/*
 * pci.c :  this file contains basic PCI Io functions.
 *
 *  CopyRight (C) 1999 valette@crf.canon.fr
 *
 *  This code is heavilly inspired by the public specification of STREAM V2
 *  that can be found at :
 *
 *      <http://www.chorus.com/Documentation/index.html> by following
 *  the STREAM API Specification Document link.
 *
 *  The license and distribution terms for this file may be
 *  found in found in the file LICENSE in this distribution or at
 *  http://www.rtems.com/license/LICENSE.
 *
 *  $Id$
 *
 *  Till Straumann, <strauman@slac.stanford.edu>, 1/2002
 *   - separated bridge detection code out of this file
 */

#include <libcpu/io.h>
#include <bsp/pci.h>
#include <rtems/bspIo.h>

/* allow for overriding these definitions */
#ifndef PCI_CONFIG_ADDR
#define PCI_CONFIG_ADDR			0xcf8
#endif
#ifndef PCI_CONFIG_DATA
#define PCI_CONFIG_DATA			0xcfc
#endif

#define PCI_INVALID_VENDORDEVICEID	0xffffffff
#define PCI_MULTI_FUNCTION		0x80

/* define a shortcut */
#define pci	BSP_pci_configuration



/*
 * Bit encode for PCI_CONFIG_HEADER_TYPE register
 */
unsigned char ucMaxPCIBus;

static int
indirect_pci_read_config_byte(unsigned char bus, unsigned char slot,
			      unsigned char function,
			      unsigned char offset, unsigned char *val) {
	out_be32((unsigned int*) pci.pci_config_addr,
		 0x80|(bus<<8)|(PCI_DEVFN(slot,function)<<16)|((offset&~3)<<24));
	*val = in_8(pci.pci_config_data + (offset&3));
	return PCIBIOS_SUCCESSFUL;
}

static int
indirect_pci_read_config_word(unsigned char bus, unsigned char slot,
			      unsigned char function,
			      unsigned char offset, unsigned short *val) {
	*val = 0xffff;
	if (offset&1) return PCIBIOS_BAD_REGISTER_NUMBER;
	out_be32((unsigned int*) pci.pci_config_addr,
		 0x80|(bus<<8)|(PCI_DEVFN(slot,function)<<16)|((offset&~3)<<24));
	*val = in_le16((volatile unsigned short *)(pci.pci_config_data + (offset&3)));
	return PCIBIOS_SUCCESSFUL;
}

static int
indirect_pci_read_config_dword(unsigned char bus, unsigned char slot,
			      unsigned char function,
			      unsigned char offset, unsigned int *val) {
	*val = 0xffffffff;
	if (offset&3) return PCIBIOS_BAD_REGISTER_NUMBER;
	out_be32((unsigned int*) pci.pci_config_addr,
		 0x80|(bus<<8)|(PCI_DEVFN(slot,function)<<16)|(offset<<24));
	*val = in_le32((volatile unsigned int *)pci.pci_config_data);
	return PCIBIOS_SUCCESSFUL;
}

static int
indirect_pci_write_config_byte(unsigned char bus, unsigned char slot,
			       unsigned char function,
			       unsigned char offset, unsigned char val) {
	out_be32((unsigned int*) pci.pci_config_addr,
		 0x80|(bus<<8)|(PCI_DEVFN(slot,function)<<16)|((offset&~3)<<24));
	out_8(pci.pci_config_data + (offset&3), val);
	return PCIBIOS_SUCCESSFUL;
}

static int
indirect_pci_write_config_word(unsigned char bus, unsigned char slot,
			       unsigned char function,
			       unsigned char offset, unsigned short val) {
	if (offset&1) return PCIBIOS_BAD_REGISTER_NUMBER;
	out_be32((unsigned int*) pci.pci_config_addr,
		 0x80|(bus<<8)|(PCI_DEVFN(slot,function)<<16)|((offset&~3)<<24));
	out_le16((volatile unsigned short *)(pci.pci_config_data + (offset&3)), val);
	return PCIBIOS_SUCCESSFUL;
}

static int
indirect_pci_write_config_dword(unsigned char bus, unsigned char slot,
				unsigned char function,
				unsigned char offset, unsigned int val) {
	if (offset&3) return PCIBIOS_BAD_REGISTER_NUMBER;
	out_be32((unsigned int*) pci.pci_config_addr,
		 0x80|(bus<<8)|(PCI_DEVFN(slot,function)<<16)|(offset<<24));
	out_le32((volatile unsigned int *)pci.pci_config_data, val);
	return PCIBIOS_SUCCESSFUL;
}

const pci_config_access_functions pci_indirect_functions = {
  	indirect_pci_read_config_byte,
  	indirect_pci_read_config_word,
  	indirect_pci_read_config_dword,
  	indirect_pci_write_config_byte,
  	indirect_pci_write_config_word,
  	indirect_pci_write_config_dword
};

pci_config BSP_pci_configuration = {(volatile unsigned char*)PCI_CONFIG_ADDR,
			 (volatile unsigned char*)PCI_CONFIG_DATA,
			 &pci_indirect_functions};

static int
direct_pci_read_config_byte(unsigned char bus, unsigned char slot,
			    unsigned char function,
			    unsigned char offset, unsigned char *val) {
	if (bus != 0 || (1<<slot & 0xff8007fe)) {
		*val=0xff;
 		return PCIBIOS_DEVICE_NOT_FOUND;
	}
	*val=in_8(pci.pci_config_data + ((1<<slot)&~1)
		  + (function<<8) + offset);
	return PCIBIOS_SUCCESSFUL;
}

static int
direct_pci_read_config_word(unsigned char bus, unsigned char slot,
			    unsigned char function,
			    unsigned char offset, unsigned short *val) {
	*val = 0xffff;
	if (offset&1) return PCIBIOS_BAD_REGISTER_NUMBER;
	if (bus != 0 || (1<<slot & 0xff8007fe)) {
 		return PCIBIOS_DEVICE_NOT_FOUND;
	}
	*val=in_le16((volatile unsigned short *)
		     (pci.pci_config_data + ((1<<slot)&~1)
		      + (function<<8) + offset));
	return PCIBIOS_SUCCESSFUL;
}

static int
direct_pci_read_config_dword(unsigned char bus, unsigned char slot,
			     unsigned char function,
			     unsigned char offset, unsigned int *val) {
	*val = 0xffffffff;
	if (offset&3) return PCIBIOS_BAD_REGISTER_NUMBER;
	if (bus != 0 || (1<<slot & 0xff8007fe)) {
 		return PCIBIOS_DEVICE_NOT_FOUND;
	}
	*val=in_le32((volatile unsigned int *)
		     (pci.pci_config_data + ((1<<slot)&~1)
		      + (function<<8) + offset));
	return PCIBIOS_SUCCESSFUL;
}

static int
direct_pci_write_config_byte(unsigned char bus, unsigned char slot,
			     unsigned char function,
			     unsigned char offset, unsigned char val) {
	if (bus != 0 || (1<<slot & 0xff8007fe)) {
 		return PCIBIOS_DEVICE_NOT_FOUND;
	}
	out_8(pci.pci_config_data + ((1<<slot)&~1)
	      + (function<<8) + offset,
	      val);
	return PCIBIOS_SUCCESSFUL;
}

static int
direct_pci_write_config_word(unsigned char bus, unsigned char slot,
			     unsigned char function,
			     unsigned char offset, unsigned short val) {
	if (offset&1) return PCIBIOS_BAD_REGISTER_NUMBER;
	if (bus != 0 || (1<<slot & 0xff8007fe)) {
 		return PCIBIOS_DEVICE_NOT_FOUND;
	}
	out_le16((volatile unsigned short *)
		 (pci.pci_config_data + ((1<<slot)&~1)
		  + (function<<8) + offset),
		 val);
	return PCIBIOS_SUCCESSFUL;
}

static int
direct_pci_write_config_dword(unsigned char bus, unsigned char slot,
			      unsigned char function,
			      unsigned char offset, unsigned int val) {
	if (offset&3) return PCIBIOS_BAD_REGISTER_NUMBER;
	if (bus != 0 || (1<<slot & 0xff8007fe)) {
 		return PCIBIOS_DEVICE_NOT_FOUND;
	}
	out_le32((volatile unsigned int *)
		 (pci.pci_config_data + ((1<<slot)&~1)
		  + (function<<8) + offset),
		 val);
	return PCIBIOS_SUCCESSFUL;
}

const pci_config_access_functions pci_direct_functions = {
  	direct_pci_read_config_byte,
  	direct_pci_read_config_word,
  	direct_pci_read_config_dword,
  	direct_pci_write_config_byte,
  	direct_pci_write_config_word,
  	direct_pci_write_config_dword
};

#define PRINT_MSG() \
             printk("pci : Device %d:%02x routed to interrupt_line %d\n", pbus, pslot, int_name )

/*
** Validate a test interrupt name and print a warning if its not one of
** the names defined in the routing record.
*/
static int test_intname(
  const struct _int_map *row, int pbus, int pslot, int int_pin, int int_name )
{
   int j,k;
   int _nopin= -1, _noname= -1;

   for(j=0; row->pin_route[j].pin > -1; j++)
   {
      if( row->pin_route[j].pin == int_pin )
      {
         _nopin = 0;

         for(k=0; k<4 && row->pin_route[j].int_name[k] > -1; k++ )
         {
            if( row->pin_route[j].int_name[k] == int_name ){ _noname=0; break; }
         }
         break;
      }
   }

   if( _nopin  )
   {
      printk("pci : Device %d:%02x supplied a bogus interrupt_pin %d\n", pbus, pslot, int_pin );
      return -1;
   }
   else
   {
      if( _noname )
         printk("pci : Device %d:%02x supplied a suspicious interrupt_line %d, using it anyway\n", pbus, pslot, int_name );
   }
   return 0;
}

struct pcibridge
{
      int bus,slot;
};

static int FindPCIbridge( int mybus, struct pcibridge *pb )
{
   int          pbus, pslot;
   uint8_t      bussec, buspri;
   uint16_t     devid, vendorid, dclass;

   for(pbus=0; pbus< BusCountPCI(); pbus++)
   {
      for(pslot=0; pslot< PCI_MAX_DEVICES; pslot++)
      {
         pci_read_config_word(pbus, pslot, 0, PCI_DEVICE_ID, &devid);
         if( devid == 0xffff ) continue;

         pci_read_config_word(pbus, pslot, 0, PCI_DEVICE_ID, &vendorid);
         if( vendorid == 0xffff ) continue;

         pci_read_config_word(pbus, pslot, 0, PCI_CLASS_DEVICE, &dclass);

         if( dclass == PCI_CLASS_BRIDGE_PCI )
         {
            pci_read_config_byte(pbus, pslot, 0, PCI_PRIMARY_BUS,    &buspri);
            pci_read_config_byte(pbus, pslot, 0, PCI_SECONDARY_BUS,  &bussec);

#if 0
            printk("pci : Found bridge at %d:%d, mybus %d, pribus %d, secbus %d  ", pbus, pslot, mybus, buspri, bussec );
#endif
            if( bussec == mybus )
            {
#if 0
               printk("match\n");
#endif
               /* found our nearest bridge going towards the root */
               pb->bus = pbus;
               pb->slot = pslot;

               return 0;
            }
#if 0
            printk("no match\n");
#endif
         }

      }
   }
   return -1;
}

void FixupPCI( const struct _int_map *bspmap, int (*swizzler)(int,int) )
{
   unsigned char        cvalue;
   uint16_t             devid;
   int                  ismatch, i, j, pbus, pslot, int_pin, int_name;

   /*
   ** If the device has a non-zero INTERRUPT_PIN, assign a bsp-specific
   ** INTERRUPT_NAME if one isn't already in place.  Then, drivers can
   ** trivially use INTERRUPT_NAME to hook up with devices.
   */

   for(pbus=0; pbus< BusCountPCI(); pbus++)
   {
      for(pslot=0; pslot< PCI_MAX_DEVICES; pslot++)
      {
         pci_read_config_word(pbus, pslot, 0, PCI_DEVICE_ID, &devid);
         if( devid == 0xffff ) continue;

         /* got a device */

         pci_read_config_byte( pbus, pslot, 0, PCI_INTERRUPT_PIN, &cvalue);
         int_pin = cvalue;

         pci_read_config_byte( pbus, pslot, 0, PCI_INTERRUPT_LINE, &cvalue);
         int_name = cvalue;

/* printk("pci : device %d:%02x devid %04x, intpin %d, intline  %d\n", pbus, pslot, devid, int_pin, int_name ); */

         if( int_pin > 0 )
         {
            ismatch = 0;

            /*
            ** first run thru the bspmap table and see if we have an explicit configuration
            */
            for(i=0; bspmap[i].bus > -1; i++)
            {
               if( bspmap[i].bus == pbus && bspmap[i].slot == pslot )
               {
                  ismatch = -1;
                  /* we have a record in the table that gives specific
                   * pins and interrupts for devices in this slot */
                  if( int_name == 255 )
                  {
                     /* find the vector associated with whatever pin the device gives us */
                     for( int_name=-1, j=0; bspmap[i].pin_route[j].pin > -1; j++ )
                     {
                        if( bspmap[i].pin_route[j].pin == int_pin )
                        {
                           int_name = bspmap[i].pin_route[j].int_name[0];
                           break;
                        }
                     }
                     if( int_name == -1 )
                     {
                        printk("pci : Unable to resolve device %d:%d w/ swizzled int pin %d to an interrupt_line.\n", pbus, pslot, int_pin );
                     }
                     else
                     {
                        PRINT_MSG();
                        pci_write_config_byte(pbus,pslot,0,PCI_INTERRUPT_LINE,(cvalue= int_name, cvalue));
                     }
                  }
                  else
                  {
                     test_intname( &bspmap[i],pbus,pslot,int_pin,int_name);
                  }
                  break;
               }
            }

            if( !ismatch )
            {
               /*
               ** no match, which means we're on a bus someplace.  Work
               ** backwards from it to one of our defined busses,
               ** swizzling thru each bridge on the way.
               */

               /* keep pbus, pslot pointed to the device being
               configured while we track down the bridges using
               tbus,tslot.  We keep searching the routing table because
               we may end up finding our bridge in it */

               int tbus= pbus, tslot= pslot;

               for(;;)
               {

                  for(i=0; bspmap[i].bus > -1; i++)
                  {
                     if( bspmap[i].bus == tbus && (bspmap[i].slot == tslot || bspmap[i].slot == -1) )
                     {
                        ismatch = -1;
                        /* found a record for this bus, so swizzle the
                         * int_pin which we then use to find the
                         * interrupt_name.
                         */

                        if( int_name == 255 )
                        {
                           /*
                           ** FIXME.  I can't believe this little hack
                           ** is right.  It does not yield an error in
                           ** convienently simple situations.
                           */
                           if( tbus ) int_pin = (*swizzler)(tslot,int_pin);

                           /*
                           ** int_pin points to the interrupt channel
                           ** this card ends up delivering interrupts
                           ** on.  Find the int_name servicing it.
                           */
                           for( int_name=-1, j=0; bspmap[i].pin_route[j].pin > -1; j++ )
                           {
                              if( bspmap[i].pin_route[j].pin == int_pin )
                              {
                                 int_name = bspmap[i].pin_route[j].int_name[0];
                                 break;
                              }
                           }
                           if( int_name == -1 )
                           {
                              printk("pci : Unable to resolve device %d:%d w/ swizzled int pin %d to an interrupt_line.\n", pbus, pslot, int_pin );
                           }
                           else
                           {
                              PRINT_MSG();
                              pci_write_config_byte(pbus,pslot,0,PCI_INTERRUPT_LINE,(cvalue= int_name, cvalue));
                           }
                        }
                        else
                        {
                           test_intname(&bspmap[i],pbus,pslot,int_pin,int_name);
                        }
                        goto donesearch;
                     }
                  }

                  if( !ismatch )
                  {
                     struct pcibridge   pb;

                     /*
                     ** Haven't found our bus in the int map, so work
                     ** upwards thru the bridges till we find it.
                     */

                     if( FindPCIbridge( tbus, &pb )== 0 )
                     {
                        int_pin = (*swizzler)(tslot,int_pin);

                        /* our next bridge up is on pb.bus, pb.slot- now
                        ** instead of pointing to the device we're
                        ** trying to configure, we move from bridge to
                        ** bridge.
                        */

                        tbus = pb.bus;
                        tslot = pb.slot;
                     }
                     else
                     {
                        printk("pci : No bridge from bus %d towards root found\n", tbus );
                        goto donesearch;
                     }

                  }

               }
            }
           donesearch:

            if( !ismatch && int_pin != 0 && int_name == 255 )
            {
               printk("pci : Unable to match device %d:%d with an int routing table entry\n", pbus, pslot  );
            }

         }
      }
   }
}

/*
 * This routine determines the maximum bus number in the system
 */
void InitializePCI()
{
  extern void detect_host_bridge();
  unsigned char ucSlotNumber, ucFnNumber, ucNumFuncs;
  unsigned char ucHeader;
  unsigned char ucMaxSubordinate;
  unsigned int  ulClass, ulDeviceID;

  detect_host_bridge();

  /*
   * Scan PCI bus 0 looking for PCI-PCI bridges
   */
  for(ucSlotNumber=0;ucSlotNumber<PCI_MAX_DEVICES;ucSlotNumber++) {
    (void)pci_read_config_dword(0,
				ucSlotNumber,
				0,
				PCI_VENDOR_ID,
				&ulDeviceID);
    if(ulDeviceID==PCI_INVALID_VENDORDEVICEID) {
      /*
       * This slot is empty
       */
      continue;
    }
    (void)pci_read_config_byte(0,
			       ucSlotNumber,
			       0,
			       PCI_HEADER_TYPE,
			       &ucHeader);
    if(ucHeader&PCI_MULTI_FUNCTION)	{
      ucNumFuncs=PCI_MAX_FUNCTIONS;
    }
    else {
      ucNumFuncs=1;
    }
    for(ucFnNumber=0;ucFnNumber<ucNumFuncs;ucFnNumber++) {
      (void)pci_read_config_dword(0,
				  ucSlotNumber,
				  ucFnNumber,
				  PCI_VENDOR_ID,
				  &ulDeviceID);
      if(ulDeviceID==PCI_INVALID_VENDORDEVICEID) {
				/*
				 * This slot/function is empty
				 */
	continue;
      }

      /*
       * This slot/function has a device fitted.
       */
      (void)pci_read_config_dword(0,
				  ucSlotNumber,
				  ucFnNumber,
				  PCI_CLASS_REVISION,
				  &ulClass);
      ulClass >>= 16;
      if (ulClass == PCI_CLASS_BRIDGE_PCI) {
				/*
				 * We have found a PCI-PCI bridge
				 */
	(void)pci_read_config_byte(0,
				   ucSlotNumber,
				   ucFnNumber,
				   PCI_SUBORDINATE_BUS,
				   &ucMaxSubordinate);
	if(ucMaxSubordinate>ucMaxPCIBus) {
	  ucMaxPCIBus=ucMaxSubordinate;
	}
      }
    }
  }
}

/*
 * Return the number of PCI busses in the system
 */
unsigned char BusCountPCI()
{
  return(ucMaxPCIBus+1);
}