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