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