1 /* mac_esp.c: ESP front-end for Macintosh Quadra systems. 2 * 3 * Adapted from jazz_esp.c and the old mac_esp.c. 4 * 5 * The pseudo DMA algorithm is based on the one used in NetBSD. 6 * See sys/arch/mac68k/obio/esp.c for some background information. 7 * 8 * Copyright (C) 2007-2008 Finn Thain 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/types.h> 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/interrupt.h> 16 #include <linux/platform_device.h> 17 #include <linux/dma-mapping.h> 18 #include <linux/scatterlist.h> 19 #include <linux/delay.h> 20 #include <linux/io.h> 21 #include <linux/nubus.h> 22 23 #include <asm/irq.h> 24 #include <asm/dma.h> 25 #include <asm/macints.h> 26 #include <asm/macintosh.h> 27 28 #include <scsi/scsi_host.h> 29 30 #include "esp_scsi.h" 31 32 #define DRV_MODULE_NAME "mac_esp" 33 #define PFX DRV_MODULE_NAME ": " 34 #define DRV_VERSION "1.000" 35 #define DRV_MODULE_RELDATE "Sept 15, 2007" 36 37 #define MAC_ESP_IO_BASE 0x50F00000 38 #define MAC_ESP_REGS_QUADRA (MAC_ESP_IO_BASE + 0x10000) 39 #define MAC_ESP_REGS_QUADRA2 (MAC_ESP_IO_BASE + 0xF000) 40 #define MAC_ESP_REGS_QUADRA3 (MAC_ESP_IO_BASE + 0x18000) 41 #define MAC_ESP_REGS_SPACING 0x402 42 #define MAC_ESP_PDMA_REG 0xF9800024 43 #define MAC_ESP_PDMA_REG_SPACING 0x4 44 #define MAC_ESP_PDMA_IO_OFFSET 0x100 45 46 #define esp_read8(REG) mac_esp_read8(esp, REG) 47 #define esp_write8(VAL, REG) mac_esp_write8(esp, VAL, REG) 48 49 struct mac_esp_priv { 50 struct esp *esp; 51 void __iomem *pdma_regs; 52 void __iomem *pdma_io; 53 int error; 54 }; 55 static struct esp *esp_chips[2]; 56 57 #define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \ 58 platform_get_drvdata((struct platform_device *) \ 59 (esp->dev))) 60 61 static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg) 62 { 63 nubus_writeb(val, esp->regs + reg * 16); 64 } 65 66 static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg) 67 { 68 return nubus_readb(esp->regs + reg * 16); 69 } 70 71 /* For pseudo DMA and PIO we need the virtual address 72 * so this address mapping is the identity mapping. 73 */ 74 75 static dma_addr_t mac_esp_map_single(struct esp *esp, void *buf, 76 size_t sz, int dir) 77 { 78 return (dma_addr_t)buf; 79 } 80 81 static int mac_esp_map_sg(struct esp *esp, struct scatterlist *sg, 82 int num_sg, int dir) 83 { 84 int i; 85 86 for (i = 0; i < num_sg; i++) 87 sg[i].dma_address = (u32)sg_virt(&sg[i]); 88 return num_sg; 89 } 90 91 static void mac_esp_unmap_single(struct esp *esp, dma_addr_t addr, 92 size_t sz, int dir) 93 { 94 /* Nothing to do. */ 95 } 96 97 static void mac_esp_unmap_sg(struct esp *esp, struct scatterlist *sg, 98 int num_sg, int dir) 99 { 100 /* Nothing to do. */ 101 } 102 103 static void mac_esp_reset_dma(struct esp *esp) 104 { 105 /* Nothing to do. */ 106 } 107 108 static void mac_esp_dma_drain(struct esp *esp) 109 { 110 /* Nothing to do. */ 111 } 112 113 static void mac_esp_dma_invalidate(struct esp *esp) 114 { 115 /* Nothing to do. */ 116 } 117 118 static int mac_esp_dma_error(struct esp *esp) 119 { 120 return MAC_ESP_GET_PRIV(esp)->error; 121 } 122 123 static inline int mac_esp_wait_for_empty_fifo(struct esp *esp) 124 { 125 struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp); 126 int i = 500000; 127 128 do { 129 if (!(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES)) 130 return 0; 131 132 if (esp_read8(ESP_STATUS) & ESP_STAT_INTR) 133 return 1; 134 135 udelay(2); 136 } while (--i); 137 138 printk(KERN_ERR PFX "FIFO is not empty (sreg %02x)\n", 139 esp_read8(ESP_STATUS)); 140 mep->error = 1; 141 return 1; 142 } 143 144 static inline int mac_esp_wait_for_dreq(struct esp *esp) 145 { 146 struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp); 147 int i = 500000; 148 149 do { 150 if (mep->pdma_regs == NULL) { 151 if (mac_irq_pending(IRQ_MAC_SCSIDRQ)) 152 return 0; 153 } else { 154 if (nubus_readl(mep->pdma_regs) & 0x200) 155 return 0; 156 } 157 158 if (esp_read8(ESP_STATUS) & ESP_STAT_INTR) 159 return 1; 160 161 udelay(2); 162 } while (--i); 163 164 printk(KERN_ERR PFX "PDMA timeout (sreg %02x)\n", 165 esp_read8(ESP_STATUS)); 166 mep->error = 1; 167 return 1; 168 } 169 170 #define MAC_ESP_PDMA_LOOP(operands) \ 171 asm volatile ( \ 172 " tstw %1 \n" \ 173 " jbeq 20f \n" \ 174 "1: movew " operands " \n" \ 175 "2: movew " operands " \n" \ 176 "3: movew " operands " \n" \ 177 "4: movew " operands " \n" \ 178 "5: movew " operands " \n" \ 179 "6: movew " operands " \n" \ 180 "7: movew " operands " \n" \ 181 "8: movew " operands " \n" \ 182 "9: movew " operands " \n" \ 183 "10: movew " operands " \n" \ 184 "11: movew " operands " \n" \ 185 "12: movew " operands " \n" \ 186 "13: movew " operands " \n" \ 187 "14: movew " operands " \n" \ 188 "15: movew " operands " \n" \ 189 "16: movew " operands " \n" \ 190 " subqw #1,%1 \n" \ 191 " jbne 1b \n" \ 192 "20: tstw %2 \n" \ 193 " jbeq 30f \n" \ 194 "21: movew " operands " \n" \ 195 " subqw #1,%2 \n" \ 196 " jbne 21b \n" \ 197 "30: tstw %3 \n" \ 198 " jbeq 40f \n" \ 199 "31: moveb " operands " \n" \ 200 "32: nop \n" \ 201 "40: \n" \ 202 " \n" \ 203 " .section __ex_table,\"a\" \n" \ 204 " .align 4 \n" \ 205 " .long 1b,40b \n" \ 206 " .long 2b,40b \n" \ 207 " .long 3b,40b \n" \ 208 " .long 4b,40b \n" \ 209 " .long 5b,40b \n" \ 210 " .long 6b,40b \n" \ 211 " .long 7b,40b \n" \ 212 " .long 8b,40b \n" \ 213 " .long 9b,40b \n" \ 214 " .long 10b,40b \n" \ 215 " .long 11b,40b \n" \ 216 " .long 12b,40b \n" \ 217 " .long 13b,40b \n" \ 218 " .long 14b,40b \n" \ 219 " .long 15b,40b \n" \ 220 " .long 16b,40b \n" \ 221 " .long 21b,40b \n" \ 222 " .long 31b,40b \n" \ 223 " .long 32b,40b \n" \ 224 " .previous \n" \ 225 : "+a" (addr), "+r" (count32), "+r" (count2) \ 226 : "g" (count1), "a" (mep->pdma_io)) 227 228 static void mac_esp_send_pdma_cmd(struct esp *esp, u32 addr, u32 esp_count, 229 u32 dma_count, int write, u8 cmd) 230 { 231 struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp); 232 unsigned long flags; 233 234 local_irq_save(flags); 235 236 mep->error = 0; 237 238 if (!write) 239 scsi_esp_cmd(esp, ESP_CMD_FLUSH); 240 241 esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW); 242 esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED); 243 244 scsi_esp_cmd(esp, cmd); 245 246 do { 247 unsigned int count32 = esp_count >> 5; 248 unsigned int count2 = (esp_count & 0x1F) >> 1; 249 unsigned int count1 = esp_count & 1; 250 unsigned int start_addr = addr; 251 252 if (mac_esp_wait_for_dreq(esp)) 253 break; 254 255 if (write) { 256 MAC_ESP_PDMA_LOOP("%4@,%0@+"); 257 258 esp_count -= addr - start_addr; 259 } else { 260 unsigned int n; 261 262 MAC_ESP_PDMA_LOOP("%0@+,%4@"); 263 264 if (mac_esp_wait_for_empty_fifo(esp)) 265 break; 266 267 n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW); 268 addr = start_addr + esp_count - n; 269 esp_count = n; 270 } 271 } while (esp_count); 272 273 local_irq_restore(flags); 274 } 275 276 /* 277 * Programmed IO routines follow. 278 */ 279 280 static inline unsigned int mac_esp_wait_for_fifo(struct esp *esp) 281 { 282 int i = 500000; 283 284 do { 285 unsigned int fbytes = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES; 286 287 if (fbytes) 288 return fbytes; 289 290 udelay(2); 291 } while (--i); 292 293 printk(KERN_ERR PFX "FIFO is empty (sreg %02x)\n", 294 esp_read8(ESP_STATUS)); 295 return 0; 296 } 297 298 static inline int mac_esp_wait_for_intr(struct esp *esp) 299 { 300 struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp); 301 int i = 500000; 302 303 do { 304 esp->sreg = esp_read8(ESP_STATUS); 305 if (esp->sreg & ESP_STAT_INTR) 306 return 0; 307 308 udelay(2); 309 } while (--i); 310 311 printk(KERN_ERR PFX "IRQ timeout (sreg %02x)\n", esp->sreg); 312 mep->error = 1; 313 return 1; 314 } 315 316 #define MAC_ESP_PIO_LOOP(operands, reg1) \ 317 asm volatile ( \ 318 "1: moveb " operands " \n" \ 319 " subqw #1,%1 \n" \ 320 " jbne 1b \n" \ 321 : "+a" (addr), "+r" (reg1) \ 322 : "a" (fifo)) 323 324 #define MAC_ESP_PIO_FILL(operands, reg1) \ 325 asm volatile ( \ 326 " moveb " operands " \n" \ 327 " moveb " operands " \n" \ 328 " moveb " operands " \n" \ 329 " moveb " operands " \n" \ 330 " moveb " operands " \n" \ 331 " moveb " operands " \n" \ 332 " moveb " operands " \n" \ 333 " moveb " operands " \n" \ 334 " moveb " operands " \n" \ 335 " moveb " operands " \n" \ 336 " moveb " operands " \n" \ 337 " moveb " operands " \n" \ 338 " moveb " operands " \n" \ 339 " moveb " operands " \n" \ 340 " moveb " operands " \n" \ 341 " moveb " operands " \n" \ 342 " subqw #8,%1 \n" \ 343 " subqw #8,%1 \n" \ 344 : "+a" (addr), "+r" (reg1) \ 345 : "a" (fifo)) 346 347 #define MAC_ESP_FIFO_SIZE 16 348 349 static void mac_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count, 350 u32 dma_count, int write, u8 cmd) 351 { 352 struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp); 353 u8 *fifo = esp->regs + ESP_FDATA * 16; 354 355 disable_irq(esp->host->irq); 356 357 cmd &= ~ESP_CMD_DMA; 358 mep->error = 0; 359 360 if (write) { 361 scsi_esp_cmd(esp, cmd); 362 363 while (1) { 364 unsigned int n; 365 366 n = mac_esp_wait_for_fifo(esp); 367 if (!n) 368 break; 369 370 if (n > esp_count) 371 n = esp_count; 372 esp_count -= n; 373 374 MAC_ESP_PIO_LOOP("%2@,%0@+", n); 375 376 if (!esp_count) 377 break; 378 379 if (mac_esp_wait_for_intr(esp)) 380 break; 381 382 if (((esp->sreg & ESP_STAT_PMASK) != ESP_DIP) && 383 ((esp->sreg & ESP_STAT_PMASK) != ESP_MIP)) 384 break; 385 386 esp->ireg = esp_read8(ESP_INTRPT); 387 if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) != 388 ESP_INTR_BSERV) 389 break; 390 391 scsi_esp_cmd(esp, ESP_CMD_TI); 392 } 393 } else { 394 scsi_esp_cmd(esp, ESP_CMD_FLUSH); 395 396 if (esp_count >= MAC_ESP_FIFO_SIZE) 397 MAC_ESP_PIO_FILL("%0@+,%2@", esp_count); 398 else 399 MAC_ESP_PIO_LOOP("%0@+,%2@", esp_count); 400 401 scsi_esp_cmd(esp, cmd); 402 403 while (esp_count) { 404 unsigned int n; 405 406 if (mac_esp_wait_for_intr(esp)) 407 break; 408 409 if (((esp->sreg & ESP_STAT_PMASK) != ESP_DOP) && 410 ((esp->sreg & ESP_STAT_PMASK) != ESP_MOP)) 411 break; 412 413 esp->ireg = esp_read8(ESP_INTRPT); 414 if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) != 415 ESP_INTR_BSERV) 416 break; 417 418 n = MAC_ESP_FIFO_SIZE - 419 (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES); 420 if (n > esp_count) 421 n = esp_count; 422 423 if (n == MAC_ESP_FIFO_SIZE) { 424 MAC_ESP_PIO_FILL("%0@+,%2@", esp_count); 425 } else { 426 esp_count -= n; 427 MAC_ESP_PIO_LOOP("%0@+,%2@", n); 428 } 429 430 scsi_esp_cmd(esp, ESP_CMD_TI); 431 } 432 } 433 434 enable_irq(esp->host->irq); 435 } 436 437 static int mac_esp_irq_pending(struct esp *esp) 438 { 439 if (esp_read8(ESP_STATUS) & ESP_STAT_INTR) 440 return 1; 441 return 0; 442 } 443 444 static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len) 445 { 446 return dma_len > 0xFFFF ? 0xFFFF : dma_len; 447 } 448 449 static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id) 450 { 451 int got_intr; 452 453 /* 454 * This is an edge triggered IRQ, so we have to be careful to 455 * avoid missing a transition when it is shared by two ESP devices. 456 */ 457 458 do { 459 got_intr = 0; 460 if (esp_chips[0] && 461 (mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) { 462 (void)scsi_esp_intr(irq, esp_chips[0]); 463 got_intr = 1; 464 } 465 if (esp_chips[1] && 466 (mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) { 467 (void)scsi_esp_intr(irq, esp_chips[1]); 468 got_intr = 1; 469 } 470 } while (got_intr); 471 472 return IRQ_HANDLED; 473 } 474 475 static struct esp_driver_ops mac_esp_ops = { 476 .esp_write8 = mac_esp_write8, 477 .esp_read8 = mac_esp_read8, 478 .map_single = mac_esp_map_single, 479 .map_sg = mac_esp_map_sg, 480 .unmap_single = mac_esp_unmap_single, 481 .unmap_sg = mac_esp_unmap_sg, 482 .irq_pending = mac_esp_irq_pending, 483 .dma_length_limit = mac_esp_dma_length_limit, 484 .reset_dma = mac_esp_reset_dma, 485 .dma_drain = mac_esp_dma_drain, 486 .dma_invalidate = mac_esp_dma_invalidate, 487 .send_dma_cmd = mac_esp_send_pdma_cmd, 488 .dma_error = mac_esp_dma_error, 489 }; 490 491 static int __devinit esp_mac_probe(struct platform_device *dev) 492 { 493 struct scsi_host_template *tpnt = &scsi_esp_template; 494 struct Scsi_Host *host; 495 struct esp *esp; 496 int err; 497 struct mac_esp_priv *mep; 498 499 if (!MACH_IS_MAC) 500 return -ENODEV; 501 502 if (dev->id > 1) 503 return -ENODEV; 504 505 host = scsi_host_alloc(tpnt, sizeof(struct esp)); 506 507 err = -ENOMEM; 508 if (!host) 509 goto fail; 510 511 host->max_id = 8; 512 host->use_clustering = DISABLE_CLUSTERING; 513 esp = shost_priv(host); 514 515 esp->host = host; 516 esp->dev = dev; 517 518 esp->command_block = kzalloc(16, GFP_KERNEL); 519 if (!esp->command_block) 520 goto fail_unlink; 521 esp->command_block_dma = (dma_addr_t)esp->command_block; 522 523 esp->scsi_id = 7; 524 host->this_id = esp->scsi_id; 525 esp->scsi_id_mask = 1 << esp->scsi_id; 526 527 mep = kzalloc(sizeof(struct mac_esp_priv), GFP_KERNEL); 528 if (!mep) 529 goto fail_free_command_block; 530 mep->esp = esp; 531 platform_set_drvdata(dev, mep); 532 533 switch (macintosh_config->scsi_type) { 534 case MAC_SCSI_QUADRA: 535 esp->cfreq = 16500000; 536 esp->regs = (void __iomem *)MAC_ESP_REGS_QUADRA; 537 mep->pdma_io = esp->regs + MAC_ESP_PDMA_IO_OFFSET; 538 mep->pdma_regs = NULL; 539 break; 540 case MAC_SCSI_QUADRA2: 541 esp->cfreq = 25000000; 542 esp->regs = (void __iomem *)(MAC_ESP_REGS_QUADRA2 + 543 dev->id * MAC_ESP_REGS_SPACING); 544 mep->pdma_io = esp->regs + MAC_ESP_PDMA_IO_OFFSET; 545 mep->pdma_regs = (void __iomem *)(MAC_ESP_PDMA_REG + 546 dev->id * MAC_ESP_PDMA_REG_SPACING); 547 nubus_writel(0x1d1, mep->pdma_regs); 548 break; 549 case MAC_SCSI_QUADRA3: 550 /* These quadras have a real DMA controller (the PSC) but we 551 * don't know how to drive it so we must use PIO instead. 552 */ 553 esp->cfreq = 25000000; 554 esp->regs = (void __iomem *)MAC_ESP_REGS_QUADRA3; 555 mep->pdma_io = NULL; 556 mep->pdma_regs = NULL; 557 break; 558 } 559 560 esp->ops = &mac_esp_ops; 561 if (mep->pdma_io == NULL) { 562 printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id); 563 esp_write8(0, ESP_TCLOW); 564 esp_write8(0, ESP_TCMED); 565 esp->flags = ESP_FLAG_DISABLE_SYNC; 566 mac_esp_ops.send_dma_cmd = mac_esp_send_pio_cmd; 567 } else { 568 printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id); 569 } 570 571 host->irq = IRQ_MAC_SCSI; 572 esp_chips[dev->id] = esp; 573 mb(); 574 if (esp_chips[!dev->id] == NULL) { 575 err = request_irq(host->irq, mac_scsi_esp_intr, 0, 576 "Mac ESP", NULL); 577 if (err < 0) { 578 esp_chips[dev->id] = NULL; 579 goto fail_free_priv; 580 } 581 } 582 583 err = scsi_esp_register(esp, &dev->dev); 584 if (err) 585 goto fail_free_irq; 586 587 return 0; 588 589 fail_free_irq: 590 if (esp_chips[!dev->id] == NULL) 591 free_irq(host->irq, esp); 592 fail_free_priv: 593 kfree(mep); 594 fail_free_command_block: 595 kfree(esp->command_block); 596 fail_unlink: 597 scsi_host_put(host); 598 fail: 599 return err; 600 } 601 602 static int __devexit esp_mac_remove(struct platform_device *dev) 603 { 604 struct mac_esp_priv *mep = platform_get_drvdata(dev); 605 struct esp *esp = mep->esp; 606 unsigned int irq = esp->host->irq; 607 608 scsi_esp_unregister(esp); 609 610 esp_chips[dev->id] = NULL; 611 if (!(esp_chips[0] || esp_chips[1])) 612 free_irq(irq, NULL); 613 614 kfree(mep); 615 616 kfree(esp->command_block); 617 618 scsi_host_put(esp->host); 619 620 return 0; 621 } 622 623 static struct platform_driver esp_mac_driver = { 624 .probe = esp_mac_probe, 625 .remove = __devexit_p(esp_mac_remove), 626 .driver = { 627 .name = DRV_MODULE_NAME, 628 .owner = THIS_MODULE, 629 }, 630 }; 631 632 static int __init mac_esp_init(void) 633 { 634 return platform_driver_register(&esp_mac_driver); 635 } 636 637 static void __exit mac_esp_exit(void) 638 { 639 platform_driver_unregister(&esp_mac_driver); 640 } 641 642 MODULE_DESCRIPTION("Mac ESP SCSI driver"); 643 MODULE_AUTHOR("Finn Thain <fthain@telegraphics.com.au>"); 644 MODULE_LICENSE("GPL v2"); 645 MODULE_VERSION(DRV_VERSION); 646 MODULE_ALIAS("platform:" DRV_MODULE_NAME); 647 648 module_init(mac_esp_init); 649 module_exit(mac_esp_exit); 650