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                         goto done;
 125                 }
 126
 127                 /* Mmm, a completed qTD. */
 128                 process_inactive_qtd(whc, qset, td);
 129         }
 130
 131         if (!qset->remove)
 132                 update |= qset_add_qtds(whc, qset);
 133
 134 done:
 135         /*
 136          * If there are no qTDs in this qset, remove it from the PZL.
 137          */
 138         if (qset->remove && qset->ntds == 0) {
 139                 pzl_qset_remove(whc, qset);
 140                 update |= WHC_UPDATE_REMOVED;
 141         }
 142
 143         return update;
 144 }
 145
 146 /**
 147  * pzl_start - start the periodic schedule
 148  * @whc: the WHCI host controller
 149  *
 150  * The PZL must be valid (e.g., all entries in the list should have
 151  * the T bit set).
 152  */
 153 void pzl_start(struct whc *whc)
 154 {
 155         le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
 156
 157         whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, WUSBCMD_PERIODIC_EN);
 158         whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
 159                       WUSBSTS_PERIODIC_SCHED, WUSBSTS_PERIODIC_SCHED,
 160                       1000, "start PZL");
 161 }
 162
 163 /**
 164  * pzl_stop - stop the periodic schedule
 165  * @whc: the WHCI host controller
 166  */
 167 void pzl_stop(struct whc *whc)
 168 {
 169         whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, 0);
 170         whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
 171                       WUSBSTS_PERIODIC_SCHED, 0,
 172                       1000, "stop PZL");
 173 }
 174
 175 /**
 176  * pzl_update - request a PZL update and wait for the hardware to be synced
 177  * @whc: the WHCI HC
 178  * @wusbcmd: WUSBCMD value to start the update.
 179  *
 180  * If the WUSB HC is inactive (i.e., the PZL is stopped) then the
 181  * update must be skipped as the hardware may not respond to update
 182  * requests.
 183  */
 184 void pzl_update(struct whc *whc, uint32_t wusbcmd)
 185 {
 186         struct wusbhc *wusbhc = &whc->wusbhc;
 187         long t;
 188
 189         mutex_lock(&wusbhc->mutex);
 190         if (wusbhc->active) {
 191                 whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
 192                 t = wait_event_timeout(
 193                         whc->periodic_list_wq,
 194                         (le_readl(whc->base + WUSBCMD) & WUSBCMD_PERIODIC_UPDATED) == 0,
 195                         msecs_to_jiffies(1000));
 196                 if (t == 0)
 197                         whc_hw_error(whc, "PZL update timeout");
 198         }
 199         mutex_unlock(&wusbhc->mutex);
 200 }
 201
 202 static void update_pzl_hw_view(struct whc *whc)
 203 {
 204         struct whc_qset *qset, *t;
 205         int period;
 206         u64 tmp_qh = 0;
 207
 208         for (period = 0; period < 5; period++) {
 209                 list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
 210                         whc_qset_set_link_ptr(&qset->qh.link, tmp_qh);
 211                         tmp_qh = qset->qset_dma;
 212                         qset->in_hw_list = true;
 213                 }
 214                 update_pzl_pointers(whc, period, tmp_qh);
 215         }
 216 }
 217
 218 /**
 219  * scan_periodic_work - scan the PZL for qsets to process.
 220  *
 221  * Process each qset in the PZL in turn and then signal the WHC that
 222  * the PZL has been updated.
 223  *
 224  * Then start, stop or update the periodic schedule as required.
 225  */
 226 void scan_periodic_work(struct work_struct *work)
 227 {
 228         struct whc *whc = container_of(work, struct whc, periodic_work);
 229         struct whc_qset *qset, *t;
 230         enum whc_update update = 0;
 231         int period;
 232
 233         spin_lock_irq(&whc->lock);
 234
 235         for (period = 4; period >= 0; period--) {
 236                 list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
 237                         if (!qset->in_hw_list)
 238                                 update |= WHC_UPDATE_ADDED;
 239                         update |= pzl_process_qset(whc, qset);
 240                 }
 241         }
 242
 243         if (update & (WHC_UPDATE_ADDED | WHC_UPDATE_REMOVED))
 244                 update_pzl_hw_view(whc);
 245
 246         spin_unlock_irq(&whc->lock);
 247
 248         if (update) {
 249                 uint32_t wusbcmd = WUSBCMD_PERIODIC_UPDATED | WUSBCMD_PERIODIC_SYNCED_DB;
 250                 if (update & WHC_UPDATE_REMOVED)
 251                         wusbcmd |= WUSBCMD_PERIODIC_QSET_RM;
 252                 pzl_update(whc, wusbcmd);
 253         }
 254
 255         /*
 256          * Now that the PZL is updated, complete the removal of any
 257          * removed qsets.
 258          *
 259          * If the qset was to be reset, do so and reinsert it into the
 260          * PZL if it has pending transfers.
 261          */
 262         spin_lock_irq(&whc->lock);
 263
 264         list_for_each_entry_safe(qset, t, &whc->periodic_removed_list, list_node) {
 265                 qset_remove_complete(whc, qset);
 266                 if (qset->reset) {
 267                         qset_reset(whc, qset);
 268                         if (!list_empty(&qset->stds)) {
 269                                 qset_insert_in_sw_list(whc, qset);
 270                                 queue_work(whc->workqueue, &whc->periodic_work);
 271                         }
 272                 }
 273         }
 274
 275         spin_unlock_irq(&whc->lock);
 276 }
 277
 278 /**
 279  * pzl_urb_enqueue - queue an URB onto the periodic list (PZL)
 280  * @whc: the WHCI host controller
 281  * @urb: the URB to enqueue
 282  * @mem_flags: flags for any memory allocations
 283  *
 284  * The qset for the endpoint is obtained and the urb queued on to it.
 285  *
 286  * Work is scheduled to update the hardware's view of the PZL.
 287  */
 288 int pzl_urb_enqueue(struct whc *whc, struct urb *urb, gfp_t mem_flags)
 289 {
 290         struct whc_qset *qset;
 291         int err;
 292         unsigned long flags;
 293
 294         spin_lock_irqsave(&whc->lock, flags);
 295
 296         err = usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
 297         if (err < 0) {
 298                 spin_unlock_irqrestore(&whc->lock, flags);
 299                 return err;
 300         }
 301
 302         qset = get_qset(whc, urb, GFP_ATOMIC);
 303         if (qset == NULL)
 304                 err = -ENOMEM;
 305         else
 306                 err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
 307         if (!err) {
 308                 if (!qset->in_sw_list && !qset->remove)
 309                         qset_insert_in_sw_list(whc, qset);
 310         } else
 311                 usb_hcd_unlink_urb_from_ep(&whc->wusbhc.usb_hcd, urb);
 312
 313         spin_unlock_irqrestore(&whc->lock, flags);
 314
 315         if (!err)
 316                 queue_work(whc->workqueue, &whc->periodic_work);
 317
 318         return err;
 319 }
 320
 321 /**
 322  * pzl_urb_dequeue - remove an URB (qset) from the periodic list
 323  * @whc: the WHCI host controller
 324  * @urb: the URB to dequeue
 325  * @status: the current status of the URB
 326  *
 327  * URBs that do yet have qTDs can simply be removed from the software
 328  * queue, otherwise the qset must be removed so the qTDs can be safely
 329  * removed.
 330  */
 331 int pzl_urb_dequeue(struct whc *whc, struct urb *urb, int status)
 332 {
 333         struct whc_urb *wurb = urb->hcpriv;
 334         struct whc_qset *qset = wurb->qset;
 335         struct whc_std *std, *t;
 336         bool has_qtd = false;
 337         int ret;
 338         unsigned long flags;
 339
 340         spin_lock_irqsave(&whc->lock, flags);
 341
 342         ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
 343         if (ret < 0)
 344                 goto out;
 345
 346         list_for_each_entry_safe(std, t, &qset->stds, list_node) {
 347                 if (std->urb == urb) {
 348                         if (std->qtd)
 349                                 has_qtd = true;
 350                         qset_free_std(whc, std);
 351                 } else
 352                         std->qtd = NULL; /* so this std is re-added when the qset is */
 353         }
 354
 355         if (has_qtd) {
 356                 pzl_qset_remove(whc, qset);
 357                 update_pzl_hw_view(whc);
 358                 wurb->status = status;
 359                 wurb->is_async = false;
 360                 queue_work(whc->workqueue, &wurb->dequeue_work);
 361         } else
 362                 qset_remove_urb(whc, qset, urb, status);
 363 out:
 364         spin_unlock_irqrestore(&whc->lock, flags);
 365
 366         return ret;
 367 }
 368
 369 /**
 370  * pzl_qset_delete - delete a qset from the PZL
 371  */
 372 void pzl_qset_delete(struct whc *whc, struct whc_qset *qset)
 373 {
 374         qset->remove = 1;
 375         queue_work(whc->workqueue, &whc->periodic_work);
 376         qset_delete(whc, qset);
 377 }
 378
 379 /**
 380  * pzl_init - initialize the periodic zone list
 381  * @whc: the WHCI host controller
 382  */
 383 int pzl_init(struct whc *whc)
 384 {
 385         int i;
 386
 387         whc->pz_list = dma_alloc_coherent(&whc->umc->dev, sizeof(u64) * 16,
 388                                           &whc->pz_list_dma, GFP_KERNEL);
 389         if (whc->pz_list == NULL)
 390                 return -ENOMEM;
 391
 392         /* Set T bit on all elements in PZL. */
 393         for (i = 0; i < 16; i++)
 394                 whc->pz_list[i] = cpu_to_le64(QH_LINK_NTDS(8) | QH_LINK_T);
 395
 396         le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
 397
 398         return 0;
 399 }
 400
 401 /**
 402  * pzl_clean_up - free PZL resources
 403  * @whc: the WHCI host controller
 404  *
 405  * The PZL is stopped and empty.
 406  */
 407 void pzl_clean_up(struct whc *whc)
 408 {
 409         if (whc->pz_list)
 410                 dma_free_coherent(&whc->umc->dev,  sizeof(u64) * 16, whc->pz_list,
 411                                   whc->pz_list_dma);
 412 }