53c7,8xx.c

基于组件方式开发操作系统的OSKIT源代码

 * Purpose : Initialize internal structures, as required on startup, or 
 *	after a SCSI bus reset.
 * 
 * Inputs : host - pointer to this host adapter's structure
 */

static void 
NCR53c7x0_driver_init (struct Scsi_Host *host) {
    struct NCR53c7x0_hostdata *hostdata = (struct NCR53c7x0_hostdata *)
	host->hostdata;
    int i, j;
    u32 *curr;
    for (i = 0; i < 16; ++i) {
	hostdata->request_sense[i] = 0;
    	for (j = 0; j < 8; ++j) 
	    hostdata->busy[i][j] = 0;
	set_synchronous (host, i, /* sxfer */ 0, hostdata->saved_scntl3, 0);
    }
    hostdata->issue_queue = NULL;
    hostdata->running_list = hostdata->finished_queue = 
	hostdata->curr = NULL;
    for (i = 0, curr = (u32 *) hostdata->schedule; 
	i < host->can_queue; ++i, curr += 2) {
	curr[0] = hostdata->NOP_insn;
	curr[1] = le32_to_cpu(0xdeadbeef);
    }
    curr[0] = le32_to_cpu(((DCMD_TYPE_TCI|DCMD_TCI_OP_JUMP) << 24) | DBC_TCI_TRUE);
    curr[1] = (u32) le32_to_cpu(virt_to_bus (hostdata->script) +
	hostdata->E_wait_reselect);
    hostdata->reconnect_dsa_head = 0;
    hostdata->addr_reconnect_dsa_head = (u32) 
	le32_to_cpu(virt_to_bus((void *) &(hostdata->reconnect_dsa_head)));
    hostdata->expecting_iid = 0;
    hostdata->expecting_sto = 0;
    if (hostdata->options & OPTION_ALWAYS_SYNCHRONOUS) 
	hostdata->initiate_sdtr = le32_to_cpu(0xffff); 
    else
    	hostdata->initiate_sdtr = 0;
    hostdata->talked_to = 0;
    hostdata->idle = 1;
}

/* 
 * Function : static int ccf_to_clock (int ccf)
 *
 * Purpose :  Return the largest SCSI clock allowable for a given
 *	clock conversion factor, allowing us to do synchronous periods
 *	when we don't know what the SCSI clock is by taking at least 
 *	as long as the device says we can.
 *
 * Inputs : ccf
 *
 * Returns : clock on success, -1 on failure.
 */

static int 
ccf_to_clock (int ccf) {
    switch (ccf) {
    case 1: return 25000000; 	/* Divide by 1.0 */
    case 2: return 37500000;	/* Divide by 1.5 */
    case 3: return 50000000;  	/* Divide by 2.0 */
    case 0: 			/* Divide by 3.0 */
    case 4: return 66000000; 
    default: return -1;
    }
}

/* 
 * Function : static int clock_to_ccf (int clock)
 *
 * Purpose :  Return the clock conversion factor for a given SCSI clock.
 *
 * Inputs : clock - SCSI clock expressed in Hz.
 *
 * Returns : ccf on success, -1 on failure.
 */

static int 
clock_to_ccf (int clock) {
    if (clock < 16666666)
	return -1;
    if (clock < 25000000)
	return 1; 	/* Divide by 1.0 */
    else if (clock < 37500000)
	return 2; 	/* Divide by 1.5 */
    else if (clock < 50000000)
	return 3;	/* Divide by 2.0 */
    else if (clock < 66000000)
	return 4;	/* Divide by 3.0 */
    else 
	return -1;
}
    
/* 
 * Function : static int NCR53c7x0_init (struct Scsi_Host *host)
 *
 * Purpose :  initialize the internal structures for a given SCSI host
 *
 * Inputs : host - pointer to this host adapter's structure
 *
 * Preconditions : when this function is called, the chip_type 
 * 	field of the hostdata structure MUST have been set.
 *
 * Returns : 0 on success, -1 on failure.
 */

static int 
NCR53c7x0_init (struct Scsi_Host *host) {
    NCR53c7x0_local_declare();
    int i, ccf, expected_ccf;
    struct NCR53c7x0_hostdata *hostdata = (struct NCR53c7x0_hostdata *)
	host->hostdata;
    struct Scsi_Host *search;
    /* 
     * There are some things which we need to know about in order to provide
     * a semblance of support.  Print 'em if they aren't what we expect, 
     * otherwise don't add to the noise.
     * 
     * -1 means we don't know what to expect.
     */
    int expected_id = -1;
    int expected_clock = -1;
    int uninitialized = 0;
    /* 
     * FIXME : this is only on Intel boxes.  On other platforms, this
     * will differ.
     */
    int expected_mapping = OPTION_IO_MAPPED;

    NCR53c7x0_local_setup(host);

    switch (hostdata->chip) {
    case 820:
    case 825:
#ifdef notyet
	host->max_id = 15;
#endif
	/* Fall through */
    case 810:
    case 815:
    	hostdata->dstat_sir_intr = NCR53c8x0_dstat_sir_intr;
    	hostdata->init_save_regs = NULL;
    	hostdata->dsa_fixup = NCR53c8xx_dsa_fixup;
    	hostdata->init_fixup = NCR53c8x0_init_fixup;
    	hostdata->soft_reset = NCR53c8x0_soft_reset;
	hostdata->run_tests = NCR53c8xx_run_tests;
/* Is the SCSI clock ever anything else on these chips? */
	expected_clock = hostdata->scsi_clock = 40000000;
	expected_id = 7;
    	break;
    default:
	printk ("scsi%d : chip type of %d is not supported yet, detaching.\n",
	    host->host_no, hostdata->chip);
	scsi_unregister (host);
	return -1;
    }

    /* Assign constants accessed by NCR */
    hostdata->NCR53c7xx_zero = 0;			
    hostdata->NCR53c7xx_msg_reject = le32_to_cpu(MESSAGE_REJECT);
    hostdata->NCR53c7xx_msg_abort = le32_to_cpu(ABORT);
    hostdata->NCR53c7xx_msg_nop = le32_to_cpu(NOP);
    hostdata->NOP_insn = le32_to_cpu((DCMD_TYPE_TCI|DCMD_TCI_OP_JUMP) << 24);

    if (expected_mapping == -1 || 
	(hostdata->options & (OPTION_MEMORY_MAPPED)) != 
	(expected_mapping & OPTION_MEMORY_MAPPED))
	printk ("scsi%d : using %s mapped access\n", host->host_no, 
	    (hostdata->options & OPTION_MEMORY_MAPPED) ? "memory" : 
	    "io");

    hostdata->dmode = (hostdata->chip == 700 || hostdata->chip == 70066) ? 
	DMODE_REG_00 : DMODE_REG_10;
    hostdata->istat = ((hostdata->chip / 100) == 8) ? 
    	ISTAT_REG_800 : ISTAT_REG_700;

/* Only the ISTAT register is readable when the NCR is running, so make 
   sure it's halted. */
    ncr_halt(host);

/* 
 * XXX - the NCR53c700 uses bitfielded registers for SCID, SDID, etc,
 *	as does the 710 with one bit per SCSI ID.  Conversely, the NCR
 * 	uses a normal, 3 bit binary representation of these values.
 *
 * Get the rest of the NCR documentation, and FIND OUT where the change
 * was.
 */
#if 0
    tmp = hostdata->this_id_mask = NCR53c7x0_read8(SCID_REG);
    for (host->this_id = 0; tmp != 1; tmp >>=1, ++host->this_id);
#else
    host->this_id = NCR53c7x0_read8(SCID_REG) & 15;
    if (host->this_id == 0)
	host->this_id = 7;	/* sanitize hostid---0 doesn't make sense */
    hostdata->this_id_mask = 1 << host->this_id;
#endif

/*
 * Note : we should never encounter a board setup for ID0.  So,
 * 	if we see ID0, assume that it was uninitialized and set it
 * 	to the industry standard 7.
 */
    if (!host->this_id) {
	printk("scsi%d : initiator ID was %d, changing to 7\n",
	    host->host_no, host->this_id);
	host->this_id = 7;
	hostdata->this_id_mask = 1 << 7;
	uninitialized = 1;
    };

    if (expected_id == -1 || host->this_id != expected_id)
    	printk("scsi%d : using initiator ID %d\n", host->host_no,
    	    host->this_id);

    /*
     * Save important registers to allow a soft reset.
     */

    if ((hostdata->chip / 100) == 8) {
    /* 
     * CTEST4 controls burst mode disable.
     */
	hostdata->saved_ctest4 = NCR53c7x0_read8(CTEST4_REG_800) & 
    	    CTEST4_800_SAVE;
    } else {
    /*
     * CTEST7 controls cache snooping, burst mode, and support for 
     * external differential drivers.
     */
	hostdata->saved_ctest7 = NCR53c7x0_read8(CTEST7_REG) & CTEST7_SAVE;
    }

    /*
     * On NCR53c700 series chips, DCNTL controls the SCSI clock divisor,
     * on 800 series chips, it allows for a totem-pole IRQ driver.
     */

    hostdata->saved_dcntl = NCR53c7x0_read8(DCNTL_REG);

    /* 
     * DCNTL_800_IRQM controls weather we are using an open drain
     * driver (reset) or totem pole driver (set).  In all cases, 
     * it's level active.  I suppose this is an issue when we're trying to 
     * wire-or the same PCI INTx line?
     */
    if ((hostdata->chip / 100) == 8)
	hostdata->saved_dcntl &= ~DCNTL_800_IRQM;

    /*
     * DMODE controls DMA burst length, and on 700 series chips,
     * 286 mode and bus width  
     */
    hostdata->saved_dmode = NCR53c7x0_read8(hostdata->dmode);

    /* 
     * Now that burst length and enabled/disabled status is known, 
     * clue the user in on it.  
     */
   
    if ((hostdata->chip / 100) == 8) {
	if (hostdata->saved_ctest4 & CTEST4_800_BDIS) {
	    printk ("scsi%d : burst mode disabled\n", host->host_no);
	} else {
	    switch (hostdata->saved_dmode & DMODE_BL_MASK) {
	    case DMODE_BL_2: i = 2; break;
	    case DMODE_BL_4: i = 4; break;
	    case DMODE_BL_8: i = 8; break;
	    case DMODE_BL_16: i = 16; break;
            default: i = 0;
	    }
	    printk ("scsi%d : burst length %d\n", host->host_no, i);
	}
    }

    /*
     * On NCR53c810 and NCR53c820 chips, SCNTL3 contails the synchronous
     * and normal clock conversion factors.
     */
    if (hostdata->chip / 100 == 8)  {
	expected_ccf = clock_to_ccf (expected_clock);
	hostdata->saved_scntl3 = NCR53c7x0_read8(SCNTL3_REG_800);
	ccf = hostdata->saved_scntl3 & SCNTL3_800_CCF_MASK;
	if (expected_ccf != -1 && ccf != expected_ccf && !ccf) {
	    hostdata->saved_scntl3 = (hostdata->saved_scntl3 &
		~SCNTL3_800_CCF_MASK) | expected_ccf;
	    if (!uninitialized) {
		printk ("scsi%d : reset ccf to %d from %d\n", 
		    host->host_no, expected_ccf, ccf);
		uninitialized = 1;
	    }
	}
    } else
    	ccf = 0;

    /*
     * If we don't have a SCSI clock programmed, pick one on the upper
     * bound of that allowed by NCR so that our transfers err on the 
     * slow side, since transfer period must be >= the agreed 
     * upon period.
     */

    if ((!hostdata->scsi_clock) && (hostdata->scsi_clock = ccf_to_clock (ccf)) 
	== -1) {
	printk ("scsi%d : clock conversion factor %d unknown.\n"
		"         synchronous transfers disabled\n",
		host->host_no, ccf);
	hostdata->options &= ~OPTION_SYNCHRONOUS;
	hostdata->scsi_clock = 0; 
    }

    if (expected_clock == -1 || hostdata->scsi_clock != expected_clock)
    	printk ("scsi%d : using %dMHz SCSI clock\n", host->host_no, 
	    hostdata->scsi_clock / 1000000);

    for (i = 0; i < 16; ++i) 
	hostdata->cmd_allocated[i] = 0;

    if (hostdata->init_save_regs)
    	hostdata->init_save_regs (host);
    if (hostdata->init_fixup)
    	hostdata->init_fixup (host);

    if (!the_template) {
	the_template = host->hostt;
	first_host = host;
    }

    /* 
     * Linux SCSI drivers have always been plagued with initialization 
     * problems - some didn't work with the BIOS disabled since they expected
     * initialization from it, some didn't work when the networking code
     * was enabled and registers got scrambled, etc.
     *
     * To avoid problems like this, in the future, we will do a soft 
     * reset on the SCSI chip, taking it back to a sane state.
     */

    hostdata->soft_reset (host);

#if 1
    hostdata->debug_count_limit = -1;
#else
    hostdata->debug_count_limit = 1;
#endif
    hostdata->intrs = -1;
    hostdata->resets = -1;
    memcpy ((void *) hostdata->synchronous_want, (void *) sdtr_message, 
	sizeof (hostdata->synchronous_want));

    NCR53c7x0_driver_init (host);

    /*
     * Set up an interrupt handler if we aren't already sharing an IRQ
     * with another board.
     */

    for (search = first_host; search && !(search->hostt == the_template &&
	search->irq == host->irq && search != host); search=search->next);

    if (!search) {
#ifdef __powerpc__
	if (request_irq(host->irq, do_NCR53c7x0_intr, SA_SHIRQ, "53c7,8xx", NULL)) 
#else
	if (request_irq(host->irq, do_NCR53c7x0_intr, SA_INTERRUPT, "53c7,8xx", NULL))
#endif
	  {
	  
	  
	    printk("scsi%d : IRQ%d not free, detaching\n"
	           "         You have either a configuration problem, or a\n"
                   "         broken BIOS.  You may wish to manually assign\n"
	           "         an interrupt to the NCR board rather than using\n"
                   "         an automatic setting.\n", 
		host->host_no, host->irq);
	    scsi_unregister (host);
	    return -1;
	} 
    } else {
	printk("scsi%d : using interrupt handler previously installed for scsi%d\n",
	    host->host_no, search->host_no);
    }


    if ((hostdata->run_tests && hostdata->run_tests(host) == -1) ||
        (hostdata->options & OPTION_DEBUG_TESTS_ONLY)) {
    	/* XXX Should disable interrupts, etc. here */
	scsi_unregister (host);