root/drivers/staging/uwb/reset.c

DEFINITIONS

1. uwb_rc_strerror
2. uwb_rc_cmd_async
3. uwb_rc_cmd_done
4. __uwb_rc_cmd
5. uwb_rc_cmd
6. uwb_rc_vcmd
7. uwb_rc_reset
8. uwbd_msg_handle_reset
9. uwb_rc_reset_all
10. uwb_rc_pre_reset
11. uwb_rc_post_reset

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Ultra Wide Band
   4  * UWB basic command support and radio reset
   5  *
   6  * Copyright (C) 2005-2006 Intel Corporation
   7  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   8  *
   9  * FIXME:
  10  *
  11  *  - docs
  12  *
  13  *  - Now we are serializing (using the uwb_dev->mutex) the command
  14  *    execution; it should be parallelized as much as possible some
  15  *    day.
  16  */
  17 #include <linux/kernel.h>
  18 #include <linux/err.h>
  19 #include <linux/slab.h>
  20 #include <linux/delay.h>
  21 #include <linux/export.h>
  22 
  23 #include "uwb-internal.h"
  24 
  25 /**
  26  * Command result codes (WUSB1.0[T8-69])
  27  */
  28 static
  29 const char *__strerror[] = {
  30         "success",
  31         "failure",
  32         "hardware failure",
  33         "no more slots",
  34         "beacon is too large",
  35         "invalid parameter",
  36         "unsupported power level",
  37         "time out (wa) or invalid ie data (whci)",
  38         "beacon size exceeded",
  39         "cancelled",
  40         "invalid state",
  41         "invalid size",
  42         "ack not received",
  43         "no more asie notification",
  44 };
  45 
  46 
  47 /** Return a string matching the given error code */
  48 const char *uwb_rc_strerror(unsigned code)
  49 {
  50         if (code == 255)
  51                 return "time out";
  52         if (code >= ARRAY_SIZE(__strerror))
  53                 return "unknown error";
  54         return __strerror[code];
  55 }
  56 
  57 int uwb_rc_cmd_async(struct uwb_rc *rc, const char *cmd_name,
  58                      struct uwb_rccb *cmd, size_t cmd_size,
  59                      u8 expected_type, u16 expected_event,
  60                      uwb_rc_cmd_cb_f cb, void *arg)
  61 {
  62         struct device *dev = &rc->uwb_dev.dev;
  63         struct uwb_rc_neh *neh;
  64         int needtofree = 0;
  65         int result;
  66 
  67         uwb_dev_lock(&rc->uwb_dev);     /* Protect against rc->priv being removed */
  68         if (rc->priv == NULL) {
  69                 uwb_dev_unlock(&rc->uwb_dev);
  70                 return -ESHUTDOWN;
  71         }
  72 
  73         if (rc->filter_cmd) {
  74                 needtofree = rc->filter_cmd(rc, &cmd, &cmd_size);
  75                 if (needtofree < 0 && needtofree != -ENOANO) {
  76                         dev_err(dev, "%s: filter error: %d\n",
  77                                 cmd_name, needtofree);
  78                         uwb_dev_unlock(&rc->uwb_dev);
  79                         return needtofree;
  80                 }
  81         }
  82 
  83         neh = uwb_rc_neh_add(rc, cmd, expected_type, expected_event, cb, arg);
  84         if (IS_ERR(neh)) {
  85                 result = PTR_ERR(neh);
  86                 uwb_dev_unlock(&rc->uwb_dev);
  87                 goto out;
  88         }
  89 
  90         result = rc->cmd(rc, cmd, cmd_size);
  91         uwb_dev_unlock(&rc->uwb_dev);
  92         if (result < 0)
  93                 uwb_rc_neh_rm(rc, neh);
  94         else
  95                 uwb_rc_neh_arm(rc, neh);
  96         uwb_rc_neh_put(neh);
  97 out:
  98         if (needtofree == 1)
  99                 kfree(cmd);
 100         return result < 0 ? result : 0;
 101 }
 102 EXPORT_SYMBOL_GPL(uwb_rc_cmd_async);
 103 
 104 struct uwb_rc_cmd_done_params {
 105         struct completion completion;
 106         struct uwb_rceb *reply;
 107         ssize_t reply_size;
 108 };
 109 
 110 static void uwb_rc_cmd_done(struct uwb_rc *rc, void *arg,
 111                             struct uwb_rceb *reply, ssize_t reply_size)
 112 {
 113         struct uwb_rc_cmd_done_params *p = (struct uwb_rc_cmd_done_params *)arg;
 114 
 115         if (reply_size > 0) {
 116                 if (p->reply)
 117                         reply_size = min(p->reply_size, reply_size);
 118                 else
 119                         p->reply = kmalloc(reply_size, GFP_ATOMIC);
 120 
 121                 if (p->reply)
 122                         memcpy(p->reply, reply, reply_size);
 123                 else
 124                         reply_size = -ENOMEM;
 125         }
 126         p->reply_size = reply_size;
 127         complete(&p->completion);
 128 }
 129 
 130 
 131 /**
 132  * Generic function for issuing commands to the Radio Control Interface
 133  *
 134  * @rc:       UWB Radio Control descriptor
 135  * @cmd_name: Name of the command being issued (for error messages)
 136  * @cmd:      Pointer to rccb structure containing the command;
 137  *            normally you embed this structure as the first member of
 138  *            the full command structure.
 139  * @cmd_size: Size of the whole command buffer pointed to by @cmd.
 140  * @reply:    Pointer to where to store the reply
 141  * @reply_size: @reply's size
 142  * @expected_type: Expected type in the return event
 143  * @expected_event: Expected event code in the return event
 144  * @preply:   Here a pointer to where the event data is received will
 145  *            be stored. Once done with the data, free with kfree().
 146  *
 147  * This function is generic; it works for commands that return a fixed
 148  * and known size or for commands that return a variable amount of data.
 149  *
 150  * If a buffer is provided, that is used, although it could be chopped
 151  * to the maximum size of the buffer. If the buffer is NULL, then one
 152  * be allocated in *preply with the whole contents of the reply.
 153  *
 154  * @rc needs to be referenced
 155  */
 156 static
 157 ssize_t __uwb_rc_cmd(struct uwb_rc *rc, const char *cmd_name,
 158                      struct uwb_rccb *cmd, size_t cmd_size,
 159                      struct uwb_rceb *reply, size_t reply_size,
 160                      u8 expected_type, u16 expected_event,
 161                      struct uwb_rceb **preply)
 162 {
 163         ssize_t result = 0;
 164         struct device *dev = &rc->uwb_dev.dev;
 165         struct uwb_rc_cmd_done_params params;
 166 
 167         init_completion(&params.completion);
 168         params.reply = reply;
 169         params.reply_size = reply_size;
 170 
 171         result = uwb_rc_cmd_async(rc, cmd_name, cmd, cmd_size,
 172                                   expected_type, expected_event,
 173                                   uwb_rc_cmd_done, &params);
 174         if (result)
 175                 return result;
 176 
 177         wait_for_completion(&params.completion);
 178 
 179         if (preply)
 180                 *preply = params.reply;
 181 
 182         if (params.reply_size < 0)
 183                 dev_err(dev, "%s: confirmation event 0x%02x/%04x/%02x "
 184                         "reception failed: %d\n", cmd_name,
 185                         expected_type, expected_event, cmd->bCommandContext,
 186                         (int)params.reply_size);
 187         return params.reply_size;
 188 }
 189 
 190 
 191 /**
 192  * Generic function for issuing commands to the Radio Control Interface
 193  *
 194  * @rc:       UWB Radio Control descriptor
 195  * @cmd_name: Name of the command being issued (for error messages)
 196  * @cmd:      Pointer to rccb structure containing the command;
 197  *            normally you embed this structure as the first member of
 198  *            the full command structure.
 199  * @cmd_size: Size of the whole command buffer pointed to by @cmd.
 200  * @reply:    Pointer to the beginning of the confirmation event
 201  *            buffer. Normally bigger than an 'struct hwarc_rceb'.
 202  *            You need to fill out reply->bEventType and reply->wEvent (in
 203  *            cpu order) as the function will use them to verify the
 204  *            confirmation event.
 205  * @reply_size: Size of the reply buffer
 206  *
 207  * The function checks that the length returned in the reply is at
 208  * least as big as @reply_size; if not, it will be deemed an error and
 209  * -EIO returned.
 210  *
 211  * @rc needs to be referenced
 212  */
 213 ssize_t uwb_rc_cmd(struct uwb_rc *rc, const char *cmd_name,
 214                    struct uwb_rccb *cmd, size_t cmd_size,
 215                    struct uwb_rceb *reply, size_t reply_size)
 216 {
 217         struct device *dev = &rc->uwb_dev.dev;
 218         ssize_t result;
 219 
 220         result = __uwb_rc_cmd(rc, cmd_name,
 221                               cmd, cmd_size, reply, reply_size,
 222                               reply->bEventType, reply->wEvent, NULL);
 223 
 224         if (result > 0 && result < reply_size) {
 225                 dev_err(dev, "%s: not enough data returned for decoding reply "
 226                         "(%zu bytes received vs at least %zu needed)\n",
 227                         cmd_name, result, reply_size);
 228                 result = -EIO;
 229         }
 230         return result;
 231 }
 232 EXPORT_SYMBOL_GPL(uwb_rc_cmd);
 233 
 234 
 235 /**
 236  * Generic function for issuing commands to the Radio Control
 237  * Interface that return an unknown amount of data
 238  *
 239  * @rc:       UWB Radio Control descriptor
 240  * @cmd_name: Name of the command being issued (for error messages)
 241  * @cmd:      Pointer to rccb structure containing the command;
 242  *            normally you embed this structure as the first member of
 243  *            the full command structure.
 244  * @cmd_size: Size of the whole command buffer pointed to by @cmd.
 245  * @expected_type: Expected type in the return event
 246  * @expected_event: Expected event code in the return event
 247  * @preply:   Here a pointer to where the event data is received will
 248  *            be stored. Once done with the data, free with kfree().
 249  *
 250  * The function checks that the length returned in the reply is at
 251  * least as big as a 'struct uwb_rceb *'; if not, it will be deemed an
 252  * error and -EIO returned.
 253  *
 254  * @rc needs to be referenced
 255  */
 256 ssize_t uwb_rc_vcmd(struct uwb_rc *rc, const char *cmd_name,
 257                     struct uwb_rccb *cmd, size_t cmd_size,
 258                     u8 expected_type, u16 expected_event,
 259                     struct uwb_rceb **preply)
 260 {
 261         return __uwb_rc_cmd(rc, cmd_name, cmd, cmd_size, NULL, 0,
 262                             expected_type, expected_event, preply);
 263 }
 264 EXPORT_SYMBOL_GPL(uwb_rc_vcmd);
 265 
 266 
 267 /**
 268  * Reset a UWB Host Controller (and all radio settings)
 269  *
 270  * @rc:      Host Controller descriptor
 271  * @returns: 0 if ok, < 0 errno code on error
 272  *
 273  * We put the command on kmalloc'ed memory as some arches cannot do
 274  * USB from the stack. The reply event is copied from an stage buffer,
 275  * so it can be in the stack. See WUSB1.0[8.6.2.4] for more details.
 276  */
 277 int uwb_rc_reset(struct uwb_rc *rc)
 278 {
 279         int result = -ENOMEM;
 280         struct uwb_rc_evt_confirm reply;
 281         struct uwb_rccb *cmd;
 282         size_t cmd_size = sizeof(*cmd);
 283 
 284         mutex_lock(&rc->uwb_dev.mutex);
 285         cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
 286         if (cmd == NULL)
 287                 goto error_kzalloc;
 288         cmd->bCommandType = UWB_RC_CET_GENERAL;
 289         cmd->wCommand = cpu_to_le16(UWB_RC_CMD_RESET);
 290         reply.rceb.bEventType = UWB_RC_CET_GENERAL;
 291         reply.rceb.wEvent = UWB_RC_CMD_RESET;
 292         result = uwb_rc_cmd(rc, "RESET", cmd, cmd_size,
 293                             &reply.rceb, sizeof(reply));
 294         if (result < 0)
 295                 goto error_cmd;
 296         if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
 297                 dev_err(&rc->uwb_dev.dev,
 298                         "RESET: command execution failed: %s (%d)\n",
 299                         uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
 300                 result = -EIO;
 301         }
 302 error_cmd:
 303         kfree(cmd);
 304 error_kzalloc:
 305         mutex_unlock(&rc->uwb_dev.mutex);
 306         return result;
 307 }
 308 
 309 int uwbd_msg_handle_reset(struct uwb_event *evt)
 310 {
 311         struct uwb_rc *rc = evt->rc;
 312         int ret;
 313 
 314         dev_info(&rc->uwb_dev.dev, "resetting radio controller\n");
 315         ret = rc->reset(rc);
 316         if (ret < 0) {
 317                 dev_err(&rc->uwb_dev.dev, "failed to reset hardware: %d\n", ret);
 318                 goto error;
 319         }
 320         return 0;
 321 error:
 322         /* Nothing can be done except try the reset again. Wait a bit
 323            to avoid reset loops during probe() or remove(). */
 324         msleep(1000);
 325         uwb_rc_reset_all(rc);
 326         return ret;
 327 }
 328 
 329 /**
 330  * uwb_rc_reset_all - request a reset of the radio controller and PALs
 331  * @rc: the radio controller of the hardware device to be reset.
 332  *
 333  * The full hardware reset of the radio controller and all the PALs
 334  * will be scheduled.
 335  */
 336 void uwb_rc_reset_all(struct uwb_rc *rc)
 337 {
 338         struct uwb_event *evt;
 339 
 340         evt = kzalloc(sizeof(struct uwb_event), GFP_ATOMIC);
 341         if (unlikely(evt == NULL))
 342                 return;
 343 
 344         evt->rc = __uwb_rc_get(rc);     /* will be put by uwbd's uwbd_event_handle() */
 345         evt->ts_jiffies = jiffies;
 346         evt->type = UWB_EVT_TYPE_MSG;
 347         evt->message = UWB_EVT_MSG_RESET;
 348 
 349         uwbd_event_queue(evt);
 350 }
 351 EXPORT_SYMBOL_GPL(uwb_rc_reset_all);
 352 
 353 void uwb_rc_pre_reset(struct uwb_rc *rc)
 354 {
 355         rc->stop(rc);
 356         uwbd_flush(rc);
 357 
 358         uwb_radio_reset_state(rc);
 359         uwb_rsv_remove_all(rc);
 360 }
 361 EXPORT_SYMBOL_GPL(uwb_rc_pre_reset);
 362 
 363 int uwb_rc_post_reset(struct uwb_rc *rc)
 364 {
 365         int ret;
 366 
 367         ret = rc->start(rc);
 368         if (ret)
 369                 goto out;
 370         ret = uwb_rc_mac_addr_set(rc, &rc->uwb_dev.mac_addr);
 371         if (ret)
 372                 goto out;
 373         ret = uwb_rc_dev_addr_set(rc, &rc->uwb_dev.dev_addr);
 374         if (ret)
 375                 goto out;
 376 out:
 377         return ret;
 378 }
 379 EXPORT_SYMBOL_GPL(uwb_rc_post_reset);