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, ®s->command); /* assert RST */ 112 udelay(100); /* leave it on for a while (>= 25us) */ 113 writeb(CMD_RESET, ®s->command); 114 udelay(20); 115 mac53c94_init(state); 116 writeb(CMD_NOP, ®s->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, ®s->config1); 129 writeb(TIMO_VAL(250), ®s->sel_timeout); /* 250ms */ 130 writeb(CLKF_VAL(state->clk_freq), ®s->clk_factor); 131 writeb(CF2_FEATURE_EN, ®s->config2); 132 writeb(0, ®s->config3); 133 writeb(0, ®s->sync_period); 134 writeb(0, ®s->sync_offset); 135 x = readb(®s->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, ®s->count_lo); 158 writeb(0, ®s->count_mid); 159 writeb(0, ®s->count_hi); 160 writeb(CMD_NOP + CMD_DMA_MODE, ®s->command); 161 udelay(1); 162 writeb(CMD_FLUSH, ®s->command); 163 udelay(1); 164 writeb(cmd->device->id, ®s->dest_id); 165 writeb(0, ®s->sync_period); 166 writeb(0, ®s->sync_offset); 167 168 /* load the command into the FIFO */ 169 for (i = 0; i < cmd->cmd_len; ++i) 170 writeb(cmd->cmnd[i], ®s->fifo); 171 172 /* do select without ATN XXX */ 173 writeb(CMD_SELECT, ®s->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(®s->seqstep); 205 stat = readb(®s->status); 206 intr = readb(®s->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, ®s->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, ®s->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, ®s->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, ®s->count_lo); 271 writeb(nb >> 8, ®s->count_mid); 272 writeb(CMD_DMA_MODE + CMD_NOP, ®s->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, ®s->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, ®s->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, ®s->count_lo); 304 writeb(nb >> 8, ®s->count_mid); 305 writeb(CMD_DMA_MODE + CMD_NOP, ®s->command); 306 writeb(CMD_DMA_MODE + CMD_XFER_DATA, ®s->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, ®s->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(®s->fifo); 332 cmd->SCp.Message = readb(®s->fifo); 333 cmd->result = CMD_ACCEPT_MSG; 334 writeb(CMD_ACCEPT_MSG, ®s->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->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_match *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 unsigned char *clkprop; 435 int proplen; 436 437 if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) { 438 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs (got %d/%d)\n", 439 node->n_addrs, node->n_intrs); 440 return -ENODEV; 441 } 442 443 if (macio_request_resources(mdev, "mac53c94") != 0) { 444 printk(KERN_ERR "mac53c94: unable to request memory resources"); 445 return -EBUSY; 446 } 447 448 host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state)); 449 if (host == NULL) { 450 printk(KERN_ERR "mac53c94: couldn't register host"); 451 goto out_release; 452 } 453 454 state = (struct fsc_state *) host->hostdata; 455 macio_set_drvdata(mdev, state); 456 state->host = host; 457 state->pdev = pdev; 458 state->mdev = mdev; 459 460 state->regs = (struct mac53c94_regs __iomem *) 461 ioremap(macio_resource_start(mdev, 0), 0x1000); 462 state->intr = macio_irq(mdev, 0); 463 state->dma = (struct dbdma_regs __iomem *) 464 ioremap(macio_resource_start(mdev, 1), 0x1000); 465 state->dmaintr = macio_irq(mdev, 1); 466 if (state->regs == NULL || state->dma == NULL) { 467 printk(KERN_ERR "mac53c94: ioremap failed for %s\n", 468 node->full_name); 469 goto out_free; 470 } 471 472 clkprop = get_property(node, "clock-frequency", &proplen); 473 if (clkprop == NULL || proplen != sizeof(int)) { 474 printk(KERN_ERR "%s: can't get clock frequency, " 475 "assuming 25MHz\n", node->full_name); 476 state->clk_freq = 25000000; 477 } else 478 state->clk_freq = *(int *)clkprop; 479 480 /* Space for dma command list: +1 for stop command, 481 * +1 to allow for aligning. 482 * XXX FIXME: Use DMA consistent routines 483 */ 484 dma_cmd_space = kmalloc((host->sg_tablesize + 2) * 485 sizeof(struct dbdma_cmd), GFP_KERNEL); 486 if (dma_cmd_space == 0) { 487 printk(KERN_ERR "mac53c94: couldn't allocate dma " 488 "command space for %s\n", node->full_name); 489 goto out_free; 490 } 491 state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space); 492 memset(state->dma_cmds, 0, (host->sg_tablesize + 1) 493 * sizeof(struct dbdma_cmd)); 494 state->dma_cmd_space = dma_cmd_space; 495 496 mac53c94_init(state); 497 498 if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94", state)) { 499 printk(KERN_ERR "mac53C94: can't get irq %d for %s\n", 500 state->intr, node->full_name); 501 goto out_free_dma; 502 } 503 504 /* XXX FIXME: handle failure */ 505 scsi_add_host(host, &mdev->ofdev.dev); 506 scsi_scan_host(host); 507 508 return 0; 509 510 out_free_dma: 511 kfree(state->dma_cmd_space); 512 out_free: 513 if (state->dma != NULL) 514 iounmap(state->dma); 515 if (state->regs != NULL) 516 iounmap(state->regs); 517 scsi_host_put(host); 518 out_release: 519 macio_release_resources(mdev); 520 521 return -ENODEV; 522 } 523 524 static int mac53c94_remove(struct macio_dev *mdev) 525 { 526 struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev); 527 struct Scsi_Host *host = fp->host; 528 529 scsi_remove_host(host); 530 531 free_irq(fp->intr, fp); 532 533 if (fp->regs) 534 iounmap((void *) fp->regs); 535 if (fp->dma) 536 iounmap((void *) fp->dma); 537 kfree(fp->dma_cmd_space); 538 539 scsi_host_put(host); 540 541 macio_release_resources(mdev); 542 543 return 0; 544 } 545 546 547 static struct of_match mac53c94_match[] = 548 { 549 { 550 .name = "53c94", 551 .type = OF_ANY_MATCH, 552 .compatible = OF_ANY_MATCH 553 }, 554 {}, 555 }; 556 557 static struct macio_driver mac53c94_driver = 558 { 559 .name = "mac53c94", 560 .match_table = mac53c94_match, 561 .probe = mac53c94_probe, 562 .remove = mac53c94_remove, 563 }; 564 565 566 static int __init init_mac53c94(void) 567 { 568 return macio_register_driver(&mac53c94_driver); 569 } 570 571 static void __exit exit_mac53c94(void) 572 { 573 return macio_unregister_driver(&mac53c94_driver); 574 } 575 576 module_init(init_mac53c94); 577 module_exit(exit_mac53c94); 578 579 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver"); 580 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>"); 581 MODULE_LICENSE("GPL"); 582