linux/drivers/scsi/mac_esp.c
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   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#include <linux/slab.h>
  23
  24#include <asm/irq.h>
  25#include <asm/dma.h>
  26#include <asm/macints.h>
  27#include <asm/macintosh.h>
  28
  29#include <scsi/scsi_host.h>
  30
  31#include "esp_scsi.h"
  32
  33#define DRV_MODULE_NAME     "mac_esp"
  34#define PFX                 DRV_MODULE_NAME ": "
  35#define DRV_VERSION         "1.000"
  36#define DRV_MODULE_RELDATE  "Sept 15, 2007"
  37
  38#define MAC_ESP_IO_BASE          0x50F00000
  39#define MAC_ESP_REGS_QUADRA      (MAC_ESP_IO_BASE + 0x10000)
  40#define MAC_ESP_REGS_QUADRA2     (MAC_ESP_IO_BASE + 0xF000)
  41#define MAC_ESP_REGS_QUADRA3     (MAC_ESP_IO_BASE + 0x18000)
  42#define MAC_ESP_REGS_SPACING     0x402
  43#define MAC_ESP_PDMA_REG         0xF9800024
  44#define MAC_ESP_PDMA_REG_SPACING 0x4
  45#define MAC_ESP_PDMA_IO_OFFSET   0x100
  46
  47#define esp_read8(REG)          mac_esp_read8(esp, REG)
  48#define esp_write8(VAL, REG)    mac_esp_write8(esp, VAL, REG)
  49
  50struct mac_esp_priv {
  51        struct esp *esp;
  52        void __iomem *pdma_regs;
  53        void __iomem *pdma_io;
  54        int error;
  55};
  56static struct esp *esp_chips[2];
  57
  58#define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \
  59                               platform_get_drvdata((struct platform_device *) \
  60                                                    (esp->dev)))
  61
  62static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg)
  63{
  64        nubus_writeb(val, esp->regs + reg * 16);
  65}
  66
  67static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg)
  68{
  69        return nubus_readb(esp->regs + reg * 16);
  70}
  71
  72/* For pseudo DMA and PIO we need the virtual address
  73 * so this address mapping is the identity mapping.
  74 */
  75
  76static dma_addr_t mac_esp_map_single(struct esp *esp, void *buf,
  77                                     size_t sz, int dir)
  78{
  79        return (dma_addr_t)buf;
  80}
  81
  82static int mac_esp_map_sg(struct esp *esp, struct scatterlist *sg,
  83                          int num_sg, int dir)
  84{
  85        int i;
  86
  87        for (i = 0; i < num_sg; i++)
  88                sg[i].dma_address = (u32)sg_virt(&sg[i]);
  89        return num_sg;
  90}
  91
  92static void mac_esp_unmap_single(struct esp *esp, dma_addr_t addr,
  93                                 size_t sz, int dir)
  94{
  95        /* Nothing to do. */
  96}
  97
  98static void mac_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
  99                             int num_sg, int dir)
 100{
 101        /* Nothing to do. */
 102}
 103
 104static void mac_esp_reset_dma(struct esp *esp)
 105{
 106        /* Nothing to do. */
 107}
 108
 109static void mac_esp_dma_drain(struct esp *esp)
 110{
 111        /* Nothing to do. */
 112}
 113
 114static void mac_esp_dma_invalidate(struct esp *esp)
 115{
 116        /* Nothing to do. */
 117}
 118
 119static int mac_esp_dma_error(struct esp *esp)
 120{
 121        return MAC_ESP_GET_PRIV(esp)->error;
 122}
 123
 124static inline int mac_esp_wait_for_empty_fifo(struct esp *esp)
 125{
 126        struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 127        int i = 500000;
 128
 129        do {
 130                if (!(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES))
 131                        return 0;
 132
 133                if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
 134                        return 1;
 135
 136                udelay(2);
 137        } while (--i);
 138
 139        printk(KERN_ERR PFX "FIFO is not empty (sreg %02x)\n",
 140               esp_read8(ESP_STATUS));
 141        mep->error = 1;
 142        return 1;
 143}
 144
 145static inline int mac_esp_wait_for_dreq(struct esp *esp)
 146{
 147        struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 148        int i = 500000;
 149
 150        do {
 151                if (mep->pdma_regs == NULL) {
 152                        if (mac_irq_pending(IRQ_MAC_SCSIDRQ))
 153                                return 0;
 154                } else {
 155                        if (nubus_readl(mep->pdma_regs) & 0x200)
 156                                return 0;
 157                }
 158
 159                if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
 160                        return 1;
 161
 162                udelay(2);
 163        } while (--i);
 164
 165        printk(KERN_ERR PFX "PDMA timeout (sreg %02x)\n",
 166               esp_read8(ESP_STATUS));
 167        mep->error = 1;
 168        return 1;
 169}
 170
 171#define MAC_ESP_PDMA_LOOP(operands) \
 172        asm volatile ( \
 173             "       tstw %1                   \n" \
 174             "       jbeq 20f                  \n" \
 175             "1:     movew " operands "        \n" \
 176             "2:     movew " operands "        \n" \
 177             "3:     movew " operands "        \n" \
 178             "4:     movew " operands "        \n" \
 179             "5:     movew " operands "        \n" \
 180             "6:     movew " operands "        \n" \
 181             "7:     movew " operands "        \n" \
 182             "8:     movew " operands "        \n" \
 183             "9:     movew " operands "        \n" \
 184             "10:    movew " operands "        \n" \
 185             "11:    movew " operands "        \n" \
 186             "12:    movew " operands "        \n" \
 187             "13:    movew " operands "        \n" \
 188             "14:    movew " operands "        \n" \
 189             "15:    movew " operands "        \n" \
 190             "16:    movew " operands "        \n" \
 191             "       subqw #1,%1               \n" \
 192             "       jbne 1b                   \n" \
 193             "20:    tstw %2                   \n" \
 194             "       jbeq 30f                  \n" \
 195             "21:    movew " operands "        \n" \
 196             "       subqw #1,%2               \n" \
 197             "       jbne 21b                  \n" \
 198             "30:    tstw %3                   \n" \
 199             "       jbeq 40f                  \n" \
 200             "31:    moveb " operands "        \n" \
 201             "32:    nop                       \n" \
 202             "40:                              \n" \
 203             "                                 \n" \
 204             "       .section __ex_table,\"a\" \n" \
 205             "       .align  4                 \n" \
 206             "       .long   1b,40b            \n" \
 207             "       .long   2b,40b            \n" \
 208             "       .long   3b,40b            \n" \
 209             "       .long   4b,40b            \n" \
 210             "       .long   5b,40b            \n" \
 211             "       .long   6b,40b            \n" \
 212             "       .long   7b,40b            \n" \
 213             "       .long   8b,40b            \n" \
 214             "       .long   9b,40b            \n" \
 215             "       .long  10b,40b            \n" \
 216             "       .long  11b,40b            \n" \
 217             "       .long  12b,40b            \n" \
 218             "       .long  13b,40b            \n" \
 219             "       .long  14b,40b            \n" \
 220             "       .long  15b,40b            \n" \
 221             "       .long  16b,40b            \n" \
 222             "       .long  21b,40b            \n" \
 223             "       .long  31b,40b            \n" \
 224             "       .long  32b,40b            \n" \
 225             "       .previous                 \n" \
 226             : "+a" (addr), "+r" (count32), "+r" (count2) \
 227             : "g" (count1), "a" (mep->pdma_io))
 228
 229static void mac_esp_send_pdma_cmd(struct esp *esp, u32 addr, u32 esp_count,
 230                                  u32 dma_count, int write, u8 cmd)
 231{
 232        struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 233        unsigned long flags;
 234
 235        local_irq_save(flags);
 236
 237        mep->error = 0;
 238
 239        if (!write)
 240                scsi_esp_cmd(esp, ESP_CMD_FLUSH);
 241
 242        esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW);
 243        esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED);
 244
 245        scsi_esp_cmd(esp, cmd);
 246
 247        do {
 248                unsigned int count32 = esp_count >> 5;
 249                unsigned int count2 = (esp_count & 0x1F) >> 1;
 250                unsigned int count1 = esp_count & 1;
 251                unsigned int start_addr = addr;
 252
 253                if (mac_esp_wait_for_dreq(esp))
 254                        break;
 255
 256                if (write) {
 257                        MAC_ESP_PDMA_LOOP("%4@,%0@+");
 258
 259                        esp_count -= addr - start_addr;
 260                } else {
 261                        unsigned int n;
 262
 263                        MAC_ESP_PDMA_LOOP("%0@+,%4@");
 264
 265                        if (mac_esp_wait_for_empty_fifo(esp))
 266                                break;
 267
 268                        n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW);
 269                        addr = start_addr + esp_count - n;
 270                        esp_count = n;
 271                }
 272        } while (esp_count);
 273
 274        local_irq_restore(flags);
 275}
 276
 277/*
 278 * Programmed IO routines follow.
 279 */
 280
 281static inline unsigned int mac_esp_wait_for_fifo(struct esp *esp)
 282{
 283        int i = 500000;
 284
 285        do {
 286                unsigned int fbytes = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
 287
 288                if (fbytes)
 289                        return fbytes;
 290
 291                udelay(2);
 292        } while (--i);
 293
 294        printk(KERN_ERR PFX "FIFO is empty (sreg %02x)\n",
 295               esp_read8(ESP_STATUS));
 296        return 0;
 297}
 298
 299static inline int mac_esp_wait_for_intr(struct esp *esp)
 300{
 301        struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 302        int i = 500000;
 303
 304        do {
 305                esp->sreg = esp_read8(ESP_STATUS);
 306                if (esp->sreg & ESP_STAT_INTR)
 307                        return 0;
 308
 309                udelay(2);
 310        } while (--i);
 311
 312        printk(KERN_ERR PFX "IRQ timeout (sreg %02x)\n", esp->sreg);
 313        mep->error = 1;
 314        return 1;
 315}
 316
 317#define MAC_ESP_PIO_LOOP(operands, reg1) \
 318        asm volatile ( \
 319             "1:     moveb " operands " \n" \
 320             "       subqw #1,%1        \n" \
 321             "       jbne 1b            \n" \
 322             : "+a" (addr), "+r" (reg1) \
 323             : "a" (fifo))
 324
 325#define MAC_ESP_PIO_FILL(operands, reg1) \
 326        asm volatile ( \
 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             "       moveb " operands " \n" \
 343             "       subqw #8,%1        \n" \
 344             "       subqw #8,%1        \n" \
 345             : "+a" (addr), "+r" (reg1) \
 346             : "a" (fifo))
 347
 348#define MAC_ESP_FIFO_SIZE 16
 349
 350static void mac_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count,
 351                                 u32 dma_count, int write, u8 cmd)
 352{
 353        struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 354        u8 *fifo = esp->regs + ESP_FDATA * 16;
 355
 356        disable_irq(esp->host->irq);
 357
 358        cmd &= ~ESP_CMD_DMA;
 359        mep->error = 0;
 360
 361        if (write) {
 362                scsi_esp_cmd(esp, cmd);
 363
 364                while (1) {
 365                        unsigned int n;
 366
 367                        n = mac_esp_wait_for_fifo(esp);
 368                        if (!n)
 369                                break;
 370
 371                        if (n > esp_count)
 372                                n = esp_count;
 373                        esp_count -= n;
 374
 375                        MAC_ESP_PIO_LOOP("%2@,%0@+", n);
 376
 377                        if (!esp_count)
 378                                break;
 379
 380                        if (mac_esp_wait_for_intr(esp))
 381                                break;
 382
 383                        if (((esp->sreg & ESP_STAT_PMASK) != ESP_DIP) &&
 384                            ((esp->sreg & ESP_STAT_PMASK) != ESP_MIP))
 385                                break;
 386
 387                        esp->ireg = esp_read8(ESP_INTRPT);
 388                        if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
 389                            ESP_INTR_BSERV)
 390                                break;
 391
 392                        scsi_esp_cmd(esp, ESP_CMD_TI);
 393                }
 394        } else {
 395                scsi_esp_cmd(esp, ESP_CMD_FLUSH);
 396
 397                if (esp_count >= MAC_ESP_FIFO_SIZE)
 398                        MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
 399                else
 400                        MAC_ESP_PIO_LOOP("%0@+,%2@", esp_count);
 401
 402                scsi_esp_cmd(esp, cmd);
 403
 404                while (esp_count) {
 405                        unsigned int n;
 406
 407                        if (mac_esp_wait_for_intr(esp))
 408                                break;
 409
 410                        if (((esp->sreg & ESP_STAT_PMASK) != ESP_DOP) &&
 411                            ((esp->sreg & ESP_STAT_PMASK) != ESP_MOP))
 412                                break;
 413
 414                        esp->ireg = esp_read8(ESP_INTRPT);
 415                        if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
 416                            ESP_INTR_BSERV)
 417                                break;
 418
 419                        n = MAC_ESP_FIFO_SIZE -
 420                            (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES);
 421                        if (n > esp_count)
 422                                n = esp_count;
 423
 424                        if (n == MAC_ESP_FIFO_SIZE) {
 425                                MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
 426                        } else {
 427                                esp_count -= n;
 428                                MAC_ESP_PIO_LOOP("%0@+,%2@", n);
 429                        }
 430
 431                        scsi_esp_cmd(esp, ESP_CMD_TI);
 432                }
 433        }
 434
 435        enable_irq(esp->host->irq);
 436}
 437
 438static int mac_esp_irq_pending(struct esp *esp)
 439{
 440        if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
 441                return 1;
 442        return 0;
 443}
 444
 445static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
 446{
 447        return dma_len > 0xFFFF ? 0xFFFF : dma_len;
 448}
 449
 450static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id)
 451{
 452        int got_intr;
 453
 454        /*
 455         * This is an edge triggered IRQ, so we have to be careful to
 456         * avoid missing a transition when it is shared by two ESP devices.
 457         */
 458
 459        do {
 460                got_intr = 0;
 461                if (esp_chips[0] &&
 462                    (mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) {
 463                        (void)scsi_esp_intr(irq, esp_chips[0]);
 464                        got_intr = 1;
 465                }
 466                if (esp_chips[1] &&
 467                    (mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) {
 468                        (void)scsi_esp_intr(irq, esp_chips[1]);
 469                        got_intr = 1;
 470                }
 471        } while (got_intr);
 472
 473        return IRQ_HANDLED;
 474}
 475
 476static struct esp_driver_ops mac_esp_ops = {
 477        .esp_write8       = mac_esp_write8,
 478        .esp_read8        = mac_esp_read8,
 479        .map_single       = mac_esp_map_single,
 480        .map_sg           = mac_esp_map_sg,
 481        .unmap_single     = mac_esp_unmap_single,
 482        .unmap_sg         = mac_esp_unmap_sg,
 483        .irq_pending      = mac_esp_irq_pending,
 484        .dma_length_limit = mac_esp_dma_length_limit,
 485        .reset_dma        = mac_esp_reset_dma,
 486        .dma_drain        = mac_esp_dma_drain,
 487        .dma_invalidate   = mac_esp_dma_invalidate,
 488        .send_dma_cmd     = mac_esp_send_pdma_cmd,
 489        .dma_error        = mac_esp_dma_error,
 490};
 491
 492static int __devinit esp_mac_probe(struct platform_device *dev)
 493{
 494        struct scsi_host_template *tpnt = &scsi_esp_template;
 495        struct Scsi_Host *host;
 496        struct esp *esp;
 497        int err;
 498        struct mac_esp_priv *mep;
 499
 500        if (!MACH_IS_MAC)
 501                return -ENODEV;
 502
 503        if (dev->id > 1)
 504                return -ENODEV;
 505
 506        host = scsi_host_alloc(tpnt, sizeof(struct esp));
 507
 508        err = -ENOMEM;
 509        if (!host)
 510                goto fail;
 511
 512        host->max_id = 8;
 513        host->use_clustering = DISABLE_CLUSTERING;
 514        esp = shost_priv(host);
 515
 516        esp->host = host;
 517        esp->dev = dev;
 518
 519        esp->command_block = kzalloc(16, GFP_KERNEL);
 520        if (!esp->command_block)
 521                goto fail_unlink;
 522        esp->command_block_dma = (dma_addr_t)esp->command_block;
 523
 524        esp->scsi_id = 7;
 525        host->this_id = esp->scsi_id;
 526        esp->scsi_id_mask = 1 << esp->scsi_id;
 527
 528        mep = kzalloc(sizeof(struct mac_esp_priv), GFP_KERNEL);
 529        if (!mep)
 530                goto fail_free_command_block;
 531        mep->esp = esp;
 532        platform_set_drvdata(dev, mep);
 533
 534        switch (macintosh_config->scsi_type) {
 535        case MAC_SCSI_QUADRA:
 536                esp->cfreq     = 16500000;
 537                esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA;
 538                mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
 539                mep->pdma_regs = NULL;
 540                break;
 541        case MAC_SCSI_QUADRA2:
 542                esp->cfreq     = 25000000;
 543                esp->regs      = (void __iomem *)(MAC_ESP_REGS_QUADRA2 +
 544                                 dev->id * MAC_ESP_REGS_SPACING);
 545                mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
 546                mep->pdma_regs = (void __iomem *)(MAC_ESP_PDMA_REG +
 547                                 dev->id * MAC_ESP_PDMA_REG_SPACING);
 548                nubus_writel(0x1d1, mep->pdma_regs);
 549                break;
 550        case MAC_SCSI_QUADRA3:
 551                /* These quadras have a real DMA controller (the PSC) but we
 552                 * don't know how to drive it so we must use PIO instead.
 553                 */
 554                esp->cfreq     = 25000000;
 555                esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA3;
 556                mep->pdma_io   = NULL;
 557                mep->pdma_regs = NULL;
 558                break;
 559        }
 560
 561        esp->ops = &mac_esp_ops;
 562        if (mep->pdma_io == NULL) {
 563                printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id);
 564                esp_write8(0, ESP_TCLOW);
 565                esp_write8(0, ESP_TCMED);
 566                esp->flags = ESP_FLAG_DISABLE_SYNC;
 567                mac_esp_ops.send_dma_cmd = mac_esp_send_pio_cmd;
 568        } else {
 569                printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);
 570        }
 571
 572        host->irq = IRQ_MAC_SCSI;
 573        esp_chips[dev->id] = esp;
 574        mb();
 575        if (esp_chips[!dev->id] == NULL) {
 576                err = request_irq(host->irq, mac_scsi_esp_intr, 0,
 577                                  "Mac ESP", NULL);
 578                if (err < 0) {
 579                        esp_chips[dev->id] = NULL;
 580                        goto fail_free_priv;
 581                }
 582        }
 583
 584        err = scsi_esp_register(esp, &dev->dev);
 585        if (err)
 586                goto fail_free_irq;
 587
 588        return 0;
 589
 590fail_free_irq:
 591        if (esp_chips[!dev->id] == NULL)
 592                free_irq(host->irq, esp);
 593fail_free_priv:
 594        kfree(mep);
 595fail_free_command_block:
 596        kfree(esp->command_block);
 597fail_unlink:
 598        scsi_host_put(host);
 599fail:
 600        return err;
 601}
 602
 603static int __devexit esp_mac_remove(struct platform_device *dev)
 604{
 605        struct mac_esp_priv *mep = platform_get_drvdata(dev);
 606        struct esp *esp = mep->esp;
 607        unsigned int irq = esp->host->irq;
 608
 609        scsi_esp_unregister(esp);
 610
 611        esp_chips[dev->id] = NULL;
 612        if (!(esp_chips[0] || esp_chips[1]))
 613                free_irq(irq, NULL);
 614
 615        kfree(mep);
 616
 617        kfree(esp->command_block);
 618
 619        scsi_host_put(esp->host);
 620
 621        return 0;
 622}
 623
 624static struct platform_driver esp_mac_driver = {
 625        .probe    = esp_mac_probe,
 626        .remove   = __devexit_p(esp_mac_remove),
 627        .driver   = {
 628                .name   = DRV_MODULE_NAME,
 629                .owner  = THIS_MODULE,
 630        },
 631};
 632
 633static int __init mac_esp_init(void)
 634{
 635        return platform_driver_register(&esp_mac_driver);
 636}
 637
 638static void __exit mac_esp_exit(void)
 639{
 640        platform_driver_unregister(&esp_mac_driver);
 641}
 642
 643MODULE_DESCRIPTION("Mac ESP SCSI driver");
 644MODULE_AUTHOR("Finn Thain <fthain@telegraphics.com.au>");
 645MODULE_LICENSE("GPL v2");
 646MODULE_VERSION(DRV_VERSION);
 647MODULE_ALIAS("platform:" DRV_MODULE_NAME);
 648
 649module_init(mac_esp_init);
 650module_exit(mac_esp_exit);
 651