drivers/usb/host/whci/pzl.c

   1 /*
   2  * Wireless Host Controller (WHC) periodic schedule management.
   3  *
   4  * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License version
   8  * 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 #include <linux/kernel.h>
  19 #include <linux/gfp.h>
  20 #include <linux/dma-mapping.h>
  21 #include <linux/uwb/umc.h>
  22 #include <linux/usb.h>
  23
  24 #include "../../wusbcore/wusbhc.h"
  25
  26 #include "whcd.h"
  27
  28 static void update_pzl_pointers(struct whc *whc, int period, u64 addr)
  29 {
  30         switch (period) {
  31         case 0:
  32                 whc_qset_set_link_ptr(&whc->pz_list[0], addr);
  33                 whc_qset_set_link_ptr(&whc->pz_list[2], addr);
  34                 whc_qset_set_link_ptr(&whc->pz_list[4], addr);
  35                 whc_qset_set_link_ptr(&whc->pz_list[6], addr);
  36                 whc_qset_set_link_ptr(&whc->pz_list[8], addr);
  37                 whc_qset_set_link_ptr(&whc->pz_list[10], addr);
  38                 whc_qset_set_link_ptr(&whc->pz_list[12], addr);
  39                 whc_qset_set_link_ptr(&whc->pz_list[14], addr);
  40                 break;
  41         case 1:
  42                 whc_qset_set_link_ptr(&whc->pz_list[1], addr);
  43                 whc_qset_set_link_ptr(&whc->pz_list[5], addr);
  44                 whc_qset_set_link_ptr(&whc->pz_list[9], addr);
  45                 whc_qset_set_link_ptr(&whc->pz_list[13], addr);
  46                 break;
  47         case 2:
  48                 whc_qset_set_link_ptr(&whc->pz_list[3], addr);
  49                 whc_qset_set_link_ptr(&whc->pz_list[11], addr);
  50                 break;
  51         case 3:
  52                 whc_qset_set_link_ptr(&whc->pz_list[7], addr);
  53                 break;
  54         case 4:
  55                 whc_qset_set_link_ptr(&whc->pz_list[15], addr);
  56                 break;
  57         }
  58 }
  59
  60 /*
  61  * Return the 'period' to use for this qset.  The minimum interval for
  62  * the endpoint is used so whatever urbs are submitted the device is
  63  * polled often enough.
  64  */
  65 static int qset_get_period(struct whc *whc, struct whc_qset *qset)
  66 {
  67         uint8_t bInterval = qset->ep->desc.bInterval;
  68
  69         if (bInterval < 6)
  70                 bInterval = 6;
  71         if (bInterval > 10)
  72                 bInterval = 10;
  73         return bInterval - 6;
  74 }
  75
  76 static void qset_insert_in_sw_list(struct whc *whc, struct whc_qset *qset)
  77 {
  78         int period;
  79
  80         period = qset_get_period(whc, qset);
  81
  82         qset_clear(whc, qset);
  83         list_move(&qset->list_node, &whc->periodic_list[period]);
  84         qset->in_sw_list = true;
  85 }
  86
  87 static void pzl_qset_remove(struct whc *whc, struct whc_qset *qset)
  88 {
  89         list_move(&qset->list_node, &whc->periodic_removed_list);
  90         qset->in_hw_list = false;
  91         qset->in_sw_list = false;
  92 }
  93
  94 /**
  95  * pzl_process_qset - process any recently inactivated or halted qTDs
  96  * in a qset.
  97  *
  98  * After inactive qTDs are removed, new qTDs can be added if the
  99  * urb queue still contains URBs.
 100  *
 101  * Returns the schedule updates required.
 102  */
 103 static enum whc_update pzl_process_qset(struct whc *whc, struct whc_qset *qset)
 104 {
 105         enum whc_update update = 0;
 106         uint32_t status = 0;
 107
 108         while (qset->ntds) {
 109                 struct whc_qtd *td;
 110                 int t;
 111
 112                 t = qset->td_start;
 113                 td = &qset->qtd[qset->td_start];
 114                 status = le32_to_cpu(td->status);
 115
 116                 /*
 117                  * Nothing to do with a still active qTD.
 118                  */
 119                 if (status & QTD_STS_ACTIVE)
 120                         break;
 121
 122                 if (status & QTD_STS_HALTED) {
 123                         /* Ug, an error. */
 124                         process_halted_qtd(whc, qset, td);
 125                         /* A halted qTD always triggers an update
 126                            because the qset was either removed or
 127                            reactivated. */
 128                         update |= WHC_UPDATE_UPDATED;
 129                         goto done;
 130                 }
 131
 132                 /* Mmm, a completed qTD. */
 133                 process_inactive_qtd(whc, qset, td);
 134         }
 135
 136         if (!qset->remove)
 137                 update |= qset_add_qtds(whc, qset);
 138
 139 done:
 140         /*
 141          * If there are no qTDs in this qset, remove it from the PZL.
 142          */
 143         if (qset->remove && qset->ntds == 0) {
 144                 pzl_qset_remove(whc, qset);
 145                 update |= WHC_UPDATE_REMOVED;
 146         }
 147
 148         return update;
 149 }
 150
 151 /**
 152  * pzl_start - start the periodic schedule
 153  * @whc: the WHCI host controller
 154  *
 155  * The PZL must be valid (e.g., all entries in the list should have
 156  * the T bit set).
 157  */
 158 void pzl_start(struct whc *whc)
 159 {
 160         le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
 161
 162         whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, WUSBCMD_PERIODIC_EN);
 163         whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
 164                       WUSBSTS_PERIODIC_SCHED, WUSBSTS_PERIODIC_SCHED,
 165                       1000, "start PZL");
 166 }
 167
 168 /**
 169  * pzl_stop - stop the periodic schedule
 170  * @whc: the WHCI host controller
 171  */
 172 void pzl_stop(struct whc *whc)
 173 {
 174         whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, 0);
 175         whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
 176                       WUSBSTS_PERIODIC_SCHED, 0,
 177                       1000, "stop PZL");
 178 }
 179
 180 /**
 181  * pzl_update - request a PZL update and wait for the hardware to be synced
 182  * @whc: the WHCI HC
 183  * @wusbcmd: WUSBCMD value to start the update.
 184  *
 185  * If the WUSB HC is inactive (i.e., the PZL is stopped) then the
 186  * update must be skipped as the hardware may not respond to update
 187  * requests.
 188  */
 189 void pzl_update(struct whc *whc, uint32_t wusbcmd)
 190 {
 191         struct wusbhc *wusbhc = &whc->wusbhc;
 192         long t;
 193
 194         mutex_lock(&wusbhc->mutex);
 195         if (wusbhc->active) {
 196                 whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
 197                 t = wait_event_timeout(
 198                         whc->periodic_list_wq,
 199                         (le_readl(whc->base + WUSBCMD) & WUSBCMD_PERIODIC_UPDATED) == 0,
 200                         msecs_to_jiffies(1000));
 201                 if (t == 0)
 202                         whc_hw_error(whc, "PZL update timeout");
 203         }
 204         mutex_unlock(&wusbhc->mutex);
 205 }
 206
 207 static void update_pzl_hw_view(struct whc *whc)
 208 {
 209         struct whc_qset *qset, *t;
 210         int period;
 211         u64 tmp_qh = 0;
 212
 213         for (period = 0; period < 5; period++) {
 214                 list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
 215                         whc_qset_set_link_ptr(&qset->qh.link, tmp_qh);
 216                         tmp_qh = qset->qset_dma;
 217                         qset->in_hw_list = true;
 218                 }
 219                 update_pzl_pointers(whc, period, tmp_qh);
 220         }
 221 }
 222
 223 /**
 224  * scan_periodic_work - scan the PZL for qsets to process.
 225  *
 226  * Process each qset in the PZL in turn and then signal the WHC that
 227  * the PZL has been updated.
 228  *
 229  * Then start, stop or update the periodic schedule as required.
 230  */
 231 void scan_periodic_work(struct work_struct *work)
 232 {
 233         struct whc *whc = container_of(work, struct whc, periodic_work);
 234         struct whc_qset *qset, *t;
 235         enum whc_update update = 0;
 236         int period;
 237
 238         spin_lock_irq(&whc->lock);
 239
 240         for (period = 4; period >= 0; period--) {
 241                 list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
 242                         if (!qset->in_hw_list)
 243                                 update |= WHC_UPDATE_ADDED;
 244                         update |= pzl_process_qset(whc, qset);
 245                 }
 246         }
 247
 248         if (update & (WHC_UPDATE_ADDED | WHC_UPDATE_REMOVED))
 249                 update_pzl_hw_view(whc);
 250
 251         spin_unlock_irq(&whc->lock);
 252
 253         if (update) {
 254                 uint32_t wusbcmd = WUSBCMD_PERIODIC_UPDATED | WUSBCMD_PERIODIC_SYNCED_DB;
 255                 if (update & WHC_UPDATE_REMOVED)
 256                         wusbcmd |= WUSBCMD_PERIODIC_QSET_RM;
 257                 pzl_update(whc, wusbcmd);
 258         }
 259
 260         /*
 261          * Now that the PZL is updated, complete the removal of any
 262          * removed qsets.
 263          *
 264          * If the qset was to be reset, do so and reinsert it into the
 265          * PZL if it has pending transfers.
 266          */
 267         spin_lock_irq(&whc->lock);
 268
 269         list_for_each_entry_safe(qset, t, &whc->periodic_removed_list, list_node) {
 270                 qset_remove_complete(whc, qset);
 271                 if (qset->reset) {
 272                         qset_reset(whc, qset);
 273                         if (!list_empty(&qset->stds)) {
 274                                 qset_insert_in_sw_list(whc, qset);
 275                                 queue_work(whc->workqueue, &whc->periodic_work);
 276                         }
 277                 }
 278         }
 279
 280         spin_unlock_irq(&whc->lock);
 281 }
 282
 283 /**
 284  * pzl_urb_enqueue - queue an URB onto the periodic list (PZL)
 285  * @whc: the WHCI host controller
 286  * @urb: the URB to enqueue
 287  * @mem_flags: flags for any memory allocations
 288  *
 289  * The qset for the endpoint is obtained and the urb queued on to it.
 290  *
 291  * Work is scheduled to update the hardware's view of the PZL.
 292  */
 293 int pzl_urb_enqueue(struct whc *whc, struct urb *urb, gfp_t mem_flags)
 294 {
 295         struct whc_qset *qset;
 296         int err;
 297         unsigned long flags;
 298
 299         spin_lock_irqsave(&whc->lock, flags);
 300
 301         err = usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
 302         if (err < 0) {
 303                 spin_unlock_irqrestore(&whc->lock, flags);
 304                 return err;
 305         }
 306
 307         qset = get_qset(whc, urb, GFP_ATOMIC);
 308         if (qset == NULL)
 309                 err = -ENOMEM;
 310         else
 311                 err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
 312         if (!err) {
 313                 if (!qset->in_sw_list && !qset->remove)
 314                         qset_insert_in_sw_list(whc, qset);
 315         } else
 316                 usb_hcd_unlink_urb_from_ep(&whc->wusbhc.usb_hcd, urb);
 317
 318         spin_unlock_irqrestore(&whc->lock, flags);
 319
 320         if (!err)
 321                 queue_work(whc->workqueue, &whc->periodic_work);
 322
 323         return err;
 324 }
 325
 326 /**
 327  * pzl_urb_dequeue - remove an URB (qset) from the periodic list
 328  * @whc: the WHCI host controller
 329  * @urb: the URB to dequeue
 330  * @status: the current status of the URB
 331  *
 332  * URBs that do yet have qTDs can simply be removed from the software
 333  * queue, otherwise the qset must be removed so the qTDs can be safely
 334  * removed.
 335  */
 336 int pzl_urb_dequeue(struct whc *whc, struct urb *urb, int status)
 337 {
 338         struct whc_urb *wurb = urb->hcpriv;
 339         struct whc_qset *qset = wurb->qset;
 340         struct whc_std *std, *t;
 341         bool has_qtd = false;
 342         int ret;
 343         unsigned long flags;
 344
 345         spin_lock_irqsave(&whc->lock, flags);
 346
 347         ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
 348         if (ret < 0)
 349                 goto out;
 350
 351         list_for_each_entry_safe(std, t, &qset->stds, list_node) {
 352                 if (std->urb == urb) {
 353                         if (std->qtd)
 354                                 has_qtd = true;
 355                         qset_free_std(whc, std);
 356                 } else
 357                         std->qtd = NULL; /* so this std is re-added when the qset is */
 358         }
 359
 360         if (has_qtd) {
 361                 pzl_qset_remove(whc, qset);
 362                 update_pzl_hw_view(whc);
 363                 wurb->status = status;
 364                 wurb->is_async = false;
 365                 queue_work(whc->workqueue, &wurb->dequeue_work);
 366         } else
 367                 qset_remove_urb(whc, qset, urb, status);
 368 out:
 369         spin_unlock_irqrestore(&whc->lock, flags);
 370
 371         return ret;
 372 }
 373
 374 /**
 375  * pzl_qset_delete - delete a qset from the PZL
 376  */
 377 void pzl_qset_delete(struct whc *whc, struct whc_qset *qset)
 378 {
 379         qset->remove = 1;
 380         queue_work(whc->workqueue, &whc->periodic_work);
 381         qset_delete(whc, qset);
 382 }
 383
 384 /**
 385  * pzl_init - initialize the periodic zone list
 386  * @whc: the WHCI host controller
 387  */
 388 int pzl_init(struct whc *whc)
 389 {
 390         int i;
 391
 392         whc->pz_list = dma_alloc_coherent(&whc->umc->dev, sizeof(u64) * 16,
 393                                           &whc->pz_list_dma, GFP_KERNEL);
 394         if (whc->pz_list == NULL)
 395                 return -ENOMEM;
 396
 397         /* Set T bit on all elements in PZL. */
 398         for (i = 0; i < 16; i++)
 399                 whc->pz_list[i] = cpu_to_le64(QH_LINK_NTDS(8) | QH_LINK_T);
 400
 401         le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
 402
 403         return 0;
 404 }
 405
 406 /**
 407  * pzl_clean_up - free PZL resources
 408  * @whc: the WHCI host controller
 409  *
 410  * The PZL is stopped and empty.
 411  */
 412 void pzl_clean_up(struct whc *whc)
 413 {
 414         if (whc->pz_list)
 415                 dma_free_coherent(&whc->umc->dev,  sizeof(u64) * 16, whc->pz_list,
 416                                   whc->pz_list_dma);
 417 }