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#include <asm/mac_via.h>
  29
  30#include <scsi/scsi_host.h>
  31
  32#include "esp_scsi.h"
  33
  34#define DRV_MODULE_NAME     "mac_esp"
  35#define PFX                 DRV_MODULE_NAME ": "
  36#define DRV_VERSION         "1.000"
  37#define DRV_MODULE_RELDATE  "Sept 15, 2007"
  38
  39#define MAC_ESP_IO_BASE          0x50F00000
  40#define MAC_ESP_REGS_QUADRA      (MAC_ESP_IO_BASE + 0x10000)
  41#define MAC_ESP_REGS_QUADRA2     (MAC_ESP_IO_BASE + 0xF000)
  42#define MAC_ESP_REGS_QUADRA3     (MAC_ESP_IO_BASE + 0x18000)
  43#define MAC_ESP_REGS_SPACING     0x402
  44#define MAC_ESP_PDMA_REG         0xF9800024
  45#define MAC_ESP_PDMA_REG_SPACING 0x4
  46#define MAC_ESP_PDMA_IO_OFFSET   0x100
  47
  48#define esp_read8(REG)          mac_esp_read8(esp, REG)
  49#define esp_write8(VAL, REG)    mac_esp_write8(esp, VAL, REG)
  50
  51struct mac_esp_priv {
  52        struct esp *esp;
  53        void __iomem *pdma_regs;
  54        void __iomem *pdma_io;
  55        int error;
  56};
  57static struct esp *esp_chips[2];
  58
  59#define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \
  60                               platform_get_drvdata((struct platform_device *) \
  61                                                    (esp->dev)))
  62
  63static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg)
  64{
  65        nubus_writeb(val, esp->regs + reg * 16);
  66}
  67
  68static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg)
  69{
  70        return nubus_readb(esp->regs + reg * 16);
  71}
  72
  73/* For pseudo DMA and PIO we need the virtual address
  74 * so this address mapping is the identity mapping.
  75 */
  76
  77static dma_addr_t mac_esp_map_single(struct esp *esp, void *buf,
  78                                     size_t sz, int dir)
  79{
  80        return (dma_addr_t)buf;
  81}
  82
  83static int mac_esp_map_sg(struct esp *esp, struct scatterlist *sg,
  84                          int num_sg, int dir)
  85{
  86        int i;
  87
  88        for (i = 0; i < num_sg; i++)
  89                sg[i].dma_address = (u32)sg_virt(&sg[i]);
  90        return num_sg;
  91}
  92
  93static void mac_esp_unmap_single(struct esp *esp, dma_addr_t addr,
  94                                 size_t sz, int dir)
  95{
  96        /* Nothing to do. */
  97}
  98
  99static void mac_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
 100                             int num_sg, int dir)
 101{
 102        /* Nothing to do. */
 103}
 104
 105static void mac_esp_reset_dma(struct esp *esp)
 106{
 107        /* Nothing to do. */
 108}
 109
 110static void mac_esp_dma_drain(struct esp *esp)
 111{
 112        /* Nothing to do. */
 113}
 114
 115static void mac_esp_dma_invalidate(struct esp *esp)
 116{
 117        /* Nothing to do. */
 118}
 119
 120static int mac_esp_dma_error(struct esp *esp)
 121{
 122        return MAC_ESP_GET_PRIV(esp)->error;
 123}
 124
 125static inline int mac_esp_wait_for_empty_fifo(struct esp *esp)
 126{
 127        struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 128        int i = 500000;
 129
 130        do {
 131                if (!(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES))
 132                        return 0;
 133
 134                if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
 135                        return 1;
 136
 137                udelay(2);
 138        } while (--i);
 139
 140        printk(KERN_ERR PFX "FIFO is not empty (sreg %02x)\n",
 141               esp_read8(ESP_STATUS));
 142        mep->error = 1;
 143        return 1;
 144}
 145
 146static inline int mac_esp_wait_for_dreq(struct esp *esp)
 147{
 148        struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 149        int i = 500000;
 150
 151        do {
 152                if (mep->pdma_regs == NULL) {
 153                        if (via2_scsi_drq_pending())
 154                                return 0;
 155                } else {
 156                        if (nubus_readl(mep->pdma_regs) & 0x200)
 157                                return 0;
 158                }
 159
 160                if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
 161                        return 1;
 162
 163                udelay(2);
 164        } while (--i);
 165
 166        printk(KERN_ERR PFX "PDMA timeout (sreg %02x)\n",
 167               esp_read8(ESP_STATUS));
 168        mep->error = 1;
 169        return 1;
 170}
 171
 172#define MAC_ESP_PDMA_LOOP(operands) \
 173        asm volatile ( \
 174             "       tstw %1                   \n" \
 175             "       jbeq 20f                  \n" \
 176             "1:     movew " operands "        \n" \
 177             "2:     movew " operands "        \n" \
 178             "3:     movew " operands "        \n" \
 179             "4:     movew " operands "        \n" \
 180             "5:     movew " operands "        \n" \
 181             "6:     movew " operands "        \n" \
 182             "7:     movew " operands "        \n" \
 183             "8:     movew " operands "        \n" \
 184             "9:     movew " operands "        \n" \
 185             "10:    movew " operands "        \n" \
 186             "11:    movew " operands "        \n" \
 187             "12:    movew " operands "        \n" \
 188             "13:    movew " operands "        \n" \
 189             "14:    movew " operands "        \n" \
 190             "15:    movew " operands "        \n" \
 191             "16:    movew " operands "        \n" \
 192             "       subqw #1,%1               \n" \
 193             "       jbne 1b                   \n" \
 194             "20:    tstw %2                   \n" \
 195             "       jbeq 30f                  \n" \
 196             "21:    movew " operands "        \n" \
 197             "       subqw #1,%2               \n" \
 198             "       jbne 21b                  \n" \
 199             "30:    tstw %3                   \n" \
 200             "       jbeq 40f                  \n" \
 201             "31:    moveb " operands "        \n" \
 202             "32:    nop                       \n" \
 203             "40:                              \n" \
 204             "                                 \n" \
 205             "       .section __ex_table,\"a\" \n" \
 206             "       .align  4                 \n" \
 207             "       .long   1b,40b            \n" \
 208             "       .long   2b,40b            \n" \
 209             "       .long   3b,40b            \n" \
 210             "       .long   4b,40b            \n" \
 211             "       .long   5b,40b            \n" \
 212             "       .long   6b,40b            \n" \
 213             "       .long   7b,40b            \n" \
 214             "       .long   8b,40b            \n" \
 215             "       .long   9b,40b            \n" \
 216             "       .long  10b,40b            \n" \
 217             "       .long  11b,40b            \n" \
 218             "       .long  12b,40b            \n" \
 219             "       .long  13b,40b            \n" \
 220             "       .long  14b,40b            \n" \
 221             "       .long  15b,40b            \n" \
 222             "       .long  16b,40b            \n" \
 223             "       .long  21b,40b            \n" \
 224             "       .long  31b,40b            \n" \
 225             "       .long  32b,40b            \n" \
 226             "       .previous                 \n" \
 227             : "+a" (addr), "+r" (count32), "+r" (count2) \
 228             : "g" (count1), "a" (mep->pdma_io))
 229
 230static void mac_esp_send_pdma_cmd(struct esp *esp, u32 addr, u32 esp_count,
 231                                  u32 dma_count, int write, u8 cmd)
 232{
 233        struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 234
 235        mep->error = 0;
 236
 237        if (!write)
 238                scsi_esp_cmd(esp, ESP_CMD_FLUSH);
 239
 240        esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW);
 241        esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED);
 242
 243        scsi_esp_cmd(esp, cmd);
 244
 245        do {
 246                unsigned int count32 = esp_count >> 5;
 247                unsigned int count2 = (esp_count & 0x1F) >> 1;
 248                unsigned int count1 = esp_count & 1;
 249                unsigned int start_addr = addr;
 250
 251                if (mac_esp_wait_for_dreq(esp))
 252                        break;
 253
 254                if (write) {
 255                        MAC_ESP_PDMA_LOOP("%4@,%0@+");
 256
 257                        esp_count -= addr - start_addr;
 258                } else {
 259                        unsigned int n;
 260
 261                        MAC_ESP_PDMA_LOOP("%0@+,%4@");
 262
 263                        if (mac_esp_wait_for_empty_fifo(esp))
 264                                break;
 265
 266                        n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW);
 267                        addr = start_addr + esp_count - n;
 268                        esp_count = n;
 269                }
 270        } while (esp_count);
 271}
 272
 273/*
 274 * Programmed IO routines follow.
 275 */
 276
 277static inline unsigned int mac_esp_wait_for_fifo(struct esp *esp)
 278{
 279        int i = 500000;
 280
 281        do {
 282                unsigned int fbytes = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
 283
 284                if (fbytes)
 285                        return fbytes;
 286
 287                udelay(2);
 288        } while (--i);
 289
 290        printk(KERN_ERR PFX "FIFO is empty (sreg %02x)\n",
 291               esp_read8(ESP_STATUS));
 292        return 0;
 293}
 294
 295static inline int mac_esp_wait_for_intr(struct esp *esp)
 296{
 297        struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 298        int i = 500000;
 299
 300        do {
 301                esp->sreg = esp_read8(ESP_STATUS);
 302                if (esp->sreg & ESP_STAT_INTR)
 303                        return 0;
 304
 305                udelay(2);
 306        } while (--i);
 307
 308        printk(KERN_ERR PFX "IRQ timeout (sreg %02x)\n", esp->sreg);
 309        mep->error = 1;
 310        return 1;
 311}
 312
 313#define MAC_ESP_PIO_LOOP(operands, reg1) \
 314        asm volatile ( \
 315             "1:     moveb " operands " \n" \
 316             "       subqw #1,%1        \n" \
 317             "       jbne 1b            \n" \
 318             : "+a" (addr), "+r" (reg1) \
 319             : "a" (fifo))
 320
 321#define MAC_ESP_PIO_FILL(operands, reg1) \
 322        asm volatile ( \
 323             "       moveb " operands " \n" \
 324             "       moveb " operands " \n" \
 325             "       moveb " operands " \n" \
 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             "       subqw #8,%1        \n" \
 340             "       subqw #8,%1        \n" \
 341             : "+a" (addr), "+r" (reg1) \
 342             : "a" (fifo))
 343
 344#define MAC_ESP_FIFO_SIZE 16
 345
 346static void mac_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count,
 347                                 u32 dma_count, int write, u8 cmd)
 348{
 349        struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 350        u8 *fifo = esp->regs + ESP_FDATA * 16;
 351
 352        cmd &= ~ESP_CMD_DMA;
 353        mep->error = 0;
 354
 355        if (write) {
 356                scsi_esp_cmd(esp, cmd);
 357
 358                while (1) {
 359                        unsigned int n;
 360
 361                        n = mac_esp_wait_for_fifo(esp);
 362                        if (!n)
 363                                break;
 364
 365                        if (n > esp_count)
 366                                n = esp_count;
 367                        esp_count -= n;
 368
 369                        MAC_ESP_PIO_LOOP("%2@,%0@+", n);
 370
 371                        if (!esp_count)
 372                                break;
 373
 374                        if (mac_esp_wait_for_intr(esp))
 375                                break;
 376
 377                        if (((esp->sreg & ESP_STAT_PMASK) != ESP_DIP) &&
 378                            ((esp->sreg & ESP_STAT_PMASK) != ESP_MIP))
 379                                break;
 380
 381                        esp->ireg = esp_read8(ESP_INTRPT);
 382                        if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
 383                            ESP_INTR_BSERV)
 384                                break;
 385
 386                        scsi_esp_cmd(esp, ESP_CMD_TI);
 387                }
 388        } else {
 389                scsi_esp_cmd(esp, ESP_CMD_FLUSH);
 390
 391                if (esp_count >= MAC_ESP_FIFO_SIZE)
 392                        MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
 393                else
 394                        MAC_ESP_PIO_LOOP("%0@+,%2@", esp_count);
 395
 396                scsi_esp_cmd(esp, cmd);
 397
 398                while (esp_count) {
 399                        unsigned int n;
 400
 401                        if (mac_esp_wait_for_intr(esp))
 402                                break;
 403
 404                        if (((esp->sreg & ESP_STAT_PMASK) != ESP_DOP) &&
 405                            ((esp->sreg & ESP_STAT_PMASK) != ESP_MOP))
 406                                break;
 407
 408                        esp->ireg = esp_read8(ESP_INTRPT);
 409                        if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
 410                            ESP_INTR_BSERV)
 411                                break;
 412
 413                        n = MAC_ESP_FIFO_SIZE -
 414                            (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES);
 415                        if (n > esp_count)
 416                                n = esp_count;
 417
 418                        if (n == MAC_ESP_FIFO_SIZE) {
 419                                MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
 420                        } else {
 421                                esp_count -= n;
 422                                MAC_ESP_PIO_LOOP("%0@+,%2@", n);
 423                        }
 424
 425                        scsi_esp_cmd(esp, ESP_CMD_TI);
 426                }
 427        }
 428}
 429
 430static int mac_esp_irq_pending(struct esp *esp)
 431{
 432        if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
 433                return 1;
 434        return 0;
 435}
 436
 437static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
 438{
 439        return dma_len > 0xFFFF ? 0xFFFF : dma_len;
 440}
 441
 442static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id)
 443{
 444        int got_intr;
 445
 446        /*
 447         * This is an edge triggered IRQ, so we have to be careful to
 448         * avoid missing a transition when it is shared by two ESP devices.
 449         */
 450
 451        do {
 452                got_intr = 0;
 453                if (esp_chips[0] &&
 454                    (mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) {
 455                        (void)scsi_esp_intr(irq, esp_chips[0]);
 456                        got_intr = 1;
 457                }
 458                if (esp_chips[1] &&
 459                    (mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) {
 460                        (void)scsi_esp_intr(irq, esp_chips[1]);
 461                        got_intr = 1;
 462                }
 463        } while (got_intr);
 464
 465        return IRQ_HANDLED;
 466}
 467
 468static struct esp_driver_ops mac_esp_ops = {
 469        .esp_write8       = mac_esp_write8,
 470        .esp_read8        = mac_esp_read8,
 471        .map_single       = mac_esp_map_single,
 472        .map_sg           = mac_esp_map_sg,
 473        .unmap_single     = mac_esp_unmap_single,
 474        .unmap_sg         = mac_esp_unmap_sg,
 475        .irq_pending      = mac_esp_irq_pending,
 476        .dma_length_limit = mac_esp_dma_length_limit,
 477        .reset_dma        = mac_esp_reset_dma,
 478        .dma_drain        = mac_esp_dma_drain,
 479        .dma_invalidate   = mac_esp_dma_invalidate,
 480        .send_dma_cmd     = mac_esp_send_pdma_cmd,
 481        .dma_error        = mac_esp_dma_error,
 482};
 483
 484static int __devinit esp_mac_probe(struct platform_device *dev)
 485{
 486        struct scsi_host_template *tpnt = &scsi_esp_template;
 487        struct Scsi_Host *host;
 488        struct esp *esp;
 489        int err;
 490        struct mac_esp_priv *mep;
 491
 492        if (!MACH_IS_MAC)
 493                return -ENODEV;
 494
 495        if (dev->id > 1)
 496                return -ENODEV;
 497
 498        host = scsi_host_alloc(tpnt, sizeof(struct esp));
 499
 500        err = -ENOMEM;
 501        if (!host)
 502                goto fail;
 503
 504        host->max_id = 8;
 505        host->use_clustering = DISABLE_CLUSTERING;
 506        esp = shost_priv(host);
 507
 508        esp->host = host;
 509        esp->dev = dev;
 510
 511        esp->command_block = kzalloc(16, GFP_KERNEL);
 512        if (!esp->command_block)
 513                goto fail_unlink;
 514        esp->command_block_dma = (dma_addr_t)esp->command_block;
 515
 516        esp->scsi_id = 7;
 517        host->this_id = esp->scsi_id;
 518        esp->scsi_id_mask = 1 << esp->scsi_id;
 519
 520        mep = kzalloc(sizeof(struct mac_esp_priv), GFP_KERNEL);
 521        if (!mep)
 522                goto fail_free_command_block;
 523        mep->esp = esp;
 524        platform_set_drvdata(dev, mep);
 525
 526        switch (macintosh_config->scsi_type) {
 527        case MAC_SCSI_QUADRA:
 528                esp->cfreq     = 16500000;
 529                esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA;
 530                mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
 531                mep->pdma_regs = NULL;
 532                break;
 533        case MAC_SCSI_QUADRA2:
 534                esp->cfreq     = 25000000;
 535                esp->regs      = (void __iomem *)(MAC_ESP_REGS_QUADRA2 +
 536                                 dev->id * MAC_ESP_REGS_SPACING);
 537                mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
 538                mep->pdma_regs = (void __iomem *)(MAC_ESP_PDMA_REG +
 539                                 dev->id * MAC_ESP_PDMA_REG_SPACING);
 540                nubus_writel(0x1d1, mep->pdma_regs);
 541                break;
 542        case MAC_SCSI_QUADRA3:
 543                /* These quadras have a real DMA controller (the PSC) but we
 544                 * don't know how to drive it so we must use PIO instead.
 545                 */
 546                esp->cfreq     = 25000000;
 547                esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA3;
 548                mep->pdma_io   = NULL;
 549                mep->pdma_regs = NULL;
 550                break;
 551        }
 552
 553        esp->ops = &mac_esp_ops;
 554        if (mep->pdma_io == NULL) {
 555                printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id);
 556                esp_write8(0, ESP_TCLOW);
 557                esp_write8(0, ESP_TCMED);
 558                esp->flags = ESP_FLAG_DISABLE_SYNC;
 559                mac_esp_ops.send_dma_cmd = mac_esp_send_pio_cmd;
 560        } else {
 561                printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);
 562        }
 563
 564        host->irq = IRQ_MAC_SCSI;
 565        esp_chips[dev->id] = esp;
 566        mb();
 567        if (esp_chips[!dev->id] == NULL) {
 568                err = request_irq(host->irq, mac_scsi_esp_intr, 0, "ESP", NULL);
 569                if (err < 0) {
 570                        esp_chips[dev->id] = NULL;
 571                        goto fail_free_priv;
 572                }
 573        }
 574
 575        err = scsi_esp_register(esp, &dev->dev);
 576        if (err)
 577                goto fail_free_irq;
 578
 579        return 0;
 580
 581fail_free_irq:
 582        if (esp_chips[!dev->id] == NULL)
 583                free_irq(host->irq, esp);
 584fail_free_priv:
 585        kfree(mep);
 586fail_free_command_block:
 587        kfree(esp->command_block);
 588fail_unlink:
 589        scsi_host_put(host);
 590fail:
 591        return err;
 592}
 593
 594static int __devexit esp_mac_remove(struct platform_device *dev)
 595{
 596        struct mac_esp_priv *mep = platform_get_drvdata(dev);
 597        struct esp *esp = mep->esp;
 598        unsigned int irq = esp->host->irq;
 599
 600        scsi_esp_unregister(esp);
 601
 602        esp_chips[dev->id] = NULL;
 603        if (!(esp_chips[0] || esp_chips[1]))
 604                free_irq(irq, NULL);
 605
 606        kfree(mep);
 607
 608        kfree(esp->command_block);
 609
 610        scsi_host_put(esp->host);
 611
 612        return 0;
 613}
 614
 615static struct platform_driver esp_mac_driver = {
 616        .probe    = esp_mac_probe,
 617        .remove   = __devexit_p(esp_mac_remove),
 618        .driver   = {
 619                .name   = DRV_MODULE_NAME,
 620                .owner  = THIS_MODULE,
 621        },
 622};
 623
 624static int __init mac_esp_init(void)
 625{
 626        return platform_driver_register(&esp_mac_driver);
 627}
 628
 629static void __exit mac_esp_exit(void)
 630{
 631        platform_driver_unregister(&esp_mac_driver);
 632}
 633
 634MODULE_DESCRIPTION("Mac ESP SCSI driver");
 635MODULE_AUTHOR("Finn Thain <fthain@telegraphics.com.au>");
 636MODULE_LICENSE("GPL v2");
 637MODULE_VERSION(DRV_VERSION);
 638MODULE_ALIAS("platform:" DRV_MODULE_NAME);
 639
 640module_init(mac_esp_init);
 641module_exit(mac_esp_exit);
 642
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