From beb116954b9b7f3bb56412b2494b562f02b864b1 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Tue, 7 Jan 1997 02:33:00 +0000 Subject: Import of Linux/MIPS 2.1.14 --- Documentation/isdn/INTERFACE | 644 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 644 insertions(+) create mode 100644 Documentation/isdn/INTERFACE (limited to 'Documentation/isdn/INTERFACE') diff --git a/Documentation/isdn/INTERFACE b/Documentation/isdn/INTERFACE new file mode 100644 index 000000000..6ba401123 --- /dev/null +++ b/Documentation/isdn/INTERFACE @@ -0,0 +1,644 @@ +$Id: INTERFACE,v 1.3 1996/06/25 17:52:41 fritz 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 + + 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. + + 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. + +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 to 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; + + ***CHANGED.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 put + initialize this field to 0. + + void (*rcvcallb)(int, int, u_char*, int); + + ***CHANGEc1.14: Declared obsolete. Do NOT use this field/function + anymore, since it will be removed when all current + LL drivers have been changed accordingly. Use + rcvcallb_skb instead. + + This field will be set by LL. The HL-driver delivers received data- + packets by calling this function. + + Parameter: + int driver-Id + int Channel-number locally to the driver. (starting with 0) + u_char Pointer to received data. (in kernel-space) + int length of data-packet. + + void (*rcvcallb_skb)(int, int, struct sk_buff *) + + ***CHANGED.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)(int, int, u_char*, int, int); + + ***CHANGEc1.14: Declared obsolete. Do NOT use this field/function + anymore, since it will be removed when all current + LL drivers have been changed accordingly. Set this + field to NULL and use writebuf_skb instead. + + 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 ***CHANGE.7.4: New parameter. + int channel-number locally to the HL-driver. (starts with 0) + u_char* pointer to data. + int length of data-packet. + 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) + + Returnvalue: + Length of data accepted on success, else error-code (-EINVAL on + oversized packets etc.) + + int (*writebuf_skb)(int, int, struct sk_buff *) + + ***CHANGED.7.4: 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 ***CHANGE.7.4: New parameter. + int channel-number locally to the HL-driver. (starts with 0) + 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) + +***CHANGEc1.14: 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) + +***CHANGEc1.14: 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 always is set to the + appropriate driver-Id. + + Until now, the following commands are defined: + + + 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 + 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) + num = An ASCII-String containing the number to dial, the own + EAZ or MSN, the Service-Indicator and the Additional + Info. Format: + "%s,%s,%d,%d" RemotePhoneNumber,EazOrMsn,SI,AI + If the Line has been designed as SPV (a special german + feature, meaning semi-leased-line) the number 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) + num = 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) + num = 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) + num = 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) + num = 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) + 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) + 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) + 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) + 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... + num = 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) + num = 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... + num = unused. + + 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) + num = unused. + Returnvalue: + current protocol-Id (one of the constants ISDN_L3_PROTO) + + ISDN_CMD_LOCK: + + With this command the HL-driver is told, that it will be used by the + LL and therefore may not be unloaded. The HL-driver should use + MOD_INC_USE_COUNT to tell that to the kernel. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_LOCK + arg = unused. + num = unused. + + ISDN_CMD_UNLOCK: + + With this command the HL-driver is told, that it is no more used by the + LL and therefore may be unloaded. The HL-driver should use + DEC_INC_USE_COUNT to tell that to the kernel. + + Parameter: + driver = driver-Id. + command = ISDN_CMD_UNLOCK + arg = unused. + num = unused. + +3. Description of the events to be signaled by the HL-driver to th 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. + num = unused. + + ISDN_STAT_ICALL: + + With this call, the HL-driver signals an incoming call to the LL. + + Parameter: + driver = driver-Id + command = ISDN_STAT_ICALL + arg = channel-number, locally to the driver. (starting with 0) + num = ASCII-String in the following format: + "%s,%d,%d,%s",CallerNumber,ServiceIndicator,AddInfo, + CalledNumber. + + 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. + num = 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. + num = 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) + num = 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) + + Parameter: + driver = driver-Id + command = ISDN_STAT_BCONN + arg = channel-number, locally to the driver. (starting with 0) + num = unused. + + 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) + num = 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. + + Parameter: + driver = driver-Id + command = ISDN_STAT_BHUP + arg = channel-number, locally to the driver. (starting with 0) + num = 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) + 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. + num = 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) + num = unused. + + 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) + num = unused. + + ISDN_STAT_ADDCH: (currently unused) + + This call is planned 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 zero + or 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 = to be defined. + num = to be defined. + + 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 currently 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) + num = ASCII string containing CAUSE-message. + -- cgit v1.2.3