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