drivers/usb/wusbcore/mmc.c

   1 /*
   2  * WUSB Wire Adapter: Control/Data Streaming Interface (WUSB[8])
   3  * MMC (Microscheduled Management Command) handling
   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  * WUIEs and MMC IEs...well, they are almost the same at the end. MMC
  24  * IEs are Wireless USB IEs that go into the MMC period...[what is
  25  * that? look in Design-overview.txt].
  26  *
  27  *
  28  * This is a simple subsystem to keep track of which IEs are being
  29  * sent by the host in the MMC period.
  30  *
  31  * For each WUIE we ask to send, we keep it in an array, so we can
  32  * request its removal later, or replace the content. They are tracked
  33  * by pointer, so be sure to use the same pointer if you want to
  34  * remove it or update the contents.
  35  *
  36  * FIXME:
  37  *  - add timers that autoremove intervalled IEs?
  38  */
  39 #include <linux/usb/wusb.h>
  40 #include <linux/slab.h>
  41 #include "wusbhc.h"
  42
  43 /* Initialize the MMCIEs handling mechanism */
  44 int wusbhc_mmcie_create(struct wusbhc *wusbhc)
  45 {
  46         u8 mmcies = wusbhc->mmcies_max;
  47         wusbhc->mmcie = kcalloc(mmcies, sizeof(wusbhc->mmcie[0]), GFP_KERNEL);
  48         if (wusbhc->mmcie == NULL)
  49                 return -ENOMEM;
  50         mutex_init(&wusbhc->mmcie_mutex);
  51         return 0;
  52 }
  53
  54 /* Release resources used by the MMCIEs handling mechanism */
  55 void wusbhc_mmcie_destroy(struct wusbhc *wusbhc)
  56 {
  57         kfree(wusbhc->mmcie);
  58 }
  59
  60 /*
  61  * Add or replace an MMC Wireless USB IE.
  62  *
  63  * @interval:    See WUSB1.0[8.5.3.1]
  64  * @repeat_cnt:  See WUSB1.0[8.5.3.1]
  65  * @handle:      See WUSB1.0[8.5.3.1]
  66  * @wuie:        Pointer to the header of the WUSB IE data to add.
  67  *               MUST BE allocated in a kmalloc buffer (no stack or
  68  *               vmalloc).
  69  *               THE CALLER ALWAYS OWNS THE POINTER (we don't free it
  70  *               on remove, we just forget about it).
  71  * @returns:     0 if ok, < 0 errno code on error.
  72  *
  73  * Goes over the *whole* @wusbhc->mmcie array looking for (a) the
  74  * first free spot and (b) if @wuie is already in the array (aka:
  75  * transmitted in the MMCs) the spot were it is.
  76  *
  77  * If present, we "overwrite it" (update).
  78  *
  79  *
  80  * NOTE: Need special ordering rules -- see below WUSB1.0 Table 7-38.
  81  *       The host uses the handle as the 'sort' index. We
  82  *       allocate the last one always for the WUIE_ID_HOST_INFO, and
  83  *       the rest, first come first serve in inverse order.
  84  *
  85  *       Host software must make sure that it adds the other IEs in
  86  *       the right order... the host hardware is responsible for
  87  *       placing the WCTA IEs in the right place with the other IEs
  88  *       set by host software.
  89  *
  90  * NOTE: we can access wusbhc->wa_descr without locking because it is
  91  *       read only.
  92  */
  93 int wusbhc_mmcie_set(struct wusbhc *wusbhc, u8 interval, u8 repeat_cnt,
  94                      struct wuie_hdr *wuie)
  95 {
  96         int result = -ENOBUFS;
  97         unsigned handle, itr;
  98
  99         /* Search a handle, taking into account the ordering */
 100         mutex_lock(&wusbhc->mmcie_mutex);
 101         switch (wuie->bIEIdentifier) {
 102         case WUIE_ID_HOST_INFO:
 103                 /* Always last */
 104                 handle = wusbhc->mmcies_max - 1;
 105                 break;
 106         case WUIE_ID_ISOCH_DISCARD:
 107                 dev_err(wusbhc->dev, "Special ordering case for WUIE ID 0x%x "
 108                         "unimplemented\n", wuie->bIEIdentifier);
 109                 result = -ENOSYS;
 110                 goto error_unlock;
 111         default:
 112                 /* search for it or find the last empty slot */
 113                 handle = ~0;
 114                 for (itr = 0; itr < wusbhc->mmcies_max - 1; itr++) {
 115                         if (wusbhc->mmcie[itr] == wuie) {
 116                                 handle = itr;
 117                                 break;
 118                         }
 119                         if (wusbhc->mmcie[itr] == NULL)
 120                                 handle = itr;
 121                 }
 122                 if (handle == ~0)
 123                         goto error_unlock;
 124         }
 125         result = (wusbhc->mmcie_add)(wusbhc, interval, repeat_cnt, handle,
 126                                      wuie);
 127         if (result >= 0)
 128                 wusbhc->mmcie[handle] = wuie;
 129 error_unlock:
 130         mutex_unlock(&wusbhc->mmcie_mutex);
 131         return result;
 132 }
 133 EXPORT_SYMBOL_GPL(wusbhc_mmcie_set);
 134
 135 /*
 136  * Remove an MMC IE previously added with wusbhc_mmcie_set()
 137  *
 138  * @wuie        Pointer used to add the WUIE
 139  */
 140 void wusbhc_mmcie_rm(struct wusbhc *wusbhc, struct wuie_hdr *wuie)
 141 {
 142         int result;
 143         unsigned handle, itr;
 144
 145         mutex_lock(&wusbhc->mmcie_mutex);
 146         for (itr = 0; itr < wusbhc->mmcies_max; itr++) {
 147                 if (wusbhc->mmcie[itr] == wuie) {
 148                         handle = itr;
 149                         goto found;
 150                 }
 151         }
 152         mutex_unlock(&wusbhc->mmcie_mutex);
 153         return;
 154
 155 found:
 156         result = (wusbhc->mmcie_rm)(wusbhc, handle);
 157         if (result == 0)
 158                 wusbhc->mmcie[itr] = NULL;
 159         mutex_unlock(&wusbhc->mmcie_mutex);
 160 }
 161 EXPORT_SYMBOL_GPL(wusbhc_mmcie_rm);
 162
 163 static int wusbhc_mmc_start(struct wusbhc *wusbhc)
 164 {
 165         int ret;
 166
 167         mutex_lock(&wusbhc->mutex);
 168         ret = wusbhc->start(wusbhc);
 169         if (ret >= 0)
 170                 wusbhc->active = 1;
 171         mutex_unlock(&wusbhc->mutex);
 172
 173         return ret;
 174 }
 175
 176 static void wusbhc_mmc_stop(struct wusbhc *wusbhc)
 177 {
 178         mutex_lock(&wusbhc->mutex);
 179         wusbhc->active = 0;
 180         wusbhc->stop(wusbhc, WUSB_CHANNEL_STOP_DELAY_MS);
 181         mutex_unlock(&wusbhc->mutex);
 182 }
 183
 184 /*
 185  * wusbhc_start - start transmitting MMCs and accepting connections
 186  * @wusbhc: the HC to start
 187  *
 188  * Establishes a cluster reservation, enables device connections, and
 189  * starts MMCs with appropriate DNTS parameters.
 190  */
 191 int wusbhc_start(struct wusbhc *wusbhc)
 192 {
 193         int result;
 194         struct device *dev = wusbhc->dev;
 195
 196         WARN_ON(wusbhc->wuie_host_info != NULL);
 197
 198         result = wusbhc_rsv_establish(wusbhc);
 199         if (result < 0) {
 200                 dev_err(dev, "cannot establish cluster reservation: %d\n",
 201                         result);
 202                 goto error_rsv_establish;
 203         }
 204
 205         result = wusbhc_devconnect_start(wusbhc);
 206         if (result < 0) {
 207                 dev_err(dev, "error enabling device connections: %d\n", result);
 208                 goto error_devconnect_start;
 209         }
 210
 211         result = wusbhc_sec_start(wusbhc);
 212         if (result < 0) {
 213                 dev_err(dev, "error starting security in the HC: %d\n", result);
 214                 goto error_sec_start;
 215         }
 216         /* FIXME: the choice of the DNTS parameters is somewhat
 217          * arbitrary */
 218         result = wusbhc->set_num_dnts(wusbhc, 0, 15);
 219         if (result < 0) {
 220                 dev_err(dev, "Cannot set DNTS parameters: %d\n", result);
 221                 goto error_set_num_dnts;
 222         }
 223         result = wusbhc_mmc_start(wusbhc);
 224         if (result < 0) {
 225                 dev_err(dev, "error starting wusbch: %d\n", result);
 226                 goto error_wusbhc_start;
 227         }
 228
 229         return 0;
 230
 231 error_wusbhc_start:
 232         wusbhc_sec_stop(wusbhc);
 233 error_set_num_dnts:
 234 error_sec_start:
 235         wusbhc_devconnect_stop(wusbhc);
 236 error_devconnect_start:
 237         wusbhc_rsv_terminate(wusbhc);
 238 error_rsv_establish:
 239         return result;
 240 }
 241
 242 /*
 243  * wusbhc_stop - stop transmitting MMCs
 244  * @wusbhc: the HC to stop
 245  *
 246  * Stops the WUSB channel and removes the cluster reservation.
 247  */
 248 void wusbhc_stop(struct wusbhc *wusbhc)
 249 {
 250         wusbhc_mmc_stop(wusbhc);
 251         wusbhc_sec_stop(wusbhc);
 252         wusbhc_devconnect_stop(wusbhc);
 253         wusbhc_rsv_terminate(wusbhc);
 254 }
 255
 256 /*
 257  * Set/reset/update a new CHID
 258  *
 259  * Depending on the previous state of the MMCs, start, stop or change
 260  * the sent MMC. This effectively switches the host controller on and
 261  * off (radio wise).
 262  */
 263 int wusbhc_chid_set(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid)
 264 {
 265         int result = 0;
 266
 267         if (memcmp(chid, &wusb_ckhdid_zero, sizeof(*chid)) == 0)
 268                 chid = NULL;
 269
 270         mutex_lock(&wusbhc->mutex);
 271         if (chid) {
 272                 if (wusbhc->active) {
 273                         mutex_unlock(&wusbhc->mutex);
 274                         return -EBUSY;
 275                 }
 276                 wusbhc->chid = *chid;
 277         }
 278         mutex_unlock(&wusbhc->mutex);
 279
 280         if (chid)
 281                 result = uwb_radio_start(&wusbhc->pal);
 282         else
 283                 uwb_radio_stop(&wusbhc->pal);
 284         return result;
 285 }
 286 EXPORT_SYMBOL_GPL(wusbhc_chid_set);