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Diffstat (limited to 'kernel/Documentation/isdn/INTERFACE')
| -rw-r--r-- | kernel/Documentation/isdn/INTERFACE | 759 |
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diff --git a/kernel/Documentation/isdn/INTERFACE b/kernel/Documentation/isdn/INTERFACE new file mode 100644 index 000000000..5df17e5b2 --- /dev/null +++ b/kernel/Documentation/isdn/INTERFACE @@ -0,0 +1,759 @@ +$Id: INTERFACE,v 1.15.8.2 2001/03/13 16:17:07 kai Exp $ + +Description of the Interface between Linklevel and Hardwarelevel + of isdn4linux: + + + The Communication between Linklevel (LL) and Hardwarelevel (HL) + is based on the struct isdn_if (defined in isdnif.h). + + An HL-driver can register itself at LL by calling the function + register_isdn() with a pointer to that struct. Prior to that, it has + to preset some of the fields of isdn_if. The LL sets the rest of + the fields. All further communication is done via callbacks using + the function-pointers defined in isdn_if. + + Changes/Version numbering: + + During development of the ISDN subsystem, several changes have been + made to the interface. Before it went into kernel, the package + had a unique version number. The last version, distributed separately + was 0.7.4. When the subsystem went into kernel, every functional unit + got a separate version number. These numbers are shown at initialization, + separated by slashes: + + c.c/t.t/n.n/p.p/a.a/v.v + + where + + c.c is the revision of the common code. + t.t is the revision of the tty related code. + n.n is the revision of the network related code. + p.p is the revision of the ppp related code. + a.a is the revision of the audio related code. + v.v is the revision of the V.110 related code. + + Changes in this document are marked with '***CHANGEx' where x representing + the version number. If that number starts with 0, it refers to the old, + separately distributed package. If it starts with one of the letters + above, it refers to the revision of the corresponding module. + ***CHANGEIx refers to the revision number of the isdnif.h + +1. Description of the fields of isdn_if: + + int channels; + + This field has to be set by the HL-driver to the number of channels + supported prior to calling register_isdn(). Upon return of the call, + the LL puts an id there, which has to be used by the HL-driver when + invoking the other callbacks. + + int maxbufsize; + + ***CHANGE0.6: New since this version. + + Also to be preset by the HL-driver. With this value the HL-driver + tells the LL the maximum size of a data-packet it will accept. + + unsigned long features; + + To be preset by the HL-driver. Using this field, the HL-driver + announces the features supported. At the moment this is limited to + report the supported layer2 and layer3-protocols. For setting this + field the constants ISDN_FEATURE..., declared in isdnif.h have to be + used. + + ***CHANGE0.7.1: The line type (1TR6, EDSS1) has to be set. + + unsigned short hl_hdrlen; + + ***CHANGE0.7.4: New field. + + To be preset by the HL-driver, if it supports sk_buff's. The driver + should put here the amount of additional space needed in sk_buff's for + its internal purposes. Drivers not supporting sk_buff's should + initialize this field to 0. + + void (*rcvcallb_skb)(int, int, struct sk_buff *) + + ***CHANGE0.7.4: New field. + + This field will be set by LL. The HL-driver delivers received data- + packets by calling this function. Upon calling, the HL-driver must + already have its private data pulled off the head of the sk_buff. + + Parameter: + int driver-Id + int Channel-number locally to the driver. (starting with 0) + struct sk_buff * Pointer to sk_buff, containing received data. + + int (*statcallb)(isdn_ctrl*); + + This field will be set by LL. This function has to be called by the + HL-driver for signaling status-changes or other events to the LL. + + Parameter: + isdn_ctrl* + + The struct isdn_ctrl also defined in isdn_if. The exact meanings of its + fields are described together with the descriptions of the possible + events. Here is only a short description of the fields: + + driver = driver Id. + command = event-type. (one of the constants ISDN_STAT_...) + arg = depends on event-type. + num = depends on event-type. + + Returnvalue: + 0 on success, else -1 + + int (*command)(isdn_ctrl*); + + This field has to be preset by the HL-driver. It points to a function, + to be called by LL to perform functions like dialing, B-channel + setup, etc. The exact meaning of the parameters is described with the + descriptions of the possible commands. + + Parameter: + isdn_ctrl* + driver = driver-Id + command = command to perform. (one of the constants ISDN_CMD_...) + arg = depends on command. + num = depends on command. + + Returnvalue: + >=0 on success, else error-code (-ENODEV etc.) + + int (*writebuf_skb)(int, int, int, struct sk_buff *) + + ***CHANGE0.7.4: New field. + ***CHANGEI.1.21: New field. + + This field has to be preset by the HL-driver. The given function will + be called by the LL for delivering data to be send via B-Channel. + + + Parameter: + int driver-Id ***CHANGE0.7.4: New parameter. + int channel-number locally to the HL-driver. (starts with 0) + int ack ***ChangeI1.21: New parameter + If this is !0, the driver has to signal the delivery + by sending an ISDN_STAT_BSENT. If this is 0, the driver + MUST NOT send an ISDN_STAT_BSENT. + struct sk_buff * Pointer to sk_buff containing data to be send via + B-channel. + + Returnvalue: + Length of data accepted on success, else error-code (-EINVAL on + oversized packets etc.) + + int (*writecmd)(u_char*, int, int, int, int); + + This field has to be preset by the HL-driver. The given function will be + called to perform write-requests on /dev/isdnctrl (i.e. sending commands + to the card) The data-format is hardware-specific. This function is + intended for debugging only. It is not necessary for normal operation + and never will be called by the tty-emulation- or network-code. If + this function is not supported, the driver has to set NULL here. + + Parameter: + u_char* pointer to data. + int length of data. + int flag: 0 = call from within kernel-space. (HL-driver must use + memcpy, may NOT use schedule()) + 1 = call from user-space. (HL-driver must use + memcpy_fromfs, use of schedule() allowed) + int driver-Id. + int channel-number locally to the HL-driver. (starts with 0) + +***CHANGEI1.14: The driver-Id and channel-number are new since this revision. + + Returnvalue: + Length of data accepted on success, else error-code (-EINVAL etc.) + + int (*readstat)(u_char*, int, int, int, int); + + This field has to be preset by the HL-driver. The given function will be + called to perform read-requests on /dev/isdnctrl (i.e. reading replies + from the card) The data-format is hardware-specific. This function is + intended for debugging only. It is not necessary for normal operation + and never will be called by the tty-emulation- or network-code. If + this function is not supported, the driver has to set NULL here. + + Parameter: + u_char* pointer to data. + int length of data. + int flag: 0 = call from within kernel-space. (HL-driver must use + memcpy, may NOT use schedule()) + 1 = call from user-space. (HL-driver must use + memcpy_fromfs, use of schedule() allowed) + int driver-Id. + int channel-number locally to the HL-driver. (starts with 0) + +***CHANGEI1.14: The driver-Id and channel-number are new since this revision. + + Returnvalue: + Length of data on success, else error-code (-EINVAL etc.) + + char id[20]; + ***CHANGE0.7: New since this version. + + This string has to be preset by the HL-driver. Its purpose is for + identification of the driver by the user. Eg.: it is shown in the + status-info of /dev/isdninfo. Furthermore it is used as Id for binding + net-interfaces to a specific channel. If a string of length zero is + given, upon return, isdn4linux will replace it by a generic name. (line0, + line1 etc.) It is recommended to make this string configurable during + module-load-time. (copy a global variable to this string.) For doing that, + modules 1.2.8 or newer are necessary. + +2. Description of the commands, a HL-driver has to support: + + All commands will be performed by calling the function command() described + above from within the LL. The field command of the struct-parameter will + contain the desired command, the field driver is always set to the + appropriate driver-Id. + + Until now, the following commands are defined: + +***CHANGEI1.34: The parameter "num" has been replaced by a union "parm" containing + the old "num" and a new setup_type struct used for ISDN_CMD_DIAL + and ISDN_STAT_ICALL callback. + + ISDN_CMD_IOCTL: + + This command is intended for performing ioctl-calls for configuring + hardware or similar purposes (setting port-addresses, loading firmware + etc.) For this purpose, in the LL all ioctl-calls with an argument + >= IIOCDRVCTL (0x100) will be handed transparently to this + function after subtracting 0x100 and placing the result in arg. + Example: + If a userlevel-program calls ioctl(0x101,...) the function gets + called with the field command set to 1. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_IOCTL + arg = Original ioctl-cmd - IIOCDRVCTL + parm.num = first bytes filled with (unsigned long)arg + + Returnvalue: + Depending on driver. + + + ISDN_CMD_DIAL: + + This command is used to tell the HL-driver it should dial a given + number. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_DIAL + arg = channel-number locally to the driver. (starting with 0) + + parm.setup.phone = An ASCII-String containing the number to dial. + parm.setup.eazmsn = An ASCII-Sting containing the own EAZ or MSN. + parm.setup.si1 = The Service-Indicator. + parm.setup.si2 = Additional Service-Indicator. + + If the Line has been designed as SPV (a special german + feature, meaning semi-leased-line) the phone has to + start with an "S". + ***CHANGE0.6: In previous versions the EAZ has been given in the + highbyte of arg. + ***CHANGE0.7.1: New since this version: ServiceIndicator and AddInfo. + + ISDN_CMD_ACCEPTD: + + With this command, the HL-driver is told to accept a D-Channel-setup. + (Response to an incoming call) + + Parameter: + driver = driver-Id. + command = ISDN_CMD_ACCEPTD + arg = channel-number locally to the driver. (starting with 0) + parm = unused. + + ISDN_CMD_ACCEPTB: + + With this command, the HL-driver is told to perform a B-Channel-setup. + (after establishing D-Channel-Connection) + + Parameter: + driver = driver-Id. + command = ISDN_CMD_ACCEPTB + arg = channel-number locally to the driver. (starting with 0) + parm = unused. + + ISDN_CMD_HANGUP: + + With this command, the HL-driver is told to hangup (B-Channel if + established first, then D-Channel). This command is also used for + actively rejecting an incoming call. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_HANGUP + arg = channel-number locally to the driver. (starting with 0) + parm = unused. + + ISDN_CMD_CLREAZ: + + With this command, the HL-driver is told not to signal incoming + calls to the LL. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_CLREAZ + arg = channel-number locally to the driver. (starting with 0) + parm = unused. + + ISDN_CMD_SETEAZ: + + With this command, the HL-driver is told to signal incoming calls for + the given EAZs/MSNs to the LL. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_SETEAZ + arg = channel-number locally to the driver. (starting with 0) + parm.num = ASCII-String, containing the desired EAZ's/MSN's + (comma-separated). If an empty String is given, the + HL-driver should respond to ALL incoming calls, + regardless of the destination-address. + ***CHANGE0.6: New since this version the "empty-string"-feature. + + ISDN_CMD_GETEAZ: (currently unused) + + With this command, the HL-driver is told to report the current setting + given with ISDN_CMD_SETEAZ. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_GETEAZ + arg = channel-number locally to the driver. (starting with 0) + parm.num = ASCII-String, containing the current EAZ's/MSN's + + ISDN_CMD_SETSIL: (currently unused) + + With this command, the HL-driver is told to signal only incoming + calls with the given Service-Indicators. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_SETSIL + arg = channel-number locally to the driver. (starting with 0) + parm.num = ASCII-String, containing the desired Service-Indicators. + + ISDN_CMD_GETSIL: (currently unused) + + With this command, the HL-driver is told to return the current + Service-Indicators it will respond to. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_SETSIL + arg = channel-number locally to the driver. (starting with 0) + parm.num = ASCII-String, containing the current Service-Indicators. + + ISDN_CMD_SETL2: + + With this command, the HL-driver is told to select the given Layer-2- + protocol. This command is issued by the LL prior to ISDN_CMD_DIAL or + ISDN_CMD_ACCEPTD. + + + Parameter: + driver = driver-Id. + command = ISDN_CMD_SETL2 + arg = channel-number locally to the driver. (starting with 0) + logical or'ed with (protocol-Id << 8) + protocol-Id is one of the constants ISDN_PROTO_L2... + parm = unused. + + ISDN_CMD_GETL2: (currently unused) + + With this command, the HL-driver is told to return the current + setting of the Layer-2-protocol. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_GETL2 + arg = channel-number locally to the driver. (starting with 0) + parm = unused. + Returnvalue: + current protocol-Id (one of the constants ISDN_L2_PROTO) + + ISDN_CMD_SETL3: + + With this command, the HL-driver is told to select the given Layer-3- + protocol. This command is issued by the LL prior to ISDN_CMD_DIAL or + ISDN_CMD_ACCEPTD. + + + Parameter: + driver = driver-Id. + command = ISDN_CMD_SETL3 + arg = channel-number locally to the driver. (starting with 0) + logical or'ed with (protocol-Id << 8) + protocol-Id is one of the constants ISDN_PROTO_L3... + parm.fax = Pointer to T30_s fax struct. (fax usage only) + + ISDN_CMD_GETL2: (currently unused) + + With this command, the HL-driver is told to return the current + setting of the Layer-3-protocol. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_GETL3 + arg = channel-number locally to the driver. (starting with 0) + parm = unused. + Returnvalue: + current protocol-Id (one of the constants ISDN_L3_PROTO) + + ISDN_CMD_PROCEED: + + With this command, the HL-driver is told to proceed with a incoming call. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_PROCEED + arg = channel-number locally to the driver. (starting with 0) + setup.eazmsn= empty string or string send as uus1 in DSS1 with + PROCEED message + + ISDN_CMD_ALERT: + + With this command, the HL-driver is told to alert a proceeding call. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_ALERT + arg = channel-number locally to the driver. (starting with 0) + setup.eazmsn= empty string or string send as uus1 in DSS1 with + ALERT message + + ISDN_CMD_REDIR: + + With this command, the HL-driver is told to redirect a call in proceeding + or alerting state. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_REDIR + arg = channel-number locally to the driver. (starting with 0) + setup.eazmsn= empty string or string send as uus1 in DSS1 protocol + setup.screen= screening indicator + setup.phone = redirected to party number + + ISDN_CMD_PROT_IO: + + With this call, the LL-driver invokes protocol specific features through + the LL. + The call is not implicitely bound to a connection. + + Parameter: + driver = driver-Id + command = ISDN_CMD_PROT_IO + arg = The lower 8 Bits define the addressed protocol as defined + in ISDN_PTYPE..., the upper bits are used to differentiate + the protocol specific CMD. + + para = protocol and function specific. See isdnif.h for detail. + + + ISDN_CMD_FAXCMD: + + With this command the HL-driver receives a fax sub-command. + For details refer to INTERFACE.fax + + Parameter: + driver = driver-Id. + command = ISDN_CMD_FAXCMD + arg = channel-number locally to the driver. (starting with 0) + parm = unused. + + +3. Description of the events to be signaled by the HL-driver to the LL. + + All status-changes are signaled via calling the previously described + function statcallb(). The field command of the struct isdn_cmd has + to be set by the HL-driver with the appropriate Status-Id (event-number). + The field arg has to be set to the channel-number (locally to the driver, + starting with 0) to which this event applies. (Exception: STAVAIL-event) + + Until now, the following Status-Ids are defined: + + ISDN_STAT_AVAIL: + + With this call, the HL-driver signals the availability of new data + for readstat(). Used only for debugging-purposes, see description + of readstat(). + + Parameter: + driver = driver-Id + command = ISDN_STAT_STAVAIL + arg = length of available data. + parm = unused. + + ISDN_STAT_ICALL: + ISDN_STAT_ICALLW: + + With this call, the HL-driver signals an incoming call to the LL. + If ICALLW is signalled the incoming call is a waiting call without + a available B-chan. + + Parameter: + driver = driver-Id + command = ISDN_STAT_ICALL + arg = channel-number, locally to the driver. (starting with 0) + para.setup.phone = Callernumber. + para.setup.eazmsn = CalledNumber. + para.setup.si1 = Service Indicator. + para.setup.si2 = Additional Service Indicator. + para.setup.plan = octet 3 from Calling party number Information Element. + para.setup.screen = octet 3a from Calling party number Information Element. + + Return: + 0 = No device matching this call. + 1 = At least one device matching this call (RING on ttyI). + HL-driver may send ALERTING on the D-channel in this case. + 2 = Call will be rejected. + 3 = Incoming called party number is currently incomplete. + Additional digits are required. + Used for signalling with PtP connections. + 4 = Call will be held in a proceeding state + (HL driver sends PROCEEDING) + Used when a user space prog needs time to interpret a call + para.setup.eazmsn may be filled with an uus1 message of + 30 octets maximum. Empty string if no uus. + 5 = Call will be actively deflected to another party + Only available in DSS1/EURO protocol + para.setup.phone must be set to destination party number + para.setup.eazmsn may be filled with an uus1 message of + 30 octets maximum. Empty string if no uus. + -1 = An error happened. (Invalid parameters for example.) + The keypad support now is included in the dial command. + + + ISDN_STAT_RUN: + + With this call, the HL-driver signals availability of the ISDN-card. + (after initializing, loading firmware) + + Parameter: + driver = driver-Id + command = ISDN_STAT_RUN + arg = unused. + parm = unused. + + ISDN_STAT_STOP: + + With this call, the HL-driver signals unavailability of the ISDN-card. + (before unloading, while resetting/reconfiguring the card) + + Parameter: + driver = driver-Id + command = ISDN_STAT_STOP + arg = unused. + parm = unused. + + ISDN_STAT_DCONN: + + With this call, the HL-driver signals the successful establishment of + a D-Channel-connection. (Response to ISDN_CMD_ACCEPTD or ISDN_CMD_DIAL) + + Parameter: + driver = driver-Id + command = ISDN_STAT_DCONN + arg = channel-number, locally to the driver. (starting with 0) + parm = unused. + + ISDN_STAT_BCONN: + + With this call, the HL-driver signals the successful establishment of + a B-Channel-connection. (Response to ISDN_CMD_ACCEPTB or because the + remote-station has initiated establishment) + + The HL driver should call this when the logical l2/l3 protocol + connection on top of the physical B-channel is established. + + Parameter: + driver = driver-Id + command = ISDN_STAT_BCONN + arg = channel-number, locally to the driver. (starting with 0) + parm.num = ASCII-String, containing type of connection (for analog + modem only). This will be appended to the CONNECT message + e.g. 14400/V.32bis + + ISDN_STAT_DHUP: + + With this call, the HL-driver signals the shutdown of a + D-Channel-connection. This could be a response to a prior ISDN_CMD_HANGUP, + or caused by a remote-hangup or if the remote-station has actively + rejected a call. + + Parameter: + driver = driver-Id + command = ISDN_STAT_DHUP + arg = channel-number, locally to the driver. (starting with 0) + parm = unused. + + ISDN_STAT_BHUP: + + With this call, the HL-driver signals the shutdown of a + B-Channel-connection. This could be a response to a prior ISDN_CMD_HANGUP, + or caused by a remote-hangup. + + The HL driver should call this as soon as the logical l2/l3 protocol + connection on top of the physical B-channel is released. + + Parameter: + driver = driver-Id + command = ISDN_STAT_BHUP + arg = channel-number, locally to the driver. (starting with 0) + parm = unused. + + ISDN_STAT_CINF: + + With this call, the HL-driver delivers charge-unit information to the + LL. + + Parameter: + driver = driver-Id + command = ISDN_STAT_CINF + arg = channel-number, locally to the driver. (starting with 0) + parm.num = ASCII string containing charge-units (digits only). + + ISDN_STAT_LOAD: (currently unused) + + ISDN_STAT_UNLOAD: + + With this call, the HL-driver signals that it will be unloaded now. This + tells the LL to release all corresponding data-structures. + + Parameter: + driver = driver-Id + command = ISDN_STAT_UNLOAD + arg = unused. + parm = unused. + + ISDN_STAT_BSENT: + + With this call the HL-driver signals the delivery of a data-packet. + This callback is used by the network-interfaces only, tty-Emulation + does not need this call. + + Parameter: + driver = driver-Id + command = ISDN_STAT_BSENT + arg = channel-number, locally to the driver. (starting with 0) + parm.length = ***CHANGEI.1.21: New field. + the driver has to set this to the original length + of the skb at the time of receiving it from the linklevel. + + ISDN_STAT_NODCH: + + With this call, the driver has to respond to a prior ISDN_CMD_DIAL, if + no D-Channel is available. + + Parameter: + driver = driver-Id + command = ISDN_STAT_NODCH + arg = channel-number, locally to the driver. (starting with 0) + parm = unused. + + ISDN_STAT_ADDCH: + + This call is for HL-drivers, which are unable to check card-type + or numbers of supported channels before they have loaded any firmware + using ioctl. Those HL-driver simply set the channel-parameter to a + minimum channel-number when registering, and later if they know + the real amount, perform this call, allocating additional channels. + + Parameter: + driver = driver-Id + command = ISDN_STAT_ADDCH + arg = number of channels to be added. + parm = unused. + + ISDN_STAT_CAUSE: + + With this call, the HL-driver delivers CAUSE-messages to the LL. + Currently the LL does not use this messages. Their contents is simply + logged via kernel-messages. Therefore, currently the format of the + messages is completely free. However they should be printable. + + Parameter: + driver = driver-Id + command = ISDN_STAT_NODCH + arg = channel-number, locally to the driver. (starting with 0) + parm.num = ASCII string containing CAUSE-message. + + ISDN_STAT_DISPLAY: + + With this call, the HL-driver delivers DISPLAY-messages to the LL. + Currently the LL does not use this messages. + + Parameter: + driver = driver-Id + command = ISDN_STAT_DISPLAY + arg = channel-number, locally to the driver. (starting with 0) + para.display= string containing DISPLAY-message. + + ISDN_STAT_PROT: + + With this call, the HL-driver delivers protocol specific infos to the LL. + The call is not implicitely bound to a connection. + + Parameter: + driver = driver-Id + command = ISDN_STAT_PROT + arg = The lower 8 Bits define the addressed protocol as defined + in ISDN_PTYPE..., the upper bits are used to differentiate + the protocol specific STAT. + + para = protocol and function specific. See isdnif.h for detail. + + ISDN_STAT_DISCH: + + With this call, the HL-driver signals the LL to disable or enable the + use of supplied channel and driver. + The call may be used to reduce the available number of B-channels after + loading the driver. The LL has to ignore a disabled channel when searching + for free channels. The HL driver itself never delivers STAT callbacks for + disabled channels. + The LL returns a nonzero code if the operation was not successful or the + selected channel is actually regarded as busy. + + Parameter: + driver = driver-Id + command = ISDN_STAT_DISCH + arg = channel-number, locally to the driver. (starting with 0) + parm.num[0] = 0 if channel shall be disabled, else enabled. + + ISDN_STAT_L1ERR: + + ***CHANGEI1.21 new status message. + A signal can be sent to the linklevel if an Layer1-error results in + packet-loss on receive or send. The field errcode of the cmd.parm + union describes the error more precisely. + + Parameter: + driver = driver-Id + command = ISDN_STAT_L1ERR + arg = channel-number, locally to the driver. (starting with 0) + parm.errcode= ISDN_STAT_L1ERR_SEND: Packet lost while sending. + ISDN_STAT_L1ERR_RECV: Packet lost while receiving. + ISDN_STAT_FAXIND: + + With this call the HL-driver signals a fax sub-command to the LL. + For details refer to INTERFACE.fax + + Parameter: + driver = driver-Id. + command = ISDN_STAT_FAXIND + arg = channel-number, locally to the driver. (starting with 0) + parm = unused. + |