diff options
Diffstat (limited to 'Documentation/isdn')
| -rw-r--r-- | Documentation/isdn/INTERFACE.CAPI | 90 |
1 files changed, 88 insertions, 2 deletions
diff --git a/Documentation/isdn/INTERFACE.CAPI b/Documentation/isdn/INTERFACE.CAPI index 463153816162..686e107923ec 100644 --- a/Documentation/isdn/INTERFACE.CAPI +++ b/Documentation/isdn/INTERFACE.CAPI @@ -114,20 +114,36 @@ char *driver_name int (*load_firmware)(struct capi_ctr *ctrlr, capiloaddata *ldata) (optional) pointer to a callback function for sending firmware and configuration data to the device + Return value: 0 on success, error code on error + Called in process context. void (*reset_ctr)(struct capi_ctr *ctrlr) - pointer to a callback function for performing a reset on the device, - releasing all registered applications + (optional) pointer to a callback function for performing a reset on + the device, releasing all registered applications + Called in process context. void (*register_appl)(struct capi_ctr *ctrlr, u16 applid, capi_register_params *rparam) void (*release_appl)(struct capi_ctr *ctrlr, u16 applid) pointers to callback functions for registration and deregistration of applications with the device + Calls to these functions are serialized by Kernel CAPI so that only + one call to any of them is active at any time. u16 (*send_message)(struct capi_ctr *ctrlr, struct sk_buff *skb) pointer to a callback function for sending a CAPI message to the device + Return value: CAPI error code + If the method returns 0 (CAPI_NOERROR) the driver has taken ownership + of the skb and the caller may no longer access it. If it returns a + non-zero (error) value then ownership of the skb returns to the caller + who may reuse or free it. + The return value should only be used to signal problems with respect + to accepting or queueing the message. Errors occurring during the + actual processing of the message should be signaled with an + appropriate reply message. + Calls to this function are not serialized by Kernel CAPI, ie. it must + be prepared to be re-entered. char *(*procinfo)(struct capi_ctr *ctrlr) pointer to a callback function returning the entry for the device in @@ -138,6 +154,8 @@ read_proc_t *ctr_read_proc system entry, /proc/capi/controllers/<n>; will be called with a pointer to the device's capi_ctr structure as the last (data) argument +Note: Callback functions are never called in interrupt context. + - to be filled in before calling capi_ctr_ready(): u8 manu[CAPI_MANUFACTURER_LEN] @@ -153,6 +171,45 @@ u8 serial[CAPI_SERIAL_LEN] value to return for CAPI_GET_SERIAL +4.3 The _cmsg Structure + +(declared in <linux/isdn/capiutil.h>) + +The _cmsg structure stores the contents of a CAPI 2.0 message in an easily +accessible form. It contains members for all possible CAPI 2.0 parameters, of +which only those appearing in the message type currently being processed are +actually used. Unused members should be set to zero. + +Members are named after the CAPI 2.0 standard names of the parameters they +represent. See <linux/isdn/capiutil.h> for the exact spelling. Member data +types are: + +u8 for CAPI parameters of type 'byte' + +u16 for CAPI parameters of type 'word' + +u32 for CAPI parameters of type 'dword' + +_cstruct for CAPI parameters of type 'struct' not containing any + variably-sized (struct) subparameters (eg. 'Called Party Number') + The member is a pointer to a buffer containing the parameter in + CAPI encoding (length + content). It may also be NULL, which will + be taken to represent an empty (zero length) parameter. + +_cmstruct for CAPI parameters of type 'struct' containing 'struct' + subparameters ('Additional Info' and 'B Protocol') + The representation is a single byte containing one of the values: + CAPI_DEFAULT: the parameter is empty + CAPI_COMPOSE: the values of the subparameters are stored + individually in the corresponding _cmsg structure members + +Functions capi_cmsg2message() and capi_message2cmsg() are provided to convert +messages between their transport encoding described in the CAPI 2.0 standard +and their _cmsg structure representation. Note that capi_cmsg2message() does +not know or check the size of its destination buffer. The caller must make +sure it is big enough to accomodate the resulting CAPI message. + + 5. Lower Layer Interface Functions (declared in <linux/isdn/capilli.h>) @@ -211,3 +268,32 @@ CAPIMSG_CONTROL(m) CAPIMSG_SETCONTROL(m, contr) Controller/PLCI/NCCI (u32) CAPIMSG_DATALEN(m) CAPIMSG_SETDATALEN(m, len) Data Length (u16) + +Library functions for working with _cmsg structures +(from <linux/isdn/capiutil.h>): + +unsigned capi_cmsg2message(_cmsg *cmsg, u8 *msg) + Assembles a CAPI 2.0 message from the parameters in *cmsg, storing the + result in *msg. + +unsigned capi_message2cmsg(_cmsg *cmsg, u8 *msg) + Disassembles the CAPI 2.0 message in *msg, storing the parameters in + *cmsg. + +unsigned capi_cmsg_header(_cmsg *cmsg, u16 ApplId, u8 Command, u8 Subcommand, + u16 Messagenumber, u32 Controller) + Fills the header part and address field of the _cmsg structure *cmsg + with the given values, zeroing the remainder of the structure so only + parameters with non-default values need to be changed before sending + the message. + +void capi_cmsg_answer(_cmsg *cmsg) + Sets the low bit of the Subcommand field in *cmsg, thereby converting + _REQ to _CONF and _IND to _RESP. + +char *capi_cmd2str(u8 Command, u8 Subcommand) + Returns the CAPI 2.0 message name corresponding to the given command + and subcommand values, as a static ASCII string. The return value may + be NULL if the command/subcommand is not one of those defined in the + CAPI 2.0 standard. + |