        if (result < 0)
 308                goto error_cmd;
 309        if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
 310                dev_err(&rc->uwb_dev.dev,
 311                        "RESET: command execution failed: %s (%d)\n",
 312                        uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
 313                result = -EIO;
 314        }
 315error_cmd:
 316        kfree(cmd);
 317error_kzalloc:
 318        mutex_unlock(&rc->uwb_dev.mutex);
 319        return result;
 320}
 321
 322int uwbd_msg_handle_reset(struct uwb_event *evt)
 323{
 324        struct uwb_rc *rc = evt->rc;
 325        int ret;
 326
 327        dev_info(&rc->uwb_dev.dev, "resetting radio controller\n");
 328        ret = rc->reset(rc);
 329        if (ret < 0) {
 330                dev_err(&rc->uwb_dev.dev, "failed to reset hardware: %d\n", ret);
 331                goto error;
 332        }
 333        return 0;
 334error:
 335        /* Nothing can be done except try the reset again. Wait a bit
 336           to avoid reset loops during probe() or remove(). */
 337        msleep(1000);
 338        uwb_rc_reset_all(rc);
 339        return ret;
 340}
 341
 342/**
 343 * uwb_rc_reset_all - request a reset of the radio controller and PALs
 344 * @rc: the radio controller of the hardware device to be reset.
 345 *
 346 * The full hardware reset of the radio controller and all the PALs
 347 * will be scheduled.
 348 */
 349void uwb_rc_reset_all(struct uwb_rc *rc)
 350{
 351        struct uwb_event *evt;
 352
 353        evt = kzalloc(sizeof(struct uwb_event), GFP_ATOMIC);
 354        if (unlikely(evt == NULL))
 355                return;
 356
 357        evt->rc = __uwb_rc_get(rc);     /* will be put by uwbd's uwbd_event_handle() */
 358        evt->ts_jiffies = jiffies;
 359        evt->type = UWB_EVT_TYPE_MSG;
 360        evt->message = UWB_EVT_MSG_RESET;
 361
 362        uwbd_event_queue(evt);
 363}
 364EXPORT_SYMBOL_GPL(uwb_rc_reset_all);
 365
 366void uwb_rc_pre_reset(struct uwb_rc *rc)
 367{
 368        rc->stop(rc);
 369        uwbd_flush(rc);
 370
 371        uwb_radio_reset_state(rc);
 372        uwb_rsv_remove_all(rc);
 373}
 374EXPORT_SYMBOL_GPL(uwb_rc_pre_reset);
 375
 376int uwb_rc_post_reset(struct uwb_rc *rc)
 377{
 378        int ret;
 379
 380        ret = rc->start(rc);
 381        if (ret)
 382                goto out;
 383        ret = uwb_rc_mac_addr_set(rc, &rc->uwb_dev.mac_addr);
 384        if (ret)
 385                goto out;
 386        ret = uwb_rc_dev_addr_set(rc, &rc->uwb_dev.dev_addr);
 387        if (ret)
 388                goto out;
 389out:
 390        return ret;
 391}
 392EXPORT_SYMBOL_GPL(uwb_rc_post_reset);
 393
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