/* -*- mode: c; c-basic-offset: 8 -*- */
  
  /* NCR Dual 700 MCA SCSI Driver
   *
   * Copyright (C) 2001 by James.Bottomley@HansenPartnership.com
  **-----------------------------------------------------------------------------
  **  
  **  This program is free software; you can redistribute it and/or modify
  **  it under the terms of the GNU General Public License as published by
  **  the Free Software Foundation; either version 2 of the License, or
  **  (at your option) any later version.
  **
  **  This program is distributed in the hope that it will be useful,
  **  but WITHOUT ANY WARRANTY; without even the implied warranty of
  **  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  **  GNU General Public License for more details.
  **
  **  You should have received a copy of the GNU General Public License
  **  along with this program; if not, write to the Free Software
  **  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  **
  **-----------------------------------------------------------------------------
   */
  
  /* Notes:
   *
   * Most of the work is done in the chip specific module, 53c700.o
   *
   * TODO List:
   *
   * 1. Extract the SCSI ID from the voyager CMOS table (necessary to
   *    support multi-host environments.
   *
   * */
  
  
  /* CHANGELOG 
   *
   * Version 2.2
   *
   * Added mca_set_adapter_name().
   *
   * Version 2.1
   *
   * Modularise the driver into a Board piece (this file) and a chip
   * piece 53c700.[ch] and 53c700.scr, added module options.  You can
   * now specify the scsi id by the parameters
   *
   * NCR_D700=slot:<n> [siop:<n>] id:<n> ....
   *
   * They need to be comma separated if compiled into the kernel
   *
   * Version 2.0
   *
   * Initial implementation of TCQ (Tag Command Queueing).  TCQ is full
   * featured and uses the clock algorithm to keep track of outstanding
   * tags and guard against individual tag starvation.  Also fixed a bug
   * in all of the 1.x versions where the D700_data_residue() function
   * was returning results off by 32 bytes (and thus causing the same 32
   * bytes to be written twice corrupting the data block).  It turns out
   * the 53c700 only has a 6 bit DBC and DFIFO registers not 7 bit ones
   * like the 53c710 (The 710 is the only data manual still available,
   * which I'd been using to program the 700).
   *
   * Version 1.2
   *
   * Much improved message handling engine
   *
   * Version 1.1
   *
   * Add code to handle selection reasonably correctly.  By the time we
   * get the selection interrupt, we've already responded, but drop off the
   * bus and hope the selector will go away.
   *
   * Version 1.0:
   *
   *   Initial release.  Fully functional except for procfs and tag
   * command queueing.  Has only been tested on cards with 53c700-66
   * chips and only single ended. Features are
   *
   * 1. Synchronous data transfers to offset 8 (limit of 700-66) and
   *    100ns (10MHz) limit of SCSI-2
   *
   * 2. Disconnection and reselection
   *
   * Testing:
   * 
   *  I've only really tested this with the 700-66 chip, but have done
   * soak tests in multi-device environments to verify that
   * disconnections and reselections are being processed correctly.
   * */
  
  #define NCR_D700_VERSION "2.2"
  
  #include <linux/blkdev.h>
  #include <linux/interrupt.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/mca.h>

  #include <linux/slab.h>

  #include <asm/io.h>
  #include <scsi/scsi_host.h>
  #include <scsi/scsi_device.h>
  #include <scsi/scsi_transport.h>
  #include <scsi/scsi_transport_spi.h>
  
  #include "53c700.h"
  #include "NCR_D700.h"
  
  static char *NCR_D700;		/* command line from insmod */
  
  MODULE_AUTHOR("James Bottomley");
  MODULE_DESCRIPTION("NCR Dual700 SCSI Driver");
  MODULE_LICENSE("GPL");
  module_param(NCR_D700, charp, 0);

  static __u8 __devinitdata id_array[2*(MCA_MAX_SLOT_NR + 1)] =

  	{ [0 ... 2*(MCA_MAX_SLOT_NR + 1)-1] = 7 };
  
  #ifdef MODULE
  #define ARG_SEP ' '
  #else
  #define ARG_SEP ','
  #endif
  
  static int __init
  param_setup(char *string)
  {
  	char *pos = string, *next;
  	int slot = -1, siop = -1;
  
  	while(pos != NULL && (next = strchr(pos, ':')) != NULL) {
  		int val = (int)simple_strtoul(++next, NULL, 0);
  
  		if(!strncmp(pos, "slot:", 5))
  			slot = val;
  		else if(!strncmp(pos, "siop:", 5))
  			siop = val;
  		else if(!strncmp(pos, "id:", 3)) {
  			if(slot == -1) {
  				printk(KERN_WARNING "NCR D700: Must specify slot for id parameter
  ");
  			} else if(slot > MCA_MAX_SLOT_NR) {
  				printk(KERN_WARNING "NCR D700: Illegal slot %d for id %d
  ", slot, val);
  			} else {
  				if(siop != 0 && siop != 1) {
  					id_array[slot*2] = val;
  					id_array[slot*2 + 1] =val;
  				} else {
  					id_array[slot*2 + siop] = val;
  				}
  			}
  		}
  		if((pos = strchr(pos, ARG_SEP)) != NULL)
  			pos++;
  	}
  	return 1;
  }
  
  /* Host template.  The 53c700 routine NCR_700_detect will
   * fill in all of the missing routines */
  static struct scsi_host_template NCR_D700_driver_template = {
  	.module			= THIS_MODULE,
  	.name			= "NCR Dual 700 MCA",
  	.proc_name		= "NCR_D700",
  	.this_id		= 7,
  };
  
  /* We needs this helper because we have two hosts per struct device */
  struct NCR_D700_private {
  	struct device		*dev;
  	struct Scsi_Host	*hosts[2];
  	char			name[30];
  	char			pad;
  };

  static int __devinit

  NCR_D700_probe_one(struct NCR_D700_private *p, int siop, int irq,
  		   int slot, u32 region, int differential)
  {
  	struct NCR_700_Host_Parameters *hostdata;
  	struct Scsi_Host *host;
  	int ret;

  	hostdata = kzalloc(sizeof(*hostdata), GFP_KERNEL);

  	if (!hostdata) {
  		printk(KERN_ERR "NCR D700: SIOP%d: Failed to allocate host"
  		       "data, detatching
  ", siop);
  		return -ENOMEM;
  	}

  
  	if (!request_region(region, 64, "NCR_D700")) {
  		printk(KERN_ERR "NCR D700: Failed to reserve IO region 0x%x
  ",
  				region);
  		ret = -ENODEV;
  		goto region_failed;
  	}
  		
  	/* Fill in the three required pieces of hostdata */

  	hostdata->base = ioport_map(region, 64);

  	hostdata->differential = (((1<<siop) & differential) != 0);
  	hostdata->clock = NCR_D700_CLOCK_MHZ;

  	hostdata->burst_length = 8;

  	/* and register the siop */
  	host = NCR_700_detect(&NCR_D700_driver_template, hostdata, p->dev);
  	if (!host) {
  		ret = -ENOMEM;
  		goto detect_failed;
  	}
  
  	p->hosts[siop] = host;
  	/* FIXME: read this from SUS */
  	host->this_id = id_array[slot * 2 + siop];
  	host->irq = irq;

  	host->base = region;

  	scsi_scan_host(host);
  
  	return 0;
  
   detect_failed:

  	release_region(region, 64);

   region_failed:
  	kfree(hostdata);
  
  	return ret;
  }

  static irqreturn_t

  NCR_D700_intr(int irq, void *data)

  {
  	struct NCR_D700_private *p = (struct NCR_D700_private *)data;
  	int i, found = 0;
  
  	for (i = 0; i < 2; i++)
  		if (p->hosts[i] &&

  		    NCR_700_intr(irq, p->hosts[i]) == IRQ_HANDLED)

  			found++;
  
  	return found ? IRQ_HANDLED : IRQ_NONE;
  }
  
  /* Detect a D700 card.  Note, because of the setup --- the chips are
   * essentially connectecd to the MCA bus independently, it is easier
   * to set them up as two separate host adapters, rather than one
   * adapter with two channels */

  static int __devinit

  NCR_D700_probe(struct device *dev)
  {
  	struct NCR_D700_private *p;
  	int differential;
  	static int banner = 1;
  	struct mca_device *mca_dev = to_mca_device(dev);
  	int slot = mca_dev->slot;
  	int found = 0;
  	int irq, i;
  	int pos3j, pos3k, pos3a, pos3b, pos4;
  	__u32 base_addr, offset_addr;
  
  	/* enable board interrupt */
  	pos4 = mca_device_read_pos(mca_dev, 4);
  	pos4 |= 0x4;
  	mca_device_write_pos(mca_dev, 4, pos4);
  
  	mca_device_write_pos(mca_dev, 6, 9);
  	pos3j = mca_device_read_pos(mca_dev, 3);
  	mca_device_write_pos(mca_dev, 6, 10);
  	pos3k = mca_device_read_pos(mca_dev, 3);
  	mca_device_write_pos(mca_dev, 6, 0);
  	pos3a = mca_device_read_pos(mca_dev, 3);
  	mca_device_write_pos(mca_dev, 6, 1);
  	pos3b = mca_device_read_pos(mca_dev, 3);
  
  	base_addr = ((pos3j << 8) | pos3k) & 0xfffffff0;
  	offset_addr = ((pos3a << 8) | pos3b) & 0xffffff70;
  
  	irq = (pos4 & 0x3) + 11;
  	if(irq >= 13)
  		irq++;
  	if(banner) {
  		printk(KERN_NOTICE "NCR D700: Driver Version " NCR_D700_VERSION "
  "
  		       "NCR D700:  Copyright (c) 2001 by James.Bottomley@HansenPartnership.com
  "
  		       "NCR D700:
  ");
  		banner = 0;
  	}
  	/* now do the bus related transforms */
  	irq = mca_device_transform_irq(mca_dev, irq);
  	base_addr = mca_device_transform_ioport(mca_dev, base_addr);
  	offset_addr = mca_device_transform_ioport(mca_dev, offset_addr);
  
  	printk(KERN_NOTICE "NCR D700: found in slot %d  irq = %d  I/O base = 0x%x
  ", slot, irq, offset_addr);
  
  	/*outb(BOARD_RESET, base_addr);*/
  
  	/* clear any pending interrupts */
  	(void)inb(base_addr + 0x08);
  	/* get modctl, used later for setting diff bits */
  	switch(differential = (inb(base_addr + 0x08) >> 6)) {
  	case 0x00:
  		/* only SIOP1 differential */
  		differential = 0x02;
  		break;
  	case 0x01:
  		/* Both SIOPs differential */
  		differential = 0x03;
  		break;
  	case 0x03:
  		/* No SIOPs differential */
  		differential = 0x00;
  		break;
  	default:
  		printk(KERN_ERR "D700: UNEXPECTED DIFFERENTIAL RESULT 0x%02x
  ",
  		       differential);
  		differential = 0x00;
  		break;
  	}

  	p = kzalloc(sizeof(*p), GFP_KERNEL);

  	if (!p)
  		return -ENOMEM;

  	p->dev = dev;

  	snprintf(p->name, sizeof(p->name), "D700(%s)", dev_name(dev));

  	if (request_irq(irq, NCR_D700_intr, IRQF_SHARED, p->name, p)) {

  		printk(KERN_ERR "D700: request_irq failed
  ");
  		kfree(p);
  		return -EBUSY;
  	}
  	/* plumb in both 700 chips */
  	for (i = 0; i < 2; i++) {
  		int err;

  		if ((err = NCR_D700_probe_one(p, i, irq, slot,

  					      offset_addr + (0x80 * i),
  					      differential)) != 0)
  			printk("D700: SIOP%d: probe failed, error = %d
  ",
  			       i, err);
  		else
  			found++;
  	}
  
  	if (!found) {
  		kfree(p);
  		return -ENODEV;
  	}
  
  	mca_device_set_claim(mca_dev, 1);
  	mca_device_set_name(mca_dev, "NCR_D700");
  	dev_set_drvdata(dev, p);
  	return 0;
  }

  static void __devexit

  NCR_D700_remove_one(struct Scsi_Host *host)
  {
  	scsi_remove_host(host);
  	NCR_700_release(host);
  	kfree((struct NCR_700_Host_Parameters *)host->hostdata[0]);
  	free_irq(host->irq, host);
  	release_region(host->base, 64);
  }

  static int __devexit

  NCR_D700_remove(struct device *dev)
  {
  	struct NCR_D700_private *p = dev_get_drvdata(dev);
  	int i;
  
  	for (i = 0; i < 2; i++)
  		NCR_D700_remove_one(p->hosts[i]);
  
  	kfree(p);
  	return 0;
  }
  
  static short NCR_D700_id_table[] = { NCR_D700_MCA_ID, 0 };
  
  static struct mca_driver NCR_D700_driver = {
  	.id_table = NCR_D700_id_table,
  	.driver = {
  		.name		= "NCR_D700",
  		.bus		= &mca_bus_type,
  		.probe		= NCR_D700_probe,

  		.remove		= __devexit_p(NCR_D700_remove),

  	},
  };
  
  static int __init NCR_D700_init(void)
  {
  #ifdef MODULE
  	if (NCR_D700)
  		param_setup(NCR_D700);
  #endif
  
  	return mca_register_driver(&NCR_D700_driver);
  }
  
  static void __exit NCR_D700_exit(void)
  {
  	mca_unregister_driver(&NCR_D700_driver);
  }
  
  module_init(NCR_D700_init);
  module_exit(NCR_D700_exit);
  
  __setup("NCR_D700=", param_setup);