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         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         if (cmd->use_sg > 0 || cmd->request_bufflen != 0)
 177                 set_dma_cmds(state, cmd);
 178 }
 179
 180 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
 181 {
 182         unsigned long flags;
 183         struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
 184
 185         spin_lock_irqsave(dev->host_lock, flags);
 186         mac53c94_interrupt(irq, dev_id, ptregs);
 187         spin_unlock_irqrestore(dev->host_lock, flags);
 188         return IRQ_HANDLED;
 189 }
 190
 191 static void mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
 192 {
 193         struct fsc_state *state = (struct fsc_state *) dev_id;
 194         struct mac53c94_regs __iomem *regs = state->regs;
 195         struct dbdma_regs __iomem *dma = state->dma;
 196         struct scsi_cmnd *cmd = state->current_req;
 197         int nb, stat, seq, intr;
 198         static int mac53c94_errors;
 199
 200         /*
 201          * Apparently, reading the interrupt register unlatches
 202          * the status and sequence step registers.
 203          */
 204         seq = readb(&regs->seqstep);
 205         stat = readb(&regs->status);
 206         intr = readb(&regs->interrupt);
 207
 208 #if 0
 209         printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
 210                intr, stat, seq, state->phase);
 211 #endif
 212
 213         if (intr & INTR_RESET) {
 214                 /* SCSI bus was reset */
 215                 printk(KERN_INFO "external SCSI bus reset detected\n");
 216                 writeb(CMD_NOP, &regs->command);
 217                 writel(RUN << 16, &dma->control);       /* stop dma */
 218                 cmd_done(state, DID_RESET << 16);
 219                 return;
 220         }
 221         if (intr & INTR_ILL_CMD) {
 222                 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
 223                        intr, stat, seq, state->phase);
 224                 cmd_done(state, DID_ERROR << 16);
 225                 return;
 226         }
 227         if (stat & STAT_ERROR) {
 228 #if 0
 229                 /* XXX these seem to be harmless? */
 230                 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
 231                        intr, stat, seq, state->phase);
 232 #endif
 233                 ++mac53c94_errors;
 234                 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
 235         }
 236         if (cmd == 0) {
 237                 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
 238                 return;
 239         }
 240         if (stat & STAT_PARITY) {
 241                 printk(KERN_ERR "mac53c94: parity error\n");
 242                 cmd_done(state, DID_PARITY << 16);
 243                 return;
 244         }
 245         switch (state->phase) {
 246         case selecting:
 247                 if (intr & INTR_DISCONNECT) {
 248                         /* selection timed out */
 249                         cmd_done(state, DID_BAD_TARGET << 16);
 250                         return;
 251                 }
 252                 if (intr != INTR_BUS_SERV + INTR_DONE) {
 253                         printk(KERN_DEBUG "got intr %x during selection\n", intr);
 254                         cmd_done(state, DID_ERROR << 16);
 255                         return;
 256                 }
 257                 if ((seq & SS_MASK) != SS_DONE) {
 258                         printk(KERN_DEBUG "seq step %x after command\n", seq);
 259                         cmd_done(state, DID_ERROR << 16);
 260                         return;
 261                 }
 262                 writeb(CMD_NOP, &regs->command);
 263                 /* set DMA controller going if any data to transfer */
 264                 if ((stat & (STAT_MSG|STAT_CD)) == 0
 265                     && (cmd->use_sg > 0 || cmd->request_bufflen != 0)) {
 266                         nb = cmd->SCp.this_residual;
 267                         if (nb > 0xfff0)
 268                                 nb = 0xfff0;
 269                         cmd->SCp.this_residual -= nb;
 270                         writeb(nb, &regs->count_lo);
 271                         writeb(nb >> 8, &regs->count_mid);
 272                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
 273                         writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
 274                         writel((RUN << 16) | RUN, &dma->control);
 275                         writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
 276                         state->phase = dataing;
 277                         break;
 278                 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
 279                         /* up to status phase already */
 280                         writeb(CMD_I_COMPLETE, &regs->command);
 281                         state->phase = completing;
 282                 } else {
 283                         printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
 284                                stat & STAT_PHASE);
 285                         cmd_done(state, DID_ERROR << 16);
 286                         return;
 287                 }
 288                 break;
 289
 290         case dataing:
 291                 if (intr != INTR_BUS_SERV) {
 292                         printk(KERN_DEBUG "got intr %x before status\n", intr);
 293                         cmd_done(state, DID_ERROR << 16);
 294                         return;
 295                 }
 296                 if (cmd->SCp.this_residual != 0
 297                     && (stat & (STAT_MSG|STAT_CD)) == 0) {
 298                         /* Set up the count regs to transfer more */
 299                         nb = cmd->SCp.this_residual;
 300                         if (nb > 0xfff0)
 301                                 nb = 0xfff0;
 302                         cmd->SCp.this_residual -= nb;
 303                         writeb(nb, &regs->count_lo);
 304                         writeb(nb >> 8, &regs->count_mid);
 305                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
 306                         writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
 307                         break;
 308                 }
 309                 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
 310                         printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
 311                 }
 312                 writel(RUN << 16, &dma->control);       /* stop dma */
 313                 if (cmd->use_sg != 0) {
 314                         pci_unmap_sg(state->pdev,
 315                                 (struct scatterlist *)cmd->request_buffer,
 316                                 cmd->use_sg, cmd->sc_data_direction);
 317                 } else {
 318                         pci_unmap_single(state->pdev, state->dma_addr,
 319                                 cmd->request_bufflen, cmd->sc_data_direction);
 320                 }
 321                 /* should check dma status */
 322                 writeb(CMD_I_COMPLETE, &regs->command);
 323                 state->phase = completing;
 324                 break;
 325         case completing:
 326                 if (intr != INTR_DONE) {
 327                         printk(KERN_DEBUG "got intr %x on completion\n", intr);
 328                         cmd_done(state, DID_ERROR << 16);
 329                         return;
 330                 }
 331                 cmd->SCp.Status = readb(&regs->fifo);
 332                 cmd->SCp.Message = readb(&regs->fifo);
 333                 cmd->result = CMD_ACCEPT_MSG;
 334                 writeb(CMD_ACCEPT_MSG, &regs->command);
 335                 state->phase = busfreeing;
 336                 break;
 337         case busfreeing:
 338                 if (intr != INTR_DISCONNECT) {
 339                         printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
 340                 }
 341                 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
 342                          + cmd->SCp.Status);
 343                 break;
 344         default:
 345                 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
 346         }
 347 }
 348
 349 static void cmd_done(struct fsc_state *state, int result)
 350 {
 351         struct scsi_cmnd *cmd;
 352
 353         cmd = state->current_req;
 354         if (cmd != 0) {
 355                 cmd->result = result;
 356                 (*cmd->scsi_done)(cmd);
 357                 state->current_req = NULL;
 358         }
 359         state->phase = idle;
 360         mac53c94_start(state);
 361 }
 362
 363 /*
 364  * Set up DMA commands for transferring data.
 365  */
 366 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
 367 {
 368         int i, dma_cmd, total;
 369         struct scatterlist *scl;
 370         struct dbdma_cmd *dcmds;
 371         dma_addr_t dma_addr;
 372         u32 dma_len;
 373
 374         dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
 375                         OUTPUT_MORE : INPUT_MORE;
 376         dcmds = state->dma_cmds;
 377         if (cmd->use_sg > 0) {
 378                 int nseg;
 379
 380                 total = 0;
 381                 scl = (struct scatterlist *) cmd->request_buffer;
 382                 nseg = pci_map_sg(state->pdev, scl, cmd->use_sg,
 383                                 cmd->sc_data_direction);
 384                 for (i = 0; i < nseg; ++i) {
 385                         dma_addr = sg_dma_address(scl);
 386                         dma_len = sg_dma_len(scl);
 387                         if (dma_len > 0xffff)
 388                                 panic("mac53c94: scatterlist element >= 64k");
 389                         total += dma_len;
 390                         st_le16(&dcmds->req_count, dma_len);
 391                         st_le16(&dcmds->command, dma_cmd);
 392                         st_le32(&dcmds->phy_addr, dma_addr);
 393                         dcmds->xfer_status = 0;
 394                         ++scl;
 395                         ++dcmds;
 396                 }
 397         } else {
 398                 total = cmd->request_bufflen;
 399                 if (total > 0xffff)
 400                         panic("mac53c94: transfer size >= 64k");
 401                 dma_addr = pci_map_single(state->pdev, cmd->request_buffer,
 402                                           total, cmd->sc_data_direction);
 403                 state->dma_addr = dma_addr;
 404                 st_le16(&dcmds->req_count, total);
 405                 st_le32(&dcmds->phy_addr, dma_addr);
 406                 dcmds->xfer_status = 0;
 407                 ++dcmds;
 408         }
 409         dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
 410         st_le16(&dcmds[-1].command, dma_cmd);
 411         st_le16(&dcmds->command, DBDMA_STOP);
 412         cmd->SCp.this_residual = total;
 413 }
 414
 415 static struct scsi_host_template mac53c94_template = {
 416         .proc_name      = "53c94",
 417         .name           = "53C94",
 418         .queuecommand   = mac53c94_queue,
 419         .eh_host_reset_handler = mac53c94_host_reset,
 420         .can_queue      = 1,
 421         .this_id        = 7,
 422         .sg_tablesize   = SG_ALL,
 423         .cmd_per_lun    = 1,
 424         .use_clustering = DISABLE_CLUSTERING,
 425 };
 426
 427 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
 428 {
 429         struct device_node *node = macio_get_of_node(mdev);
 430         struct pci_dev *pdev = macio_get_pci_dev(mdev);
 431         struct fsc_state *state;
 432         struct Scsi_Host *host;
 433         void *dma_cmd_space;
 434         const unsigned char *clkprop;
 435         int proplen, rc = -ENODEV;
 436
 437         if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
 438                 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs"
 439                        " (got %d/%d)\n",
 440                        macio_resource_count(mdev), macio_irq_count(mdev));
 441                 return -ENODEV;
 442         }
 443
 444         if (macio_request_resources(mdev, "mac53c94") != 0) {
 445                 printk(KERN_ERR "mac53c94: unable to request memory resources");
 446                 return -EBUSY;
 447         }
 448
 449         host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
 450         if (host == NULL) {
 451                 printk(KERN_ERR "mac53c94: couldn't register host");
 452                 rc = -ENOMEM;
 453                 goto out_release;
 454         }
 455
 456         state = (struct fsc_state *) host->hostdata;
 457         macio_set_drvdata(mdev, state);
 458         state->host = host;
 459         state->pdev = pdev;
 460         state->mdev = mdev;
 461
 462         state->regs = (struct mac53c94_regs __iomem *)
 463                 ioremap(macio_resource_start(mdev, 0), 0x1000);
 464         state->intr = macio_irq(mdev, 0);
 465         state->dma = (struct dbdma_regs __iomem *)
 466                 ioremap(macio_resource_start(mdev, 1), 0x1000);
 467         state->dmaintr = macio_irq(mdev, 1);
 468         if (state->regs == NULL || state->dma == NULL) {
 469                 printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
 470                        node->full_name);
 471                 goto out_free;
 472         }
 473
 474         clkprop = get_property(node, "clock-frequency", &proplen);
 475         if (clkprop == NULL || proplen != sizeof(int)) {
 476                 printk(KERN_ERR "%s: can't get clock frequency, "
 477                        "assuming 25MHz\n", node->full_name);
 478                 state->clk_freq = 25000000;
 479         } else
 480                 state->clk_freq = *(int *)clkprop;
 481
 482         /* Space for dma command list: +1 for stop command,
 483          * +1 to allow for aligning.
 484          * XXX FIXME: Use DMA consistent routines
 485          */
 486         dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
 487                                 sizeof(struct dbdma_cmd), GFP_KERNEL);
 488         if (dma_cmd_space == 0) {
 489                 printk(KERN_ERR "mac53c94: couldn't allocate dma "
 490                        "command space for %s\n", node->full_name);
 491                 rc = -ENOMEM;
 492                 goto out_free;
 493         }
 494         state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);
 495         memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
 496                * sizeof(struct dbdma_cmd));
 497         state->dma_cmd_space = dma_cmd_space;
 498
 499         mac53c94_init(state);
 500
 501         if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) {
 502                 printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
 503                        state->intr, node->full_name);
 504                 goto out_free_dma;
 505         }
 506
 507         rc = scsi_add_host(host, &mdev->ofdev.dev);
 508         if (rc != 0)
 509                 goto out_release_irq;
 510
 511         scsi_scan_host(host);
 512         return 0;
 513
 514  out_release_irq:
 515         free_irq(state->intr, state);
 516  out_free_dma:
 517         kfree(state->dma_cmd_space);
 518  out_free:
 519         if (state->dma != NULL)
 520                 iounmap(state->dma);
 521         if (state->regs != NULL)
 522                 iounmap(state->regs);
 523         scsi_host_put(host);
 524  out_release:
 525         macio_release_resources(mdev);
 526
 527         return rc;
 528 }
 529
 530 static int mac53c94_remove(struct macio_dev *mdev)
 531 {
 532         struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
 533         struct Scsi_Host *host = fp->host;
 534
 535         scsi_remove_host(host);
 536
 537         free_irq(fp->intr, fp);
 538
 539         if (fp->regs)
 540                 iounmap(fp->regs);
 541         if (fp->dma)
 542                 iounmap(fp->dma);
 543         kfree(fp->dma_cmd_space);
 544
 545         scsi_host_put(host);
 546
 547         macio_release_resources(mdev);
 548
 549         return 0;
 550 }
 551
 552
 553 static struct of_device_id mac53c94_match[] =
 554 {
 555         {
 556         .name           = "53c94",
 557         },
 558         {},
 559 };
 560 MODULE_DEVICE_TABLE (of, mac53c94_match);
 561
 562 static struct macio_driver mac53c94_driver =
 563 {
 564         .name           = "mac53c94",
 565         .match_table    = mac53c94_match,
 566         .probe          = mac53c94_probe,
 567         .remove         = mac53c94_remove,
 568 };
 569
 570
 571 static int __init init_mac53c94(void)
 572 {
 573         return macio_register_driver(&mac53c94_driver);
 574 }
 575
 576 static void __exit exit_mac53c94(void)
 577 {
 578         return macio_unregister_driver(&mac53c94_driver);
 579 }
 580
 581 module_init(init_mac53c94);
 582 module_exit(exit_mac53c94);
 583
 584 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
 585 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
 586 MODULE_LICENSE("GPL");