drivers/scsi/mac_esp.c

   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
  51 struct mac_esp_priv {
  52         struct esp *esp;
  53         void __iomem *pdma_regs;
  54         void __iomem *pdma_io;
  55 };
  56 static struct esp *esp_chips[2];
  57 static DEFINE_SPINLOCK(esp_chips_lock);
  58
  59 #define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \
  60                                dev_get_drvdata((esp)->dev))
  61
  62 static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg)
  63 {
  64         nubus_writeb(val, esp->regs + reg * 16);
  65 }
  66
  67 static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg)
  68 {
  69         return nubus_readb(esp->regs + reg * 16);
  70 }
  71
  72 static void mac_esp_reset_dma(struct esp *esp)
  73 {
  74         /* Nothing to do. */
  75 }
  76
  77 static void mac_esp_dma_drain(struct esp *esp)
  78 {
  79         /* Nothing to do. */
  80 }
  81
  82 static void mac_esp_dma_invalidate(struct esp *esp)
  83 {
  84         /* Nothing to do. */
  85 }
  86
  87 static int mac_esp_dma_error(struct esp *esp)
  88 {
  89         return esp->send_cmd_error;
  90 }
  91
  92 static inline int mac_esp_wait_for_empty_fifo(struct esp *esp)
  93 {
  94         int i = 500000;
  95
  96         do {
  97                 if (!(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES))
  98                         return 0;
  99
 100                 if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
 101                         return 1;
 102
 103                 udelay(2);
 104         } while (--i);
 105
 106         printk(KERN_ERR PFX "FIFO is not empty (sreg %02x)\n",
 107                esp_read8(ESP_STATUS));
 108         esp->send_cmd_error = 1;
 109         return 1;
 110 }
 111
 112 static inline int mac_esp_wait_for_dreq(struct esp *esp)
 113 {
 114         struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 115         int i = 500000;
 116
 117         do {
 118                 if (mep->pdma_regs == NULL) {
 119                         if (via2_scsi_drq_pending())
 120                                 return 0;
 121                 } else {
 122                         if (nubus_readl(mep->pdma_regs) & 0x200)
 123                                 return 0;
 124                 }
 125
 126                 if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
 127                         return 1;
 128
 129                 udelay(2);
 130         } while (--i);
 131
 132         printk(KERN_ERR PFX "PDMA timeout (sreg %02x)\n",
 133                esp_read8(ESP_STATUS));
 134         esp->send_cmd_error = 1;
 135         return 1;
 136 }
 137
 138 #define MAC_ESP_PDMA_LOOP(operands) \
 139         asm volatile ( \
 140              "       tstw %1                   \n" \
 141              "       jbeq 20f                  \n" \
 142              "1:     movew " operands "        \n" \
 143              "2:     movew " operands "        \n" \
 144              "3:     movew " operands "        \n" \
 145              "4:     movew " operands "        \n" \
 146              "5:     movew " operands "        \n" \
 147              "6:     movew " operands "        \n" \
 148              "7:     movew " operands "        \n" \
 149              "8:     movew " operands "        \n" \
 150              "9:     movew " operands "        \n" \
 151              "10:    movew " operands "        \n" \
 152              "11:    movew " operands "        \n" \
 153              "12:    movew " operands "        \n" \
 154              "13:    movew " operands "        \n" \
 155              "14:    movew " operands "        \n" \
 156              "15:    movew " operands "        \n" \
 157              "16:    movew " operands "        \n" \
 158              "       subqw #1,%1               \n" \
 159              "       jbne 1b                   \n" \
 160              "20:    tstw %2                   \n" \
 161              "       jbeq 30f                  \n" \
 162              "21:    movew " operands "        \n" \
 163              "       subqw #1,%2               \n" \
 164              "       jbne 21b                  \n" \
 165              "30:    tstw %3                   \n" \
 166              "       jbeq 40f                  \n" \
 167              "31:    moveb " operands "        \n" \
 168              "32:    nop                       \n" \
 169              "40:                              \n" \
 170              "                                 \n" \
 171              "       .section __ex_table,\"a\" \n" \
 172              "       .align  4                 \n" \
 173              "       .long   1b,40b            \n" \
 174              "       .long   2b,40b            \n" \
 175              "       .long   3b,40b            \n" \
 176              "       .long   4b,40b            \n" \
 177              "       .long   5b,40b            \n" \
 178              "       .long   6b,40b            \n" \
 179              "       .long   7b,40b            \n" \
 180              "       .long   8b,40b            \n" \
 181              "       .long   9b,40b            \n" \
 182              "       .long  10b,40b            \n" \
 183              "       .long  11b,40b            \n" \
 184              "       .long  12b,40b            \n" \
 185              "       .long  13b,40b            \n" \
 186              "       .long  14b,40b            \n" \
 187              "       .long  15b,40b            \n" \
 188              "       .long  16b,40b            \n" \
 189              "       .long  21b,40b            \n" \
 190              "       .long  31b,40b            \n" \
 191              "       .long  32b,40b            \n" \
 192              "       .previous                 \n" \
 193              : "+a" (addr), "+r" (count32), "+r" (count2) \
 194              : "g" (count1), "a" (mep->pdma_io))
 195
 196 static void mac_esp_send_pdma_cmd(struct esp *esp, u32 addr, u32 esp_count,
 197                                   u32 dma_count, int write, u8 cmd)
 198 {
 199         struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
 200
 201         esp->send_cmd_error = 0;
 202
 203         if (!write)
 204                 scsi_esp_cmd(esp, ESP_CMD_FLUSH);
 205
 206         esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW);
 207         esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED);
 208
 209         scsi_esp_cmd(esp, cmd);
 210
 211         do {
 212                 unsigned int count32 = esp_count >> 5;
 213                 unsigned int count2 = (esp_count & 0x1F) >> 1;
 214                 unsigned int count1 = esp_count & 1;
 215                 unsigned int start_addr = addr;
 216
 217                 if (mac_esp_wait_for_dreq(esp))
 218                         break;
 219
 220                 if (write) {
 221                         MAC_ESP_PDMA_LOOP("%4@,%0@+");
 222
 223                         esp_count -= addr - start_addr;
 224                 } else {
 225                         unsigned int n;
 226
 227                         MAC_ESP_PDMA_LOOP("%0@+,%4@");
 228
 229                         if (mac_esp_wait_for_empty_fifo(esp))
 230                                 break;
 231
 232                         n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW);
 233                         addr = start_addr + esp_count - n;
 234                         esp_count = n;
 235                 }
 236         } while (esp_count);
 237 }
 238
 239 static int mac_esp_irq_pending(struct esp *esp)
 240 {
 241         if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
 242                 return 1;
 243         return 0;
 244 }
 245
 246 static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
 247 {
 248         return dma_len > 0xFFFF ? 0xFFFF : dma_len;
 249 }
 250
 251 static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id)
 252 {
 253         int got_intr;
 254
 255         /*
 256          * This is an edge triggered IRQ, so we have to be careful to
 257          * avoid missing a transition when it is shared by two ESP devices.
 258          */
 259
 260         do {
 261                 got_intr = 0;
 262                 if (esp_chips[0] &&
 263                     (mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) {
 264                         (void)scsi_esp_intr(irq, esp_chips[0]);
 265                         got_intr = 1;
 266                 }
 267                 if (esp_chips[1] &&
 268                     (mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) {
 269                         (void)scsi_esp_intr(irq, esp_chips[1]);
 270                         got_intr = 1;
 271                 }
 272         } while (got_intr);
 273
 274         return IRQ_HANDLED;
 275 }
 276
 277 static struct esp_driver_ops mac_esp_ops = {
 278         .esp_write8       = mac_esp_write8,
 279         .esp_read8        = mac_esp_read8,
 280         .irq_pending      = mac_esp_irq_pending,
 281         .dma_length_limit = mac_esp_dma_length_limit,
 282         .reset_dma        = mac_esp_reset_dma,
 283         .dma_drain        = mac_esp_dma_drain,
 284         .dma_invalidate   = mac_esp_dma_invalidate,
 285         .send_dma_cmd     = mac_esp_send_pdma_cmd,
 286         .dma_error        = mac_esp_dma_error,
 287 };
 288
 289 static int esp_mac_probe(struct platform_device *dev)
 290 {
 291         struct scsi_host_template *tpnt = &scsi_esp_template;
 292         struct Scsi_Host *host;
 293         struct esp *esp;
 294         int err;
 295         struct mac_esp_priv *mep;
 296
 297         if (!MACH_IS_MAC)
 298                 return -ENODEV;
 299
 300         if (dev->id > 1)
 301                 return -ENODEV;
 302
 303         host = scsi_host_alloc(tpnt, sizeof(struct esp));
 304
 305         err = -ENOMEM;
 306         if (!host)
 307                 goto fail;
 308
 309         host->max_id = 8;
 310         host->dma_boundary = PAGE_SIZE - 1;
 311         esp = shost_priv(host);
 312
 313         esp->host = host;
 314         esp->dev = &dev->dev;
 315
 316         esp->command_block = kzalloc(16, GFP_KERNEL);
 317         if (!esp->command_block)
 318                 goto fail_unlink;
 319         esp->command_block_dma = (dma_addr_t)esp->command_block;
 320
 321         esp->scsi_id = 7;
 322         host->this_id = esp->scsi_id;
 323         esp->scsi_id_mask = 1 << esp->scsi_id;
 324
 325         mep = kzalloc(sizeof(struct mac_esp_priv), GFP_KERNEL);
 326         if (!mep)
 327                 goto fail_free_command_block;
 328         mep->esp = esp;
 329         platform_set_drvdata(dev, mep);
 330
 331         switch (macintosh_config->scsi_type) {
 332         case MAC_SCSI_QUADRA:
 333                 esp->cfreq     = 16500000;
 334                 esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA;
 335                 mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
 336                 mep->pdma_regs = NULL;
 337                 break;
 338         case MAC_SCSI_QUADRA2:
 339                 esp->cfreq     = 25000000;
 340                 esp->regs      = (void __iomem *)(MAC_ESP_REGS_QUADRA2 +
 341                                  dev->id * MAC_ESP_REGS_SPACING);
 342                 mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
 343                 mep->pdma_regs = (void __iomem *)(MAC_ESP_PDMA_REG +
 344                                  dev->id * MAC_ESP_PDMA_REG_SPACING);
 345                 nubus_writel(0x1d1, mep->pdma_regs);
 346                 break;
 347         case MAC_SCSI_QUADRA3:
 348                 /* These quadras have a real DMA controller (the PSC) but we
 349                  * don't know how to drive it so we must use PIO instead.
 350                  */
 351                 esp->cfreq     = 25000000;
 352                 esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA3;
 353                 mep->pdma_io   = NULL;
 354                 mep->pdma_regs = NULL;
 355                 break;
 356         }
 357         esp->fifo_reg = esp->regs + ESP_FDATA * 16;
 358
 359         esp->ops = &mac_esp_ops;
 360         esp->flags = ESP_FLAG_NO_DMA_MAP;
 361         if (mep->pdma_io == NULL) {
 362                 printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id);
 363                 esp_write8(0, ESP_TCLOW);
 364                 esp_write8(0, ESP_TCMED);
 365                 esp->flags |= ESP_FLAG_DISABLE_SYNC;
 366                 mac_esp_ops.send_dma_cmd = esp_send_pio_cmd;
 367         } else {
 368                 printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);
 369         }
 370
 371         host->irq = IRQ_MAC_SCSI;
 372
 373         /* The request_irq() call is intended to succeed for the first device
 374          * and fail for the second device.
 375          */
 376         err = request_irq(host->irq, mac_scsi_esp_intr, 0, "ESP", NULL);
 377         spin_lock(&esp_chips_lock);
 378         if (err < 0 && esp_chips[!dev->id] == NULL) {
 379                 spin_unlock(&esp_chips_lock);
 380                 goto fail_free_priv;
 381         }
 382         esp_chips[dev->id] = esp;
 383         spin_unlock(&esp_chips_lock);
 384
 385         err = scsi_esp_register(esp);
 386         if (err)
 387                 goto fail_free_irq;
 388
 389         return 0;
 390
 391 fail_free_irq:
 392         spin_lock(&esp_chips_lock);
 393         esp_chips[dev->id] = NULL;
 394         if (esp_chips[!dev->id] == NULL) {
 395                 spin_unlock(&esp_chips_lock);
 396                 free_irq(host->irq, NULL);
 397         } else
 398                 spin_unlock(&esp_chips_lock);
 399 fail_free_priv:
 400         kfree(mep);
 401 fail_free_command_block:
 402         kfree(esp->command_block);
 403 fail_unlink:
 404         scsi_host_put(host);
 405 fail:
 406         return err;
 407 }
 408
 409 static int esp_mac_remove(struct platform_device *dev)
 410 {
 411         struct mac_esp_priv *mep = platform_get_drvdata(dev);
 412         struct esp *esp = mep->esp;
 413         unsigned int irq = esp->host->irq;
 414
 415         scsi_esp_unregister(esp);
 416
 417         spin_lock(&esp_chips_lock);
 418         esp_chips[dev->id] = NULL;
 419         if (esp_chips[!dev->id] == NULL) {
 420                 spin_unlock(&esp_chips_lock);
 421                 free_irq(irq, NULL);
 422         } else
 423                 spin_unlock(&esp_chips_lock);
 424
 425         kfree(mep);
 426
 427         kfree(esp->command_block);
 428
 429         scsi_host_put(esp->host);
 430
 431         return 0;
 432 }
 433
 434 static struct platform_driver esp_mac_driver = {
 435         .probe    = esp_mac_probe,
 436         .remove   = esp_mac_remove,
 437         .driver   = {
 438                 .name   = DRV_MODULE_NAME,
 439         },
 440 };
 441
 442 static int __init mac_esp_init(void)
 443 {
 444         return platform_driver_register(&esp_mac_driver);
 445 }
 446
 447 static void __exit mac_esp_exit(void)
 448 {
 449         platform_driver_unregister(&esp_mac_driver);
 450 }
 451
 452 MODULE_DESCRIPTION("Mac ESP SCSI driver");
 453 MODULE_AUTHOR("Finn Thain");
 454 MODULE_LICENSE("GPL v2");
 455 MODULE_VERSION(DRV_VERSION);
 456 MODULE_ALIAS("platform:" DRV_MODULE_NAME);
 457
 458 module_init(mac_esp_init);
 459 module_exit(mac_esp_exit);