  Linux PCMCIA Programmer's Guide
  David Hinds, dhinds@hyper.stanford.edu
  v1.32, 1997/02/08 06:40:14

  This document describes how to write kernel device drivers for the
  Linux PCMCIA Card Services interface.  It also describes how to write
  user-mode utilities for communicating with Card Services.  The latest
  version of this document can always be found at hyper.stanford.edu in
  /pub/pcmcia/doc.  An HTML version is at http://hyper.stan-
  ford.edu/HyperNews/get/pcmcia/home.html
  ______________________________________________________________________

  Table of Contents:

  1.      Introduction

  1.1.    Copyright notice and disclaimer

  1.2.    Acknowledgements

  2.      Basic PCMCIA Concepts

  2.1.    The PCMCIA socket interface

  2.2.    The PCMCIA socket controller

  3.      Card Services subfunction descriptions

  3.1.    Client management functions

  3.1.1.  RegisterClient

  3.1.2.  DeregisterClient

  3.1.3.  SetEventMask

  3.1.4.  BindDevice

  3.2.    Socket state control

  3.2.1.  GetStatus

  3.2.2.  ResetCard

  3.2.3.  SuspendCard

  3.2.4.  ResumeCard

  3.2.5.  EjectCard

  3.2.6.  InsertCard

  3.3.    IO card configuration calls

  3.3.1.  RequestIO

  3.3.2.  ReleaseIO

  3.3.3.  RequestIRQ

  3.3.4.  ReleaseIRQ

  3.3.5.  RequestConfiguration

  3.3.6.  ModifyConfiguration

  3.3.7.  ReleaseConfiguration

  3.3.8.  GetConfigurationInfo

  3.4.    Card Information Structure (CIS) calls

  3.4.1.  GetFirstTuple, GetNextTuple

  3.4.2.  GetTupleData

  3.4.3.  ParseTuple

  3.4.4.  ValidateCIS

  3.5.    Memory window control

  3.5.1.  RequestWindow

  3.5.2.  ModifyWindow

  3.5.3.  MapMemPage

  3.5.4.  ReleaseWindow

  3.6.    Bulk Memory Services

  3.6.1.  RegisterMTD

  3.6.2.  GetFirstRegion, GetNextRegion

  3.6.3.  OpenMemory

  3.6.4.  CloseMemory

  3.6.5.  ReadMemory, WriteMemory

  3.6.6.  RegisterEraseQueue

  3.6.7.  DeregisterEraseQueue

  3.6.8.  CheckEraseQueue

  3.7.    Miscellaneous calls

  3.7.1.  GetCardServicesInfo

  3.7.2.  AccessConfigurationRegister

  3.7.3.  AdjustResourceInfo

  3.7.4.  ReportError

  4.      Card Information Structure Definitions

  4.1.    CIS Tuple Definitions

  4.1.1.  CISTPL_CHECKSUM

  4.1.2.  CISTPL_LONGLINK_A, CISTPL_LONGLINK_C, CISTPL_LINKTARGET,
  CISTPL_NOLINK

  4.1.3.  CISTPL_LONGLINK_MFC

  4.1.4.  CISTPL_DEVICE, CISTPL_DEVICE_A

  4.1.5.  CISTPL_VERS_1

  4.1.6.  CISTPL_ALTSTR

  4.1.7.  CISTPL_JEDEC_C, CISTPL_JEDEC_A

  4.1.8.  CISTPL_CONFIG

  4.1.9.  CISTPL_CFTABLE_ENTRY

  4.1.10. CISTPL_MANFID

  4.1.11. CISTPL_FUNCID

  4.1.12. CISTPL_DEVICE_GEO

  4.1.13. CISTPL_VERS_2

  4.1.14. CISTPL_ORG

  4.2.    CIS configuration registers

  4.2.1.  Configuration Option Register

  4.2.2.  Card Configuration and Status Register

  4.2.3.  Pin Replacement Register

  4.2.4.  Socket and Copy Register

  4.2.5.  Extended Status Register

  5.      Card Services Event Handling

  5.1.    Event handler operations

  5.2.    Event descriptions

  5.3.    Client driver event handling responsibilities

  6.      Memory Technology Drivers

  6.1.    MTD request handling

  6.2.    MTD helper functions

  6.2.1.  MTDModifyWindow

  6.2.2.  MTDSetVpp

  6.2.3.  MTDRDYMask

  7.      Driver Services interface

  7.1.    Interface to other client drivers

  7.1.1.  The dev_link_t structure

  7.1.2.  register_pcmcia_driver

  7.1.3.  unregister_pcmcia_driver

  7.2.    Interface to user mode PCMCIA utilities

  7.2.1.  Card Services event notifications

  7.2.2.  Ioctl descriptions

  8.      Anatomy of a Card Services Client Driver

  8.1.    Module initialization and cleanup

  8.2.    The *_attach() and *_detach() functions

  8.3.    The *_config() and *_release() functions

  8.4.    The PCMCIA event handler

  8.5.    Locking and synchronization issues

  8.6.    Using existing Linux drivers to access PCMCIA devices

  9.      Where to Go for More Information
  ______________________________________________________________________

  11..  IInnttrroodduuccttiioonn

  The Linux kernel PCMCIA system has three main components.  At the
  lowest level are the socket drivers.  Next is the Card Services
  module.  Drivers for specific cards are layered on top of Card
  Services.  One special Card Services client, called Driver Services,
  provides a link betweek user level PCMCIA utility programs and the
  kernel PCMCIA facilities.

  The socket driver layer is loosely based on the Socket Services API.
  There are two socket driver modules.  The tcic module supports the
  Databook TCIC-2 family of PCMCIA controllers.  The i82365 module
  supports the Intel i82365sl family and various Intel-compatible
  controllers, including Cirrus, VLSI, Ricoh, and Vadem chips.

  Card Services is the largest single component of the PCMCIA package.
  It provides an API somewhat similar to DOS Card Services, adapted to a
  Unix environment.  The Linux implementation was based in part on the
  Solaris PCMCIA interface specification.  It is implemented in the
  pcmcia_core module.  Most version 2.1 features are implemented, with
  some PC Card 95 features.

  The Driver Services layer implements a user mode pseudo-device for
  accessing some Card Services functions from PCMCIA utility programs.
  It is responsible for keeping track of all PCMCIA client drivers, and
  for matching up drivers with physical sockets.  It is implemented in
  the ds module.

  This document describes the kernel interface to the Card Services and
  Driver Services modules, and the user interface to Driver Services.
  It is intended for use by PCMCIA device driver developers.  The Linux
  PCMCIA-HOWTO describes how to install and use Linux PCMCIA support.
  It is available from cb-iris.stanford.edu in /pub/pcmcia.

  11..11..  CCooppyyrriigghhtt nnoottiiccee aanndd ddiissccllaaiimmeerr

  Copyright (c) 1996, 1997 David A. Hinds

  This document may be reproduced or distributed in any form without my
  prior permission.  Modified versions of this document, including
  translations into other languages, may be freely distributed, provided
  that they are clearly identified as such, and this copyright is
  included intact.

  This document may be included in commercial distributions without my
  prior consent.  While it is not required, I would like to be informed
  of such usage.  If you intend to incorporate this document in a
  published work, please contact me to make sure you have the latest
  available version.

  This document is provided ``as is'', with no explicit or implied
  warranties.  Use the information in this document at your own risk.

  11..22..  AAcckknnoowwlleeddggeemmeennttss

  I'd like to thank all the Linux users who have helped test and debug
  this PCMCIA software, and who have helped with driver development.  I
  should also thank Linus Torvalds, Donald Becker, Alan Cox, and Bjorn
  Ekwall for Linux kernel development help.  I'm especially grateful to
  Michael Bender for many helpful discussions about the Solaris PCMCIA
  implementation.

  22..  BBaassiicc PPCCMMCCIIAA CCoonncceeppttss

  22..11..  TThhee PPCCMMCCIIAA ssoocckkeett iinntteerrffaaccee

  The PCMCIA card bus has two basic operating modes: ``memory-only'' and
  ``memory and IO''.  The first mode was defined by the original Version
  1.0 specification and only supports simple memory cards.  The second
  mode, defined in Version 2.0, redefines a few of the memory card
  control signals to support IO port addressing and IO interrupt
  signalling.

  PCMCIA cards have two memory spaces: ``attribute memory'' and ``common
  memory''.  The PCMCIA interface can address up to 16MB of each type of
  memory.  Attribute memory is typically used for holding descriptive
  information and configuration registers.  Common memory may include
  the bulk storage of a memory card, or device buffers in the case of IO
  cards.  All cards that are compliant with the version 2.0 PCMCIA
  specification should have a Card Information Structure (or ``CIS'') in
  attribute memory, which describes the card and how it should be
  configured.

  Separate control signals allow cards to signal their operating status
  to the host.  These signals include card detect, ready/busy, write
  protect, battery low, and battery dead.

  The ``memory and IO'' interface mode allows cards to address up to 64K
  of IO ports.  It also allows cards to signal IO interrupts, and routes
  one card output to the host system's speaker.  In this mode, several
  of the memory card control signals are unavailable because those pins
  are used to carry the extra IO card signals.  On some cards, these
  signals can instead be read from a special configuration register in
  attribute memory, the ``Pin Replacement Register''.

  22..22..  TThhee PPCCMMCCIIAA ssoocckkeett ccoonnttrroolllleerr

  The PCMCIA controller serves as a bridge between PCMCIA cards and the
  system bus.  There are several varieties of controllers, but all share
  the same basic functionality.  The Socket Services software layer
  takes care of all the details of how to program the PCMCIA controller.

  The PCMCIA controller has the job of mapping windows of addresses in
  the host memory and IO spaces to windows of addresses in card space.
  All controllers support at least four independent memory windows and
  two IO windows per socket.

  Each memory window is defined by a base address in the host address
  space, a base address in the card address space, and a window size.
  Some controllers differ in their alignment rules for memory windows,
  but all controllers will support windows whose size is at least 4K and
  also a power of two, and where the base address is a multiple of the
  window size.  Each window can be programmed to point to either
  attribute or common memory.

  IO windows differ from memory windows in that host addresses that fall
  within an IO window are not modified before they are passed on to an
  IO card.  Effectively, the base addresses of the window in the host
  and card address spaces are always equal.  IO windows also have no
  alignment or size restrictions; an IO window can start and end on any
  byte boundary in the 64K IO address space.

  The PCMCIA card bus defines a single interrupt signal from the card to
  the controller.  The controller then has the responsibility of
  steering this interrupt to an appropriate interrupt request (``irq'')
  line.  All controllers support steering card IO interrupts to
  essentially any free interrupt line.  Because steering happens in the
  controller, the card itself is unaware of which interrupt it uses.

  All PCMCIA controllers can generate interrupts in response to card
  status changes.  These interrupts are distinct from the IO interrupts
  generated by an IO card, and use a separate interrupt line.  Signals
  that can generate interrupts include card detect, ready/busy, write
  protect, battery low, and battery dead.

  33..  CCaarrdd SSeerrvviicceess ssuubbffuunnccttiioonn ddeessccrriippttiioonnss

  Card Services calls have the general form:

       #include "cs_types.h"
       #include "cs.h"

       int CardServices(int subfunc, void *arg1, void *arg2, ...);

  Some Card Services functions require additional #include statements.
  The particular subfunction determines the number of expected
  arguments.  A return code of CS_SUCCESS indicates that a call
  succeeded.  Other return codes indicate errors.

  33..11..  CClliieenntt mmaannaaggeemmeenntt ffuunnccttiioonnss

  Device drivers that use Card Services functions are called
  ``clients''.  A device driver should use the RegisterClient call to
  get a client handle before using other services.  Most Card Services
  functions will take this client handle as an argument.  Before
  unloading, drivers should also unregister with DeregisterClient.

  33..11..11..  RReeggiisstteerrCClliieenntt

       int CardServices(RegisterClient, client_handle_t *client, client_reg_t *reg);

  The client_reg_t data structure is given by:

       typedef struct client_reg_t {
               dev_info_t              *dev_info;
               u_long                  Attributes;
               u_long                  EventMask;
               int                     (*event_handler)(event_t event, int priority,
                                                        event_callback_args_t *args);
               event_callback_args_t   event_callback_args;
               u_long                  Version;
       } client_reg_t;

  RegisterClient establishes a link between a client driver and Card
  Services, and connects the client with an appropriate socket.  The
  dev_info parameter is used by Card Services to match the client with a
  socket and function; this correspondence is normally established by
  Driver Services via a call to BindDevice.  If successful, a client
  handle will be returned in client.

  The following flags can be specified in Attributes:

     IINNFFOO__MMAASSTTEERR__CCLLIIEENNTT
        For use only by the Driver Services client.  Among other things,
        specifies that this client should not be automatically unbound
        when a card is ejected from this socket.

     IINNFFOO__IIOO__CCLLIIEENNTT
        Specifies that this client is an IO card driver.

     IINNFFOO__MMTTDD__CCLLIIEENNTT
        Specifies that this client is a Memory Technology Driver.

     IINNFFOO__MMEEMM__CCLLIIEENNTT
        Specifies that this client is a memory card driver.

     IINNFFOO__CCAARRDD__SSHHAARREE
        Included for compatibility, has no effect.

     IINNFFOO__CCAARRDD__EEXXCCLL
        Included for compatibility, has no effect.

  EventMask specifies what events this client should be notified of.
  The event_handler entry point will be called by Card Services when an
  event in EventMask is processed.  The event_handler_args structure is
  a template for the structure that will be passed to the event handler.
  The Version parameter identifies the Card Services version level that
  this driver expects; it is currently ignored.

  A driver should be prepared to handle Card Services events before
  calling RegisterClient.  This call will always generate a
  CS_REGISTRATION_COMPLETE event, and may also generate an artificial
  CS_CARD_INSERTION event if the socket is currently occupied.

  Return codes:

     CCSS__OOUUTT__OOFF__RREESSOOUURRCCEE
        An appropriate socket could not be found for this driver.

  33..11..22..  DDeerreeggiisstteerrCClliieenntt

       int CardServices(DeregisterClient, client_handle_t client);

  DeregisterClient severs the connection between a client and Card
  Services.  It should be called after the client has freed any
  resources it has allocated.  Once a connection is broken, it cannot be
  reestablished until after another call to BindDevice.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__IINN__UUSSEE
        The client still has allocated resources, such as IO port
        windows or an interrupt, or the socket configuration is locked.

  33..11..33..  SSeettEEvveennttMMaasskk

       int CardServices(SetEventMask, client_handle_t client, eventmask_t *mask);

  The eventmask_t structure is given by:

       typedef struct eventmask_t {
               u_long          Attributes;
               u_long          EventMask;
       } eventmask_t;

  SetEventMask updates the mask that determines which events this client
  will be notified of.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

  33..11..44..  BBiinnddDDeevviiccee

  int CardServices(BindDevice, bind_req_t *req);

  The bind_req structure is given by:

       typedef struct bind_req_t {
               socket_t        Socket;
               u_char          Function;
               dev_info_t      *dev_info;
       } bind_req_t;

  BindDevice associates a device driver with a particular socket.  It is
  normally called by Driver Services after a newly inserted card has
  been identified.  Once a driver has been bound to a socket, it will be
  eligible to register as a client of that socket.  Note that this call
  does not take a client handle as an argument.  This is the only Card
  Services call that takes a socket number as an argument.

  The Function field specifies which function(s) of a multifunction card
  are to be bound to this driver.  Function numbers correspond to
  entries in the card's CISTPL_LONGLINK_MFC tuple.  If Function is set
  to BIND_FN_ALL, the driver will be bound to all card functions.  A
  driver will only be able to access CIS tuples corresponding to
  functions for which it is bound.

  Return codes:

     CCSS__BBAADD__SSOOCCKKEETT
        The specified socket number is invalid.

  33..22..  SSoocckkeett ssttaattee ccoonnttrrooll

  These functions are more or less concerned with getting and setting
  the current operating state of a socket.  GetStatus returns the
  current socket state.  ResetCard is used to send a hard reset signal
  to a socket.  SuspendCard and ResumeCard can be used to power down and
  power up a socket without releasing the drivers currently bound to
  that socket.  EjectCard and InsertCard essentially mimic real card
  ejection and insertion events.

  33..22..11..  GGeettSSttaattuuss

       int CardServices(GetStatus, client_handle_t client, status_t *status);

  The status_t data structure is given by:

  typedef struct status_t {
          u_char          Function;
          u_long          CardState;
          u_long          SocketState;
  } status_t;

  GetStatus returns the current status of a client's socket.  For cards
  that are configured in IO mode, GetStatus uses the Pin Replacement
  Register and Extended Status Register to determine the card status.
  For normal clients, the Function field is ignored, but for clients
  bound with BIND_FN_ALL, this field specifies the function whose
  configuration registers should be used to determine the socket state,
  if the socket is currently configured.  The following flags are
  defined in CardState:

     CCSS__EEVVEENNTT__CCAARRDD__DDEETTEECCTT
        Specifies that the socket is occupied.

     CCSS__EEVVEENNTT__WWRRIITTEE__PPRROOTTEECCTT
        Specifies that the card is currently write protected.

     CCSS__EEVVEENNTT__BBAATTTTEERRYY__LLOOWW
        Specifies that the card battery is low.

     CCSS__EEVVEENNTT__BBAATTTTEERRYY__DDEEAADD
        Specifies that the card battery is dead.

     CCSS__EEVVEENNTT__RREEAADDYY__CCHHAANNGGEE
        Specifies that the card is ready.

     CCSS__EEVVEENNTT__PPMM__SSUUSSPPEENNDD
        Specifies that the socket is suspended.

     CCSS__EEVVEENNTT__RREEQQUUEESSTT__AATTTTEENNTTIIOONN
        Specifies that the request attention bit in the extended status
        register is set.

  SocketState is currently unused, but in theory, it should latch
  changes in the state of the fields in CardState.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

  33..22..22..  RReesseettCCaarrdd

       int CardServices(ResetCard, client_handle_t client);

  ResetCard requests that a client's socket be reset.  When this call is
  made, Card Services sends all clients a CS_EVENT_RESET_REQUEST event.
  If any client rejects the request, Card Services sends the initiating
  client a CS_EVENT_RESET_COMPLETE event with event_callback_args.info
  set to the return code of the client that rejected the request.

  If all clients agree to the request, Card Services sends a
  CS_EVENT_RESET_PHYSICAL event, then resets the socket.  When the
  socket signals that it is ready, a CS_EVENT_CARD_RESET event is
  generated.  Finally, a CS_EVENT_RESET_COMPLETE event is sent to the
  initiating client, with event_callback_args.info set to zero.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__NNOO__CCAARRDD
        The socket assigned to this client is currently vacant.

     CCSS__IINN__UUSSEE
        This socket is currently being reset.

  33..22..33..  SSuussppeennddCCaarrdd

       int CardServices(SuspendCard, client_handle_t client);

  Card Services sends all clients CS_EVENT_PM_SUSPEND events, then shuts
  down and turns off power to the socket.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__NNOO__CCAARRDD
        The socket assigned to this client is currently vacant.

     CCSS__IINN__UUSSEE
        This socket is already suspended.

  33..22..44..  RReessuummeeCCaarrdd

       int CardServices(ResumeCard, client_handle_t client);

  After restoring power to the socket, Card Services will notify all
  clients with CS_EVENT_PM_RESUME events.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__NNOO__CCAARRDD
        The socket assigned to this client is currently vacant.

     CCSS__IINN__UUSSEE
        This socket is not currently suspended.
  33..22..55..  EEjjeeccttCCaarrdd

       int CardServices(EjectCard, client_handle_t client);

  Card Services sends eject events to all clients, then shuts down and
  turns off power to the socket.  All clients except for Driver Services
  will be unlinked from the socket.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__NNOO__CCAARRDD
        The socket assigned to this client is currently vacant.

  33..22..66..  IInnsseerrttCCaarrdd

       int CardServices(InsertCard, client_handle_t client);

  Card Services sends insertion events to all clients of this socket
  (normally, only Driver Services).

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__NNOO__CCAARRDD
        The socket assigned to this client is currently vacant.

     CCSS__IINN__UUSSEE
        The socket has already been configured.

  33..33..  IIOO ccaarrdd ccoonnffiigguurraattiioonn ccaallllss

  The normal order of events is for a driver to reserve IO ports and an
  interrupt line with calls to RequestIO and RequestIRQ, then to call
  RequestConfiguration to actually configure the socket.  If any of
  these calls fails, a driver should be sure to release any resources it
  successfully reserved.

  Multifunction cards can have separate configurations for each card
  function.  However, the configurations do need to be consistent with
  one another.  While each card function has its own set of
  configuration registers, each socket has only a single interrupt line
  and can only map two contiguous ranges of IO ports.

  33..33..11..  RReeqquueessttIIOO

       int CardServices(RequestIO, client_handle_t client, io_req_t *req);

  The io_req_t data structure is given by:

       typedef struct io_req_t {
               ioaddr_t        BasePort1;
               ioaddr_t        NumPorts1;
               u_long          Attributes1;
               ioaddr_t        BasePort2;
               ioaddr_t        NumPorts2;
               u_long          Attributes2;
               u_long          IOAddrLines;
       } io_req_t;

  RequestIO reserves IO port windows for a card.  If BasePort1 is non-
  zero, it specifies the IO port address of the window to be reserved;
  if it is zero, Card Services will find an available window and set
  BasePort1 to this address.  If NumPorts2 is non-zero, a second IO port
  window will also be reserved.  IOAddrLines specifies the number of
  address lines that are actually decoded by the PCMCIA card; this is
  not currently used.

  With multifunction cards, this call will allocate IO ports for each
  card function in such a way that all a card's ports can be mapped by
  the two low-level IO port windows associated with each physical
  socket.  For example, if the drivers for a hypothetical four-function
  card each attempt to allocate one IO window of 8 ports, Card Services
  will consolidate these into a single contiguous 32-port block.

  This call does not actually configure a socket's IO windows: this is
  done by a subsequent call to RequestConfiguration.

  The following flags can be specified in Attributes1 and Attributes2:

     IIOO__DDAATTAA__PPAATTHH__WWIIDDTTHH
        This field may either be IO_DATA_PATH_WIDTH_16 for 16-bit
        access, or IO_DATA_PATH_WIDTH_8 for 8-bit access, or
        IO_DATA_PATH_WIDTH_AUTO to dynamically size the bus based on the
        access size.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__NNOO__CCAARRDD
        The socket assigned to this client is currently vacant.

     CCSS__IINN__UUSSEE
        This socket's IO windows have already been reserved.

     CCSS__CCOONNFFIIGGUURRAATTIIOONN__LLOOCCKKEEDD
        This socket's configuration has been locked by a call to
        RequestConfiguration.

     CCSS__BBAADD__AATTTTRRIIBBUUTTEE
        An unsupported attribute flag was specified.

  33..33..22..  RReelleeaasseeIIOO

       int CardServices(ReleaseIO, client_handle_t client, io_req_t *req);

  ReleaseIO un-reserves IO port windows allocated by a previous call to
  RequestIO.  The req parameter should be the same one passed to
  RequestIO.  If several card functions are sharing a larger IO port
  window, ports released by one function may not become available for
  other uses until all card functions have released their IO ports.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__CCOONNFFIIGGUURRAATTIIOONN__LLOOCCKKEEDD
        This socket's configuration has been locked by a call to
        RequestConfiguration.  The configuration should be released
        before calling ReleaseIO.

     CCSS__BBAADD__AARRGGSS
        The parameters in req do not match the parameters passed to
        RequestIO.

  33..33..33..  RReeqquueessttIIRRQQ

       int CardServices(RequestIRQ, client_handle_t client, irq_req_t *req);

  The irq_req_t structure is given by:

       typedef struct irq_req_t {
               u_long          Attributes;
               u_long          AssignedIRQ;
               u_long          IRQInfo1, IRQInfo2;
               void            *(Handler)(int, struct pt_regs *);
       } irq_req_t;

  RequestIRQ reserves an interrupt line for use by a PCMCIA card.  The
  IRQInfo1 and IRQInfo2 fields correspond to the interrupt description
  bytes in a CFTABLE_ENTRY tuple.  If IRQ_INFO2_VALID is set in
  IRQInfo1, then IRQInfo2 is a bit-mapped mask of allowed interrupt
  values.  Each bit corresponds to one interrupt line: bit 0 = irq 0,
  bit 1 = irq 1, etc.  So, a mask of 0x1100 would mean that interrupts
  12 and 8 could be used.  If IRQ_INFO2_VALID is not set, IRQInfo1 is
  just the desired interrupt number.  If the call is successful, the
  reserved interrupt is returned in AssignedIRQ.

  If the IRQ_HANDLER_PRESENT flag is set, then this call will also
  install the interrupt handler specified by Handler.  With
  multifunction cards, the interrupt will be allocated in shared mode,
  and the handler(s) have responsibility for determining which card
  function(s) require attention when an interrupt is received.  If a
  client instead bypasses Card Services to install its own interrupt
  service routine, it should allocate the interrupt in shared mode if
  this client could be bound to a multifunction card.  The socket
  interrupt will not be actually enabled until a call to
  RequestConfiguration.

  The following flags can be specified in Attributes:

     IIRRQQ__FFOORRCCEEDD__PPUULLSSEE
        Specifies that the interrupt should be configured for pulsed
        mode, rather than the default level mode.

     IIRRQQ__TTYYPPEE__TTIIMMEE
        Specifies that this interrupt can be time-shared with other Card
        Services drivers.  Only one driver should enable the interrupt
        at any time.

     IIRRQQ__FFIIRRSSTT__SSHHAARREEDD
        In conjunction with IRQ_TYPE_TIME, this should be set by the
        first driver requesting a shared interrupt.

     IIRRQQ__HHAANNDDLLEERR__PPRREESSEENNTT
        Indicates that the Handler field points to an interrupt service
        routine that should be installed.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__NNOO__CCAARRDD
        The socket assigned to this client is currently vacant.

     CCSS__IINN__UUSSEE
        An interrupt has already been reserved for this socket, or the
        requested interrupt is unavailable.

     CCSS__CCOONNFFIIGGUURRAATTIIOONN__LLOOCCKKEEDD
        This card function's configuration has been locked by a call to
        RequestConfiguration.

     CCSS__BBAADD__AATTTTRRIIBBUUTTEE
        An unsupported attribute flag was specified.

  33..33..44..  RReelleeaasseeIIRRQQ

       int CardServices(ReleaseIRQ, client_handle_t client, irq_req_t *req);

  ReleaseIRQ un-reserves an interrupt assigned by an earlier call to
  RequestIRQ.  The req structure should be the same structure that was
  passed to RequestIRQ.  If a handler was specified in the RequestIRQ
  call, it will be unregistered at this time.
  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__CCOONNFFIIGGUURRAATTIIOONN__LLOOCCKKEEDD
        This socket's configuration has been locked by a call to
        RequestConfiguration.  The configuration should be released
        before calling ReleaseIRQ.

     CCSS__BBAADD__IIRRQQ
        The parameters in req do not match the parameters passed to
        RequestIRQ.

  33..33..55..  RReeqquueessttCCoonnffiigguurraattiioonn

       int CardServices(RequestConfiguration, client_handle_t client, config_req_t *req);

  The config_req_t structure is given by:

       typedef struct config_req_t {
               u_long          Attributes;
               u_long          Vcc, Vpp1, Vpp2;
               u_long          IntType;
               caddr_t         ConfigBase;
               u_char          Status, Pin, Copy, ExtStatus;
               u_char          ConfigIndex;
               u_long          Present;
       } config_req_t;

  RequestConfiguration is responsible for actually configuring a socket.
  This includes setting voltages, setting CIS configuration registers,
  setting up IO port windows, and setting up interrupts.

  IntType specifies the type of interface to use for this card.  It may
  either be INT_MEMORY or INT_MEMORY_AND_IO.  Voltages are specified in
  units of 1/10 volt.  Currently, Vpp1 must equal Vpp2.

  With multifunction cards, each card function is configured separately.
  Each function has its own set of CIS configuration registers.
  However, all functions must be configured with the same power and
  interface settings.

  The following flags can be specified in Attributes.  DMA and speaker
  control are not supported on all systems.

     CCOONNFF__EENNAABBLLEE__IIRRQQ
        Enable the IO interrupt reserved by a previous call to
        RequestIRQ.

     CCOONNFF__EENNAABBLLEE__DDMMAA
        Enable DMA accesses for this socket.

     CCOONNFF__EENNAABBLLEE__SSPPKKRR
        Enable speaker output from this socket.
  The Present parameter is a bit map specifying which CIS configuration
  registers are implemented by this card.  ConfigBase gives the offset
  of the configuration registers in attribute memory.  The following
  registers can be specified:

     PPRREESSEENNTT__OOPPTTIIOONN
        Specifies that the Configuration Option Register is present.
        The COR register will be set using the ConfigIndex parameter.

     PPRREESSEENNTT__SSTTAATTUUSS
        Specifies that the Card Configuration and Status Register is
        present.  The CCSR will be initialized with the Status
        parameter.

     PPRREESSEENNTT__PPIINN__RREEPPLLAACCEE
        Specifies that the Pin Replacement Register is present.  The PRR
        will be initialized with the Pin parameter.

     PPRREESSEENNTT__CCOOPPYY
        Specifies that the Socket and Copy Register is present.  The SCR
        will be initialized with the Copy parameter.

     PPRREESSEENNTT__EEXXTT__SSTTAATTUUSS
        Specifies that the Extended Status Register is present.  The ESR
        will be initialized with the ExtStatus parameter.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__NNOO__CCAARRDD
        The socket assigned to this client is currently vacant.

     CCSS__OOUUTT__OOFF__RREESSOOUURRCCEE
        Card Services was unable to allocate a memory window to access
        the card's configuration registers.

     CCSS__CCOONNFFIIGGUURRAATTIIOONN__LLOOCCKKEEDD
        This card's configuration has already been locked by another
        call to RequestConfiguration.

     CCSS__BBAADD__VVCCCC
        The requested Vcc voltage is not supported.

     CCSS__BBAADD__VVPPPP
        The requested Vpp1/Vpp2 voltage is not supported.

  33..33..66..  MMooddiiffyyCCoonnffiigguurraattiioonn

       int CardServices(ModifyConfiguration, client_handle_t client, modconf_t *mod);

  The modconf_t structure is given by:

  typedef struct modconf_t {
          u_long          Attributes;
          u_long          Vcc, Vpp1, Vpp2;
  } modconf_t;

  ModifyConfiguration modifies some attributes of a socket that has been
  configured by a call to RequestConfiguration.

  The following flags can be specified in Attributes:

     CCOONNFF__IIRRQQ__CCHHAANNGGEE__VVAALLIIDD
        Indicates that the CONF_ENABLE_IRQ setting should be updated.

     CCOONNFF__EENNAABBLLEE__IIRRQQ
        Specifies that IO interrupts should be enabled for this socket.

     CCOONNFF__VVCCCC__CCHHAANNGGEE__VVAALLIIDD
        Indicates that Vcc should be updated.

     CCOONNFF__VVPPPP11__CCHHAANNGGEE__VVAALLIIDD
        Indicates that Vpp1 should be updated.

     CCOONNFF__VVPPPP22__CCHHAANNGGEE__VVAALLIIDD
        Indicates that Vpp2 should be updated.

  Currently, Vpp1 and Vpp2 must always have the same value.  So, the two
  values must always be changed at the same time.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__NNOO__CCAARRDD
        The socket assigned to this client is currently vacant.

     CCSS__CCOONNFFIIGGUURRAATTIIOONN__LLOOCCKKEEDD
        This actually means that this socket has nnoott been locked.

     CCSS__BBAADD__VVCCCC
        The requested Vcc voltage is not supported.

     CCSS__BBAADD__VVPPPP
        The requested Vpp1/Vpp2 voltage is not supported.

  33..33..77..  RReelleeaasseeCCoonnffiigguurraattiioonn

       int CardServices(ReleaseConfiguration, client_handle_t client, config_req_t *req);

  ReleaseConfiguration un-configures a socket previously set up by a
  call to RequestConfiguration.  The req parameter should be the same
  one used to configure the socket.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The window handle is invalid, or the socket is not configured.

  33..33..88..  GGeettCCoonnffiigguurraattiioonnIInnffoo

       int CardServices(GetConfigurationInfo, client_handle_t client, config_info_t *config);

  The config_info_t structure is given by:

       typedef struct config_info_t {
               u_char          Function;
               u_long          Attributes;
               u_long          Vcc, Vpp1, Vpp2;
               u_long          IntType;
               caddr_t         ConfigBase;
               u_char          Status, Pin, Copy, Option, ExtStatus;
               u_long          Present;
               u_long          AssignedIRQ;
               u_long          IRQAttributes;
               ioaddr_t        BasePort1;
               ioaddr_t        NumPorts1;
               u_long          Attributes1;
               ioaddr_t        BasePort2;
               ioaddr_t        NumPorts2;
               u_long          Attributes2;
               u_long          IOAddrLines;
       } config_info_t;

  GetConfigurationInfo returns the current socket configuration as it
  was set up by RequestIO, RequestIRQ, and RequestConfiguration.  It can
  only be applied to a fully configured socket.  For normal clients
  bound to a single card function, the Function field is ignored, and
  data for that client's assigned function is returned.  For clients
  bound to BIND_FN_ALL, this field specifies which function's
  configuration data should be returned.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The window handle is invalid, or the socket is not configured.

     CCSS__NNOO__CCAARRDD
        The socket assigned to this client is currently vacant.

     CCSS__CCOONNFFIIGGUURRAATTIIOONN__LLOOCCKKEEDD
        This actually means that the configuration has nnoott been locked.

  33..44..  CCaarrdd IInnffoorrmmaattiioonn SSttrruuccttuurree ((CCIISS)) ccaallllss

  The definition of the Card Information Structure (CIS) is the darkest
  chapter of the PCMCIA standard.  All version 2 PCMCIA cards should
  have a CIS, which describes the card and how it should be configured.
  The CIS is a linked list of ``tuples'' in the card's attribute memory
  space.  Each tuple consists of an identification code, a length byte,
  and a series of data bytes.  The layout of the data bytes for some
  tuple types is absurdly complicated, in an apparent effort to use
  every last bit.

  The ValidateCIS call checks to see if a card has a reasonable CIS.
  The GetFirstTuple and GetNextTuple calls are used to step through CIS
  tuple lists.  GetTupleData extracts data bytes from a tuple.  And
  ParseTuple interprets a limited number of particularly important tuple
  types.

  33..44..11..  GGeettFFiirrssttTTuuppllee,, GGeettNNeexxttTTuuppllee

       #include "cistpl.h"

       int CardServices(GetFirstTuple, client_handle_t client, tuple_t *tuple);
       int CardServices(GetNextTuple, client_handle_t client, tuple_t *tuple);

  The tuple_t data structure is given by:

       typedef struct tuple_t {
               u_long          Attributes;
               cis_data_t      DesiredTuple;
               u_long          Flags;
               cisdata_t       TupleCode;
               u_long          TupleLink;
               cisdata_t       TupleOffset;
               cisdata_t       TupleDataMax;
               cisdata_t       TupleDataLen;
               cisdata_t       *TupleData;
       } tuple_t;

  GetFirstTuple searches a card's CIS for the first tuple code matching
  DesiredTuple.  The special code RETURN_FIRST_TUPLE will match the
  first tuple of any kind.  If successful, TupleCode is set to the code
  of the first matching tuple found, and TupleLink is the address of
  this tuple in attribute memory.

  GetNextTuple is like GetFirstTuple, except that given a tuple_t
  structure returned by a previous call to GetFirstTuple or
  GetNextTuple, it will return the next tuple matching DesiredTuple.

  These functions will automatically traverse any link tuples found in
  the CIS.  For multifunction cards having a CISTPL_LONGLINK_MFC tuple,
  these functions will automatically follow just the CIS chain specific
  to a client driver's assigned function.  If a client was bound to
  BIND_FN_ALL, then all tuples will be returned.

  The following flags can be specified in Attributes:

     TTUUPPLLEE__RREETTUURRNN__LLIINNKK
        Indicates that link tuples (CISTPL_LONGLINK_A,
        CISTPL_LONGLINK_C, CISTPL_LONGLINK_MFC, CISTPL_NOLINK,
        CISTPL_LINKTARGET) should be returned.  Normally these tuples
        are processed silently.

     TTUUPPLLEE__RREETTUURRNN__CCOOMMMMOONN
        Indicates that tuples in the ``common'' CIS section of a
        multifunction CIS should be returned.  In the absence of this
        flag, normally, Card Services will only return tuples specific
        to the function bound to the client.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__OOUUTT__OOFF__RREESSOOUURRCCEE
        Card Services was unable to set up a memory window to map the
        card's CIS.

     CCSS__NNOO__MMOORREE__IITTEEMMSS
        There were no tuples matching DesiredTuple.

  33..44..22..  GGeettTTuupplleeDDaattaa

       #include "cistpl.h"

       int CardServices(GetTupleData, client_handle_t client, tuple_t *tuple);

  GetTupleData extracts a series of data bytes from the specified tuple,
  which must have been returned by a previous call to GetFirstTuple or
  GetNextTuple.  A maximum of TupleDataMax bytes will be copied into the
  TupleData buffer, starting at an offset of TupleOffset bytes.  The
  number of bytes copied is returned in TupleDataLen.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__OOUUTT__OOFF__RREESSOOUURRCCEE
        Card Services was unable to set up a memory window to map the
        card's CIS.

     CCSS__NNOO__MMOORREE__IITTEEMMSS
        The tuple does not contain any more data.  TuppleOffset is
        greater than or equal to the length of the tuple.

  33..44..33..  PPaarrsseeTTuuppllee

       #include "cistpl.h"

       int CardServices(ParseTuple, client_handle_t client, tuple_t *tuple, cisparse_t *parse);

  The cisparse_t data structure is given by:
       typedef union cisparse_t {
               cistpl_device_t         device;
               cistpl_checksum_t       checksum;
               cistpl_longlink_t       longlink;
               cistpl_longlink_mfc_t   longlink_mfc;
               cistpl_vers_1_t         version_1;
               cistpl_altstr_t         altstr;
               cistpl_jedec_t          jedec;
               cistpl_manfid_t         manfid;
               cistpl_funcid_t         funcid;
               cistpl_config_t         config;
               cistpl_cftable_entry_t  cftable_entry;
               cistpl_device_geo_t     device_geo;
               cistpl_vers_2_t         version_2;
               cistpl_org_t            org;
       } cisparse_t;

  ParseTuple interprets tuple data returned by a previous call to
  GetTupleData.  The structure returned depends on the type of the
  parsed tuple.  See the cistpl.h file for these structure definitions;
  some of them are quite complex.

  Return codes:

     CCSS__BBAADD__TTUUPPLLEE
        An error was encounted during parsing of this tuple.  The tuple
        may be incomplete, or may be formatted incorrectly.

     CCSS__UUNNSSUUPPPPOORRTTEEDD__FFUUNNCCTTIIOONN
        ParseTuple cannot parse the specified tuple type.

  33..44..44..  VVaalliiddaatteeCCIISS

       int CardServices(ValidateCIS, client_handle_t client, cisinfo_t *cisinfo);

  The cisinfo_t structure is given by:

       typedef struct cisinfo_t {
               u_long          Chains;
       } cisinfo_t;

  ValidateCIS attempts to verify that a card has a reasonable Card
  Information Structure.  It returns the number of tuples found in
  Chains.  If the CIS appears to be uninterpretable, Chains will be set
  to 0.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__OOUUTT__OOFF__RREESSOOUURRCCEE
        Card Services was unable to set up a memory window to map the
        card's CIS.

  33..55..  MMeemmoorryy wwiinnddooww ccoonnttrrooll

  Each socket can have up to four active memory windows, mapping
  portions of PCMCIA memory into the host system address space.  A
  PCMCIA device can address at most 16MB of both common and attribute
  memory.  Windows should typically be sized to a power of two, and be
  aligned on a boundary that is a multiple of the window size in both
  the host and card address spaces.

  A memory window is initialized by a call to RequestWindow.  Some
  window attributes can be modified using ModifyWindow.  The segment of
  card memory mapped to the window can be modified using MapMemPage.
  And windows are released with ReleaseWindow.  Unlike almost all other
  Card Services subfunctions, the memory window functions normally act
  on window_handle_t handles, rather than client_handle_t handles.

  33..55..11..  RReeqquueessttWWiinnddooww

       int CardServices(RequestWindow, client_handle_t *handle, win_req_t *req);

  The win_req_t structure is given by:

       typedef struct win_req_t {
               u_long          Attributes;
               caddr_t         Base;
               u_long          Size;
               u_long          AccessSpeed;
       } win_req_t;

  RequestWindow maps a window of card memory into system memory.  On
  entry, the handle parameter should point to a valid client handle.  On
  return, this will be replaced by a window_handle_t handle that should
  be used in subsequent calls to ModifyWindow, MapMemPage, and
  ReleaseWindow.

  The following flags can be specified in Attributes:

     WWIINN__MMEEMMOORRYY__TTYYPPEE
        This field can be either WIN_MEMORY_TYPE_CM for common memory,
        or WIN_MEMORY_TYPE_AM for attribute memory.

     WWIINN__DDAATTAA__WWIIDDTTHH
        Either WIN_DATA_WIDTH_16 for 16-bit accesses, or
        WIN_DATA_WIDTH_8 for 8-bit access.

     WWIINN__EENNAABBLLEE
        If this is set, the window is turned on.

     WWIINN__UUSSEE__WWAAIITT
        Specifies that the controller should observe the card's MWAIT
        signal.

  Base specifies the base address of the window in system memory.  If
  NULL, Card Services will set Base to the first available window
  address.  Size specifies the window size in bytes.  AccessSpeed
  specifies the memory access speed, in nanoseconds.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__NNOO__CCAARRDD
        The socket assigned to this client is currently vacant.

     CCSS__BBAADD__AATTTTRRIIBBUUTTEE
        An unsupported window attribute was requested.

     CCSS__OOUUTT__OOFF__RREESSOOUURRCCEE
        The maximum number of memory windows for this socket are already
        being used.

     CCSS__IINN__UUSSEE
        RequestWindow was unable to find a free window of system memory.

  33..55..22..  MMooddiiffyyWWiinnddooww

       int CardServices(ModifyWindow, window_handle_t, modwin_t *);

  The modwin_t structure is given by:

       typedef struct modwin_t {
               u_long          Attributes;
               u_long          AccessSpeed;
       } modwin_t;

  ModifyWindow modifies the attributes of a window handle returned by a
  previous call to RequestWindow.  The following attributes can be
  changed:

     WWIINN__MMEEMMOORRYY__TTYYPPEE
        This field can be either WIN_MEMORY_TYPE_CM for common memory,
        or WIN_MEMORY_TYPE_AM for attribute memory.

     WWIINN__DDAATTAA__WWIIDDTTHH
        Either WIN_DATA_WIDTH_16 for 16-bit accesses, or
        WIN_DATA_WIDTH_8 for 8-bit access.

     WWIINN__EENNAABBLLEE
        If this is set, the window is turned on.

  AccessSpeed gives the new memory access speed, in nanoseconds.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The window handle is invalid.

  33..55..33..  MMaappMMeemmPPaaggee

       int CardServices(MapMemPage, window_handle_t, memreq_t *);

  The memreq_t structure is given by:

       typedef struct memreq_t {
               u_long          CardOffset;
               page_t          Page;
       } memreq_t;

  MapMemPage sets the address of card memory that is mapped to the base
  of a memory window to CardOffset.  The window should have been created
  by a call to RequestWindow.  The Page parameter is not implemented in
  this version and should be set to 0.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The window handle is invalid.

     CCSS__BBAADD__PPAAGGEE
        The Page value was non-zero.

  33..55..44..  RReelleeaasseeWWiinnddooww

       int CardServices(ReleaseWindow, window_handle_t handle);

  ReleaseWindow releases a memory window previously allocated with
  RequestWindow.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The window handle is invalid.

  33..66..  BBuullkk MMeemmoorryy SSeerrvviicceess

  Bulk memory services provide a higher level interface for accessing
  memory regions than that provided by the memory window services.  A
  client using bulk memory calls does not need to know anything about
  the underlying memory organization or access methods.  The device-
  specific code is packaged into a special Card Services client called a
  Memory Technology Driver.

  33..66..11..  RReeggiisstteerrMMTTDD

       int CardServices(RegisterMTD, client_handle_t handle, mtd_reg_t *reg);

  The mtd_reg_t data structure is given by:

       typedef union mtd_reg_t {
               u_long          Attributes;
               u_long          Offset;
               u_long          MediaID;
       } mtd_reg_t;

  RegisterMTD informs Card Services that this client MTD will handle
  requests for a specified memory region.  The Offset field specifies
  the starting address of the memory region.  The following fields are
  defined in Attributes:

     RREEGGIIOONN__TTYYPPEE
        Either REGION_TYPE_CM for common memory, or REGION_TYPE_AM for
        attribute memory.

  The MediaID field is recorded by Card Services, and will be passed to
  the MTD as part of any request that references this memory region.

  Once an MTD is bound to a memory region by a call to RegisterMTD, it
  will remain bound until the MTD calls DeregisterClient.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__BBAADD__OOFFFFSSEETT
        Either the offset does not match a valid memory region for this
        card, or another MTD has already registered for this region.

  33..66..22..  GGeettFFiirrssttRReeggiioonn,, GGeettNNeexxttRReeggiioonn

       int CardServices(GetFirstRegion, client_handle_t handle, region_info_t *region);
       int CardServices(GetNextRegion, client_handle_t handle, region_info_t *region);

  The region_info_t data structure is given by:

  typedef union region_info_t {
          u_long          Attributes;
          u_long          CardOffset;
          u_long          RegionSize;
          u_long          AccessSpeed;
          u_long          BlockSize;
          u_long          PartMultiple;
          u_char          JedecMfr, JedecInfo;
          memory_handle_t next;
  } region_info_t;

  GetFirstRegion and GetNextRegion summarize the information in a card's
  CISTPL_DEVICE, CISTPL_JEDEC, and CISTPL_DEVICE_GEO tuples.  CardOffset
  gives the starting address of a region. RegionSize gives the length of
  the region in bytes.  AccessSpeed gives the device's cycle time in
  nanoseconds.  BlockSize gives the erase block size in bytes, and
  PartMultiple gives the minimum granularity of partitions on this
  device, in units of BlockSize.  JedecMfr and JedecInfo give the JEDEC
  identification bytes for this region.

  The following fields are defined in Attributes:

     RREEGGIIOONN__TTYYPPEE
        Either REGION_TYPE_CM for common memory, or REGION_TYPE_AM for
        attribute memory.

  When these calls are made by an MTD client, only regions that have
  been bound to this client through calls to BindMTD will be returned.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__NNOO__MMOORREE__IITTEEMMSS
        No more memory regions are defined.

  33..66..33..  OOppeennMMeemmoorryy

       int CardServices(OpenMemory, client_handle_t *handle, open_mem_t *req);

  The open_mem_t structure is given by:

       typedef struct open_mem_t {
               u_long          Attributes;
               u_long          Offset;
       } open_mem_t;

  OpenMemory is used to obtain a handle for accessing a memory region
  via the other bulk memory services.  The Offset field specifies the
  base address of the region to be accessed.  If successful, the client
  handle argument is replaced by the new memory handle.

  The following fields are defined in Attributes:

     MMEEMMOORRYY__TTYYPPEE
        Either MEMORY_TYPE_CM for common memory, or MEMORY_TYPE_AM for
        attribute memory.

     MMEEMMOORRYY__EEXXCCLLUUSSIIVVEE
        Specifies that this client should have exclusive access to this
        memory region.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The window handle is invalid.

     CCSS__BBAADD__OOFFFFSSEETT
        Either the offset does not specify a valid region, or the region
        does not have an associated MTD to service bulk memory requests.

  33..66..44..  CClloosseeMMeemmoorryy

       int CardServices(CloseMemory, memory_handle_t handle);

  CloseMemory releases a memory handle returned by a previous call to
  OpenMemory.  A client should release all memory handles before calling
  DeregisterClient.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The memory handle is invalid.

  33..66..55..  RReeaaddMMeemmoorryy,, WWrriitteeMMeemmoorryy

       int CardServices(ReadMemory, memory_handle_t handle mem_op_t *req, caddr_t buf);
       int CardServices(WriteMemory, memory_handle_t handle, mem_op_t *req, caddr_t buf);

  The mem_io_t structure is given by:

       typedef struct mem_op_t {
               u_long          Attributes;
               u_long          Offset;
               u_long          Count;
       } mem_op_t;

  ReadMemory and WriteMemory read from and write to a card memory area
  defined by the specified memory handle, returned by a previous call to
  OpenMemory.  The Offset field gives the offset of the operation from
  the start of the card memory region.  The Count field gives the number
  of bytes to be transferred.  The buf field points to a host memory
  buffer to be the destination for a ReadMemory operation, or the source
  for a WriteMemory operation.

  The following fields are defined in Attributes:

     MMEEMM__OOPP__BBUUFFFFEERR
        Either MEM_OP_BUFFER_USER if the host buffer is in a user memory
        segment, or MEM_OP_BUFFER_KERNEL if the host buffer is in kernel
        memory.

     MMEEMM__OOPP__DDIISSAABBLLEE__EERRAASSEE
        Specifies that a card area should not be erased before it is
        written.

     MMEEMM__OOPP__VVEERRIIFFYY
        Specifies verification of write operations.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The window handle is invalid.

     CCSS__BBAADD__OOFFFFSSEETT
        The specified card offset is beyond the end of the memory
        region.

     CCSS__BBAADD__SSIIZZEE
        The specified transfer size extends past the end of the memory
        region.

  33..66..66..  RReeggiisstteerrEErraasseeQQuueeuuee

       int CardServices(RegisterEraseQueue, client_handle_t *handle, eraseq_hdr_t *header);

  The eraseq_hdr_t structure is given by:

       typedef struct erase_queue_header_t {
               int             QueueEntryCount;
               eraseq_entry_t  *QueueEntryArray;
       } eraseq_hdr_t;

  This call registers a queue of erase requests with Card Services.  An
  eraseq_handle_t handle will be returned in *handle.  When this client
  calls CheckEraseQueue, Card Services will scan the queue and begin
  asynchronous processing of any new requests.

  The eraseq_entry_t structure is given by:

  typedef struct eraseq_entry_t {
          memory_handle_t Handle;
          u_char          State;
          u_long          Size;
          u_long          Offset;
          u_long          *Optional;
  } eraseq_entry_t;

  In an erase queue entry, the Header field should be a memory handle
  returned by a previous call to OpenMemory.  The State field indicates
  the state of the erase request.  The following values are defined:

     EERRAASSEE__QQUUEEUUEEDD
        Set by the client to indicate that this is a new request.

     EERRAASSEE__IIDDLLEE
        Set by the client to indicate that this entry is not active.

     EERRAASSEE__PPAASSSSEEDD
        Set by the MTD to indicate successful completion.

     EERRAASSEE__FFAAIILLEEDD
        Set by the MTD to indicate that the erase failed.

     EERRAASSEE__MMEEDDIIAA__WWRRPPRROOTT
        Indicates that the region is write protected.

     EERRAASSEE__NNOOTT__EERRAASSAABBLLEE
        Indicates that this region does not support erase operations.

     EERRAASSEE__BBAADD__OOFFFFSSEETT
        Indicates that the erase does not start on an erase block
        boundary.

     EERRAASSEE__BBAADD__SSIIZZEE
        Indicates that the requested erase size is not a multiple of the
        erase block size.

     EERRAASSEE__BBAADD__SSOOCCKKEETT
        Set by the MTD to indicate that there is no card present.

  Additionally, the macro ERASE_IN_PROGRESS() will return a true
  condition for values of State that indicate an erase is being
  processed.

  The Size field gives the size of the erase request in bytes.  The
  Offset field gives the offset from the start of the region.  The size
  and offset should be aligned to erase block boundaries.  The Optional
  field is not used by Card Services and may be used by the client
  driver.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

  33..66..77..  DDeerreeggiisstteerrEErraasseeQQuueeuuee

  int CardServices(DeregisterEraseQueue, eraseq_handle_t handle);

  DeregisterEraseQueue frees a queue previously registered by a call to
  RegisterEraseQueue.  If there are any pending requests in the
  specified queue, the call will fail.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The erase queue handle is invalid.

     CCSS__BBUUSSYY
        The erase queue has erase requests pending.

  33..66..88..  CChheecckkEErraasseeQQuueeuuee

       int CardServices(CheckEraseQueue, eraseq_handle_t handle);

  This call notifies Card Services that there are new erase requests in
  a queue previously registered with RegisterEraseQueue.

  Typically, a client will initially assign each erase queue entry the
  state value ERASE_IDLE.  When new requests are added to the queue, the
  client will set their states to ERASE_QUEUED, and call
  CheckEraseQueue.  When the client is notified of an erase completion
  event, it will check the state field to determine whether the request
  was successful.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The erase queue handle is invalid.

  33..77..  MMiisscceellllaanneeoouuss ccaallllss

  33..77..11..  GGeettCCaarrddSSeerrvviicceessIInnffoo

       int CardServices(GetCardServicesInfo, servinfo_t *info);

  The servinfo_t structure is given by:

  typedef struct servinfo_t {
          char            Signature[2];
          u_long          Count;
          u_long          Revision;
          u_long          CSLevel;
          char            *VendorString;
  } servinfo_t;

  GetCardServicesInfo returns revision information about this version of
  Card Services.  Signature is set to ``CS''.  Count is set to the
  number of sockets currently configured.  Revision is set to the
  revision level of the Card Services package, and CSLevel is set to the
  level of compliance with the PCMCIA standard.  These are encoded as
  BCD numbers.  VendorString is set to point to an RCS identification
  string.

  This call always succeeds.

  33..77..22..  AAcccceessssCCoonnffiigguurraattiioonnRReeggiisstteerr

       #include "cisreg.h"

       int CardServices(AccessConfigurationRegister, client_handle_t handle, conf_reg_t *reg);

  The conf_reg_t structure is given by:

       typedef struct conf_reg_t {
               u_char          Function;
               u_long          Action;
               off_t           Offset;
               u_long          Value;
       } conf_reg_t;

  For normal clients bound to a specific card function, the Function
  field is ignored.  For clients bound to BIND_FN_ALL, this field
  specifies which function's configuration registers should be accessed.

  The Action parameter can be one of the following:

     CCSS__RREEAADD
        Read the specified configuration register and return Value.

     CCSS__WWRRIITTEE
        Write Value to the specified configuration register.

  AccessConfigurationRegister either reads or writes the one-byte CIS
  configuration register at offset Offset from the start of the config
  register area.  It can only be used for a socket that has been
  configured with RequestConfiguration.

  The following values for Offset are defined in cistpl.h:

     CCIISSRREEGG__CCOORR
        The Configuration Option Register.

     CCIISSRREEGG__CCCCSSRR
        The Card Configuration and Status Register.

     CCIISSRREEGG__PPRRRR
        The Pin Replacement Register.

     CCIISSRREEGG__SSCCRR
        The Socket and Copy Register.

     CCIISSRREEGG__EESSRR
        The Extended Status Register.

     CCIISSRREEGG__IIOOBBAASSEE00..CISREG_IOBASE3
        The I/O Base Registers.

     CCIISSRREEGG__IIOOSSIIZZEE
        The I/O Size Register.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__BBAADD__AARRGGSS
        The specified Action is not supported.

     CCSS__CCOONNFFIIGGUURRAATTIIOONN__LLOOCCKKEEDD
        This actually means that the configuration has nnoott been locked.

     CCSS__OOUUTT__OOFF__RREESSOOUURRCCEE
        Card Services was unable to allocate a memory window to access
        the card's configuration registers.

  33..77..33..  AAddjjuussttRReessoouurrcceeIInnffoo

       int CardServices(AdjustResourceInfo, client_handle_t handle, adjust_t *adj);

  The adjust_t structure is given by:

  typedef struct adjust_t {
          u_long          Action;
          u_long          Resource;
          u_long          Attributes;
          union {
                  struct memory {
                          caddr_t         Base;
                          u_long          Size;
                  } memory;
                  struct io {
                          ioaddr_t        BasePort;
                          ioaddr_t        NumPorts;
                          u_long          IOAddrLines;
                  } io;
                  struct irq {
                          u_long          IRQ;
                  } irq;
          } resource;
  } adjust_t;

  AdjustResourceInfo is used to tell Card Services what resources may or
  may not be allocated by PCMCIA devices.  The normal Linux resource
  management systems (the *_region calls for IO ports, interrupt
  allocation) are respected by Card Services, but this call gives the
  user another level of control.

  The Action parameter can have the following values:

     AADDDD__MMAANNAAGGEEDD__RREESSOOUURRCCEE
        Place the specified resource under Card Services control, so
        that it may be allocated by PCMCIA devices.

     RREEMMOOVVEE__MMAANNAAGGEEDD__RREESSOOUURRCCEE
        Remove the specified resource from Card Services control.

  At initialization time, Card Services assumes that it can use all
  available interrupts, but IO ports and memory regions must be
  explicitly enabled with ADD_MANAGED_RESOURCE.

  The Resource parameter can have the following values:

     RREESS__MMEEMMOORRYY__RRAANNGGEE
        Specifies a memory range resource, described by
        adj->resource.memory.

     RREESS__IIOO__RRAANNGGEE
        Specifies an IO port resource, described by adj->resource.io.

     RREESS__IIRRQQ
        Specifies an interrupt resource, described by adj->resource.irq.

  The following flags may be specified in Attributes:

     RREESS__RREESSEERRVVEEDD
        Indicates that the resource should be reserved for PCMCIA
        devices that specifically request it.  The resource will not be
        allocated for a device that asks Card Services for any available
        location.  This is not implemented yet.

  Return codes:

     CCSS__UUNNSSUUPPPPOORRTTEEDD__FFUUNNCCTTIIOONN
        The specified Action or Resource is not supported.
     CCSS__BBAADD__BBAASSEE
        The specified IO address is out of range.

     CCSS__BBAADD__SSIIZZEE
        The specified memory or IO window size is out of range.

     CCSS__IINN__UUSSEE
        The specified interrupt is currently allocated by a Card
        Services client.

  33..77..44..  RReeppoorrttEErrrroorr

       int CardServices(ReportError, char *prefix, int func, int ret);

  ReportError generates a kernel error message given a Card Services
  function code and its return code, with an optional prefix string.
  For example:

       CardServices(ReportError, "serial_cs", RequestIO, CS_BAD_HANDLE);

  would generate the following message:

       serial_cs: RequestIO: Bad handle

  This call always succeeds.

  44..  CCaarrdd IInnffoorrmmaattiioonn SSttrruuccttuurree DDeeffiinniittiioonnss

  44..11..  CCIISS TTuuppllee DDeeffiinniittiioonnss

  The Card Services ParseTuple function interprets raw CIS tuple data
  from a call to GetTupleData and returns the tuple contents in a form
  dependant on the tuple type.

       #include "cistpl.h"

  44..11..11..  CCIISSTTPPLL__CCHHEECCKKSSUUMM

  The cistpl_checksum_t structure is given by:

       typedef struct cistpl_checksum_t {
               u_short         addr;
               u_short         len;
               u_char          sum;
       } cistpl_checksum_t;

  44..11..22..  CCIISSTTPPLL__NNOOLLIINNKK CCIISSTTPPLL__LLOONNGGLLIINNKK__AA,, CCIISSTTPPLL__LLOONNGGLLIINNKK__CC,,
  CCIISSTTPPLL__LLIINNKKTTAARRGGEETT,,

  The cistpl_longlink_t structure is given by:

       typedef struct cistpl_longlink_t {
               u_long          addr;
       } cistpl_longlink_t;

  These tuples are pointers to additional chains of CIS tuples, either
  in attribute or common memory.  Each CIS tuple chain can have at most
  one long link.  CISTPL_LONGLINK_A tuples point to attribute memory,
  and CISTPL_LONGLINK_C tuples point to common memory.  The standard CIS
  chain starting at address 0 in attribute memory has an implied long
  link to address 0 in common memory.  A CISTPL_NOLINK tuple can be used
  to cancel this default link.

  The first tuple of a chain pointed to by a long link must be a
  CISTPL_LINKTARGET.  The CS tuple handling code will automatically
  follow long links and verify link targets; these tuples are normally
  invisible unless the TUPLE_RETURN_LINK attribute is specified in
  GetNextTuple.

  44..11..33..  CCIISSTTPPLL__LLOONNGGLLIINNKK__MMFFCC

  The cistpl_longlink_mfc_t structure is given by:

       typedef struct cistpl_longlink_mfc_t {
               int     nfn;
               struct {
                       u_char  space;
                       u_long  addr;
               } fn[CISTPL_MAX_FUNCTIONS;
       } cistpl_longlink_mfc_t;

  This tuple identifies a multifunction card, and specifies long link
  pointers to CIS chains specific for each function.  The space field is
  either CISTPL_MFC_ATTR or CISTPL_MFC_COMMON for attribute or common
  memory space.

  44..11..44..  CCIISSTTPPLL__DDEEVVIICCEE,, CCIISSTTPPLL__DDEEVVIICCEE__AA

  The cistpl_device_t structure is given by:

       typedef struct cistpl_device_t {
               int             ndev;
               struct device_info {
                       u_char          type;
                       u_char          wp;
                       u_long          speed;
                       u_long          size;
               } dev[CISTPL_MAX_DEVICES];
       } cistpl_device_t;

  The CISTPL_DEVICE tuple describes address regions in a card's common
  memory.  The CISTPL_DEVICE_A tuple describes regions in attribute
  memory.  The type flag indicates the type of memory device for this
  region.  The wp flag indicates if this region is write protected.  The
  speed field is in nanoseconds, and size is in bytes.  Address regions
  are assumed to be ordered consecutively starting with address 0.  The
  following device types are defined:

     CCIISSTTPPLL__DDTTYYPPEE__NNUULLLL
        Specifies that there is no device, or a ``hole'' in the card
        address space.

     CCIISSTTPPLL__DDTTYYPPEE__RROOMM
        Masked ROM

     CCIISSTTPPLL__DDTTYYPPEE__OOTTPPRROOMM
        One-type programmable ROM.

     CCIISSTTPPLL__DDTTYYPPEE__EEPPRROOMM
        UV erasable PROM.

     CCIISSTTPPLL__DDTTYYPPEE__EEEEPPRROOMM
        Electrically erasable PROM.

     CCIISSTTPPLL__DDTTYYPPEE__FFLLAASSHH
        Flash EPROM.

     CCIISSTTPPLL__DDTTYYPPEE__SSRRAAMM
        Static or non-volatile RAM.

     CCIISSTTPPLL__DDTTYYPPEE__DDRRAAMM
        Dynamic or volatile RAM.

     CCIISSTTPPLL__DDTTYYPPEE__FFUUNNCCSSPPEECC
        Specifies a function-specific device, such as a memory-mapped IO
        device or buffer, as opposed to general purpose storage.

     CCIISSTTPPLL__DDTTYYPPEE__EEXXTTEENNDD
        Specifies an extended device type.  This type is reserved for
        future use.

  44..11..55..  CCIISSTTPPLL__VVEERRSS__11

  The cistpl_vers_1_t structure is given by:

       typedef struct cistpl_vers_1_t {
               u_char          major;
               u_char          minor;
               int             ns;
               int             ofs[CISTPL_VERS_1_MAX_PROD_STRINGS];
               char            str[254];
       } cistpl_vers_1_t;

  The ns field specifies the number of product information strings in
  the tuple.  The string data is contained in the str array.  Each
  string is null terminated, and ofs gives the offset to the start of
  each string.

  44..11..66..  CCIISSTTPPLL__AALLTTSSTTRR

  The cistpl_altstr_t structure is given by:

       typedef struct cistpl_altstr_t {
               int             ns;
               int             ofs[CISTPL_ALTSTR_MAX_STRINGS];
               char            str[254];
       } cistpl_altstr_t;

  The ns field specifies the number of alternate language strings in the
  tuple.  The string data is contained in the str array.  Each string is
  null terminated, and ofs gives the offset to the start of each string.

  44..11..77..  CCIISSTTPPLL__JJEEDDEECC__CC,, CCIISSTTPPLL__JJEEDDEECC__AA

  The cistpl_jedec_t structure is given by:

       typedef struct cistpl_jedec_t {
               int             nid;
               struct jedec_id {
                       u_char  mfr;
                       u_char  info;
               } id[CISTPL_MAX_DEVICES];
       } cistpl_jedec_t;

  JEDEC identifiers describe the specific device type used to implement
  a region of PCMCIA memory.  The nid field specifies the number of
  JEDEC identifiers in the tuple.  There should be a one-to-one
  correspondence between JEDEC identifiers and device descriptions in
  the corresponding CISTPL_DEVICE tuple.

  44..11..88..  CCIISSTTPPLL__CCOONNFFIIGG

  The cistpl_config_t structure is given by:

       typedef struct cistpl_config_t {
               u_char          last_idx;
               u_long          base;
               u_long          rmask[4];
               u_char          subtuples;
       } cistpl_config_t;

  The last_idx field gives the index of the highest numbered
  configuration table entry.  The base field gives the offset of a
  card's configuration registers in attribute memory.  The rmask array
  is a series of bit masks indicating which configuration registers are
  present.  Bit 0 of rmask0 is for the COR, bit 1 is for the CCSR, and
  so on.  The subtuples field gives the number of bytes of subtuples
  following the normal tuple contents.

  44..11..99..  CCIISSTTPPLL__CCFFTTAABBLLEE__EENNTTRRYY

  The cistpl_cftable_entry_t structure is given by:

       typedef struct cistpl_cftable_entry_t {
               u_char          index;
               u_char          flags;
               u_char          interface;
               cistpl_power_t  vcc, vpp1, vpp2;
               cistpl_timing_t timing;
               cistpl_io_t     io;
               cistpl_irq_t    irq;
               cistpl_mem_t    mem;
               u_char          subtuples;
       } cistpl_cftable_entry_t;

  A CISTPL_CFTABLE_ENTRY structure describes a complete operating mode
  for a card.  Many sections are optional.  The index field gives the
  configuration index for this operating mode; writing this value to the
  card's Configuration Option Register selects this mode.  The following
  fields are defined in flags:

     CCIISSTTPPLL__CCFFTTAABBLLEE__DDEEFFAAUULLTT
        Specifies that this is the default configuration table entry.

     CCIISSTTPPLL__CCFFTTAABBLLEE__BBVVDDSS
        Specifies that this configuration implements the BVD1 and BVD2
        signals in the Pin Replacement Register.

     CCIISSTTPPLL__CCFFTTAABBLLEE__WWPP
        Specifies that this configuration implements the write protect
        signal in the Pin Replacement Register.

     CCIISSTTPPLL__CCFFTTAABBLLEE__RRDDYYBBSSYY
        Specifies that this configuration implements the Ready/Busy
        signal in the Pin Replacement Register.

     CCIISSTTPPLL__CCFFTTAABBLLEE__MMWWAAIITT
        Specifies that the WAIT signal should be observed during memory
        access cycles.

     CCIISSTTPPLL__CCFFTTAABBLLEE__AAUUDDIIOO
        Specifies that this configuration generates an audio signal that
        can be routed to the host system speaker.

     CCIISSTTPPLL__CCFFTTAABBLLEE__RREEAADDOONNLLYY
        Specifies that the card has a memory region that is read-only in
        this configuration.

     CCIISSTTPPLL__CCFFTTAABBLLEE__PPWWRRDDOOWWNN
        Specifies that this configuration supports a power down mode,
        via the Card Configuration and Status Register.

  The cistpl_power_t structure is given by:

       typedef struct cistpl_power_t {
               u_char          present;
               u_char          flags;
               u_long          param[7];
       } cistpl_power_t;

  The present field is bit mapped and indicates which parameters are
  present for this power signal.  The following indices are defined:

     CCIISSTTPPLL__PPOOWWEERR__VVNNOOMM
        The nominal supply voltage.

     CCIISSTTPPLL__PPOOWWEERR__VVMMIINN
        The minimum supply voltage.

     CCIISSTTPPLL__PPOOWWEERR__VVMMAAXX
        The maximum supply voltage.

     CCIISSTTPPLL__PPOOWWEERR__IISSTTAATTIICC
        The continuous supply current required.

     CCIISSTTPPLL__PPOOWWEERR__IIAAVVGG
        The maximum current averaged over one second.

     CCIISSTTPPLL__PPOOWWEERR__IIPPEEAAKK
        The maximum current averaged over 10 ms.

     CCIISSTTPPLL__PPOOWWEERR__IIDDOOWWNN
        The current required in power down mode.

  Voltages are given in units of 10 microvolts.  Currents are given in
  units of 100 nanoamperes.

  The cistpl_timing_t structure is given by:

  typedef cistpl_timing_t {
          u_long          wait, waitscale;
          u_long          ready, rdyscale;
          u_long          reserved, rsvscale;
  } cistpl_timing_t;

  Each time consists of a base time in nanoseconds, and a scale
  multiplier.  Unspecified times have values of 0.

  The cistpl_io_t structure is given by:

       typedef struct cistpl_io_t {
               u_char          flags;
               int             nwin;
               struct {
                       u_long          base;
                       u_long          len;
               } win[CISTPL_IO_MAX_WIN;
       } cistpl_io_t;

  The number of IO windows is given by nwin.  Each window is described
  by a base address, base, and a length in bytes, len.  The following
  bit fields are defined in flags:

     CCIISSTTPPLL__IIOO__LLIINNEESS__MMAASSKK
        The number of IO lines decoded by this card.

     CCIISSTTPPLL__IIOO__88BBIITT
        Indicates that the card supports split 8-bit accesses to 16-bit
        IO registers.

     CCIISSTTPPLL__IIOO__1166BBIITT
        Indicates that the card supports full 16-bit accesses to IO
        registers.

  The cistpl_irq_t structure is given by:

       typedef struct cistpl_irq_t {
               u_long          IRQInfo1;
               u_long          IRQInfo2;
       } cistpl_irq_t;

  The following bit fields are defined in IRQInfo1:

     IIRRQQ__MMAASSKK
        A specific interrupt number that this card should use.

     IIRRQQ__NNMMII__IIDD, IRQ_IOCK_ID, IRQ_BERR_ID,
        IRQ_VEND_ID" When IRQ_INFO2_VALID is set, these indicate if a
        corresponding special interrupt signal may be assigned to this
        card.  The four flags are for the non-maskable, IO check, bus
        error, and vendor specific interrupts.

     IIRRQQ__IINNFFOO22__VVAALLIIDD
        Indicates that IRQInfo2 contains a valid bit mask of allowed
        interrupt request numbers.

     IIRRQQ__LLEEVVEELL__IIDD
        Indicates that the card supports level mode interrupts.

     IIRRQQ__PPUULLSSEE__IIDD
        Indicates that the card supports pulse mode interrupts.

     IIRRQQ__SSHHAARREE__IIDD
        Indicates that the card supports sharing interrupts.

  If IRQInfo1 is 0, then no interrupt information is available.

  The cistpl_mem_t structure is given by:

       typedef struct cistpl_mem_t {
               u_char          nwin;
               struct {
                       u_long          len;
                       u_long          card_addr;
                       caddr_t         host_addr;
               } win[CISTPL_MEM_MAX_WIN;
       } cistpl_mem_t;

  The number of memory windows is given by nwin.  Each window is
  described by an address in the card memory space, card_addr, an
  address in the host memory space, host_addr, and a length in bytes,
  len.  If the host address is 0, the position of the window is
  arbitrary.

  44..11..1100..  CCIISSTTPPLL__MMAANNFFIIDD

  The cistpl_manfid_t structure is given by:

       typedef struct cistpl_manfid_t {
               u_short         manf;
               u_short         card;
       } cistpl_manfid_t;

  The manf field identifies the card manufacturer.  The card field is
  chosen by the vendor and should identify the card type and model.

  44..11..1111..  CCIISSTTPPLL__FFUUNNCCIIDD

  The cistpl_funcid_t structure is given by:

  typedef struct cistpl_funcid_t {
          u_char          func;
          u_char          sysinit;
  } cistpl_funcid_t;

  The func field identifies the card function.  The sysinit field
  contains several bit-mapped flags describing how the card should be
  configured at boot time.

  The following functions are defined:

     CCIISSTTPPLL__FFUUNNCCIIDD__MMUULLTTII
        A multi-function card.

     CCIISSTTPPLL__FFUUNNCCIIDD__MMEEMMOORRYY
        A simple memory device.

     CCIISSTTPPLL__FFUUNNCCIIDD__SSEERRIIAALL
        A serial port or modem device.

     CCIISSTTPPLL__FFUUNNCCIIDD__PPAARRAALLLLEELL
        A parallel port device.

     CCIISSTTPPLL__FFUUNNCCIIDD__FFIIXXEEDD
        A fixed disk device.

     CCIISSTTPPLL__FFUUNNCCIIDD__VVIIDDEEOO
        A video interface.

     CCIISSTTPPLL__FFUUNNCCIIDD__NNEETTWWOORRKK
        A network adapter.

     CCIISSTTPPLL__FFUUNNCCIIDD__AAIIMMSS
        An auto-incrementing mass storage device.

  The following flags are defined in sysinit:

     CCIISSTTPPLL__SSYYSSIINNIITT__PPOOSSTT
        Indicates that the system should attempt to configure this card
        during its power-on initialization.

     CCIISSTTPPLL__SSYYSSIINNIITT__RROOMM
        Indicates that the card contains a system expansion ROM that
        should be configured at boot time.

  44..11..1122..  CCIISSTTPPLL__DDEEVVIICCEE__GGEEOO

  The cistpl_device_geo_t structure is given by:

  typedef struct cistpl_device_geo_t {
          int             ngeo;
          struct geo {
                  u_char          buswidth;
                  u_long          erase_block;
                  u_long          read_block;
                  u_long          write_block;
                  u_long          partition;
                  u_long          interleave;
          } geo[CISTPL_MAX_DEVICES];
  } cistpl_device_geo_t;

  The erase_block, read_block, and write_block sizes are in units of
  buswidth bytes times interleave.  The partition size is in units of
  erase_block.

  44..11..1133..  CCIISSTTPPLL__VVEERRSS__22

  The cistpl_vers_2_t structure is given by:

       typedef struct cistpl_vers_2_t {
               u_char          vers;
               u_char          comply;
               u_short         dindex;
               u_char          vspec8, vspec9;
               u_char          nhdr;
               int             vendor, info;
               char            str[244];
       } cistpl_vers_2_t;

  The vers field should always be 0.  The comply field indicates the
  degree of standard compliance and should also be 0.  The dindex field
  reserves the specified number of bytes at the start of common memory.
  The vspec8 and vspec9 fields may contain vendor-specific information.
  The nhdr field gives the number of copies of the CIS that are present
  on this card.  The str array contains two strings: a vendor name, and
  an informational message describing the card.  The offset of the
  vendor string is given by vendor, and the offset of the product info
  string is in info.

  44..11..1144..  CCIISSTTPPLL__OORRGG

  The cistpl_org_t structure is given by:

       typedef struct cistpl_org_t {
               u_char          data_org;
               char            desc[30];

  This tuple describes the data organization of a memory partition.  The
  following values are defined for data_org:

     CCIISSTTPPLL__OORRGG__FFSS
        The partition contains a filesystem.

     CCIISSTTPPLL__OORRGG__AAPPPPSSPPEECC
        The partition is in an application specific format.

     CCIISSTTPPLL__OORRGG__XXIIPP
        The partition follows the Execute-In-Place specification.

  The desc field gives a text description of the data organization.

  44..22..  CCIISS ccoonnffiigguurraattiioonn rreeggiisstteerrss

  The PCMCIA standard defines a few standard configuration registers
  located in a card's attribute memory space.  A card's CONFIG tuple
  specifies which of these registers are implemented.  Programs using
  these definitions should include:

       #include "cisreg.h"

  44..22..11..  CCoonnffiigguurraattiioonn OOppttiioonn RReeggiisstteerr

  This register should be present for virtually all IO cards.  Writing
  to this register selects a configuration table entry and enables a
  card's IO functions.

  The following bit fields are defined:

     CCOORR__CCOONNFFIIGG__MMAASSKK
        Specifies the configuration table index describing the card's
        current operating mode.

     CCOORR__LLEEVVEELL__RREEQQ
        Specifies that the card should generate level mode (edge-
        triggered) interrupts, the default.

     CCOORR__SSOOFFTT__RREESSEETT
        Setting this bit performs a ``soft'' reset operation.  Drivers
        should use the ResetCard call to reset a card, rather than
        writing directly to this register.

  44..22..22..  CCaarrdd CCoonnffiigguurraattiioonn aanndd SSttaattuuss RReeggiisstteerr

  The following bit fields are defined:

     CCCCSSRR__IINNTTRR__AACCKK
        If this bit is set, then the CCSR_INTR_PENDING bit will remain
        set until it is explicitly cleared.
     CCCCSSRR__IINNTTRR__PPEENNDDIINNGG
        Signals that the card is currently asserting an interrupt
        request.  This signal can be used to support interrupt sharing.

     CCCCSSRR__PPOOWWEERR__DDOOWWNN
        Setting this bit signals that the card should enter a power down
        state.

     CCCCSSRR__AAUUDDIIOO__EENNAA
        Specifies that the card's audio output should be enabled.

     CCCCSSRR__IIOOIISS88
        This is used by the host to indicate that it can only perform
        8-bit IO operations and that 16-bit accesses will be carried out
        as two 8-bit accesses.

     CCCCSSRR__SSIIGGCCHHGG__EENNAA
        This indicates to the card that it should use the SIGCHG signal
        to indicate changes in the WP, READY, BVD1, and BVD2 signals.

     CCCCSSRR__CCHHAANNGGEEDD
        This bit signals to the host that one of the signals in the Pin
        Replacement Register has changed state.

  44..22..33..  PPiinn RReeppllaacceemmeenntt RReeggiisstteerr

  Signals in this register replace signals that are not available when a
  socket is operating in memory and IO mode.  An IO card will normally
  assert the SIGCHG signal to indicate that one of these signals has
  changed state, then a driver can poll this register to find out
  specifically what happened.

  The following bit fields are defined:

     PPRRRR__WWPP__SSTTAATTUUSS
        The current state of the write protect signal.

     PPRRRR__RREEAADDYY__SSTTAATTUUSS
        The current state of the ready signal.

     PPRRRR__BBVVDD22__SSTTAATTUUSS
        The current state of the battery warn signal.

     PPRRRR__BBVVDD11__SSTTAATTUUSS
        The current state of the battery dead signal.

     PPRRRR__WWPP__EEVVEENNTT
        Indicates that the write protect signal has changed state since
        the PRR register was last read.

     PPRRRR__RREEAADDYY__EEVVEENNTT
        Indicates that the ready signal has changed state since the PRR
        register was last read.

     PPRRRR__BBVVDD22__EEVVEENNTT
        Indicates that the battery warn signal has changed state since
        the PRR register was last read.

     PPRRRR__BBVVDD11__EEVVEENNTT
        Indicates that the battery dead signal has changed state since
        the PRR register was last read.

  This register can also be written.  In this case, the STATUS bits act
  as a mask; if a STATUS bit is set, the corresponding EVENT bit is
  updated by the write.

  44..22..44..  SSoocckkeett aanndd CCooppyy RReeggiisstteerr

  This register is used when several identical cards may be set up to
  share the same range of IO ports, to emulate an ISA bus card that
  would control several devices.  For example, an ISA hard drive
  controller might control several drives, selectable by writing a drive
  number to an IO port.  For several PCMCIA drives to emulate this
  controller interface, each needs to ``know'' which drive it is, so
  that it can identify which IO operations are intended for it.

  The following bit fields are defined:

     SSCCRR__SSOOCCKKEETT__NNUUMM
        This should indicate the socket number in which the card is
        located.

     SSCCRR__CCOOPPYY__NNUUMM
        If several identical cards are installed in a system, this field
        should be set to a unique number identifying which of the
        identical cards this is.

  44..22..55..  EExxtteennddeedd SSttaattuuss RReeggiisstteerr

  The following bit fields are defined:

     EESSRR__RREEQQ__AATTTTNN__EENNAA
        When set, the CCSR_CHANGED bit will be set when the ESR_REQ_ATTN
        bit is set, possibly generating a status change interrupt.

     EESSRR__RREEQQ__AATTTTNN
        Signals a card event, such as an incoming call for a modem.

  55..  CCaarrdd SSeerrvviicceess EEvveenntt HHaannddlliinngg

  Card Services events have several sources:

  +o  Card status changes reported by the low-level socket drivers.

  +o  Artificial events generated by Card Services itself.

  +o  Advanced Power Management (APM) events.

  +o  Events generated by other Card Services clients.

  Socket driver events may be either interrupt-driven or polled.

  55..11..  EEvveenntt hhaannddlleerr ooppeerraattiioonnss

  When Card Services recognizes that an event has occurred, it checks
  the event mask of each client to determine which clients should
  receive an event notification.  When a client registers with Card
  Services, it specifies  an event handler callback function.  This
  handler should have the form:

       int (*event_handler)(event_t event, int priority, event_callback_args_t *args);

  The priority parameter is set to either CS_EVENT_PRI_LOW for ordinary
  events, or CS_EVENT_PRI_HIGH for events that require an immediate
  response.  The only high priority event is CS_EVENT_CARD_REMOVAL.  A
  client event handler should process this event as efficiently as
  possible so that Card Services can quickly notify other clients.

  The event_callback_args_t structure is given by:

       typedef struct event_callback_args_t {
               client_handle_t         client_handle;
               void                    *info;
               void                    *mtdrequest;
               void                    *buffer;
               void                    *misc;
               void                    *client_data;
       } event_callback_args_t;

  The client_handle member is set to the handle of the client whose
  socket was responsible for the event.  This is useful if a driver is
  bound to several sockets.  The info field is currently only used to
  return an exit status from a call to ResetCard.  The client_data field
  may be used by a driver to point to a local data structure associated
  with this device.  The remaining fields are currently unused.

  55..22..  EEvveenntt ddeessccrriippttiioonnss

     CCSS__EEVVEENNTT__CCAARRDD__IINNSSEERRTTIIOONN
        This event signals that a card has been inserted.  If a driver
        is bound to an already occupied socket, Card Services will send
        the driver an artificial insertion event.

     CCSS__EEVVEENNTT__CCAARRDD__RREEMMOOVVAALL
        This event signals that a card has been removed.  This event
        should be handled with minimum delay so that Card Services can
        notify all clients as quickly as possible.

     CCSS__EEVVEENNTT__BBAATTTTEERRYY__LLOOWW
        This event signals a change of state of the ``battery low''
        signal.

     CCSS__EEVVEENNTT__BBAATTTTEERRYY__DDEEAADD
        This event signals a change of state of the ``battery dead''
        signal.

     CCSS__EEVVEENNTT__RREEAADDYY__CCHHAANNGGEE
        This event signals a change of state of the ``ready'' signal.

     CCSS__EEVVEENNTT__WWRRIITTEE__PPRROOTTEECCTT
        This event signals a change of state of the ``write protect''
        signal.

     CCSS__EEVVEENNTT__RREEGGIISSTTRRAATTIIOONN__CCOOMMPPLLEETTEE
        This event is sent to a driver after a successful call to
        RegisterClient.

     CCSS__EEVVEENNTT__RREESSEETT__RREEQQUUEESSTT
        This event is sent when a client calls ResetCard.  An event
        handler can veto the reset operation by returning failure.

     CCSS__EEVVEENNTT__RREESSEETT__PPHHYYSSIICCAALL
        This is sent to all clients just before a reset signal is sent
        to a card.

     CCSS__EEVVEENNTT__CCAARRDD__RREESSEETT
        This event signals that a reset operation is finished.  The
        success or failure of the reset should be determined using
        GetStatus.

     CCSS__EEVVEENNTT__RREESSEETT__CCOOMMPPLLEETTEE
        This event is sent to a client that has called ResetCard to
        signal the end of reset processing.

     CCSS__EEVVEENNTT__PPMM__SSUUSSPPEENNDD
        This event signals that Card Services has received either a user
        initiated or APM suspend request.  An event handler can veto the
        suspend by returning failure.

     CCSS__EEVVEENNTT__PPMM__RREESSUUMMEE
        This signals that the system is back on line after a
        suspend/resume cycle.

     CCSS__EEVVEENNTT__MMTTDD__RREEQQUUEESSTT
        This is used to initiate an MTD memory operation.  A description
        of the request is passed in the mtdrequest field of the callback
        arguments.  A host buffer address may be passed in buffer.

     CCSS__EEVVEENNTT__EERRAASSEE__CCOOMMPPLLEETTEE
        This is used to signal a client that a queued erase operation
        has completed.  A pointer to the erase queue entry is returned
        in the info field of the callback arguments.

  55..33..  CClliieenntt ddrriivveerr eevveenntt hhaannddlliinngg rreessppoonnssiibbiilliittiieess

  A client driver should respond to CS_EVENT_CARD_INSERTION and
  CS_EVENT_CARD_REMOVAL events by configuring and un-configuring the
  socket.  Because card removal is a high priority event, the driver
  should immediately block IO to the socket, perhaps by setting a flag
  in a device structure, and schedule all other shutdown processing to
  happen later using a timer interrupt.

  When a CS_EVENT_PM_RESET_REQUEST event is received, a driver should
  block IO and release a locked socket configuration.  When a
  CS_EVENT_CARD_RESET is received, a driver should restore the socket
  configuration and unblock IO.

  A CS_EVENT_PM_SUSPEND event should be handled somewhat like a
  CS_EVENT_PM_RESET_REQUEST event, in that IO should be blocked and the
  socket configuration should be released.  When a CS_EVENT_PM_RESUME
  event is received, a driver can expect a card to be ready to be
  reconfigured, similar to when a CS_EVENT_CARD_RESET event is received.

  66..  MMeemmoorryy TTeecchhnnoollooggyy DDrriivveerrss

  A Memory Technology Driver (``MTD'') is used by Card Services to
  implement bulk memory services for a particular type of memory device.
  An MTD should register as a normal Card Services client with a call to
  RegisterClient.  When it receives a card insertion event, it should
  use GetFirstRegion and GetNextRegion to identify memory regions that
  it will administer.  Then, it should use RegisterMTD to take control
  of these regions.  MTD read, write, copy, and erase requests are
  packaged into CS_EVENT_MTD_REQUEST events by Card Services, and passed
  to the MTD's event handler for processing.

  66..11..  MMTTDD rreeqquueesstt hhaannddlliinngg

  An MTD receives requests from Card Services in the form of
  CS_EVENT_MTD_REQUEST events.  Card Services passes a description of
  the request in the mtdrequest field of the event callback arguments.
  For requests that transfer data to or from the host, the host buffer
  address is passed in the buffer field.

  The mtd_request_t structure is given by:

       typedef struct mtd_request_t {
               u_long          SrcCardOffset;
               u_long          DestCardOffset;
               u_long          TransferLength;
               u_long          Function;
               u_long          MediaID;
               u_long          Status;
               u_long          Timeout;
       } mtd_request_t;

  The Function field is bit mapped and describes the action to be
  performed by this request:

     MMTTDD__RREEQQ__AACCTTIIOONN
        Either MTD_REQ_ERASE, MTD_REQ_READ, MTD_REQ_WRITE, or
        MTD_REQ_COPY.

     MMTTDD__RREEQQ__NNOOEERRAASSEE
        For a write command that is sized and aligned on erase block
        boundaries, this specifies that no erase should be performed.

     MMTTDD__RREEQQ__VVEERRIIFFYY
        Specifies that writes should be verified.

     MMTTDD__RREEQQ__RREEAADDYY
        Indicates that this request is a retry of a previously request
        that was delayed until the card asserted READY.

     MMTTDD__RREEQQ__TTIIMMEEOOUUTT
        Indicates that this request is a retry of a previously request
        that was delayed by a timeout.

     MMTTDD__RREEQQ__FFIIRRSSTT
        Indicates that this request is the first in a series of
        requests.

     MMTTDD__RREEQQ__LLAASSTT
        Indicates that this request is the last of a series of requests.
     MMTTDD__RREEQQ__KKEERRNNEELL
        Indicates that the host buffer for a read or write command is
        located in kernel memory, as opposed to user memory.

  The MediaID field is the value specified in the RegisterMTD request
  for this region.  The Status field is used by the MTD when it is
  unable to satisfy a request because a device is busy.  MTD requests
  normally run without blocking.  If an MTD request would block, it
  should return an error code of CS_BUSY, and set Status to one of the
  have the following values:

     MMTTDD__WWAAIITTRREEQQ
        Specifies that the request should be retried after another MTD
        request currently in progress completes.

     MMTTDD__WWAAIITTTTIIMMEERR
        Specifies that the request should be continued after the time
        specified in the timeout field.

     MMTTDD__WWAAIITTRRDDYY
        Specifies that the request should be continued when the card
        signals READY, or when the time specified in Timeout elapses,
        whichever happens first.

     MMTTDD__WWAAIITTPPOOWWEERR
        Specifies that the request should be retried after something
        happens that affects power availability to the socket.

  For MTD_WAITTIMER and MTD_WAITRDY, the Timeout field will specify the
  timeout interval in milliseconds.

  66..22..  MMTTDD hheellppeerr ffuunnccttiioonnss

  Since an MTD processes requests generated by Card Services, there may
  be some restrictions on the sorts of Card Services calls that can be
  safely made from the MTD event handler.  The MTD helper functions
  provide a limited set of special services that may be needed by an MTD
  but would be tricky to implement using the normal Card Services calls.
  In the Linux PCMCIA implementation, most CS calls can be safely made
  from an MTD event handler, but the MTD helper interface is included
  for compatibility.

       #include "cs_types.h"
       #include "cs.h"
       #include "bulkmem.h"

       int MTDHelperEntry(int subfunc, void *arg1, void *arg2);

  66..22..11..  MMTTDDMMooddiiffyyWWiinnddooww

       int MTDHelperEntry(MTDModifyWindow, memory_handle_t handle, mtd_mod_req_t *mod);

  The mtd_mod_req_t structure is give by:

       typedef struct mtd_mod_req_t {
               u_long          Attributes;
               u_long          AccessSpeed;
               u_long          CardOffset;
       } mtd_mod_req_t;

  MTDModifyWindow is essentially equivalent to using the normal
  ModifyWindow and MapMemPage calls.

  The following flags can be specified in Attributes:

     WWIINN__MMEEMMOORRYY__TTYYPPEE
        Either WIN_MEMORY_TYPE_CM for common memory, or
        WIN_MEMORY_TYPE_AM for attribute memory.

     WWIINN__UUSSEE__WWAAIITT
        Specifies that the controller should observe the card's MWAIT
        signal.

  A window configured with MTDModifyWindow will always be enabled, and
  have a 16 bit data width.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The memory handle is invalid.

  66..22..22..  MMTTDDSSeettVVpppp

       int MTDHelperEntry(MTDSetVpp, client_handle_t client, mtd_vpp_req_t *req);

       typedef struct mtd_vpp_req_t {
               u_char          Vpp1, Vpp2;
       } mtd_vpp_req_t;

  MTDSetVpp changes the programming voltage for a socket.  Vpp1 and Vpp2
  should be given in units of 1/10 volt.  Currently, Vpp1 should always
  equal Vpp2.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

     CCSS__BBAADD__VVPPPP
        The specified Vpp is not available, or Vpp1 does not equal Vpp2.

  66..22..33..  MMTTDDRRDDYYMMaasskk

       int MTDHelperEntry(MTDRDYMask, client_handle_t client, mtd_rdy_req_t *req);

       typedef struct mtd_rdy_req_t {
               u_long          Mask;
       } mtd_rdy_req_t;

  MTDRDYMask selects whether or not CS_EVENT_READY_CHANGE events will be
  enabled.  The client should already have indicated to Card Services
  that it should receive ready change events, via a call to either
  RegisterClient or SetEventMask.  Ready change events will be enabled
  if the CS_EVENT_READY_CHANGE bit is set in the Mask argument.

  Return codes:

     CCSS__BBAADD__HHAANNDDLLEE
        The client handle is invalid.

  77..  DDrriivveerr SSeerrvviicceess iinntteerrffaaccee

  Driver Services provides a link between Card Services client drivers
  and user mode utilities like the cardmgr daemon.  It is a sort of Card
  Services ``super-client''.  Driver Services uses the BindDevice
  function to link other client drivers with their corresponding PCMCIA
  cards.  Unlike other clients, Driver Services remains permanently
  bound to all sockets as cards are inserted and removed.

  77..11..  IInntteerrffaaccee ttoo ootthheerr cclliieenntt ddrriivveerrss

  Driver Services keeps track of all client drivers that are installed
  and ready to attach to a socket.  Client drivers need to have entry
  points for creating and deleting device ``instances'', where one
  device instance is everything needed to manage one PCMCIA card.

  Each client driver is identified by a unique 16-character tag that has
  the special type dev_info_t, defined in cs_types.h.  Each device
  instance is described by a dev_link_t structure.

  77..11..11..  TThhee ddeevv__lliinnkk__tt ssttrruuccttuurree

  The dev_node_t and dev_link_t data structures are given by:

  #include "ds.h"

  typedef struct dev_node_t {
          char                    dev_name[8];
          u_char                  major, minor;
          struct dev_node_t       *next;
  }

  typedef struct dev_link_t {
          dev_node_t              *dev;
          u_long                  state, open;
          struct wait_queue       *pending
          struct timer_list       release
          client_handle_t         handle;
          io_req_t                io;
          irq_req_t               irq;
          config_req_t            conf;
          window_handle_t         win;
          void                    *priv;
          struct dev_link_t       *next;
  } dev_link_t;

  The dev field of the dev_link_t structure points to a linked list of
  dev_node_t structures.  In dev_node_t, the dev_name field should be
  filled in by the driver with a device file name for accessing this
  device, if appropriate.  For example, the serial_cs driver uses names
  like ``ttyS1''.  The major and minor fields give major and minor
  device numbers for accessing this device.  Driver Services relays
  these fields to user mode programs via the DS_GET_DEVICE_INFO ioctl.

  In dev_link_t, the state field should be used to keep track of the
  current device state.  The following flags are defined:

     DDEEVV__PPRREESSEENNTT
        Indicates that the card is present.  This bit should be set and
        cleared by the driver's event handler in response to card
        insertion and removal events.

     DDEEVV__CCOONNFFIIGG
        Indicates that the card is configured for use.

     DDEEVV__CCOONNFFIIGG__PPEENNDDIINNGG
        Indicates that configuration is in progress.

     DDEEVV__SSUUSSPPEENNDD
        Indicates that the card is suspended.

     DDEEVV__BBUUSSYY
        Indicates that an IO operation is in progress.  This bit may be
        used as an interlock to prevent access conflicts.

     DDEEVV__SSTTAALLEE__CCOONNFFIIGG
        For some drivers, when a running card is ejected, the socket
        should not be unconfigured until any devices corresponding to
        this card are closed.  This flag indicates that the socket
        should be unconfigured when the device is closed.

     DDEEVV__SSTTAALLEE__LLIINNKK
        A driver instance should not be deleted until all its PCMCIA
        resources are released.  This flag indicates that this driver
        instance should be freed as soon as the socket is unconfigured.

  The open field is a usage count for this device.  The device should
  only be freed when the open count is zero.  The pending field can be
  used to manage a queue of processes waiting to use the device.

  The release field is used to schedule device shutdown processing when
  a card is ejected.  A card removal event needs to be handled at high
  priority, so a driver's event handler will typically deal with an
  eject by resetting the DEV_PRESENT bit in the device state, then
  scheduling the shutdown processing to run at a later time.

  The handle, io, irq, conf, and win fields comprise all the normal
  PCMCIA data structures needed to configure an ordinary PCMCIA IO card.

  The priv field can be used for any sort of private data structure
  needed to manage the device.  The next field can be used to build
  linked lists of dev_link_t structures, for drivers that can handle
  multiple instances.

  77..11..22..  rreeggiisstteerr__ppccmmcciiaa__ddrriivveerr

       int register_pcmcia_driver(dev_info_t *dev_info,
                                  dev_link_t *(*attach)(void),
                                  void (*detach)(dev_link_t *));

  register_pcmcia_driver informs Driver Services that a client driver is
  present and ready to be bound to sockets.  When Driver Services
  receives a DS_BIND_REQUEST ioctl that matches this driver's dev_info
  string, it will call the driver's attach() entry point.  When it gets
  a DS_UNBIND_REQUEST ioctl, it will call detach().

  77..11..33..  uunnrreeggiisstteerr__ppccmmcciiaa__ddrriivveerr

       int unregister_pcmcia_driver(dev_info_t *dev_info);

  This informs Driver Services that it should no longer bind sockets to
  the specified client driver.

  77..22..  IInntteerrffaaccee ttoo uusseerr mmooddee PPCCMMCCIIAA uuttiilliittiieess

  Driver Services creates a pseudo-device for communicating with user
  mode PCMCIA utilities.  The major number of the device is chosen
  dynamically, and PCMCIA utilities should read /proc/devices to
  determine it.  Minor device numbers correspond to socket numbers,
  starting with 0.

  Only one process is allowed to open a socket for read/write access.
  Other processes can open the socket in read-only mode.  A read-only
  connection to Driver Services can perform a subset of ioctl calls.  A
  read/write connection can issue all ioctl calls, and can also receive
  Card Services event notifications.
  77..22..11..  CCaarrdd SSeerrvviicceess eevveenntt nnoottiiffiiccaattiioonnss

  Driver Services implements read() and select() functions for event
  notification.  Reading from a pcmcia device returns an unsigned long
  value containing all the events received by Driver Services since the
  previous read().  If no events have been received, the call will block
  until the next event.  A select() call can be used to monitor several
  sockets for new events.

  The following events are monitored by Driver Services:
  CS_EVENT_CARD_INSERTION, CS_EVENT_CARD_REMOVAL,
  CS_EVENT_RESET_PHYSICAL, CS_EVENT_CARD_RESET, and
  CS_EVENT_RESET_COMPLETE.

  77..22..22..  IIooccttll ddeessccrriippttiioonnss

  Most Driver Services ioctl operations directly map to Card Services
  functions.  An ioctl call has the form:

       int ioctl(int fd, int cmd, ds_ioctl_arg_t *arg);

  The ds_ioctl_arg_t structure is given by:

       typedef union ds_ioctl_arg_t {
               servinfo_t      servinfo;
               adjust_t        adjust;
               config_info_t   config;
               tuple_t         tuple;
               tuple_parse_t   tuple_parse;
               client_req_t    client_req;
               status_t        status;
               conf_reg_t      conf_reg;
               cisinfo_t       cisinfo;
               region_info_t   region;
               bind_info_t     bind_info;
               mtd_info_t      mtd_info;
       } ds_ioctl_arg_t;

  The following ioctl commands execute the corresponding Card Services
  function:

     DDSS__GGEETT__CCAARRDD__SSEERRVVIICCEESS__IINNFFOO
        Calls CardServices(GetCardServicesInfo, ..., &arg->servinfo).

     DDSS__AADDJJUUSSTT__RREESSOOUURRCCEE__IINNFFOO
        Calls CardServices(AdjustResourceInfo, ..., &arg->adjust).

     DDSS__GGEETT__CCOONNFFIIGGUURRAATTIIOONN__IINNFFOO
        Calls CardServices(GetConfigurationInfo, ..., &arg->config).

     DDSS__GGEETT__FFIIRRSSTT__TTUUPPLLEE
        Calls CardServices(GetFirstTuple, ..., &arg->tuple).

     DDSS__GGEETT__NNEEXXTT__TTUUPPLLEE
        Calls CardServices(GetNextTuple, ..., &arg->tuple).
     DDSS__GGEETT__TTUUPPLLEE__DDAATTAA
        Calls CardServices(GetTupleData, ..., &arg->tuple_parse.tuple).
        The tuple data is returned in arg->tuple_parse.data.

     DDSS__PPAARRSSEE__TTUUPPLLEE
        Calls CardServices(ParseTuple, ..., &arg->tuple_parse.tuple,
        &arg->tuple_parse.parse).

     DDSS__RREESSEETT__CCAARRDD
        Calls CardServices(ResetCard, ...).

     DDSS__GGEETT__SSTTAATTUUSS
        Calls CardServices(GetStatus, ..., &arg->status).

     DDSS__AACCCCEESSSS__CCOONNFFIIGGUURRAATTIIOONN__RREEGGIISSTTEERR
        Calls CardServices(AccessConfigurationRegister, ...,
        &arg->conf_reg).

     DDSS__VVAALLIIDDAATTEE__CCIISS
        Calls CardServices(ValidateCIS, ..., &arg->cisinfo).

     DDSS__SSUUSSPPEENNDD__CCAARRDD
        Calls CardServices(SuspendCard, ...).

     DDSS__RREESSUUMMEE__CCAARRDD
        Calls CardServices(ResumeCard, ...).

     DDSS__EEJJEECCTT__CCAARRDD
        Calls CardServices(EjectCard, ...).

     DDSS__IINNSSEERRTT__CCAARRDD
        Calls CardServices(InsertCard, ...).

     DDSS__GGEETT__FFIIRRSSTT__RREEGGIIOONN
        Calls CardServices(GetFirstRegion, ..., &arg->region).

     DDSS__GGEETT__NNEEXXTT__RREEGGIIOONN
        Calls CardServices(GetNextRegion, ..., &arg->region).

  The following ioctl commands invoke special Driver Services functions.
  They act on bind_info_t structures:

       typedef struct bind_info_t {
               dev_info_t              dev_info;
               u_char                  function;
               struct dev_info_t       *instance;
               char                    name[8];
               u_char                  major, minor;
               void                    *next;
       } bind_info_t;

     DDSS__BBIINNDD__RREEQQUUEESSTT
        This call connects a socket to a client driver.  The specified
        device ID dev_info is looked up in the list of registered
        drivers.  If this is a multifunction card, the function field
        identifies which card function is being bound.  If found, the
        driver is bound to this socket and function using the BindDevice
        call.  Then, Driver Services calls the client driver's attach()
        entry point to create a device instance.  The new dev_link_t
        pointer is returned in instance.

     DDSS__GGEETT__DDEEVVIICCEE__IINNFFOO
        This call retrieves the dev_name, major, and minor entries from
        the dev_link_t structure pointed to by instance.

     DDSS__UUNNBBIINNDD__RREEQQUUEESSTT
        This call calls the detach() function for the specified driver
        and instance, shutting down this device.

  Finally, the DS_BIND_MTD request takes an argument of type mtd_info_t:

       typedef struct mtd_info_t {
               dev_info_t      dev_info;
               u_long          Attributes;
               u_long          CardOffset;
       } mtd_info_t;

  This call associates an MTD identified by dev_info with a memory
  region described by Attributes and CardOffset, which have the same
  meanings as in the Card Services BindMTD call.

  88..  AAnnaattoommyy ooff aa CCaarrdd SSeerrvviicceess CClliieenntt DDrriivveerr

  Each release of the Linux PCMCIA package comes with a well-commented
  ``skeleton'' client driver that should be used as a starting point for
  writing a new driver.  Look for it in modules/skeleton.c.

  88..11..  MMoodduullee iinniittiiaalliizzaattiioonn aanndd cclleeaannuupp

  All loadable modules must supply init_module() and cleanup_module()
  functions, which are invoked by the module support code when the
  module is installed and removed.  A PCMCIA client driver's init
  function should register the driver with Driver Services, via the
  register_pcmcia_driver() call.  The cleanup function should use
  unregister_pcmcia_driver() to unregister with Driver Services.
  Depending on the driver, the cleanup function may also need to free
  any device structures that still exist at shutdown time.

  88..22..  TThhee **__aattttaacchh(()) aanndd **__ddeettaacchh(()) ffuunnccttiioonnss

  The *_attach() entry point is responsible for creating an ``instance''
  of the driver, setting up any data structures needed to manage one
  PCMCIA card.  The *_attach() function should allocate and initialize a
  dev_link_t structure, and call RegisterClient to establish a link with
  Card Services.  It returns a pointer to the new dev_link_t structure,
  or NULL if the new instance could not be created.

  The *_detach() entry point deletes a driver instance created by a
  previous call to *_attach.  It also breaks the link with Card
  Services, using DeregisterClient.

  The *_attach() entry point is called by Driver Services when a card
  has been successfully identified and mapped to a matching driver by a
  DS_BIND_REQUEST ioctl().  The *_detach() entry point is called in
  response to a DS_UNBIND_REQUEST ioctl() call.

  88..33..  TThhee **__ccoonnffiigg(()) aanndd **__rreelleeaassee(()) ffuunnccttiioonnss

  The *_config() function is called to prepare a card for IO.  Most
  drivers read some configuration details from the card itsef, but most
  have at least some built-in knowledge of how the device should be set
  up.  For example, the serial card driver reads a card's CFTABLE_ENTRY
  tuples to determine appropriate IO port base addresses and
  corresponding configuration indices, but the driver ignores the
  interrupt information in the CIS.  The *_config function will parse
  relevant parts of a card's CIS, then make calls to RequestIO,
  RequestIRQ, and/or RequestWindow, then call RequestConfiguration.

  When a card is successfully configured, the *_config() routine should
  fill in the dev_name, major, and minor fields in the dev_link_t
  structure.  These fields will be returned to user programs by Driver
  Services in response to a DS_GET_DEVICE_INFO ioctl().

  The *_release() function should release any resource allocated by a
  previous call to *_config(), and blank out the device's dev_name
  field.

  The *_config() and *_release functions are normally called in response
  to card status change events or from timer interrupts.  Thus, they
  cannot sleep, and should not call other kernel functions that might
  block.

  88..44..  TThhee PPCCMMCCIIAA eevveenntt hhaannddlleerr

  The *_event() entry point is called from Card Services to notify a
  driver of card status change events.

  88..55..  LLoocckkiinngg aanndd ssyynncchhrroonniizzaattiioonn iissssuueess

  A configured socket should only be released when all associated
  devices are closed.  Releasing a socket allows its system resources to
  be allocated for use by another device.  If the released resources are
  reallocated while IO to the original device is still in progress, the
  original driver may interfere with use of the new device.

  A driver instance should only be freed after its corresponding socket
  configuration has been released.  Card Services requires that a client
  explicitly release any allocated resources before a call to
  DeregisterClient will succeed.

  All loadable modules have a ``use count'' that is used by the system
  to determine when it is safe to unload a module.  The convention in
  the PCMCIA client drivers is to increment the use count when a device
  is opened, and to decrement the count when a device is closed.  So, a
  driver can be unloaded whenever all associated devices are closed.  in
  particular, a driver can be unloaded even if it is still bound to a
  socket, and the module cleanup code needs to be able to appropriately
  free any such resources that are still allocated.  This should always
  be safe, because if the driver has a use count of zero, all devices
  are closed, which means all active sockets can be released, and all
  device instances can be detached.

  If a driver's *_release() function is called while a device is still
  open, it should set the DEV_STALE_CONFIG flag in the device state, to
  signal that the device should be released when the driver's close()
  function is called.  If *_detach() is called for a configured device,
  the DEV_STALE_LINK flag should be set to signal that the instance
  should be detached when the *_release() function is called.

  88..66..  UUssiinngg eexxiissttiinngg LLiinnuuxx ddrriivveerrss ttoo aacccceessss PPCCMMCCIIAA ddeevviicceess

  Many of the current PCMCIA client drivers use existing Linux driver
  code to perform device IO operations.  The Card Services client module
  handles card configuration and responds to card status change events,
  but delegates device IO to a compatible driver for a conventional ISA
  bus card.  In some cases, a conventional driver can be used without
  modification.  However, to fully support PCMCIA features like hot
  swapping and power management, there needs to be some communication
  between the PCMCIA client code and the device IO code.

  Most Linux drivers expect to probe for devices at boot time, and are
  not designed to handle adding and removing devices.  One side-effect
  of the move towards driver modularization is that it is usually easier
  to adapt a modularized driver to handle removable devices.

  It is important that a device driver be able to recover from having a
  device disappear at an inappropriate time.  At best, the driver should
  check for device presence before attempting any IO operation or before
  handling an IO interrupt.  Loops that check device status should have
  timeouts so they will eventually exit if a device never responds.

  99..  WWhheerree ttoo GGoo ffoorr MMoorree IInnffoorrmmaattiioonn

  The _L_i_n_u_x _K_e_r_n_e_l _H_a_c_k_e_r_s_' _G_u_i_d_e, written by Michael Johnson, is a good
  source of general information about writing Linux device drivers.  It
  is available from the usual Linux FTP sites, and is included in many
  compilations of Linux documentation.

  The genuine PCMCIA standard is only available for a steep price from
  the PCMCIA association itself.  The new PC Card 95 standard is
  supposed to cost $399, but old copies of the 2.1 standard may still be
  available at a deep discount.

       Personal Computer Memory Card International Association
       1030 East Duane Avenue, Suite G
       Sunnyvale, CA 94086 USA
       (408) 720-0107, (408) 720-9416 FAX, (408) 720-9388 BBS
       http://www.pc-card.com

  One alternative is the _P_C_M_C_I_A _D_e_v_e_l_o_p_e_r_'_s _G_u_i_d_e, written by Michael
  Mori, available from Sycard Technology, ISBN 0-9640342-1-2, for
  approximately $89.95:

       Sycard Technology
       1180-F Miraloma Way
       Sunnyvale, CA 94086 USA
       (408) 749-0130, (408) 749-1323 FAX

  The _P_C_M_C_I_A _S_o_f_t_w_a_r_e _D_e_v_e_l_o_p_e_r_'_s _H_a_n_d_b_o_o_k by Dana Beatty, Steven
  Kipisz, and Brian Moore includes an overview of the PCMCIA standard,
  and descriptions of how to write client drivers.  It also includes the
  Linux PCMCIA Programmer's Guide, as an appendix.  It is published by
  Peer-to-Peer Communications, ISBN 1-57398-010-2.
  Larry Levine has written a more general introduction to PCMCIA called
  the _P_C_M_C_I_A _P_r_i_m_e_r, which should be on bookstore shelves in the summer
  of 1995.  It is published by M & T Books, ISBN 1-55828-437-0.

  Programming information for various PCMCIA controllers is available
  from the corresponding chip vendors:

       Intel Corporation
       (800) 628-8686

       Cirrus Logic
       (510) 623-8300

       Vadem
       (408) 943-9301

       Databook Inc.
       (716) 889-4204

