text: /*
  	Copyright 1999, Be Incorporated.   All Rights Reserved.
  	This file may be used under the terms of the Be Sample Code License.
  
  	Other authors:
  	Mark Watson;
  	Rudolf Cornelissen 3/2002-1/2016.
  */
  
  /* standard kernel driver stuff */
  #include <KernelExport.h>
  #include <ISA.h>
  #include <PCI.h>
  #include <OS.h>
  #include <directories.h>
  #include <driver_settings.h>
  #include <malloc.h>
  #include <stdlib.h> // for strtoXX
  #include "AGP.h"
  
  /* this is for the standardized portion of the driver API */
  /* currently only one operation is defined: B_GET_ACCELERANT_SIGNATURE */
  #include <graphic_driver.h>
  
  /* this is for sprintf() */
  #include <stdio.h>
  
  /* this is for string compares */
  #include <string.h>
  
  /* The private interface between the accelerant and the kernel driver. */
  #include "DriverInterface.h"
  #include "macros.h"
  
  #define get_pci(o, s) (*pci_bus->read_pci_config)(pcii->bus, pcii->device, pcii->function, (o), (s))
  #define set_pci(o, s, v) (*pci_bus->write_pci_config)(pcii->bus, pcii->device, pcii->function, (o), (s), (v))
  
  #define MAX_DEVICES	  8
  
  #define DEVICE_FORMAT "%04x_%04x_%02x%02x%02x" // apsed
  
  /* Tell the kernel what revision of the driver API we support */
  int32	api_version = B_CUR_DRIVER_API_VERSION; // apsed, was 2, is 2 in R5
  
  /* these structures are private to the kernel driver */
  typedef struct device_info device_info;
  
  typedef struct {
  	timer		te;				/* timer entry for add_timer() */
  	device_info	*di;			/* pointer to the owning device */
  	bigtime_t	when_target;	/* when we're supposed to wake up */
  } timer_info;
  
  struct device_info {
  	uint32		is_open;			/* a count of how many times the devices has been opened */
  	area_id		shared_area;		/* the area shared between the driver and all of the accelerants */
  	shared_info	*si;				/* a pointer to the shared area, for convenience */
  	vuint32		*regs;				/* kernel's pointer to memory mapped registers */
  	pci_info	pcii;					/* a convenience copy of the pci info for this device */
  	char		name[B_OS_NAME_LENGTH];	/* where we keep the name of the device for publishing and comparing */
  };
  
  typedef struct {
  	uint32		count;				/* number of devices actually found */
  	benaphore	kernel;				/* for serializing opens/closes */
  	char		*device_names[MAX_DEVICES+1];	/* device name pointer storage */
  	device_info	di[MAX_DEVICES];	/* device specific stuff */
  } DeviceData;
  
  /* prototypes for our private functions */
  static status_t open_hook (const char* name, uint32 flags, void** cookie);
  static status_t close_hook (void* dev);
  static status_t free_hook (void* dev);
  static status_t read_hook (void* dev, off_t pos, void* buf, size_t* len);
  static status_t write_hook (void* dev, off_t pos, const void* buf, size_t* len);
  static status_t control_hook (void* dev, uint32 msg, void *buf, size_t len);
  static status_t map_device(device_info *di);
  static void unmap_device(device_info *di);
  static void probe_devices(void);
  static int32 eng_interrupt(void *data);
  
  static DeviceData		*pd;
  static isa_module_info	*isa_bus = NULL;
  static pci_module_info	*pci_bus = NULL;
  static agp_gart_module_info *agp_bus = NULL;
  static device_hooks graphics_device_hooks = {
  	open_hook,
  	close_hook,
  	free_hook,
  	control_hook,
  	read_hook,
  	write_hook,
  	NULL,
  	NULL,
  	NULL,
  	NULL
  };
  
  #define VENDOR_ID_VIA	0x1106 /* Via */
  
  static uint16 via_device_list[] = {
  	0x3022, /* CLE266 Unichrome Pro (CLE3022) */
  	0x3108, /* K8M800 Unichrome Pro (unknown chiptype) */
  	0x3122, /* CLE266 Unichrome Pro (CLE3122) */
  	0x3205, /* KM400 Unichrome (VT3205) */
  //	0x3344, /* P4M800 Pro (VT3344) */
  	0x7205, /* KM400 Unichrome (VT7205) */
  	0
  };
  
  static struct {
  	uint16	vendor;
  	uint16	*devices;
  } SupportedDevices[] = {
  	{VENDOR_ID_VIA, via_device_list},
  	{0x0000, NULL}
  };
  
  static settings current_settings = { // see comments in skel.settings
  	// for driver
  	DRIVER_PREFIX ".accelerant",
  	false,      // dumprom
  	// for accelerant
  	0x00000000, // logmask
  	0,          // memory
  	true,       // usebios
  	true,       // hardcursor
  	false,		// switchhead
  	false,		// force_pci
  	false,		// unhide_fw
  	true,		// pgm_panel
  };
  
  static void dumprom (void *rom, uint32 size)
  {
  	int fd;
  	uint32 cnt;
  
  	fd = open (kUserDirectory "/" DRIVER_PREFIX ".rom",
  		O_WRONLY | O_CREAT, 0666);
  	if (fd < 0) return;
  
  	/* apparantly max. 32kb may be written at once;
  	 * the ROM size is a multiple of that anyway. */
  	for (cnt = 0; (cnt < size); cnt += 32768)
  		write (fd, ((void *)(((uint8 *)rom) + cnt)), 32768);
  	close (fd);
  }
  
  /* return 1 if vblank interrupt has occured */
  static int caused_vbi(vuint32 * regs)
  {
  //	return (ENG_REG32(RG32_CRTC_INTS) & 0x00000001);
  return 0;
  }
  
  /* clear the vblank interrupt */
  static void clear_vbi(vuint32 * regs)
  {
  //	ENG_REG32(RG32_CRTC_INTS) = 0x00000001;
  }
  
  static void enable_vbi(vuint32 * regs)
  {
  	/* clear the vblank interrupt */
  //	ENG_REG32(RG32_CRTC_INTS) = 0x00000001;
  	/* enable nVidia interrupt source vblank */
  //	ENG_REG32(RG32_CRTC_INTE) |= 0x00000001;
  	/* enable nVidia interrupt system hardware (b0-1) */
  //	ENG_REG32(RG32_MAIN_INTE) = 0x00000001;
  }
  
  static void disable_vbi(vuint32 * regs)
  {
  	/* disable nVidia interrupt source vblank */
  //	ENG_REG32(RG32_CRTC_INTE) &= 0xfffffffe;
  	/* clear the vblank interrupt */
  //	ENG_REG32(RG32_CRTC_INTS) = 0x00000001;
  	/* disable nVidia interrupt system hardware (b0-1) */
  //	ENG_REG32(RG32_MAIN_INTE) = 0x00000000;
  }
  
  /*
  	init_hardware() - Returns B_OK if one is
  	found, otherwise returns B_ERROR so the driver will be unloaded.
  */
  status_t
  init_hardware(void) {
  	long		pci_index = 0;
  	pci_info	pcii;
  	bool		found_one = false;
  
  	/* choke if we can't find the PCI bus */
  	if (get_module(B_PCI_MODULE_NAME, (module_info **)&pci_bus) != B_OK)
  		return B_ERROR;
  
  	/* choke if we can't find the ISA bus */
  	if (get_module(B_ISA_MODULE_NAME, (module_info **)&isa_bus) != B_OK)
  	{
  		put_module(B_PCI_MODULE_NAME);
  		return B_ERROR;
  	}
  
  	/* while there are more pci devices */
  	while ((*pci_bus->get_nth_pci_info)(pci_index, &pcii) == B_NO_ERROR) {
  		int vendor = 0;
  
  		/* if we match a supported vendor */
  		while (SupportedDevices[vendor].vendor) {
  			if (SupportedDevices[vendor].vendor == pcii.vendor_id) {
  				uint16 *devices = SupportedDevices[vendor].devices;
  				/* while there are more supported devices */
  				while (*devices) {
  					/* if we match a supported device */
  					if (*devices == pcii.device_id ) {
  
  						found_one = true;
  						goto done;
  					}
  					/* next supported device */
  					devices++;
  				}
  			}
  			vendor++;
  		}
  		/* next pci_info struct, please */
  		pci_index++;
  	}
  
  done:
  	/* put away the module manager */
  	put_module(B_PCI_MODULE_NAME);
  	return (found_one ? B_OK : B_ERROR);
  }
  
  status_t
  init_driver(void) {
  	void *settings_handle;
  
  	// get driver/accelerant settings, apsed
  	settings_handle  = load_driver_settings (DRIVER_PREFIX ".settings");
  	if (settings_handle != NULL) {
  		const char *item;
  		char       *end;
  		uint32      value;
  
  		// for driver
  		item = get_driver_parameter (settings_handle, "accelerant", "", "");
  		if ((strlen (item) > 0) && (strlen (item) < sizeof (current_settings.accelerant) - 1)) {
  			strcpy (current_settings.accelerant, item);
  		}
  		current_settings.dumprom = get_driver_boolean_parameter (settings_handle, "dumprom", false, false);
  
  		// for accelerant
  		item = get_driver_parameter (settings_handle, "logmask", "0x00000000", "0x00000000");
  		value = strtoul (item, &end, 0);
  		if (*end == '\0') current_settings.logmask = value;
  
  		item = get_driver_parameter (settings_handle, "memory", "0", "0");
  		value = strtoul (item, &end, 0);
  		if (*end == '\0') current_settings.memory = value;
  
  		current_settings.hardcursor = get_driver_boolean_parameter (settings_handle, "hardcursor", false, false);
  		current_settings.usebios = get_driver_boolean_parameter (settings_handle, "usebios", false, false);
  		current_settings.switchhead = get_driver_boolean_parameter (settings_handle, "switchhead", false, false);
  		current_settings.force_pci = get_driver_boolean_parameter (settings_handle, "force_pci", false, false);
  		current_settings.unhide_fw = get_driver_boolean_parameter (settings_handle, "unhide_fw", false, false);
  		current_settings.pgm_panel = get_driver_boolean_parameter (settings_handle, "pgm_panel", false, false);
  
  		unload_driver_settings (settings_handle);
  	}
  
  	/* get a handle for the pci bus */
  	if (get_module(B_PCI_MODULE_NAME, (module_info **)&pci_bus) != B_OK)
  		return B_ERROR;
  
  	/* get a handle for the isa bus */
  	if (get_module(B_ISA_MODULE_NAME, (module_info **)&isa_bus) != B_OK)
  	{
  		put_module(B_PCI_MODULE_NAME);
  		return B_ERROR;
  	}
  
  	/* get a handle for the agp bus if it exists */
  	get_module(B_AGP_GART_MODULE_NAME, (module_info **)&agp_bus);
  
  	/* driver private data */
  	pd = (DeviceData *)calloc(1, sizeof(DeviceData));
  	if (!pd) {
  		if (agp_bus)
  			put_module(B_AGP_GART_MODULE_NAME);
  		put_module(B_ISA_MODULE_NAME);
  		put_module(B_PCI_MODULE_NAME);
  		return B_ERROR;
  	}
  	/* initialize the benaphore */
  	INIT_BEN(pd->kernel);
  	/* find all of our supported devices */
  	probe_devices();
  	return B_OK;
  }
  
  const char **
  publish_devices(void) {
  	/* return the list of supported devices */
  	return (const char **)pd->device_names;
  }
  
  device_hooks *
  find_device(const char *name) {
  	int index = 0;
  	while (pd->device_names[index]) {
  		if (strcmp(name, pd->device_names[index]) == 0)
  			return &graphics_device_hooks;
  		index++;
  	}
  	return NULL;
  
  }
  
  void uninit_driver(void) {
  
  	/* free the driver data */
  	DELETE_BEN(pd->kernel);
  	free(pd);
  	pd = NULL;
  
  	/* put the pci module away */
  	put_module(B_PCI_MODULE_NAME);
  	put_module(B_ISA_MODULE_NAME);
  
  	/* put the agp module away if it's there */
  	if (agp_bus)
  		put_module(B_AGP_GART_MODULE_NAME);
  }
  
  static status_t map_device(device_info *di)
  {
  	char buffer[B_OS_NAME_LENGTH]; /*memory for device name*/
  	shared_info *si = di->si;
  	uint32	tmpUlong;
  	pci_info *pcii = &(di->pcii);
  	system_info sysinfo;
  
  	/*storage for the physical to virtual table (used for dma buffer)*/
  //	physical_entry physical_memory[2];
  //	#define G400_DMA_BUFFER_SIZE 1024*1024
  
  	/* variables for making copy of ROM */
  	uint8* rom_temp;
  	area_id rom_area;
  
  	/* Nvidia cards have registers in [0] and framebuffer in [1] */
  	int registers = 1;
  	int frame_buffer = 0;
  //	int pseudo_dma = 2;
  
  	/* enable memory mapped IO, disable VGA I/O - this is defined in the PCI standard */
  	tmpUlong = get_pci(PCI_command, 2);
  	/* enable PCI access */
  	tmpUlong |= PCI_command_memory;
  	/* enable busmastering */
  	tmpUlong |= PCI_command_master;
  	/* disable ISA I/O access */
  	tmpUlong &= ~PCI_command_io;
  	set_pci(PCI_command, 2, tmpUlong);
  
   	/*work out which version of BeOS is running*/
   	get_system_info(&sysinfo);
   	if (0)//sysinfo.kernel_build_date[0]=='J')/*FIXME - better ID version*/
   	{
   		si->use_clone_bugfix = 1;
   	}
   	else
   	{
   		si->use_clone_bugfix = 0;
   	}
  
  	/* work out a name for the register mapping */
  	sprintf(buffer, DEVICE_FORMAT " regs",
  		di->pcii.vendor_id, di->pcii.device_id,
  		di->pcii.bus, di->pcii.device, di->pcii.function);
  
  	/* get a virtual memory address for the registers*/
  	si->regs_area = map_physical_memory(
  		buffer,
  		/* WARNING: Nvidia needs to map regs as viewed from PCI space! */
  		di->pcii.u.h0.base_registers_pci[registers],
  		di->pcii.u.h0.base_register_sizes[registers],
  		B_ANY_KERNEL_ADDRESS,
  		B_CLONEABLE_AREA | (si->use_clone_bugfix ? B_READ_AREA|B_WRITE_AREA : 0),
  		(void **)&(di->regs));
   	si->clone_bugfix_regs = (uint32 *) di->regs;
  
  	/* if mapping registers to vmem failed then pass on error */
  	if (si->regs_area < 0) return si->regs_area;
  
  	/* work out a name for the ROM mapping*/
  	sprintf(buffer, DEVICE_FORMAT " rom",
  		di->pcii.vendor_id, di->pcii.device_id,
  		di->pcii.bus, di->pcii.device, di->pcii.function);
  
  	/* disable ROM shadowing, we want the guaranteed exact contents of the chip */
  	/* warning:
  	 * don't touch: (confirmed) NV04, NV05, NV05-M64, NV11 all shutoff otherwise.
  	 * NV18, NV28 and NV34 keep working.
  	 * confirmed NV28 and NV34 to use upper part of shadowed ROM for scratch purposes,
  	 * however the actual ROM content (so the used part) is intact (confirmed). */
  	//set_pci(ENCFG_ROMSHADOW, 4, 0);
  
  	/* get ROM memory mapped base adress - this is defined in the PCI standard */
  	tmpUlong = get_pci(PCI_rom_base, 4);
  	if (tmpUlong)
  	{
  		/* ROM was assigned an adress, so enable ROM decoding - see PCI standard */
  		tmpUlong |= 0x00000001;
  		set_pci(PCI_rom_base, 4, tmpUlong);
  
  		rom_area = map_physical_memory(
  			buffer,
  			di->pcii.u.h0.rom_base_pci,
  			di->pcii.u.h0.rom_size,
  			B_ANY_KERNEL_ADDRESS,
  			B_READ_AREA,
  			(void **)&(rom_temp)
  		);
  
  		/* check if we got the BIOS signature (might fail on laptops..) */
  		if (rom_temp[0]!=0x55 || rom_temp[1]!=0xaa)
  		{
  			/* apparantly no ROM is mapped here */
  			delete_area(rom_area);
  			rom_area = -1;
  			/* force using ISA legacy map as fall-back */
  			tmpUlong = 0x00000000;
  		}
  	}
  
  	if (!tmpUlong)
  	{
  		/* ROM was not assigned an adress, fetch it from ISA legacy memory map! */
  		rom_area = map_physical_memory(
  			buffer,
  			0x000c0000,
  			65536,
  			B_ANY_KERNEL_ADDRESS,
  			B_READ_AREA,
  			(void **)&(rom_temp)
  		);
  	}
  
  	/* if mapping ROM to vmem failed then clean up and pass on error */
  	if (rom_area < 0) {
  		delete_area(si->regs_area);
  		si->regs_area = -1;
  		return rom_area;
  	}
  
  	/* dump ROM to file if selected in skel.settings
  	 * (ROM always fits in 64Kb: checked TNT1 - FX5950) */
  	if (current_settings.dumprom) dumprom (rom_temp, 65536);
  	/* make a copy of ROM for future reference */
  	memcpy (si->rom_mirror, rom_temp, 65536);
  
  	/* disable ROM decoding - this is defined in the PCI standard, and delete the area */
  	tmpUlong = get_pci(PCI_rom_base, 4);
  	tmpUlong &= 0xfffffffe;
  	set_pci(PCI_rom_base, 4, tmpUlong);
  	delete_area(rom_area);
  
  	/* work out a name for the framebuffer mapping*/
  	sprintf(buffer, DEVICE_FORMAT " framebuffer",
  		di->pcii.vendor_id, di->pcii.device_id,
  		di->pcii.bus, di->pcii.device, di->pcii.function);
  
  	/* map the framebuffer into vmem, using Write Combining*/
  	si->fb_area = map_physical_memory(
  		buffer,
  		/* WARNING: Nvidia needs to map framebuffer as viewed from PCI space! */
  		di->pcii.u.h0.base_registers_pci[frame_buffer],
  		di->pcii.u.h0.base_register_sizes[frame_buffer],
  		B_ANY_KERNEL_BLOCK_ADDRESS | B_MTR_WC,
  		B_READ_AREA + B_WRITE_AREA,
  		&(si->framebuffer));
  
  	/*if failed with write combining try again without*/
  	if (si->fb_area < 0) {
  		si->fb_area = map_physical_memory(
  			buffer,
  			/* WARNING: Nvidia needs to map framebuffer as viewed from PCI space! */
  			di->pcii.u.h0.base_registers_pci[frame_buffer],
  			di->pcii.u.h0.base_register_sizes[frame_buffer],
  			B_ANY_KERNEL_BLOCK_ADDRESS,
  			B_READ_AREA + B_WRITE_AREA,
  			&(si->framebuffer));
  	}
  
  	/* if there was an error, delete our other areas and pass on error*/
  	if (si->fb_area < 0)
  	{
  		delete_area(si->regs_area);
  		si->regs_area = -1;
  		return si->fb_area;
  	}
  //fixme: retest for card coldstart and PCI/virt_mem mapping!!
  	/* remember the DMA address of the frame buffer for BDirectWindow?? purposes */
  	si->framebuffer_pci = (void *) di->pcii.u.h0.base_registers_pci[frame_buffer];
  
  	// remember settings for use here and in accelerant
  	si->settings = current_settings;
  
  	/* in any case, return the result */
  	return si->fb_area;
  }
  
  static void unmap_device(device_info *di) {
  	shared_info *si = di->si;
  	uint32	tmpUlong;
  	pci_info *pcii = &(di->pcii);
  
  	/* disable memory mapped IO */
  	tmpUlong = get_pci(PCI_command, 4);
  	tmpUlong &= 0xfffffffc;
  	set_pci(PCI_command, 4, tmpUlong);
  	/* delete the areas */
  	if (si->regs_area >= 0) delete_area(si->regs_area);
  	if (si->fb_area >= 0) delete_area(si->fb_area);
  	si->regs_area = si->fb_area = -1;
  	si->framebuffer = NULL;
  	di->regs = NULL;
  }
  
  static void probe_devices(void) {
  	uint32 pci_index = 0;
  	uint32 count = 0;
  	device_info *di = pd->di;
  
  	/* while there are more pci devices */
  	while ((count < MAX_DEVICES) && ((*pci_bus->get_nth_pci_info)(pci_index, &(di->pcii)) == B_NO_ERROR)) {
  		int vendor = 0;
  
  		/* if we match a supported vendor */
  		while (SupportedDevices[vendor].vendor) {
  			if (SupportedDevices[vendor].vendor == di->pcii.vendor_id) {
  				uint16 *devices = SupportedDevices[vendor].devices;
  				/* while there are more supported devices */
  				while (*devices) {
  					/* if we match a supported device */
  					if (*devices == di->pcii.device_id ) {
  						/* publish the device name */
  						sprintf(di->name, "graphics/" DEVICE_FORMAT,
  							di->pcii.vendor_id, di->pcii.device_id,
  							di->pcii.bus, di->pcii.device, di->pcii.function);
  
  						/* remember the name */
  						pd->device_names[count] = di->name;
  						/* mark the driver as available for R/W open */
  						di->is_open = 0;
  						/* mark areas as not yet created */
  						di->shared_area = -1;
  						/* mark pointer to shared data as invalid */
  						di->si = NULL;
  						/* inc pointer to device info */
  						di++;
  						/* inc count */
  						count++;
  						/* break out of these while loops */
  						goto next_device;
  					}
  					/* next supported device */
  					devices++;
  				}
  			}
  			vendor++;
  		}
  next_device:
  		/* next pci_info struct, please */
  		pci_index++;
  	}
  	/* propagate count */
  	pd->count = count;
  	/* terminate list of device names with a null pointer */
  	pd->device_names[pd->count] = NULL;
  }
  
  static uint32 thread_interrupt_work(int32 *flags, vuint32 *regs, shared_info *si) {
  	uint32 handled = B_HANDLED_INTERRUPT;
  	/* release the vblank semaphore */
  	if (si->vblank >= 0) {
  		int32 blocked;
  		if ((get_sem_count(si->vblank, &blocked) == B_OK) && (blocked < 0)) {
  			release_sem_etc(si->vblank, -blocked, B_DO_NOT_RESCHEDULE);
  			handled = B_INVOKE_SCHEDULER;
  		}
  	}
  	return handled;
  }
  
  static int32
  eng_interrupt(void *data)
  {
  	int32 handled = B_UNHANDLED_INTERRUPT;
  	device_info *di = (device_info *)data;
  	shared_info *si = di->si;
  	int32 *flags = &(si->flags);
  	vuint32 *regs;
  
  	/* is someone already handling an interrupt for this device? */
  	if (atomic_or(flags, SKD_HANDLER_INSTALLED) & SKD_HANDLER_INSTALLED) {
  		goto exit0;
  	}
  	/* get regs */
  	regs = di->regs;
  
  	/* was it a VBI? */
  	if (caused_vbi(regs)) {
  		/*clear the interrupt*/
  		clear_vbi(regs);
  		/*release the semaphore*/
  		handled = thread_interrupt_work(flags, regs, si);
  	}
  
  	/* note that we're not in the handler any more */
  	atomic_and(flags, ~SKD_HANDLER_INSTALLED);
  
  exit0:
  	return handled;
  }
  
  static status_t open_hook (const char* name, uint32 flags, void** cookie) {
  	int32 index = 0;
  	device_info *di;
  	shared_info *si;
  	thread_id	thid;
  	thread_info	thinfo;
  	status_t	result = B_OK;
  	vuint32		*regs;
  	char shared_name[B_OS_NAME_LENGTH];
  
  	/* find the device name in the list of devices */
  	/* we're never passed a name we didn't publish */
  	while (pd->device_names[index] && (strcmp(name, pd->device_names[index]) != 0)) index++;
  
  	/* for convienience */
  	di = &(pd->di[index]);
  
  	/* make sure no one else has write access to the common data */
  	AQUIRE_BEN(pd->kernel);
  
  	/* if it's already open for writing */
  	if (di->is_open) {
  		/* mark it open another time */
  		goto mark_as_open;
  	}
  	/* create the shared area */
  	sprintf(shared_name, DEVICE_FORMAT " shared",
  		di->pcii.vendor_id, di->pcii.device_id,
  		di->pcii.bus, di->pcii.device, di->pcii.function);
  	/* create this area with NO user-space read or write permissions, to prevent accidental dammage */
  	di->shared_area = create_area(shared_name, (void **)&(di->si), B_ANY_KERNEL_ADDRESS, ((sizeof(shared_info) + (B_PAGE_SIZE - 1)) & ~(B_PAGE_SIZE - 1)), B_FULL_LOCK,
  		B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA | B_CLONEABLE_AREA);
  	if (di->shared_area < 0) {
  		/* return the error */
  		result = di->shared_area;
  		goto done;
  	}
  
  	/* save a few dereferences */
  	si = di->si;
  
  	/* save the vendor and device IDs */
  	si->vendor_id = di->pcii.vendor_id;
  	si->device_id = di->pcii.device_id;
  	si->revision = di->pcii.revision;
  	si->bus = di->pcii.bus;
  	si->device = di->pcii.device;
  	si->function = di->pcii.function;
  
  	/* device at bus #0, device #0, function #0 holds byte value at byte-index 0xf6 */
  	si->ps.chip_rev = ((*pci_bus->read_pci_config)(0, 0, 0, 0xf6, 1));
  
  	/* map the device */
  	result = map_device(di);
  	if (result < 0) goto free_shared;
  	result = B_OK;
  
  	/* create a semaphore for vertical blank management */
  	si->vblank = create_sem(0, di->name);
  	if (si->vblank < 0) {
  		result = si->vblank;
  		goto unmap;
  	}
  
  	/* change the owner of the semaphores to the opener's team */
  	/* this is required because apps can't aquire kernel semaphores */
  	thid = find_thread(NULL);
  	get_thread_info(thid, &thinfo);
  	set_sem_owner(si->vblank, thinfo.team);
  
  	/* assign local regs pointer for SAMPLExx() macros */
  	regs = di->regs;
  
  	/* disable and clear any pending interrupts */
  	disable_vbi(regs);
  
  	/* If there is a valid interrupt line assigned then set up interrupts */
  	if ((di->pcii.u.h0.interrupt_pin == 0x00) ||
  	    (di->pcii.u.h0.interrupt_line == 0xff) || /* no IRQ assigned */
  	    (di->pcii.u.h0.interrupt_line <= 0x02))   /* system IRQ assigned */
  	{
  		/* we are aborting! */
  		/* Note: the R4 graphics driver kit lacks this statement!! */
  		result = B_ERROR;
  		/* interrupt does not exist so exit without installing our handler */
  		goto delete_the_sem;
  	}
  	else
  	{
  		/* otherwise install our interrupt handler */
  		result = install_io_interrupt_handler(di->pcii.u.h0.interrupt_line, eng_interrupt, (void *)di, 0);
  		/* bail if we couldn't install the handler */
  		if (result != B_OK) goto delete_the_sem;
  	}
  
  mark_as_open:
  	/* mark the device open */
  	di->is_open++;
  
  	/* send the cookie to the opener */
  	*cookie = di;
  
  	goto done;
  
  
  delete_the_sem:
  	delete_sem(si->vblank);
  
  unmap:
  	unmap_device(di);
  
  free_shared:
  	/* clean up our shared area */
  	delete_area(di->shared_area);
  	di->shared_area = -1;
  	di->si = NULL;
  
  done:
  	/* end of critical section */
  	RELEASE_BEN(pd->kernel);
  
  	/* all done, return the status */
  	return result;
  }
  
  /* ----------
  	read_hook - does nothing, gracefully
  ----- */
  static status_t
  read_hook (void* dev, off_t pos, void* buf, size_t* len)
  {
  	*len = 0;
  	return B_NOT_ALLOWED;
  }
  
  /* ----------
  	write_hook - does nothing, gracefully
  ----- */
  static status_t
  write_hook (void* dev, off_t pos, const void* buf, size_t* len)
  {
  	*len = 0;
  	return B_NOT_ALLOWED;
  }
  
  /* ----------
  	close_hook - does nothing, gracefully
  ----- */
  static status_t
  close_hook (void* dev)
  {
  	/* we don't do anything on close: there might be dup'd fd */
  	return B_NO_ERROR;
  }
  
  /* -----------
  	free_hook - close down the device
  ----------- */
  static status_t
  free_hook (void* dev) {
  	device_info *di = (device_info *)dev;
  	shared_info	*si = di->si;
  	vuint32 *regs = di->regs;
  
  	/* lock the driver */
  	AQUIRE_BEN(pd->kernel);
  
  	/* if opened multiple times, decrement the open count and exit */
  	if (di->is_open > 1)
  		goto unlock_and_exit;
  
  	/* disable and clear any pending interrupts */
  	disable_vbi(regs);
  
  	/* remove interrupt handler */
  	remove_io_interrupt_handler(di->pcii.u.h0.interrupt_line, eng_interrupt, di);
  
  	/* delete the semaphores, ignoring any errors ('cause the owning team may have died on us) */
  	delete_sem(si->vblank);
  	si->vblank = -1;
  
  	/* free regs and framebuffer areas */
  	unmap_device(di);
  
  	/* clean up our shared area */
  	delete_area(di->shared_area);
  	di->shared_area = -1;
  	di->si = NULL;
  
  unlock_and_exit:
  	/* mark the device available */
  	di->is_open--;
  	/* unlock the driver */
  	RELEASE_BEN(pd->kernel);
  	/* all done */
  	return B_OK;
  }
  
  /* -----------
  	control_hook - where the real work is done
  ----------- */
  static status_t
  control_hook (void* dev, uint32 msg, void *buf, size_t len) {
  	device_info *di = (device_info *)dev;
  	status_t result = B_DEV_INVALID_IOCTL;
  	uint32 tmpUlong;
  
  	switch (msg) {
  		/* the only PUBLIC ioctl */
  		case B_GET_ACCELERANT_SIGNATURE: {
  			char *sig = (char *)buf;
  			strcpy(sig, current_settings.accelerant);
  			result = B_OK;
  		} break;
  
  		/* PRIVATE ioctl from here on */
  		case ENG_GET_PRIVATE_DATA: {
  			eng_get_private_data *gpd = (eng_get_private_data *)buf;
  			if (gpd->magic == VIA_PRIVATE_DATA_MAGIC) {
  				gpd->shared_info_area = di->shared_area;
  				result = B_OK;
  			}
  		} break;
  		case ENG_GET_PCI: {
  			eng_get_set_pci *gsp = (eng_get_set_pci *)buf;
  			if (gsp->magic == VIA_PRIVATE_DATA_MAGIC) {
  				pci_info *pcii = &(di->pcii);
  				gsp->value = get_pci(gsp->offset, gsp->size);
  				result = B_OK;
  			}
  		} break;
  		case ENG_SET_PCI: {
  			eng_get_set_pci *gsp = (eng_get_set_pci *)buf;
  			if (gsp->magic == VIA_PRIVATE_DATA_MAGIC) {
  				pci_info *pcii = &(di->pcii);
  				set_pci(gsp->offset, gsp->size, gsp->value);
  				result = B_OK;
  			}
  		} break;
  		case ENG_DEVICE_NAME: { // apsed
  			eng_device_name *dn = (eng_device_name *)buf;
  			if (dn->magic == VIA_PRIVATE_DATA_MAGIC) {
  				strcpy(dn->name, di->name);
  				result = B_OK;
  			}
  		} break;
  		case ENG_RUN_INTERRUPTS: {
  			eng_set_bool_state *ri = (eng_set_bool_state *)buf;
  			if (ri->magic == VIA_PRIVATE_DATA_MAGIC) {
  				vuint32 *regs = di->regs;
  				if (ri->do_it) {
  					enable_vbi(regs);
  				} else {
  					disable_vbi(regs);
  				}
  				result = B_OK;
  			}
  		} break;
  		case ENG_GET_NTH_AGP_INFO: {
  			eng_nth_agp_info *nai = (eng_nth_agp_info *)buf;
  			if (nai->magic == VIA_PRIVATE_DATA_MAGIC) {
  				nai->exist = false;
  				nai->agp_bus = false;
  				if (agp_bus) {
  					nai->agp_bus = true;
  					if ((*agp_bus->get_nth_agp_info)(nai->index, &(nai->agpi)) == B_NO_ERROR) {
  						nai->exist = true;
  					}
  				}
  				result = B_OK;
  			}
  		} break;
  		case ENG_ENABLE_AGP: {
  			eng_cmd_agp *nca = (eng_cmd_agp *)buf;
  			if (nca->magic == VIA_PRIVATE_DATA_MAGIC) {
  				if (agp_bus) {
  					nca->agp_bus = true;
  					nca->cmd = agp_bus->set_agp_mode(nca->cmd);
  				} else {
  					nca->agp_bus = false;
  					nca->cmd = 0;
  				}
  				result = B_OK;
  			}
  		} break;
  		case ENG_ISA_OUT: {
  			eng_in_out_isa *io_isa = (eng_in_out_isa *)buf;
  			if (io_isa->magic == VIA_PRIVATE_DATA_MAGIC) {
  				pci_info *pcii = &(di->pcii);
  
  				/* lock the driver:
  				 * no other graphics card may have ISA I/O enabled when we enter */
  				AQUIRE_BEN(pd->kernel);
  
  				/* enable ISA I/O access */
  				tmpUlong = get_pci(PCI_command, 2);
  				tmpUlong |= PCI_command_io;
  				set_pci(PCI_command, 2, tmpUlong);
  
  				if (io_isa->size == 1)
    					isa_bus->write_io_8(io_isa->adress, (uint8)io_isa->data);
     				else
     					isa_bus->write_io_16(io_isa->adress, io_isa->data);
    				result = B_OK;
  
  				/* disable ISA I/O access */
  				tmpUlong = get_pci(PCI_command, 2);
  				tmpUlong &= ~PCI_command_io;
  				set_pci(PCI_command, 2, tmpUlong);
  
  				/* end of critical section */
  				RELEASE_BEN(pd->kernel);
     			}
  		} break;
  		case ENG_ISA_IN: {
  			eng_in_out_isa *io_isa = (eng_in_out_isa *)buf;
  			if (io_isa->magic == VIA_PRIVATE_DATA_MAGIC) {
  				pci_info *pcii = &(di->pcii);
  
  				/* lock the driver:
  				 * no other graphics card may have ISA I/O enabled when we enter */
  				AQUIRE_BEN(pd->kernel);
  
  				/* enable ISA I/O access */
  				tmpUlong = get_pci(PCI_command, 2);
  				tmpUlong |= PCI_command_io;
  				set_pci(PCI_command, 2, tmpUlong);
  
  				if (io_isa->size == 1)
  	   				io_isa->data = isa_bus->read_io_8(io_isa->adress);
  	   			else
  	   				io_isa->data = isa_bus->read_io_16(io_isa->adress);
     				result = B_OK;
  
  				/* disable ISA I/O access */
  				tmpUlong = get_pci(PCI_command, 2);
  				tmpUlong &= ~PCI_command_io;
  				set_pci(PCI_command, 2, tmpUlong);
  
  				/* end of critical section */
  				RELEASE_BEN(pd->kernel);
     			}
  		} break;
  	}
  	return result;
  }
  