drivers/scsi/mac53c94.c

   1 /*
   2  * SCSI low-level driver for the 53c94 SCSI bus adaptor found
   3  * on Power Macintosh computers, controlling the external SCSI chain.
   4  * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA)
   5  * controller.
   6  *
   7  * Paul Mackerras, August 1996.
   8  * Copyright (C) 1996 Paul Mackerras.
   9  */
  10 #include <linux/kernel.h>
  11 #include <linux/delay.h>
  12 #include <linux/types.h>
  13 #include <linux/string.h>
  14 #include <linux/slab.h>
  15 #include <linux/blk.h>
  16 #include <linux/proc_fs.h>
  17 #include <linux/stat.h>
  18 #include <linux/spinlock.h>
  19 #include <asm/dbdma.h>
  20 #include <asm/io.h>
  21 #include <asm/pgtable.h>
  22 #include <asm/prom.h>
  23 #include <asm/system.h>
  24
  25 #include "scsi.h"
  26 #include "hosts.h"
  27 #include "mac53c94.h"
  28
  29 enum fsc_phase {
  30         idle,
  31         selecting,
  32         dataing,
  33         completing,
  34         busfreeing,
  35 };
  36
  37 struct fsc_state {
  38         volatile struct mac53c94_regs *regs;
  39         int     intr;
  40         volatile struct dbdma_regs *dma;
  41         int     dmaintr;
  42         int     clk_freq;
  43         struct  Scsi_Host *host;
  44         struct  fsc_state *next;
  45         Scsi_Cmnd *request_q;
  46         Scsi_Cmnd *request_qtail;
  47         Scsi_Cmnd *current_req;         /* req we're currently working on */
  48         enum fsc_phase phase;           /* what we're currently trying to do */
  49         struct dbdma_cmd *dma_cmds;     /* space for dbdma commands, aligned */
  50         void    *dma_cmd_space;
  51 };
  52
  53 static struct fsc_state *all_53c94s;
  54
  55 static void mac53c94_init(struct fsc_state *);
  56 static void mac53c94_start(struct fsc_state *);
  57 static void mac53c94_interrupt(int, void *, struct pt_regs *);
  58 static void do_mac53c94_interrupt(int, void *, struct pt_regs *);
  59 static void cmd_done(struct fsc_state *, int result);
  60 static void set_dma_cmds(struct fsc_state *, Scsi_Cmnd *);
  61 static int data_goes_out(Scsi_Cmnd *);
  62
  63 int
  64 mac53c94_detect(Scsi_Host_Template *tp)
  65 {
  66         struct device_node *node;
  67         int nfscs;
  68         struct fsc_state *state, **prev_statep;
  69         struct Scsi_Host *host;
  70         void *dma_cmd_space;
  71         unsigned char *clkprop;
  72         int proplen;
  73
  74         nfscs = 0;
  75         prev_statep = &all_53c94s;
  76         for (node = find_devices("53c94"); node != 0; node = node->next) {
  77                 if (node->n_addrs != 2 || node->n_intrs != 2)
  78                         panic("53c94: expected 2 addrs and intrs (got %d/%d)",
  79                               node->n_addrs, node->n_intrs);
  80                 host = scsi_register(tp, sizeof(struct fsc_state));
  81                 if (host == NULL)
  82                         break;
  83                 host->unique_id = nfscs;
  84 #ifndef MODULE
  85                 note_scsi_host(node, host);
  86 #endif
  87
  88                 state = (struct fsc_state *) host->hostdata;
  89                 if (state == 0)
  90                         panic("no 53c94 state");
  91                 state->host = host;
  92                 state->regs = (volatile struct mac53c94_regs *)
  93                         ioremap(node->addrs[0].address, 0x1000);
  94                 state->intr = node->intrs[0].line;
  95                 state->dma = (volatile struct dbdma_regs *)
  96                         ioremap(node->addrs[1].address, 0x1000);
  97                 state->dmaintr = node->intrs[1].line;
  98
  99                 clkprop = get_property(node, "clock-frequency", &proplen);
 100                 if (clkprop == NULL || proplen != sizeof(int)) {
 101                         printk(KERN_ERR "%s: can't get clock frequency\n",
 102                                node->full_name);
 103                         state->clk_freq = 25000000;
 104                 } else
 105                         state->clk_freq = *(int *)clkprop;
 106
 107                 /* Space for dma command list: +1 for stop command,
 108                    +1 to allow for aligning. */
 109                 dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
 110                                         sizeof(struct dbdma_cmd), GFP_KERNEL);
 111                 if (dma_cmd_space == 0)
 112                         panic("53c94: couldn't allocate dma command space");
 113                 state->dma_cmds = (struct dbdma_cmd *)
 114                         DBDMA_ALIGN(dma_cmd_space);
 115                 memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
 116                        * sizeof(struct dbdma_cmd));
 117                 state->dma_cmd_space = dma_cmd_space;
 118
 119                 *prev_statep = state;
 120                 prev_statep = &state->next;
 121
 122                 if (request_irq(state->intr, do_mac53c94_interrupt, 0,
 123                                 "53C94", state)) {
 124                         printk(KERN_ERR "mac53C94: can't get irq %d\n", state->intr);
 125                 }
 126
 127                 mac53c94_init(state);
 128
 129                 ++nfscs;
 130         }
 131         return nfscs;
 132 }
 133
 134 int
 135 mac53c94_release(struct Scsi_Host *host)
 136 {
 137         struct fsc_state *fp = (struct fsc_state *) host->hostdata;
 138
 139         if (fp == 0)
 140                 return 0;
 141         if (fp->regs)
 142                 iounmap((void *) fp->regs);
 143         if (fp->dma)
 144                 iounmap((void *) fp->dma);
 145         kfree(fp->dma_cmd_space);
 146         free_irq(fp->intr, fp);
 147         return 0;
 148 }
 149
 150 int
 151 mac53c94_queue(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
 152 {
 153         unsigned long flags;
 154         struct fsc_state *state;
 155
 156 #if 0
 157         if (data_goes_out(cmd)) {
 158                 int i;
 159                 printk(KERN_DEBUG "mac53c94_queue %p: command is", cmd);
 160                 for (i = 0; i < cmd->cmd_len; ++i)
 161                         printk(" %.2x", cmd->cmnd[i]);
 162                 printk("\n" KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",
 163                        cmd->use_sg, cmd->request_bufflen, cmd->request_buffer);
 164         }
 165 #endif
 166
 167         cmd->scsi_done = done;
 168         cmd->host_scribble = NULL;
 169
 170         state = (struct fsc_state *) cmd->host->hostdata;
 171
 172         save_flags(flags);
 173         cli();
 174         if (state->request_q == NULL)
 175                 state->request_q = cmd;
 176         else
 177                 state->request_qtail->host_scribble = (void *) cmd;
 178         state->request_qtail = cmd;
 179
 180         if (state->phase == idle)
 181                 mac53c94_start(state);
 182
 183         restore_flags(flags);
 184         return 0;
 185 }
 186
 187 int
 188 mac53c94_abort(Scsi_Cmnd *cmd)
 189 {
 190         return SCSI_ABORT_SNOOZE;
 191 }
 192
 193 int
 194 mac53c94_reset(Scsi_Cmnd *cmd, unsigned how)
 195 {
 196         struct fsc_state *state = (struct fsc_state *) cmd->host->hostdata;
 197         volatile struct mac53c94_regs *regs = state->regs;
 198         volatile struct dbdma_regs *dma = state->dma;
 199         unsigned long flags;
 200
 201         save_flags(flags);
 202         cli();
 203         st_le32(&dma->control, (RUN|PAUSE|FLUSH|WAKE) << 16);
 204         regs->command = CMD_SCSI_RESET; /* assert RST */
 205         eieio();
 206         udelay(100);                    /* leave it on for a while (>= 25us) */
 207         regs->command = CMD_RESET;
 208         eieio();
 209         udelay(20);
 210         mac53c94_init(state);
 211         regs->command = CMD_NOP;
 212         eieio();
 213         restore_flags(flags);
 214         return SCSI_RESET_PENDING;
 215 }
 216
 217 int
 218 mac53c94_command(Scsi_Cmnd *cmd)
 219 {
 220         printk(KERN_DEBUG "whoops... mac53c94_command called\n");
 221         return -1;
 222 }
 223
 224 static void
 225 mac53c94_init(struct fsc_state *state)
 226 {
 227         volatile struct mac53c94_regs *regs = state->regs;
 228         volatile struct dbdma_regs *dma = state->dma;
 229         int x;
 230
 231         regs->config1 = state->host->this_id | CF1_PAR_ENABLE;
 232         regs->sel_timeout = TIMO_VAL(250);      /* 250ms */
 233         regs->clk_factor = CLKF_VAL(state->clk_freq);
 234         regs->config2 = CF2_FEATURE_EN;
 235         regs->config3 = 0;
 236         regs->sync_period = 0;
 237         regs->sync_offset = 0;
 238         eieio();
 239         x = regs->interrupt;
 240         st_le32(&dma->control, (RUN|PAUSE|FLUSH|WAKE) << 16);
 241 }
 242
 243 /*
 244  * Start the next command for a 53C94.
 245  * Should be called with interrupts disabled.
 246  */
 247 static void
 248 mac53c94_start(struct fsc_state *state)
 249 {
 250         Scsi_Cmnd *cmd;
 251         volatile struct mac53c94_regs *regs = state->regs;
 252         int i;
 253
 254         if (state->phase != idle || state->current_req != NULL)
 255                 panic("inappropriate mac53c94_start (state=%p)", state);
 256         if (state->request_q == NULL)
 257                 return;
 258         state->current_req = cmd = state->request_q;
 259         state->request_q = (Scsi_Cmnd *) cmd->host_scribble;
 260
 261         /* Off we go */
 262         regs->count_lo = 0;
 263         regs->count_mid = 0;
 264         regs->count_hi = 0;
 265         eieio();
 266         regs->command = CMD_NOP + CMD_DMA_MODE;
 267         udelay(1);
 268         eieio();
 269         regs->command = CMD_FLUSH;
 270         udelay(1);
 271         eieio();
 272         regs->dest_id = cmd->target;
 273         regs->sync_period = 0;
 274         regs->sync_offset = 0;
 275         eieio();
 276
 277         /* load the command into the FIFO */
 278         for (i = 0; i < cmd->cmd_len; ++i) {
 279                 regs->fifo = cmd->cmnd[i];
 280                 eieio();
 281         }
 282
 283         /* do select without ATN XXX */
 284         regs->command = CMD_SELECT;
 285         state->phase = selecting;
 286
 287         if (cmd->use_sg > 0 || cmd->request_bufflen != 0)
 288                 set_dma_cmds(state, cmd);
 289 }
 290
 291 static void
 292 do_mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
 293 {
 294         unsigned long flags;
 295
 296         spin_lock_irqsave(&io_request_lock, flags);
 297         mac53c94_interrupt(irq, dev_id, ptregs);
 298         spin_unlock_irqrestore(&io_request_lock, flags);
 299 }
 300
 301 static void
 302 mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
 303 {
 304         struct fsc_state *state = (struct fsc_state *) dev_id;
 305         volatile struct mac53c94_regs *regs = state->regs;
 306         volatile struct dbdma_regs *dma = state->dma;
 307         Scsi_Cmnd *cmd = state->current_req;
 308         int nb, stat, seq, intr;
 309         static int mac53c94_errors;
 310
 311         /*
 312          * Apparently, reading the interrupt register unlatches
 313          * the status and sequence step registers.
 314          */
 315         seq = regs->seqstep;
 316         stat = regs->status;
 317         intr = regs->interrupt;
 318
 319 #if 0
 320         printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
 321                intr, stat, seq, state->phase);
 322 #endif
 323
 324         if (intr & INTR_RESET) {
 325                 /* SCSI bus was reset */
 326                 printk(KERN_INFO "external SCSI bus reset detected\n");
 327                 regs->command = CMD_NOP;
 328                 st_le32(&dma->control, RUN << 16);      /* stop dma */
 329                 cmd_done(state, DID_RESET << 16);
 330                 return;
 331         }
 332         if (intr & INTR_ILL_CMD) {
 333                 printk(KERN_ERR "53c94: illegal cmd, intr=%x stat=%x seq=%x phase=%d\n",
 334                        intr, stat, seq, state->phase);
 335                 cmd_done(state, DID_ERROR << 16);
 336                 return;
 337         }
 338         if (stat & STAT_ERROR) {
 339 #if 0
 340                 /* XXX these seem to be harmless? */
 341                 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
 342                        intr, stat, seq, state->phase);
 343 #endif
 344                 ++mac53c94_errors;
 345                 regs->command = CMD_NOP + CMD_DMA_MODE;
 346                 eieio();
 347         }
 348         if (cmd == 0) {
 349                 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
 350                 return;
 351         }
 352         if (stat & STAT_PARITY) {
 353                 printk(KERN_ERR "mac53c94: parity error\n");
 354                 cmd_done(state, DID_PARITY << 16);
 355                 return;
 356         }
 357         switch (state->phase) {
 358         case selecting:
 359                 if (intr & INTR_DISCONNECT) {
 360                         /* selection timed out */
 361                         cmd_done(state, DID_BAD_TARGET << 16);
 362                         return;
 363                 }
 364                 if (intr != INTR_BUS_SERV + INTR_DONE) {
 365                         printk(KERN_DEBUG "got intr %x during selection\n", intr);
 366                         cmd_done(state, DID_ERROR << 16);
 367                         return;
 368                 }
 369                 if ((seq & SS_MASK) != SS_DONE) {
 370                         printk(KERN_DEBUG "seq step %x after command\n", seq);
 371                         cmd_done(state, DID_ERROR << 16);
 372                         return;
 373                 }
 374                 regs->command = CMD_NOP;
 375                 /* set DMA controller going if any data to transfer */
 376                 if ((stat & (STAT_MSG|STAT_CD)) == 0
 377                     && (cmd->use_sg > 0 || cmd->request_bufflen != 0)) {
 378                         nb = cmd->SCp.this_residual;
 379                         if (nb > 0xfff0)
 380                                 nb = 0xfff0;
 381                         cmd->SCp.this_residual -= nb;
 382                         regs->count_lo = nb;
 383                         regs->count_mid = nb >> 8;
 384                         eieio();
 385                         regs->command = CMD_DMA_MODE + CMD_NOP;
 386                         eieio();
 387                         st_le32(&dma->cmdptr, virt_to_phys(state->dma_cmds));
 388                         st_le32(&dma->control, (RUN << 16) | RUN);
 389                         eieio();
 390                         regs->command = CMD_DMA_MODE + CMD_XFER_DATA;
 391                         state->phase = dataing;
 392                         break;
 393                 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
 394                         /* up to status phase already */
 395                         regs->command = CMD_I_COMPLETE;
 396                         state->phase = completing;
 397                 } else {
 398                         printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
 399                                stat & STAT_PHASE);
 400                         cmd_done(state, DID_ERROR << 16);
 401                         return;
 402                 }
 403                 break;
 404
 405         case dataing:
 406                 if (intr != INTR_BUS_SERV) {
 407                         printk(KERN_DEBUG "got intr %x before status\n", intr);
 408                         cmd_done(state, DID_ERROR << 16);
 409                         return;
 410                 }
 411                 if (cmd->SCp.this_residual != 0
 412                     && (stat & (STAT_MSG|STAT_CD)) == 0) {
 413                         /* Set up the count regs to transfer more */
 414                         nb = cmd->SCp.this_residual;
 415                         if (nb > 0xfff0)
 416                                 nb = 0xfff0;
 417                         cmd->SCp.this_residual -= nb;
 418                         regs->count_lo = nb;
 419                         regs->count_mid = nb >> 8;
 420                         eieio();
 421                         regs->command = CMD_DMA_MODE + CMD_NOP;
 422                         eieio();
 423                         regs->command = CMD_DMA_MODE + CMD_XFER_DATA;
 424                         break;
 425                 }
 426                 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
 427                         printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
 428                 }
 429                 st_le32(&dma->control, RUN << 16);      /* stop dma */
 430                 /* should check dma status */
 431                 regs->command = CMD_I_COMPLETE;
 432                 state->phase = completing;
 433                 break;
 434         case completing:
 435                 if (intr != INTR_DONE) {
 436                         printk(KERN_DEBUG "got intr %x on completion\n", intr);
 437                         cmd_done(state, DID_ERROR << 16);
 438                         return;
 439                 }
 440                 cmd->SCp.Status = regs->fifo; eieio();
 441                 cmd->SCp.Message = regs->fifo; eieio();
 442                 cmd->result =
 443                 regs->command = CMD_ACCEPT_MSG;
 444                 state->phase = busfreeing;
 445                 break;
 446         case busfreeing:
 447                 if (intr != INTR_DISCONNECT) {
 448                         printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
 449                 }
 450                 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
 451                          + cmd->SCp.Status);
 452                 break;
 453         default:
 454                 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
 455         }
 456 }
 457
 458 static void
 459 cmd_done(struct fsc_state *state, int result)
 460 {
 461         Scsi_Cmnd *cmd;
 462
 463         cmd = state->current_req;
 464         if (cmd != 0) {
 465                 cmd->result = result;
 466                 (*cmd->scsi_done)(cmd);
 467                 state->current_req = NULL;
 468         }
 469         state->phase = idle;
 470         mac53c94_start(state);
 471 }
 472
 473 /*
 474  * Set up DMA commands for transferring data.
 475  */
 476 static void
 477 set_dma_cmds(struct fsc_state *state, Scsi_Cmnd *cmd)
 478 {
 479         int i, dma_cmd, total;
 480         struct scatterlist *scl;
 481         struct dbdma_cmd *dcmds;
 482
 483         dma_cmd = data_goes_out(cmd)? OUTPUT_MORE: INPUT_MORE;
 484         dcmds = state->dma_cmds;
 485         if (cmd->use_sg > 0) {
 486                 total = 0;
 487                 scl = (struct scatterlist *) cmd->buffer;
 488                 for (i = 0; i < cmd->use_sg; ++i) {
 489                         if (scl->length > 0xffff)
 490                                 panic("mac53c94: scatterlist element >= 64k");
 491                         total += scl->length;
 492                         st_le16(&dcmds->req_count, scl->length);
 493                         st_le16(&dcmds->command, dma_cmd);
 494                         st_le32(&dcmds->phy_addr, virt_to_phys(scl->address));
 495                         dcmds->xfer_status = 0;
 496                         ++scl;
 497                         ++dcmds;
 498                 }
 499         } else {
 500                 total = cmd->request_bufflen;
 501                 if (total > 0xffff)
 502                         panic("mac53c94: transfer size >= 64k");
 503                 st_le16(&dcmds->req_count, total);
 504                 st_le32(&dcmds->phy_addr, virt_to_phys(cmd->request_buffer));
 505                 dcmds->xfer_status = 0;
 506                 ++dcmds;
 507         }
 508         dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
 509         st_le16(&dcmds[-1].command, dma_cmd);
 510         st_le16(&dcmds->command, DBDMA_STOP);
 511         cmd->SCp.this_residual = total;
 512 }
 513
 514 /*
 515  * Work out whether data will be going out from the host adaptor or into it.
 516  * (If this information is available from somewhere else in the scsi
 517  * code, somebody please let me know :-)
 518  */
 519 static int
 520 data_goes_out(Scsi_Cmnd *cmd)
 521 {
 522         switch (cmd->cmnd[0]) {
 523         case CHANGE_DEFINITION:
 524         case COMPARE:
 525         case COPY:
 526         case COPY_VERIFY:
 527         case FORMAT_UNIT:
 528         case LOG_SELECT:
 529         case MEDIUM_SCAN:
 530         case MODE_SELECT:
 531         case MODE_SELECT_10:
 532         case REASSIGN_BLOCKS:
 533         case RESERVE:
 534         case SEARCH_EQUAL:
 535         case SEARCH_EQUAL_12:
 536         case SEARCH_HIGH:
 537         case SEARCH_HIGH_12:
 538         case SEARCH_LOW:
 539         case SEARCH_LOW_12:
 540         case SEND_DIAGNOSTIC:
 541         case SEND_VOLUME_TAG:
 542         case SET_WINDOW:
 543         case UPDATE_BLOCK:
 544         case WRITE_BUFFER:
 545         case WRITE_6:
 546         case WRITE_10:
 547         case WRITE_12:
 548         case WRITE_LONG:
 549         case WRITE_LONG_2:      /* alternate code for WRITE_LONG */
 550         case WRITE_SAME:
 551         case WRITE_VERIFY:
 552         case WRITE_VERIFY_12:
 553                 return 1;
 554         default:
 555                 return 0;
 556         }
 557 }
 558
 559 static Scsi_Host_Template driver_template = SCSI_MAC53C94;
 560
 561 #include "scsi_module.c"