drivers/scsi/oktagon_esp.c - linux - Git at Google

 /*
  * Oktagon_esp.c -- Driver for bsc Oktagon
  *
  * Written by Carsten Pluntke 1998
  *
  * Based on cyber_esp.c
  */


 #if defined(CONFIG_AMIGA) || defined(CONFIG_APUS)
 #define USE_BOTTOM_HALF
 #endif

 #include <linux/module.h>

 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/blkdev.h>
 #include <linux/proc_fs.h>
 #include <linux/stat.h>
 #include <linux/reboot.h>
 #include <asm/system.h>
 #include <asm/ptrace.h>
 #include <asm/pgtable.h>


 #include "scsi.h"
 #include <scsi/scsi_host.h>
 #include "NCR53C9x.h"

 #include <linux/zorro.h>
 #include <asm/irq.h>
 #include <asm/amigaints.h>
 #include <asm/amigahw.h>

 #ifdef USE_BOTTOM_HALF
 #include <linux/workqueue.h>
 #include <linux/interrupt.h>
 #endif

 /* The controller registers can be found in the Z2 config area at these
  * offsets:
  */
 #define OKTAGON_ESP_ADDR 0x03000
 #define OKTAGON_DMA_ADDR 0x01000


 static int  dma_bytes_sent(struct NCR_ESP *esp, int fifo_count);
 static int  dma_can_transfer(struct NCR_ESP *esp, Scsi_Cmnd *sp);
 static void dma_dump_state(struct NCR_ESP *esp);
 static void dma_init_read(struct NCR_ESP *esp, __u32 vaddress, int length);
 static void dma_init_write(struct NCR_ESP *esp, __u32 vaddress, int length);
 static void dma_ints_off(struct NCR_ESP *esp);
 static void dma_ints_on(struct NCR_ESP *esp);
 static int  dma_irq_p(struct NCR_ESP *esp);
 static void dma_led_off(struct NCR_ESP *esp);
 static void dma_led_on(struct NCR_ESP *esp);
 static int  dma_ports_p(struct NCR_ESP *esp);
 static void dma_setup(struct NCR_ESP *esp, __u32 addr, int count, int write);

 static void dma_irq_exit(struct NCR_ESP *esp);
 static void dma_invalidate(struct NCR_ESP *esp);

 static void dma_mmu_get_scsi_one(struct NCR_ESP *,Scsi_Cmnd *);
 static void dma_mmu_get_scsi_sgl(struct NCR_ESP *,Scsi_Cmnd *);
 static void dma_mmu_release_scsi_one(struct NCR_ESP *,Scsi_Cmnd *);
 static void dma_mmu_release_scsi_sgl(struct NCR_ESP *,Scsi_Cmnd *);
 static void dma_advance_sg(Scsi_Cmnd *);
 static int  oktagon_notify_reboot(struct notifier_block *this, unsigned long code, void *x);

 #ifdef USE_BOTTOM_HALF
 static void dma_commit(struct work_struct *unused);

 long oktag_to_io(long *paddr, long *addr, long len);
 long oktag_from_io(long *addr, long *paddr, long len);

 static DECLARE_WORK(tq_fake_dma, dma_commit);

 #define DMA_MAXTRANSFER 0x8000

 #else

 /*
  * No bottom half. Use transfer directly from IRQ. Find a narrow path
  * between too much IRQ overhead and clogging the IRQ for too long.
  */

 #define DMA_MAXTRANSFER 0x1000

 #endif

 static struct notifier_block oktagon_notifier = {
 	oktagon_notify_reboot,
 	NULL,
 	0
 };

 static long *paddress;
 static long *address;
 static long len;
 static long dma_on;
 static int direction;
 static struct NCR_ESP *current_esp;


 static volatile unsigned char cmd_buffer[16];
 				/* This is where all commands are put
 				 * before they are trasfered to the ESP chip
 				 * via PIO.
 				 */

 /***************************************************************** Detection */
 int oktagon_esp_detect(struct scsi_host_template *tpnt)
 {
 	struct NCR_ESP *esp;
 	struct zorro_dev *z = NULL;
 	unsigned long address;
 	struct ESP_regs *eregs;

 	while ((z = zorro_find_device(ZORRO_PROD_BSC_OKTAGON_2008, z))) {
 	    unsigned long board = z->resource.start;
 	    if (request_mem_region(board+OKTAGON_ESP_ADDR,
 				   sizeof(struct ESP_regs), "NCR53C9x")) {
 		/*
 		 * It is a SCSI controller.
 		 * Hardwire Host adapter to SCSI ID 7
 		 */

 		address = (unsigned long)ZTWO_VADDR(board);
 		eregs = (struct ESP_regs *)(address + OKTAGON_ESP_ADDR);

 		/* This line was 5 lines lower */
 		esp = esp_allocate(tpnt, (void *)board+OKTAGON_ESP_ADDR);

 		/* we have to shift the registers only one bit for oktagon */
 		esp->shift = 1;

 		esp_write(eregs->esp_cfg1, (ESP_CONFIG1_PENABLE | 7));
 		udelay(5);
 		if (esp_read(eregs->esp_cfg1) != (ESP_CONFIG1_PENABLE | 7))
 			return 0; /* Bail out if address did not hold data */

 		/* Do command transfer with programmed I/O */
 		esp->do_pio_cmds = 1;

 		/* Required functions */
 		esp->dma_bytes_sent = &dma_bytes_sent;
 		esp->dma_can_transfer = &dma_can_transfer;
 		esp->dma_dump_state = &dma_dump_state;
 		esp->dma_init_read = &dma_init_read;
 		esp->dma_init_write = &dma_init_write;
 		esp->dma_ints_off = &dma_ints_off;
 		esp->dma_ints_on = &dma_ints_on;
 		esp->dma_irq_p = &dma_irq_p;
 		esp->dma_ports_p = &dma_ports_p;
 		esp->dma_setup = &dma_setup;

 		/* Optional functions */
 		esp->dma_barrier = 0;
 		esp->dma_drain = 0;
 		esp->dma_invalidate = &dma_invalidate;
 		esp->dma_irq_entry = 0;
 		esp->dma_irq_exit = &dma_irq_exit;
 		esp->dma_led_on = &dma_led_on;
 		esp->dma_led_off = &dma_led_off;
 		esp->dma_poll = 0;
 		esp->dma_reset = 0;

 		esp->dma_mmu_get_scsi_one = &dma_mmu_get_scsi_one;
 		esp->dma_mmu_get_scsi_sgl = &dma_mmu_get_scsi_sgl;
 		esp->dma_mmu_release_scsi_one = &dma_mmu_release_scsi_one;
 		esp->dma_mmu_release_scsi_sgl = &dma_mmu_release_scsi_sgl;
 		esp->dma_advance_sg = &dma_advance_sg;

 		/* SCSI chip speed */
 		/* Looking at the quartz of the SCSI board... */
 		esp->cfreq = 25000000;

 		/* The DMA registers on the CyberStorm are mapped
 		 * relative to the device (i.e. in the same Zorro
 		 * I/O block).
 		 */
 		esp->dregs = (void *)(address + OKTAGON_DMA_ADDR);

 		paddress = (long *) esp->dregs;

 		/* ESP register base */
 		esp->eregs = eregs;

 		/* Set the command buffer */
 		esp->esp_command = (volatile unsigned char*) cmd_buffer;

 		/* Yes, the virtual address. See below. */
 		esp->esp_command_dvma = (__u32) cmd_buffer;

 		esp->irq = IRQ_AMIGA_PORTS;
 		request_irq(IRQ_AMIGA_PORTS, esp_intr, IRQF_SHARED,
 			    "BSC Oktagon SCSI", esp->ehost);

 		/* Figure out our scsi ID on the bus */
 		esp->scsi_id = 7;

 		/* We don't have a differential SCSI-bus. */
 		esp->diff = 0;

 		esp_initialize(esp);

 		printk("ESP_Oktagon Driver 1.1"
 #ifdef USE_BOTTOM_HALF
 		       " [BOTTOM_HALF]"
 #else
 		       " [IRQ]"
 #endif
 		       " registered.\n");
 		printk("ESP: Total of %d ESP hosts found, %d actually in use.\n", nesps,esps_in_use);
 		esps_running = esps_in_use;
 		current_esp = esp;
 		register_reboot_notifier(&oktagon_notifier);
 		return esps_in_use;
 	    }
 	}
 	return 0;
 }


 /*
  * On certain configurations the SCSI equipment gets confused on reboot,
  * so we have to reset it then.
  */

 static int
 oktagon_notify_reboot(struct notifier_block *this, unsigned long code, void *x)
 {
   struct NCR_ESP *esp;

   if((code == SYS_DOWN || code == SYS_HALT) && (esp = current_esp))
    {
     esp_bootup_reset(esp,esp->eregs);
     udelay(500); /* Settle time. Maybe unnecessary. */
    }
   return NOTIFY_DONE;
 }


 #ifdef USE_BOTTOM_HALF


 /*
  * The bsc Oktagon controller has no real DMA, so we have to do the 'DMA
  * transfer' in the interrupt (Yikes!) or use a bottom half to not to clutter
  * IRQ's for longer-than-good.
  *
  * FIXME
  * BIG PROBLEM: 'len' is usually the buffer length, not the expected length
  * of the data. So DMA may finish prematurely, further reads lead to
  * 'machine check' on APUS systems (don't know about m68k systems, AmigaOS
  * deliberately ignores the bus faults) and a normal copy-loop can't
  * be exited prematurely just at the right moment by the dma_invalidate IRQ.
  * So do it the hard way, write an own copier in assembler and
  * catch the exception.
  *                                     -- Carsten
  */


 static void dma_commit(struct work_struct *unused)
 {
     long wait,len2,pos;
     struct NCR_ESP *esp;

     ESPDATA(("Transfer: %ld bytes, Address 0x%08lX, Direction: %d\n",
          len,(long) address,direction));
     dma_ints_off(current_esp);

     pos = 0;
     wait = 1;
     if(direction) /* write? (memory to device) */
      {
       while(len > 0)
        {
         len2 = oktag_to_io(paddress, address+pos, len);
 	if(!len2)
 	 {
 	  if(wait > 1000)
 	   {
 	    printk("Expedited DMA exit (writing) %ld\n",len);
 	    break;
 	   }
 	  mdelay(wait);
 	  wait *= 2;
 	 }
 	pos += len2;
 	len -= len2*sizeof(long);
        }
      } else {
       while(len > 0)
        {
         len2 = oktag_from_io(address+pos, paddress, len);
 	if(!len2)
 	 {
 	  if(wait > 1000)
 	   {
 	    printk("Expedited DMA exit (reading) %ld\n",len);
 	    break;
 	   }
 	  mdelay(wait);
 	  wait *= 2;
 	 }
 	pos += len2;
 	len -= len2*sizeof(long);
        }
      }

     /* to make esp->shift work */
     esp=current_esp;

 #if 0
     len2 = (esp_read(current_esp->eregs->esp_tclow) & 0xff) |
            ((esp_read(current_esp->eregs->esp_tcmed) & 0xff) << 8);

     /*
      * Uh uh. If you see this, len and transfer count registers were out of
      * sync. That means really serious trouble.
      */

     if(len2)
       printk("Eeeek!! Transfer count still %ld!\n",len2);
 #endif

     /*
      * Normally we just need to exit and wait for the interrupt to come.
      * But at least one device (my Microtek ScanMaker 630) regularly mis-
      * calculates the bytes it should send which is really ugly because
      * it locks up the SCSI bus if not accounted for.
      */

     if(!(esp_read(current_esp->eregs->esp_status) & ESP_STAT_INTR))
      {
       long len = 100;
       long trash[10];

       /*
        * Interrupt bit was not set. Either the device is just plain lazy
        * so we give it a 10 ms chance or...
        */
       while(len-- && (!(esp_read(current_esp->eregs->esp_status) & ESP_STAT_INTR)))
         udelay(100);


       if(!(esp_read(current_esp->eregs->esp_status) & ESP_STAT_INTR))
        {
         /*
 	 * So we think that the transfer count is out of sync. Since we
 	 * have all we want we are happy and can ditch the trash.
 	 */

         len = DMA_MAXTRANSFER;

         while(len-- && (!(esp_read(current_esp->eregs->esp_status) & ESP_STAT_INTR)))
           oktag_from_io(trash,paddress,2);

         if(!(esp_read(current_esp->eregs->esp_status) & ESP_STAT_INTR))
          {
           /*
            * Things really have gone wrong. If we leave the system in that
            * state, the SCSI bus is locked forever. I hope that this will
            * turn the system in a more or less running state.
            */
           printk("Device is bolixed, trying bus reset...\n");
 	  esp_bootup_reset(current_esp,current_esp->eregs);
          }
        }
      }

     ESPDATA(("Transfer_finale: do_data_finale should come\n"));

     len = 0;
     dma_on = 0;
     dma_ints_on(current_esp);
 }

 #endif

 /************************************************************* DMA Functions */
 static int dma_bytes_sent(struct NCR_ESP *esp, int fifo_count)
 {
 	/* Since the CyberStorm DMA is fully dedicated to the ESP chip,
 	 * the number of bytes sent (to the ESP chip) equals the number
 	 * of bytes in the FIFO - there is no buffering in the DMA controller.
 	 * XXXX Do I read this right? It is from host to ESP, right?
 	 */
 	return fifo_count;
 }

 static int dma_can_transfer(struct NCR_ESP *esp, Scsi_Cmnd *sp)
 {
 	unsigned long sz = sp->SCp.this_residual;
 	if(sz > DMA_MAXTRANSFER)
 		sz = DMA_MAXTRANSFER;
 	return sz;
 }

 static void dma_dump_state(struct NCR_ESP *esp)
 {
 }

 /*
  * What the f$@& is this?
  *
  * Some SCSI devices (like my Microtek ScanMaker 630 scanner) want to transfer
  * more data than requested. How much? Dunno. So ditch the bogus data into
  * the sink, hoping the device will advance to the next phase sooner or later.
  *
  *                         -- Carsten
  */

 static long oktag_eva_buffer[16]; /* The data sink */

 static void oktag_check_dma(void)
 {
   struct NCR_ESP *esp;

   esp=current_esp;
   if(!len)
    {
     address = oktag_eva_buffer;
     len = 2;
     /* esp_do_data sets them to zero like len */
     esp_write(current_esp->eregs->esp_tclow,2);
     esp_write(current_esp->eregs->esp_tcmed,0);
    }
 }

 static void dma_init_read(struct NCR_ESP *esp, __u32 vaddress, int length)
 {
 	/* Zorro is noncached, everything else done using processor. */
 	/* cache_clear(addr, length); */

 	if(dma_on)
 	  panic("dma_init_read while dma process is initialized/running!\n");
 	direction = 0;
 	address = (long *) vaddress;
 	current_esp = esp;
 	len = length;
 	oktag_check_dma();
         dma_on = 1;
 }

 static void dma_init_write(struct NCR_ESP *esp, __u32 vaddress, int length)
 {
 	/* cache_push(addr, length); */

 	if(dma_on)
 	  panic("dma_init_write while dma process is initialized/running!\n");
 	direction = 1;
 	address = (long *) vaddress;
 	current_esp = esp;
 	len = length;
 	oktag_check_dma();
 	dma_on = 1;
 }

 static void dma_ints_off(struct NCR_ESP *esp)
 {
 	disable_irq(esp->irq);
 }

 static void dma_ints_on(struct NCR_ESP *esp)
 {
 	enable_irq(esp->irq);
 }

 static int dma_irq_p(struct NCR_ESP *esp)
 {
 	/* It's important to check the DMA IRQ bit in the correct way! */
 	return (esp_read(esp->eregs->esp_status) & ESP_STAT_INTR);
 }

 static void dma_led_off(struct NCR_ESP *esp)
 {
 }

 static void dma_led_on(struct NCR_ESP *esp)
 {
 }

 static int dma_ports_p(struct NCR_ESP *esp)
 {
 	return ((amiga_custom.intenar) & IF_PORTS);
 }

 static void dma_setup(struct NCR_ESP *esp, __u32 addr, int count, int write)
 {
 	/* On the Sparc, DMA_ST_WRITE means "move data from device to memory"
 	 * so when (write) is true, it actually means READ!
 	 */
 	if(write){
 		dma_init_read(esp, addr, count);
 	} else {
 		dma_init_write(esp, addr, count);
 	}
 }

 /*
  * IRQ entry when DMA transfer is ready to be started
  */

 static void dma_irq_exit(struct NCR_ESP *esp)
 {
 #ifdef USE_BOTTOM_HALF
 	if(dma_on)
 	 {
 	  schedule_work(&tq_fake_dma);
 	 }
 #else
 	while(len && !dma_irq_p(esp))
 	 {
 	  if(direction)
 	    *paddress = *address++;
 	   else
 	    *address++ = *paddress;
 	  len -= (sizeof(long));
 	 }
 	len = 0;
         dma_on = 0;
 #endif
 }

 /*
  * IRQ entry when DMA has just finished
  */

 static void dma_invalidate(struct NCR_ESP *esp)
 {
 }

 /*
  * Since the processor does the data transfer we have to use the custom
  * mmu interface to pass the virtual address, not the physical.
  */

 void dma_mmu_get_scsi_one(struct NCR_ESP *esp, Scsi_Cmnd *sp)
 {
         sp->SCp.ptr =
                 sp->request_buffer;
 }

 void dma_mmu_get_scsi_sgl(struct NCR_ESP *esp, Scsi_Cmnd *sp)
 {
         sp->SCp.ptr = page_address(sp->SCp.buffer->page)+
 		      sp->SCp.buffer->offset;
 }

 void dma_mmu_release_scsi_one(struct NCR_ESP *esp, Scsi_Cmnd *sp)
 {
 }

 void dma_mmu_release_scsi_sgl(struct NCR_ESP *esp, Scsi_Cmnd *sp)
 {
 }

 void dma_advance_sg(Scsi_Cmnd *sp)
 {
 	sp->SCp.ptr = page_address(sp->SCp.buffer->page)+
 		      sp->SCp.buffer->offset;
 }


 #define HOSTS_C

 int oktagon_esp_release(struct Scsi_Host *instance)
 {
 #ifdef MODULE
 	unsigned long address = (unsigned long)((struct NCR_ESP *)instance->hostdata)->edev;
 	esp_release();
 	release_mem_region(address, sizeof(struct ESP_regs));
 	free_irq(IRQ_AMIGA_PORTS, esp_intr);
 	unregister_reboot_notifier(&oktagon_notifier);
 #endif
 	return 1;
 }


 static struct scsi_host_template driver_template = {
 	.proc_name		= "esp-oktagon",
 	.proc_info		= &esp_proc_info,
 	.name			= "BSC Oktagon SCSI",
 	.detect			= oktagon_esp_detect,
 	.slave_alloc		= esp_slave_alloc,
 	.slave_destroy		= esp_slave_destroy,
 	.release		= oktagon_esp_release,
 	.queuecommand		= esp_queue,
 	.eh_abort_handler	= esp_abort,
 	.eh_bus_reset_handler	= esp_reset,
 	.can_queue		= 7,
 	.this_id		= 7,
 	.sg_tablesize		= SG_ALL,
 	.cmd_per_lun		= 1,
 	.use_clustering		= ENABLE_CLUSTERING
 };


 #include "scsi_module.c"

 MODULE_LICENSE("GPL");
	/*
	* Oktagon_esp.c -- Driver for bsc Oktagon
	*
	* Written by Carsten Pluntke 1998
	*
	* Based on cyber_esp.c
	*/


	#if defined(CONFIG_AMIGA) \|\| defined(CONFIG_APUS)
	#define USE_BOTTOM_HALF
	#endif

	#include <linux/module.h>

	#include <linux/kernel.h>
	#include <linux/delay.h>
	#include <linux/types.h>
	#include <linux/string.h>
	#include <linux/slab.h>
	#include <linux/blkdev.h>
	#include <linux/proc_fs.h>
	#include <linux/stat.h>
	#include <linux/reboot.h>
	#include <asm/system.h>
	#include <asm/ptrace.h>
	#include <asm/pgtable.h>


	#include "scsi.h"
	#include <scsi/scsi_host.h>
	#include "NCR53C9x.h"

	#include <linux/zorro.h>
	#include <asm/irq.h>
	#include <asm/amigaints.h>
	#include <asm/amigahw.h>

	#ifdef USE_BOTTOM_HALF
	#include <linux/workqueue.h>
	#include <linux/interrupt.h>
	#endif

	/* The controller registers can be found in the Z2 config area at these
	* offsets:
	*/
	#define OKTAGON_ESP_ADDR 0x03000
	#define OKTAGON_DMA_ADDR 0x01000


	static int dma_bytes_sent(struct NCR_ESP *esp, int fifo_count);
	static int dma_can_transfer(struct NCR_ESP esp, Scsi_Cmnd sp);
	static void dma_dump_state(struct NCR_ESP *esp);
	static void dma_init_read(struct NCR_ESP *esp, __u32 vaddress, int length);
	static void dma_init_write(struct NCR_ESP *esp, __u32 vaddress, int length);
	static void dma_ints_off(struct NCR_ESP *esp);
	static void dma_ints_on(struct NCR_ESP *esp);
	static int dma_irq_p(struct NCR_ESP *esp);
	static void dma_led_off(struct NCR_ESP *esp);
	static void dma_led_on(struct NCR_ESP *esp);
	static int dma_ports_p(struct NCR_ESP *esp);
	static void dma_setup(struct NCR_ESP *esp, __u32 addr, int count, int write);

	static void dma_irq_exit(struct NCR_ESP *esp);
	static void dma_invalidate(struct NCR_ESP *esp);

	static void dma_mmu_get_scsi_one(struct NCR_ESP ,Scsi_Cmnd );
	static void dma_mmu_get_scsi_sgl(struct NCR_ESP ,Scsi_Cmnd );
	static void dma_mmu_release_scsi_one(struct NCR_ESP ,Scsi_Cmnd );
	static void dma_mmu_release_scsi_sgl(struct NCR_ESP ,Scsi_Cmnd );
	static void dma_advance_sg(Scsi_Cmnd *);
	static int oktagon_notify_reboot(struct notifier_block this, unsigned long code, void x);

	#ifdef USE_BOTTOM_HALF
	static void dma_commit(struct work_struct *unused);

	long oktag_to_io(long paddr, long addr, long len);
	long oktag_from_io(long addr, long paddr, long len);

	static DECLARE_WORK(tq_fake_dma, dma_commit);

	#define DMA_MAXTRANSFER 0x8000

	#else

	/*
	* No bottom half. Use transfer directly from IRQ. Find a narrow path
	* between too much IRQ overhead and clogging the IRQ for too long.
	*/

	#define DMA_MAXTRANSFER 0x1000

	#endif

	static struct notifier_block oktagon_notifier = {
	oktagon_notify_reboot,
	NULL,
	0
	};

	static long *paddress;
	static long *address;
	static long len;
	static long dma_on;
	static int direction;
	static struct NCR_ESP *current_esp;


	static volatile unsigned char cmd_buffer[16];
	/* This is where all commands are put
	* before they are trasfered to the ESP chip
	* via PIO.
	*/

	/***************************************************************** Detection */
	int oktagon_esp_detect(struct scsi_host_template *tpnt)
	{
	struct NCR_ESP *esp;
	struct zorro_dev *z = NULL;
	unsigned long address;
	struct ESP_regs *eregs;

	while ((z = zorro_find_device(ZORRO_PROD_BSC_OKTAGON_2008, z))) {
	unsigned long board = z->resource.start;
	if (request_mem_region(board+OKTAGON_ESP_ADDR,
	sizeof(struct ESP_regs), "NCR53C9x")) {
	/*
	* It is a SCSI controller.
	* Hardwire Host adapter to SCSI ID 7
	*/

	address = (unsigned long)ZTWO_VADDR(board);
	eregs = (struct ESP_regs *)(address + OKTAGON_ESP_ADDR);

	/* This line was 5 lines lower */
	esp = esp_allocate(tpnt, (void *)board+OKTAGON_ESP_ADDR);

	/* we have to shift the registers only one bit for oktagon */
	esp->shift = 1;

	esp_write(eregs->esp_cfg1, (ESP_CONFIG1_PENABLE \| 7));
	udelay(5);
	if (esp_read(eregs->esp_cfg1) != (ESP_CONFIG1_PENABLE \| 7))
	return 0; /* Bail out if address did not hold data */

	/* Do command transfer with programmed I/O */
	esp->do_pio_cmds = 1;

	/* Required functions */
	esp->dma_bytes_sent = &dma_bytes_sent;
	esp->dma_can_transfer = &dma_can_transfer;
	esp->dma_dump_state = &dma_dump_state;
	esp->dma_init_read = &dma_init_read;
	esp->dma_init_write = &dma_init_write;
	esp->dma_ints_off = &dma_ints_off;
	esp->dma_ints_on = &dma_ints_on;
	esp->dma_irq_p = &dma_irq_p;
	esp->dma_ports_p = &dma_ports_p;
	esp->dma_setup = &dma_setup;

	/* Optional functions */
	esp->dma_barrier = 0;
	esp->dma_drain = 0;
	esp->dma_invalidate = &dma_invalidate;
	esp->dma_irq_entry = 0;
	esp->dma_irq_exit = &dma_irq_exit;
	esp->dma_led_on = &dma_led_on;
	esp->dma_led_off = &dma_led_off;
	esp->dma_poll = 0;
	esp->dma_reset = 0;

	esp->dma_mmu_get_scsi_one = &dma_mmu_get_scsi_one;
	esp->dma_mmu_get_scsi_sgl = &dma_mmu_get_scsi_sgl;
	esp->dma_mmu_release_scsi_one = &dma_mmu_release_scsi_one;
	esp->dma_mmu_release_scsi_sgl = &dma_mmu_release_scsi_sgl;
	esp->dma_advance_sg = &dma_advance_sg;

	/* SCSI chip speed */
	/* Looking at the quartz of the SCSI board... */
	esp->cfreq = 25000000;

	/* The DMA registers on the CyberStorm are mapped
	* relative to the device (i.e. in the same Zorro
	* I/O block).
	*/
	esp->dregs = (void *)(address + OKTAGON_DMA_ADDR);

	paddress = (long *) esp->dregs;

	/* ESP register base */
	esp->eregs = eregs;

	/* Set the command buffer */
	esp->esp_command = (volatile unsigned char*) cmd_buffer;

	/* Yes, the virtual address. See below. */
	esp->esp_command_dvma = (__u32) cmd_buffer;

	esp->irq = IRQ_AMIGA_PORTS;
	request_irq(IRQ_AMIGA_PORTS, esp_intr, IRQF_SHARED,
	"BSC Oktagon SCSI", esp->ehost);

	/* Figure out our scsi ID on the bus */
	esp->scsi_id = 7;

	/* We don't have a differential SCSI-bus. */
	esp->diff = 0;

	esp_initialize(esp);

	printk("ESP_Oktagon Driver 1.1"
	#ifdef USE_BOTTOM_HALF
	" [BOTTOM_HALF]"
	#else
	" [IRQ]"
	#endif
	" registered.\n");
	printk("ESP: Total of %d ESP hosts found, %d actually in use.\n", nesps,esps_in_use);
	esps_running = esps_in_use;
	current_esp = esp;
	register_reboot_notifier(&oktagon_notifier);
	return esps_in_use;
	}
	}
	return 0;
	}


	/*
	* On certain configurations the SCSI equipment gets confused on reboot,
	* so we have to reset it then.
	*/

	static int
	oktagon_notify_reboot(struct notifier_block this, unsigned long code, void x)
	{
	struct NCR_ESP *esp;

	if((code == SYS_DOWN \|\| code == SYS_HALT) && (esp = current_esp))
	{
	esp_bootup_reset(esp,esp->eregs);
	udelay(500); /* Settle time. Maybe unnecessary. */
	}
	return NOTIFY_DONE;
	}



	#ifdef USE_BOTTOM_HALF


	/*
	* The bsc Oktagon controller has no real DMA, so we have to do the 'DMA
	* transfer' in the interrupt (Yikes!) or use a bottom half to not to clutter
	* IRQ's for longer-than-good.
	*
	* FIXME
	* BIG PROBLEM: 'len' is usually the buffer length, not the expected length
	* of the data. So DMA may finish prematurely, further reads lead to
	* 'machine check' on APUS systems (don't know about m68k systems, AmigaOS
	* deliberately ignores the bus faults) and a normal copy-loop can't
	* be exited prematurely just at the right moment by the dma_invalidate IRQ.
	* So do it the hard way, write an own copier in assembler and
	* catch the exception.
	* -- Carsten
	*/


	static void dma_commit(struct work_struct *unused)
	{
	long wait,len2,pos;
	struct NCR_ESP *esp;

	ESPDATA(("Transfer: %ld bytes, Address 0x%08lX, Direction: %d\n",
	len,(long) address,direction));
	dma_ints_off(current_esp);

	pos = 0;
	wait = 1;
	if(direction) /* write? (memory to device) */
	{
	while(len > 0)
	{
	len2 = oktag_to_io(paddress, address+pos, len);
	if(!len2)
	{
	if(wait > 1000)
	{
	printk("Expedited DMA exit (writing) %ld\n",len);
	break;
	}
	mdelay(wait);
	wait *= 2;
	}
	pos += len2;
	len -= len2*sizeof(long);
	}
	} else {
	while(len > 0)
	{
	len2 = oktag_from_io(address+pos, paddress, len);
	if(!len2)
	{
	if(wait > 1000)
	{
	printk("Expedited DMA exit (reading) %ld\n",len);
	break;
	}
	mdelay(wait);
	wait *= 2;
	}
	pos += len2;
	len -= len2*sizeof(long);
	}
	}

	/* to make esp->shift work */
	esp=current_esp;

	#if 0
	len2 = (esp_read(current_esp->eregs->esp_tclow) & 0xff) \|
	((esp_read(current_esp->eregs->esp_tcmed) & 0xff) << 8);

	/*
	* Uh uh. If you see this, len and transfer count registers were out of
	* sync. That means really serious trouble.
	*/

	if(len2)
	printk("Eeeek!! Transfer count still %ld!\n",len2);
	#endif

	/*
	* Normally we just need to exit and wait for the interrupt to come.
	* But at least one device (my Microtek ScanMaker 630) regularly mis-
	* calculates the bytes it should send which is really ugly because
	* it locks up the SCSI bus if not accounted for.
	*/

	if(!(esp_read(current_esp->eregs->esp_status) & ESP_STAT_INTR))
	{
	long len = 100;
	long trash[10];

	/*
	* Interrupt bit was not set. Either the device is just plain lazy
	* so we give it a 10 ms chance or...
	*/
	while(len-- && (!(esp_read(current_esp->eregs->esp_status) & ESP_STAT_INTR)))
	udelay(100);


	if(!(esp_read(current_esp->eregs->esp_status) & ESP_STAT_INTR))
	{
	/*
	* So we think that the transfer count is out of sync. Since we
	* have all we want we are happy and can ditch the trash.
	*/

	len = DMA_MAXTRANSFER;

	while(len-- && (!(esp_read(current_esp->eregs->esp_status) & ESP_STAT_INTR)))
	oktag_from_io(trash,paddress,2);

	if(!(esp_read(current_esp->eregs->esp_status) & ESP_STAT_INTR))
	{
	/*
	* Things really have gone wrong. If we leave the system in that
	* state, the SCSI bus is locked forever. I hope that this will
	* turn the system in a more or less running state.
	*/
	printk("Device is bolixed, trying bus reset...\n");
	esp_bootup_reset(current_esp,current_esp->eregs);
	}
	}
	}

	ESPDATA(("Transfer_finale: do_data_finale should come\n"));

	len = 0;
	dma_on = 0;
	dma_ints_on(current_esp);
	}

	#endif

	/************************************************************* DMA Functions */
	static int dma_bytes_sent(struct NCR_ESP *esp, int fifo_count)
	{
	/* Since the CyberStorm DMA is fully dedicated to the ESP chip,
	* the number of bytes sent (to the ESP chip) equals the number
	* of bytes in the FIFO - there is no buffering in the DMA controller.
	* XXXX Do I read this right? It is from host to ESP, right?
	*/
	return fifo_count;
	}

	static int dma_can_transfer(struct NCR_ESP esp, Scsi_Cmnd sp)
	{
	unsigned long sz = sp->SCp.this_residual;
	if(sz > DMA_MAXTRANSFER)
	sz = DMA_MAXTRANSFER;
	return sz;
	}

	static void dma_dump_state(struct NCR_ESP *esp)
	{
	}

	/*
	* What the f$@& is this?
	*
	* Some SCSI devices (like my Microtek ScanMaker 630 scanner) want to transfer
	* more data than requested. How much? Dunno. So ditch the bogus data into
	* the sink, hoping the device will advance to the next phase sooner or later.
	*
	* -- Carsten
	*/

	static long oktag_eva_buffer[16]; /* The data sink */

	static void oktag_check_dma(void)
	{
	struct NCR_ESP *esp;

	esp=current_esp;
	if(!len)
	{
	address = oktag_eva_buffer;
	len = 2;
	/* esp_do_data sets them to zero like len */
	esp_write(current_esp->eregs->esp_tclow,2);
	esp_write(current_esp->eregs->esp_tcmed,0);
	}
	}

	static void dma_init_read(struct NCR_ESP *esp, __u32 vaddress, int length)
	{
	/* Zorro is noncached, everything else done using processor. */
	/* cache_clear(addr, length); */

	if(dma_on)
	panic("dma_init_read while dma process is initialized/running!\n");
	direction = 0;
	address = (long *) vaddress;
	current_esp = esp;
	len = length;
	oktag_check_dma();
	dma_on = 1;
	}

	static void dma_init_write(struct NCR_ESP *esp, __u32 vaddress, int length)
	{
	/* cache_push(addr, length); */

	if(dma_on)
	panic("dma_init_write while dma process is initialized/running!\n");
	direction = 1;
	address = (long *) vaddress;
	current_esp = esp;
	len = length;
	oktag_check_dma();
	dma_on = 1;
	}

	static void dma_ints_off(struct NCR_ESP *esp)
	{
	disable_irq(esp->irq);
	}

	static void dma_ints_on(struct NCR_ESP *esp)
	{
	enable_irq(esp->irq);
	}

	static int dma_irq_p(struct NCR_ESP *esp)
	{
	/* It's important to check the DMA IRQ bit in the correct way! */
	return (esp_read(esp->eregs->esp_status) & ESP_STAT_INTR);
	}

	static void dma_led_off(struct NCR_ESP *esp)
	{
	}

	static void dma_led_on(struct NCR_ESP *esp)
	{
	}

	static int dma_ports_p(struct NCR_ESP *esp)
	{
	return ((amiga_custom.intenar) & IF_PORTS);
	}

	static void dma_setup(struct NCR_ESP *esp, __u32 addr, int count, int write)
	{
	/* On the Sparc, DMA_ST_WRITE means "move data from device to memory"
	* so when (write) is true, it actually means READ!
	*/
	if(write){
	dma_init_read(esp, addr, count);
	} else {
	dma_init_write(esp, addr, count);
	}
	}

	/*
	* IRQ entry when DMA transfer is ready to be started
	*/

	static void dma_irq_exit(struct NCR_ESP *esp)
	{
	#ifdef USE_BOTTOM_HALF
	if(dma_on)
	{
	schedule_work(&tq_fake_dma);
	}
	#else
	while(len && !dma_irq_p(esp))
	{
	if(direction)
	paddress = address++;
	else
	address++ = paddress;
	len -= (sizeof(long));
	}
	len = 0;
	dma_on = 0;
	#endif
	}

	/*
	* IRQ entry when DMA has just finished
	*/

	static void dma_invalidate(struct NCR_ESP *esp)
	{
	}

	/*
	* Since the processor does the data transfer we have to use the custom
	* mmu interface to pass the virtual address, not the physical.
	*/

	void dma_mmu_get_scsi_one(struct NCR_ESP esp, Scsi_Cmnd sp)
	{
	sp->SCp.ptr =
	sp->request_buffer;
	}

	void dma_mmu_get_scsi_sgl(struct NCR_ESP esp, Scsi_Cmnd sp)
	{
	sp->SCp.ptr = page_address(sp->SCp.buffer->page)+
	sp->SCp.buffer->offset;
	}

	void dma_mmu_release_scsi_one(struct NCR_ESP esp, Scsi_Cmnd sp)
	{
	}

	void dma_mmu_release_scsi_sgl(struct NCR_ESP esp, Scsi_Cmnd sp)
	{
	}

	void dma_advance_sg(Scsi_Cmnd *sp)
	{
	sp->SCp.ptr = page_address(sp->SCp.buffer->page)+
	sp->SCp.buffer->offset;
	}


	#define HOSTS_C

	int oktagon_esp_release(struct Scsi_Host *instance)
	{
	#ifdef MODULE
	unsigned long address = (unsigned long)((struct NCR_ESP *)instance->hostdata)->edev;
	esp_release();
	release_mem_region(address, sizeof(struct ESP_regs));
	free_irq(IRQ_AMIGA_PORTS, esp_intr);
	unregister_reboot_notifier(&oktagon_notifier);
	#endif
	return 1;
	}


	static struct scsi_host_template driver_template = {
	.proc_name = "esp-oktagon",
	.proc_info = &esp_proc_info,
	.name = "BSC Oktagon SCSI",
	.detect = oktagon_esp_detect,
	.slave_alloc = esp_slave_alloc,
	.slave_destroy = esp_slave_destroy,
	.release = oktagon_esp_release,
	.queuecommand = esp_queue,
	.eh_abort_handler = esp_abort,
	.eh_bus_reset_handler = esp_reset,
	.can_queue = 7,
	.this_id = 7,
	.sg_tablesize = SG_ALL,
	.cmd_per_lun = 1,
	.use_clustering = ENABLE_CLUSTERING
	};


	#include "scsi_module.c"

	MODULE_LICENSE("GPL");