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