1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * SCSI low-level driver for the 53c94 SCSI bus adaptor found 4 * on Power Macintosh computers, controlling the external SCSI chain. 5 * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA) 6 * controller. 7 * 8 * Paul Mackerras, August 1996. 9 * Copyright (C) 1996 Paul Mackerras. 10 */ 11 #include <linux/kernel.h> 12 #include <linux/delay.h> 13 #include <linux/types.h> 14 #include <linux/string.h> 15 #include <linux/slab.h> 16 #include <linux/blkdev.h> 17 #include <linux/proc_fs.h> 18 #include <linux/stat.h> 19 #include <linux/spinlock.h> 20 #include <linux/interrupt.h> 21 #include <linux/module.h> 22 #include <linux/pci.h> 23 #include <linux/pgtable.h> 24 #include <asm/dbdma.h> 25 #include <asm/io.h> 26 #include <asm/prom.h> 27 #include <asm/macio.h> 28 29 #include <scsi/scsi.h> 30 #include <scsi/scsi_cmnd.h> 31 #include <scsi/scsi_device.h> 32 #include <scsi/scsi_host.h> 33 34 #include "mac53c94.h" 35 36 enum fsc_phase { 37 idle, 38 selecting, 39 dataing, 40 completing, 41 busfreeing, 42 }; 43 44 struct fsc_state { 45 struct mac53c94_regs __iomem *regs; 46 int intr; 47 struct dbdma_regs __iomem *dma; 48 int dmaintr; 49 int clk_freq; 50 struct Scsi_Host *host; 51 struct scsi_cmnd *request_q; 52 struct scsi_cmnd *request_qtail; 53 struct scsi_cmnd *current_req; /* req we're currently working on */ 54 enum fsc_phase phase; /* what we're currently trying to do */ 55 struct dbdma_cmd *dma_cmds; /* space for dbdma commands, aligned */ 56 void *dma_cmd_space; 57 struct pci_dev *pdev; 58 dma_addr_t dma_addr; 59 struct macio_dev *mdev; 60 }; 61 62 static void mac53c94_init(struct fsc_state *); 63 static void mac53c94_start(struct fsc_state *); 64 static void mac53c94_interrupt(int, void *); 65 static irqreturn_t do_mac53c94_interrupt(int, void *); 66 static void cmd_done(struct fsc_state *, int result); 67 static void set_dma_cmds(struct fsc_state *, struct scsi_cmnd *); 68 69 static int mac53c94_queue_lck(struct scsi_cmnd *cmd) 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(KERN_CONT " %.2x", cmd->cmnd[i]); 79 printk(KERN_CONT "\n"); 80 printk(KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n", 81 scsi_sg_count(cmd), scsi_bufflen(cmd), scsi_sglist(cmd)); 82 } 83 #endif 84 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 DEF_SCSI_QCMD(mac53c94_queue) 102 103 static int mac53c94_host_reset(struct scsi_cmnd *cmd) 104 { 105 struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata; 106 struct mac53c94_regs __iomem *regs = state->regs; 107 struct dbdma_regs __iomem *dma = state->dma; 108 unsigned long flags; 109 110 spin_lock_irqsave(cmd->device->host->host_lock, flags); 111 112 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control); 113 writeb(CMD_SCSI_RESET, ®s->command); /* assert RST */ 114 udelay(100); /* leave it on for a while (>= 25us) */ 115 writeb(CMD_RESET, ®s->command); 116 udelay(20); 117 mac53c94_init(state); 118 writeb(CMD_NOP, ®s->command); 119 120 spin_unlock_irqrestore(cmd->device->host->host_lock, flags); 121 return SUCCESS; 122 } 123 124 static void mac53c94_init(struct fsc_state *state) 125 { 126 struct mac53c94_regs __iomem *regs = state->regs; 127 struct dbdma_regs __iomem *dma = state->dma; 128 129 writeb(state->host->this_id | CF1_PAR_ENABLE, ®s->config1); 130 writeb(TIMO_VAL(250), ®s->sel_timeout); /* 250ms */ 131 writeb(CLKF_VAL(state->clk_freq), ®s->clk_factor); 132 writeb(CF2_FEATURE_EN, ®s->config2); 133 writeb(0, ®s->config3); 134 writeb(0, ®s->sync_period); 135 writeb(0, ®s->sync_offset); 136 (void)readb(®s->interrupt); 137 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control); 138 } 139 140 /* 141 * Start the next command for a 53C94. 142 * Should be called with interrupts disabled. 143 */ 144 static void mac53c94_start(struct fsc_state *state) 145 { 146 struct scsi_cmnd *cmd; 147 struct mac53c94_regs __iomem *regs = state->regs; 148 int i; 149 150 if (state->phase != idle || state->current_req != NULL) 151 panic("inappropriate mac53c94_start (state=%p)", state); 152 if (state->request_q == NULL) 153 return; 154 state->current_req = cmd = state->request_q; 155 state->request_q = (struct scsi_cmnd *) cmd->host_scribble; 156 157 /* Off we go */ 158 writeb(0, ®s->count_lo); 159 writeb(0, ®s->count_mid); 160 writeb(0, ®s->count_hi); 161 writeb(CMD_NOP + CMD_DMA_MODE, ®s->command); 162 udelay(1); 163 writeb(CMD_FLUSH, ®s->command); 164 udelay(1); 165 writeb(cmd->device->id, ®s->dest_id); 166 writeb(0, ®s->sync_period); 167 writeb(0, ®s->sync_offset); 168 169 /* load the command into the FIFO */ 170 for (i = 0; i < cmd->cmd_len; ++i) 171 writeb(cmd->cmnd[i], ®s->fifo); 172 173 /* do select without ATN XXX */ 174 writeb(CMD_SELECT, ®s->command); 175 state->phase = selecting; 176 177 set_dma_cmds(state, cmd); 178 } 179 180 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id) 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); 187 spin_unlock_irqrestore(dev->host_lock, flags); 188 return IRQ_HANDLED; 189 } 190 191 static void mac53c94_interrupt(int irq, void *dev_id) 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 *const cmd = state->current_req; 197 struct mac53c94_cmd_priv *const mcmd = mac53c94_priv(cmd); 198 int nb, stat, seq, intr; 199 static int mac53c94_errors; 200 201 /* 202 * Apparently, reading the interrupt register unlatches 203 * the status and sequence step registers. 204 */ 205 seq = readb(®s->seqstep); 206 stat = readb(®s->status); 207 intr = readb(®s->interrupt); 208 209 #if 0 210 printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n", 211 intr, stat, seq, state->phase); 212 #endif 213 214 if (intr & INTR_RESET) { 215 /* SCSI bus was reset */ 216 printk(KERN_INFO "external SCSI bus reset detected\n"); 217 writeb(CMD_NOP, ®s->command); 218 writel(RUN << 16, &dma->control); /* stop dma */ 219 cmd_done(state, DID_RESET << 16); 220 return; 221 } 222 if (intr & INTR_ILL_CMD) { 223 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n", 224 intr, stat, seq, state->phase); 225 cmd_done(state, DID_ERROR << 16); 226 return; 227 } 228 if (stat & STAT_ERROR) { 229 #if 0 230 /* XXX these seem to be harmless? */ 231 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n", 232 intr, stat, seq, state->phase); 233 #endif 234 ++mac53c94_errors; 235 writeb(CMD_NOP + CMD_DMA_MODE, ®s->command); 236 } 237 if (!cmd) { 238 printk(KERN_DEBUG "53c94: interrupt with no command active?\n"); 239 return; 240 } 241 if (stat & STAT_PARITY) { 242 printk(KERN_ERR "mac53c94: parity error\n"); 243 cmd_done(state, DID_PARITY << 16); 244 return; 245 } 246 switch (state->phase) { 247 case selecting: 248 if (intr & INTR_DISCONNECT) { 249 /* selection timed out */ 250 cmd_done(state, DID_BAD_TARGET << 16); 251 return; 252 } 253 if (intr != INTR_BUS_SERV + INTR_DONE) { 254 printk(KERN_DEBUG "got intr %x during selection\n", intr); 255 cmd_done(state, DID_ERROR << 16); 256 return; 257 } 258 if ((seq & SS_MASK) != SS_DONE) { 259 printk(KERN_DEBUG "seq step %x after command\n", seq); 260 cmd_done(state, DID_ERROR << 16); 261 return; 262 } 263 writeb(CMD_NOP, ®s->command); 264 /* set DMA controller going if any data to transfer */ 265 if ((stat & (STAT_MSG|STAT_CD)) == 0 266 && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) { 267 nb = mcmd->this_residual; 268 if (nb > 0xfff0) 269 nb = 0xfff0; 270 mcmd->this_residual -= nb; 271 writeb(nb, ®s->count_lo); 272 writeb(nb >> 8, ®s->count_mid); 273 writeb(CMD_DMA_MODE + CMD_NOP, ®s->command); 274 writel(virt_to_phys(state->dma_cmds), &dma->cmdptr); 275 writel((RUN << 16) | RUN, &dma->control); 276 writeb(CMD_DMA_MODE + CMD_XFER_DATA, ®s->command); 277 state->phase = dataing; 278 break; 279 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) { 280 /* up to status phase already */ 281 writeb(CMD_I_COMPLETE, ®s->command); 282 state->phase = completing; 283 } else { 284 printk(KERN_DEBUG "in unexpected phase %x after cmd\n", 285 stat & STAT_PHASE); 286 cmd_done(state, DID_ERROR << 16); 287 return; 288 } 289 break; 290 291 case dataing: 292 if (intr != INTR_BUS_SERV) { 293 printk(KERN_DEBUG "got intr %x before status\n", intr); 294 cmd_done(state, DID_ERROR << 16); 295 return; 296 } 297 if (mcmd->this_residual != 0 298 && (stat & (STAT_MSG|STAT_CD)) == 0) { 299 /* Set up the count regs to transfer more */ 300 nb = mcmd->this_residual; 301 if (nb > 0xfff0) 302 nb = 0xfff0; 303 mcmd->this_residual -= nb; 304 writeb(nb, ®s->count_lo); 305 writeb(nb >> 8, ®s->count_mid); 306 writeb(CMD_DMA_MODE + CMD_NOP, ®s->command); 307 writeb(CMD_DMA_MODE + CMD_XFER_DATA, ®s->command); 308 break; 309 } 310 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) { 311 printk(KERN_DEBUG "intr %x before data xfer complete\n", intr); 312 } 313 writel(RUN << 16, &dma->control); /* stop dma */ 314 scsi_dma_unmap(cmd); 315 /* should check dma status */ 316 writeb(CMD_I_COMPLETE, ®s->command); 317 state->phase = completing; 318 break; 319 case completing: 320 if (intr != INTR_DONE) { 321 printk(KERN_DEBUG "got intr %x on completion\n", intr); 322 cmd_done(state, DID_ERROR << 16); 323 return; 324 } 325 mcmd->status = readb(®s->fifo); 326 mcmd->message = readb(®s->fifo); 327 writeb(CMD_ACCEPT_MSG, ®s->command); 328 state->phase = busfreeing; 329 break; 330 case busfreeing: 331 if (intr != INTR_DISCONNECT) { 332 printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr); 333 } 334 cmd_done(state, (DID_OK << 16) + (mcmd->message << 8) + mcmd->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) { 347 cmd->result = result; 348 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 dcmds->req_count = cpu_to_le16(dma_len); 383 dcmds->command = cpu_to_le16(dma_cmd); 384 dcmds->phy_addr = cpu_to_le32(dma_addr); 385 dcmds->xfer_status = 0; 386 ++dcmds; 387 } 388 389 dma_cmd += OUTPUT_LAST - OUTPUT_MORE; 390 dcmds[-1].command = cpu_to_le16(dma_cmd); 391 dcmds->command = cpu_to_le16(DBDMA_STOP); 392 mac53c94_priv(cmd)->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 .max_segment_size = 65535, 404 .cmd_size = sizeof(struct mac53c94_cmd_priv), 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 %pOF\n", node); 450 goto out_free; 451 } 452 453 clkprop = of_get_property(node, "clock-frequency", &proplen); 454 if (clkprop == NULL || proplen != sizeof(int)) { 455 printk(KERN_ERR "%pOF: can't get clock frequency, " 456 "assuming 25MHz\n", node); 457 state->clk_freq = 25000000; 458 } else 459 state->clk_freq = *(int *)clkprop; 460 461 /* Space for dma command list: +1 for stop command, 462 * +1 to allow for aligning. 463 * XXX FIXME: Use DMA consistent routines 464 */ 465 dma_cmd_space = kmalloc_array(host->sg_tablesize + 2, 466 sizeof(struct dbdma_cmd), 467 GFP_KERNEL); 468 if (!dma_cmd_space) { 469 printk(KERN_ERR "mac53c94: couldn't allocate dma " 470 "command space for %pOF\n", node); 471 rc = -ENOMEM; 472 goto out_free; 473 } 474 475 state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space); 476 memset(state->dma_cmds, 0, (host->sg_tablesize + 1) 477 * sizeof(struct dbdma_cmd)); 478 state->dma_cmd_space = dma_cmd_space; 479 480 mac53c94_init(state); 481 482 if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) { 483 printk(KERN_ERR "mac53C94: can't get irq %d for %pOF\n", 484 state->intr, node); 485 goto out_free_dma; 486 } 487 488 rc = scsi_add_host(host, &mdev->ofdev.dev); 489 if (rc != 0) 490 goto out_release_irq; 491 492 scsi_scan_host(host); 493 return 0; 494 495 out_release_irq: 496 free_irq(state->intr, state); 497 out_free_dma: 498 kfree(state->dma_cmd_space); 499 out_free: 500 if (state->dma != NULL) 501 iounmap(state->dma); 502 if (state->regs != NULL) 503 iounmap(state->regs); 504 scsi_host_put(host); 505 out_release: 506 macio_release_resources(mdev); 507 508 return rc; 509 } 510 511 static int mac53c94_remove(struct macio_dev *mdev) 512 { 513 struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev); 514 struct Scsi_Host *host = fp->host; 515 516 scsi_remove_host(host); 517 518 free_irq(fp->intr, fp); 519 520 if (fp->regs) 521 iounmap(fp->regs); 522 if (fp->dma) 523 iounmap(fp->dma); 524 kfree(fp->dma_cmd_space); 525 526 scsi_host_put(host); 527 528 macio_release_resources(mdev); 529 530 return 0; 531 } 532 533 534 static struct of_device_id mac53c94_match[] = 535 { 536 { 537 .name = "53c94", 538 }, 539 {}, 540 }; 541 MODULE_DEVICE_TABLE (of, mac53c94_match); 542 543 static struct macio_driver mac53c94_driver = 544 { 545 .driver = { 546 .name = "mac53c94", 547 .owner = THIS_MODULE, 548 .of_match_table = mac53c94_match, 549 }, 550 .probe = mac53c94_probe, 551 .remove = mac53c94_remove, 552 }; 553 554 555 static int __init init_mac53c94(void) 556 { 557 return macio_register_driver(&mac53c94_driver); 558 } 559 560 static void __exit exit_mac53c94(void) 561 { 562 return macio_unregister_driver(&mac53c94_driver); 563 } 564 565 module_init(init_mac53c94); 566 module_exit(exit_mac53c94); 567 568 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver"); 569 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>"); 570 MODULE_LICENSE("GPL"); 571