err.no Git - linux-2.6/blob - drivers/scsi/mac53c94.c

   1 /*
   2  * SCSI low-level driver for the 53c94 SCSI bus adaptor found
   3  * on Power Macintosh computers, controlling the external SCSI chain.
   4  * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA)
   5  * controller.
   6  *
   7  * Paul Mackerras, August 1996.
   8  * Copyright (C) 1996 Paul Mackerras.
   9  */
  10 #include <linux/kernel.h>
  11 #include <linux/delay.h>
  12 #include <linux/types.h>
  13 #include <linux/string.h>
  14 #include <linux/slab.h>
  15 #include <linux/blkdev.h>
  16 #include <linux/proc_fs.h>
  17 #include <linux/stat.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/interrupt.h>
  20 #include <asm/dbdma.h>
  21 #include <asm/io.h>
  22 #include <asm/pgtable.h>
  23 #include <asm/prom.h>
  24 #include <asm/system.h>
  25 #include <asm/pci-bridge.h>
  26 #include <asm/macio.h>
  27
  28 #include <scsi/scsi.h>
  29 #include <scsi/scsi_cmnd.h>
  30 #include <scsi/scsi_device.h>
  31 #include <scsi/scsi_host.h>
  32
  33 #include "mac53c94.h"
  34
  35 enum fsc_phase {
  36         idle,
  37         selecting,
  38         dataing,
  39         completing,
  40         busfreeing,
  41 };
  42
  43 struct fsc_state {
  44         struct  mac53c94_regs __iomem *regs;
  45         int     intr;
  46         struct  dbdma_regs __iomem *dma;
  47         int     dmaintr;
  48         int     clk_freq;
  49         struct  Scsi_Host *host;
  50         struct scsi_cmnd *request_q;
  51         struct scsi_cmnd *request_qtail;
  52         struct scsi_cmnd *current_req;          /* req we're currently working on */
  53         enum fsc_phase phase;           /* what we're currently trying to do */
  54         struct dbdma_cmd *dma_cmds;     /* space for dbdma commands, aligned */
  55         void    *dma_cmd_space;
  56         struct  pci_dev *pdev;
  57         dma_addr_t dma_addr;
  58         struct macio_dev *mdev;
  59 };
  60
  61 static void mac53c94_init(struct fsc_state *);
  62 static void mac53c94_start(struct fsc_state *);
  63 static void mac53c94_interrupt(int, void *, struct pt_regs *);
  64 static irqreturn_t do_mac53c94_interrupt(int, void *, struct pt_regs *);
  65 static void cmd_done(struct fsc_state *, int result);
  66 static void set_dma_cmds(struct fsc_state *, struct scsi_cmnd *);
  67
  68
  69 static int mac53c94_queue(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
  70 {
  71         struct fsc_state *state;
  72
  73 #if 0
  74         if (cmd->sc_data_direction == DMA_TO_DEVICE) {
  75                 int i;
  76                 printk(KERN_DEBUG "mac53c94_queue %p: command is", cmd);
  77                 for (i = 0; i < cmd->cmd_len; ++i)
  78                         printk(" %.2x", cmd->cmnd[i]);
  79                 printk("\n" KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",
  80                        cmd->use_sg, cmd->request_bufflen, cmd->request_buffer);
  81         }
  82 #endif
  83
  84         cmd->scsi_done = done;
  85         cmd->host_scribble = NULL;
  86
  87         state = (struct fsc_state *) cmd->device->host->hostdata;
  88
  89         if (state->request_q == NULL)
  90                 state->request_q = cmd;
  91         else
  92                 state->request_qtail->host_scribble = (void *) cmd;
  93         state->request_qtail = cmd;
  94
  95         if (state->phase == idle)
  96                 mac53c94_start(state);
  97
  98         return 0;
  99 }
 100
 101 static int mac53c94_host_reset(struct scsi_cmnd *cmd)
 102 {
 103         struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;
 104         struct mac53c94_regs __iomem *regs = state->regs;
 105         struct dbdma_regs __iomem *dma = state->dma;
 106
 107         writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
 108         writeb(CMD_SCSI_RESET, &regs->command); /* assert RST */
 109         udelay(100);                    /* leave it on for a while (>= 25us) */
 110         writeb(CMD_RESET, &regs->command);
 111         udelay(20);
 112         mac53c94_init(state);
 113         writeb(CMD_NOP, &regs->command);
 114         return SUCCESS;
 115 }
 116
 117 static void mac53c94_init(struct fsc_state *state)
 118 {
 119         struct mac53c94_regs __iomem *regs = state->regs;
 120         struct dbdma_regs __iomem *dma = state->dma;
 121         int x;
 122
 123         writeb(state->host->this_id | CF1_PAR_ENABLE, &regs->config1);
 124         writeb(TIMO_VAL(250), &regs->sel_timeout);      /* 250ms */
 125         writeb(CLKF_VAL(state->clk_freq), &regs->clk_factor);
 126         writeb(CF2_FEATURE_EN, &regs->config2);
 127         writeb(0, &regs->config3);
 128         writeb(0, &regs->sync_period);
 129         writeb(0, &regs->sync_offset);
 130         x = readb(&regs->interrupt);
 131         writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
 132 }
 133
 134 /*
 135  * Start the next command for a 53C94.
 136  * Should be called with interrupts disabled.
 137  */
 138 static void mac53c94_start(struct fsc_state *state)
 139 {
 140         struct scsi_cmnd *cmd;
 141         struct mac53c94_regs __iomem *regs = state->regs;
 142         int i;
 143
 144         if (state->phase != idle || state->current_req != NULL)
 145                 panic("inappropriate mac53c94_start (state=%p)", state);
 146         if (state->request_q == NULL)
 147                 return;
 148         state->current_req = cmd = state->request_q;
 149         state->request_q = (struct scsi_cmnd *) cmd->host_scribble;
 150
 151         /* Off we go */
 152         writeb(0, &regs->count_lo);
 153         writeb(0, &regs->count_mid);
 154         writeb(0, &regs->count_hi);
 155         writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
 156         udelay(1);
 157         writeb(CMD_FLUSH, &regs->command);
 158         udelay(1);
 159         writeb(cmd->device->id, &regs->dest_id);
 160         writeb(0, &regs->sync_period);
 161         writeb(0, &regs->sync_offset);
 162
 163         /* load the command into the FIFO */
 164         for (i = 0; i < cmd->cmd_len; ++i)
 165                 writeb(cmd->cmnd[i], &regs->fifo);
 166
 167         /* do select without ATN XXX */
 168         writeb(CMD_SELECT, &regs->command);
 169         state->phase = selecting;
 170
 171         if (cmd->use_sg > 0 || cmd->request_bufflen != 0)
 172                 set_dma_cmds(state, cmd);
 173 }
 174
 175 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
 176 {
 177         unsigned long flags;
 178         struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
 179
 180         spin_lock_irqsave(dev->host_lock, flags);
 181         mac53c94_interrupt(irq, dev_id, ptregs);
 182         spin_unlock_irqrestore(dev->host_lock, flags);
 183         return IRQ_HANDLED;
 184 }
 185
 186 static void mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
 187 {
 188         struct fsc_state *state = (struct fsc_state *) dev_id;
 189         struct mac53c94_regs __iomem *regs = state->regs;
 190         struct dbdma_regs __iomem *dma = state->dma;
 191         struct scsi_cmnd *cmd = state->current_req;
 192         int nb, stat, seq, intr;
 193         static int mac53c94_errors;
 194
 195         /*
 196          * Apparently, reading the interrupt register unlatches
 197          * the status and sequence step registers.
 198          */
 199         seq = readb(&regs->seqstep);
 200         stat = readb(&regs->status);
 201         intr = readb(&regs->interrupt);
 202
 203 #if 0
 204         printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
 205                intr, stat, seq, state->phase);
 206 #endif
 207
 208         if (intr & INTR_RESET) {
 209                 /* SCSI bus was reset */
 210                 printk(KERN_INFO "external SCSI bus reset detected\n");
 211                 writeb(CMD_NOP, &regs->command);
 212                 writel(RUN << 16, &dma->control);       /* stop dma */
 213                 cmd_done(state, DID_RESET << 16);
 214                 return;
 215         }
 216         if (intr & INTR_ILL_CMD) {
 217                 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
 218                        intr, stat, seq, state->phase);
 219                 cmd_done(state, DID_ERROR << 16);
 220                 return;
 221         }
 222         if (stat & STAT_ERROR) {
 223 #if 0
 224                 /* XXX these seem to be harmless? */
 225                 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
 226                        intr, stat, seq, state->phase);
 227 #endif
 228                 ++mac53c94_errors;
 229                 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
 230         }
 231         if (cmd == 0) {
 232                 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
 233                 return;
 234         }
 235         if (stat & STAT_PARITY) {
 236                 printk(KERN_ERR "mac53c94: parity error\n");
 237                 cmd_done(state, DID_PARITY << 16);
 238                 return;
 239         }
 240         switch (state->phase) {
 241         case selecting:
 242                 if (intr & INTR_DISCONNECT) {
 243                         /* selection timed out */
 244                         cmd_done(state, DID_BAD_TARGET << 16);
 245                         return;
 246                 }
 247                 if (intr != INTR_BUS_SERV + INTR_DONE) {
 248                         printk(KERN_DEBUG "got intr %x during selection\n", intr);
 249                         cmd_done(state, DID_ERROR << 16);
 250                         return;
 251                 }
 252                 if ((seq & SS_MASK) != SS_DONE) {
 253                         printk(KERN_DEBUG "seq step %x after command\n", seq);
 254                         cmd_done(state, DID_ERROR << 16);
 255                         return;
 256                 }
 257                 writeb(CMD_NOP, &regs->command);
 258                 /* set DMA controller going if any data to transfer */
 259                 if ((stat & (STAT_MSG|STAT_CD)) == 0
 260                     && (cmd->use_sg > 0 || cmd->request_bufflen != 0)) {
 261                         nb = cmd->SCp.this_residual;
 262                         if (nb > 0xfff0)
 263                                 nb = 0xfff0;
 264                         cmd->SCp.this_residual -= nb;
 265                         writeb(nb, &regs->count_lo);
 266                         writeb(nb >> 8, &regs->count_mid);
 267                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
 268                         writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
 269                         writel((RUN << 16) | RUN, &dma->control);
 270                         writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
 271                         state->phase = dataing;
 272                         break;
 273                 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
 274                         /* up to status phase already */
 275                         writeb(CMD_I_COMPLETE, &regs->command);
 276                         state->phase = completing;
 277                 } else {
 278                         printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
 279                                stat & STAT_PHASE);
 280                         cmd_done(state, DID_ERROR << 16);
 281                         return;
 282                 }
 283                 break;
 284
 285         case dataing:
 286                 if (intr != INTR_BUS_SERV) {
 287                         printk(KERN_DEBUG "got intr %x before status\n", intr);
 288                         cmd_done(state, DID_ERROR << 16);
 289                         return;
 290                 }
 291                 if (cmd->SCp.this_residual != 0
 292                     && (stat & (STAT_MSG|STAT_CD)) == 0) {
 293                         /* Set up the count regs to transfer more */
 294                         nb = cmd->SCp.this_residual;
 295                         if (nb > 0xfff0)
 296                                 nb = 0xfff0;
 297                         cmd->SCp.this_residual -= nb;
 298                         writeb(nb, &regs->count_lo);
 299                         writeb(nb >> 8, &regs->count_mid);
 300                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
 301                         writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
 302                         break;
 303                 }
 304                 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
 305                         printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
 306                 }
 307                 writel(RUN << 16, &dma->control);       /* stop dma */
 308                 if (cmd->use_sg != 0) {
 309                         pci_unmap_sg(state->pdev,
 310                                 (struct scatterlist *)cmd->request_buffer,
 311                                 cmd->use_sg, cmd->sc_data_direction);
 312                 } else {
 313                         pci_unmap_single(state->pdev, state->dma_addr,
 314                                 cmd->request_bufflen, cmd->sc_data_direction);
 315                 }
 316                 /* should check dma status */
 317                 writeb(CMD_I_COMPLETE, &regs->command);
 318                 state->phase = completing;
 319                 break;
 320         case completing:
 321                 if (intr != INTR_DONE) {
 322                         printk(KERN_DEBUG "got intr %x on completion\n", intr);
 323                         cmd_done(state, DID_ERROR << 16);
 324                         return;
 325                 }
 326                 cmd->SCp.Status = readb(&regs->fifo);
 327                 cmd->SCp.Message = readb(&regs->fifo);
 328                 cmd->result = CMD_ACCEPT_MSG;
 329                 writeb(CMD_ACCEPT_MSG, &regs->command);
 330                 state->phase = busfreeing;
 331                 break;
 332         case busfreeing:
 333                 if (intr != INTR_DISCONNECT) {
 334                         printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
 335                 }
 336                 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
 337                          + cmd->SCp.Status);
 338                 break;
 339         default:
 340                 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
 341         }
 342 }
 343
 344 static void cmd_done(struct fsc_state *state, int result)
 345 {
 346         struct scsi_cmnd *cmd;
 347
 348         cmd = state->current_req;
 349         if (cmd != 0) {
 350                 cmd->result = result;
 351                 (*cmd->scsi_done)(cmd);
 352                 state->current_req = NULL;
 353         }
 354         state->phase = idle;
 355         mac53c94_start(state);
 356 }
 357
 358 /*
 359  * Set up DMA commands for transferring data.
 360  */
 361 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
 362 {
 363         int i, dma_cmd, total;
 364         struct scatterlist *scl;
 365         struct dbdma_cmd *dcmds;
 366         dma_addr_t dma_addr;
 367         u32 dma_len;
 368
 369         dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
 370                         OUTPUT_MORE : INPUT_MORE;
 371         dcmds = state->dma_cmds;
 372         if (cmd->use_sg > 0) {
 373                 int nseg;
 374
 375                 total = 0;
 376                 scl = (struct scatterlist *) cmd->buffer;
 377                 nseg = pci_map_sg(state->pdev, scl, cmd->use_sg,
 378                                 cmd->sc_data_direction);
 379                 for (i = 0; i < nseg; ++i) {
 380                         dma_addr = sg_dma_address(scl);
 381                         dma_len = sg_dma_len(scl);
 382                         if (dma_len > 0xffff)
 383                                 panic("mac53c94: scatterlist element >= 64k");
 384                         total += dma_len;
 385                         st_le16(&dcmds->req_count, dma_len);
 386                         st_le16(&dcmds->command, dma_cmd);
 387                         st_le32(&dcmds->phy_addr, dma_addr);
 388                         dcmds->xfer_status = 0;
 389                         ++scl;
 390                         ++dcmds;
 391                 }
 392         } else {
 393                 total = cmd->request_bufflen;
 394                 if (total > 0xffff)
 395                         panic("mac53c94: transfer size >= 64k");
 396                 dma_addr = pci_map_single(state->pdev, cmd->request_buffer,
 397                                           total, cmd->sc_data_direction);
 398                 state->dma_addr = dma_addr;
 399                 st_le16(&dcmds->req_count, total);
 400                 st_le32(&dcmds->phy_addr, dma_addr);
 401                 dcmds->xfer_status = 0;
 402                 ++dcmds;
 403         }
 404         dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
 405         st_le16(&dcmds[-1].command, dma_cmd);
 406         st_le16(&dcmds->command, DBDMA_STOP);
 407         cmd->SCp.this_residual = total;
 408 }
 409
 410 static struct scsi_host_template mac53c94_template = {
 411         .proc_name      = "53c94",
 412         .name           = "53C94",
 413         .queuecommand   = mac53c94_queue,
 414         .eh_host_reset_handler = mac53c94_host_reset,
 415         .can_queue      = 1,
 416         .this_id        = 7,
 417         .sg_tablesize   = SG_ALL,
 418         .cmd_per_lun    = 1,
 419         .use_clustering = DISABLE_CLUSTERING,
 420 };
 421
 422 static int mac53c94_probe(struct macio_dev *mdev, const struct of_match *match)
 423 {
 424         struct device_node *node = macio_get_of_node(mdev);
 425         struct pci_dev *pdev = macio_get_pci_dev(mdev);
 426         struct fsc_state *state;
 427         struct Scsi_Host *host;
 428         void *dma_cmd_space;
 429         unsigned char *clkprop;
 430         int proplen;
 431
 432         if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
 433                 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs (got %d/%d)\n",
 434                        node->n_addrs, node->n_intrs);
 435                 return -ENODEV;
 436         }
 437
 438         if (macio_request_resources(mdev, "mac53c94") != 0) {
 439                 printk(KERN_ERR "mac53c94: unable to request memory resources");
 440                 return -EBUSY;
 441         }
 442
 443         host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
 444         if (host == NULL) {
 445                 printk(KERN_ERR "mac53c94: couldn't register host");
 446                 goto out_release;
 447         }
 448
 449         state = (struct fsc_state *) host->hostdata;
 450         macio_set_drvdata(mdev, state);
 451         state->host = host;
 452         state->pdev = pdev;
 453         state->mdev = mdev;
 454
 455         state->regs = (struct mac53c94_regs __iomem *)
 456                 ioremap(macio_resource_start(mdev, 0), 0x1000);
 457         state->intr = macio_irq(mdev, 0);
 458         state->dma = (struct dbdma_regs __iomem *)
 459                 ioremap(macio_resource_start(mdev, 1), 0x1000);
 460         state->dmaintr = macio_irq(mdev, 1);
 461         if (state->regs == NULL || state->dma == NULL) {
 462                 printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
 463                        node->full_name);
 464                 goto out_free;
 465         }
 466
 467         clkprop = get_property(node, "clock-frequency", &proplen);
 468         if (clkprop == NULL || proplen != sizeof(int)) {
 469                 printk(KERN_ERR "%s: can't get clock frequency, "
 470                        "assuming 25MHz\n", node->full_name);
 471                 state->clk_freq = 25000000;
 472         } else
 473                 state->clk_freq = *(int *)clkprop;
 474
 475         /* Space for dma command list: +1 for stop command,
 476          * +1 to allow for aligning.
 477          * XXX FIXME: Use DMA consistent routines
 478          */
 479         dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
 480                                 sizeof(struct dbdma_cmd), GFP_KERNEL);
 481         if (dma_cmd_space == 0) {
 482                 printk(KERN_ERR "mac53c94: couldn't allocate dma "
 483                        "command space for %s\n", node->full_name);
 484                 goto out_free;
 485         }
 486         state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);
 487         memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
 488                * sizeof(struct dbdma_cmd));
 489         state->dma_cmd_space = dma_cmd_space;
 490
 491         mac53c94_init(state);
 492
 493         if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94", state)) {
 494                 printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
 495                        state->intr, node->full_name);
 496                 goto out_free_dma;
 497         }
 498
 499         /* XXX FIXME: handle failure */
 500         scsi_add_host(host, &mdev->ofdev.dev);
 501         scsi_scan_host(host);
 502
 503         return 0;
 504
 505  out_free_dma:
 506         kfree(state->dma_cmd_space);
 507  out_free:
 508         if (state->dma != NULL)
 509                 iounmap(state->dma);
 510         if (state->regs != NULL)
 511                 iounmap(state->regs);
 512         scsi_host_put(host);
 513  out_release:
 514         macio_release_resources(mdev);
 515
 516         return  -ENODEV;
 517 }
 518
 519 static int mac53c94_remove(struct macio_dev *mdev)
 520 {
 521         struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
 522         struct Scsi_Host *host = fp->host;
 523
 524         scsi_remove_host(host);
 525
 526         free_irq(fp->intr, fp);
 527
 528         if (fp->regs)
 529                 iounmap((void *) fp->regs);
 530         if (fp->dma)
 531                 iounmap((void *) fp->dma);
 532         kfree(fp->dma_cmd_space);
 533
 534         scsi_host_put(host);
 535
 536         macio_release_resources(mdev);
 537
 538         return 0;
 539 }
 540
 541
 542 static struct of_match mac53c94_match[] =
 543 {
 544         {
 545         .name           = "53c94",
 546         .type           = OF_ANY_MATCH,
 547         .compatible     = OF_ANY_MATCH
 548         },
 549         {},
 550 };
 551
 552 static struct macio_driver mac53c94_driver =
 553 {
 554         .name           = "mac53c94",
 555         .match_table    = mac53c94_match,
 556         .probe          = mac53c94_probe,
 557         .remove         = mac53c94_remove,
 558 };
 559
 560
 561 static int __init init_mac53c94(void)
 562 {
 563         return macio_register_driver(&mac53c94_driver);
 564 }
 565
 566 static void __exit exit_mac53c94(void)
 567 {
 568         return macio_unregister_driver(&mac53c94_driver);
 569 }
 570
 571 module_init(init_mac53c94);
 572 module_exit(exit_mac53c94);
 573
 574 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
 575 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
 576 MODULE_LICENSE("GPL");