isdn: capi: dead code removal

2. Driver and Device Registration

=================================

CAPI drivers optionally register themselves with Kernel CAPI by calling the

Kernel CAPI function register_capi_driver() with a pointer to a struct

capi_driver. This structure must be filled with the name and revision of the

driver, and optionally a pointer to a callback function, add_card(). The

registration can be revoked by calling the function unregister_capi_driver()

with a pointer to the same struct capi_driver.

CAPI drivers must register each of the ISDN devices they control with Kernel

CAPI by calling the Kernel CAPI function attach_capi_ctr() with a pointer to a

struct capi_ctr before they can be used. This structure must be filled with

	the name of the driver, as a zero-terminated ASCII string

``char revision[32]``

	the revision number of the driver, as a zero-terminated ASCII string

``int (*add_card)(struct capi_driver *driver, capicardparams *data)``

	a callback function pointer (may be NULL)

4.2 struct capi_ctr

-------------------

	pointer to a callback function returning the entry for the device in

	the CAPI controller info table, /proc/capi/controller

``const struct file_operations *proc_fops``

	pointers to callback functions for the device's proc file

	system entry, /proc/capi/controllers/<n>; pointer to the device's

	capi_ctr structure is available from struct proc_dir_entry::data

	which is available from struct inode.

Note:

  Callback functions except send_message() are never called in interrupt

  context.

	    _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 accommodate the resulting CAPI message.

5. Lower Layer Interface Functions

==================================

(declared in <linux/isdn/capilli.h>)

::

  void register_capi_driver(struct capi_driver *drvr)

  void unregister_capi_driver(struct capi_driver *drvr)

register/unregister a driver with Kernel CAPI

::

  int attach_capi_ctr(struct capi_ctr *ctrlr)

signal controller ready/not ready

::

  void capi_ctr_suspend_output(struct capi_ctr *ctrlr)

  void capi_ctr_resume_output(struct capi_ctr *ctrlr)

signal suspend/resume

::

  void capi_ctr_handle_message(struct capi_ctr * ctrlr, u16 applid,

6. Helper Functions and Macros

==============================

Library functions (from <linux/isdn/capilli.h>):

::

  void capilib_new_ncci(struct list_head *head, u16 applid,

			u32 ncci, u32 winsize)

  void capilib_free_ncci(struct list_head *head, u16 applid, u32 ncci)

  void capilib_release_appl(struct list_head *head, u16 applid)

  void capilib_release(struct list_head *head)

  void capilib_data_b3_conf(struct list_head *head, u16 applid,

			u32 ncci, u16 msgid)

  u16  capilib_data_b3_req(struct list_head *head, u16 applid,

			u32 ncci, u16 msgid)

Macros to extract/set element values from/in a CAPI message header

(from <linux/isdn/capiutil.h>):

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

# Object files in subdirectories

obj-$(CONFIG_ISDN_CAPI)			+= capi/

obj-$(CONFIG_BT_CMTP)			+= capi/

obj-$(CONFIG_MISDN)			+= mISDN/

obj-$(CONFIG_ISDN)			+= hardware/

# SPDX-License-Identifier: GPL-2.0-only

menuconfig ISDN_CAPI

	tristate "CAPI 2.0 subsystem"

config ISDN_CAPI

	def_bool ISDN && BT

	help

	  This provides CAPI (the Common ISDN Application Programming

	  Interface) Version 2.0, a standard making it easy for programs to

	  See CONFIG_BT_CMTP for the last remaining regular driver

	  in the kernel that uses the CAPI subsystem.

if ISDN_CAPI

config CAPI_TRACE

	bool "CAPI trace support"

	default y

	def_bool BT_CMTP

	help

	  If you say Y here, the kernelcapi driver can make verbose traces

	  of CAPI messages. This feature can be enabled/disabled via IOCTL for

	  every controller (default disabled).

	  This will increase the size of the kernelcapi module by 20 KB.

	  If unsure, say Y.

config ISDN_CAPI_CAPI20

	tristate "CAPI2.0 /dev/capi20 support"

	help

	  This option will provide the CAPI 2.0 interface to userspace

	  applications via /dev/capi20. Applications should use the

	  standardized libcapi20 to access this functionality.  You should say

	  Y/M here.

config ISDN_CAPI_MIDDLEWARE

	bool "CAPI2.0 Middleware support"

	depends on ISDN_CAPI_CAPI20 && TTY

	def_bool BT_CMTP && TTY

	help

	  This option will enhance the capabilities of the /dev/capi20

	  interface.  It will provide a means of moving a data connection,

	  established via the usual /dev/capi20 interface to a special tty

	  device.  If you want to use pppd with pppdcapiplugin to dial up to

	  your ISP, say Y here.

config ISDN_CAPI_CAPIDRV_VERBOSE

	bool "Verbose reason code reporting"

	depends on ISDN_CAPI_CAPIDRV

	help

	  If you say Y here, the capidrv interface will give verbose reasons

	  for disconnecting. This will increase the size of the kernel by 7 KB.

	  If unsure, say N.

endif

# SPDX-License-Identifier: GPL-2.0

# Makefile for the CAPI subsystem.

# Makefile for the CAPI subsystem used by BT_CMTP

# Ordering constraints: kernelcapi.o first

# Each configuration option enables a list of files.

obj-$(CONFIG_ISDN_CAPI)			+= kernelcapi.o

obj-$(CONFIG_ISDN_CAPI_CAPI20)		+= capi.o 

obj-$(CONFIG_ISDN_CAPI_CAPIDRV)		+= capidrv.o

# Multipart objects.

kernelcapi-y				:= kcapi.o capiutil.o capilib.o

kernelcapi-$(CONFIG_PROC_FS)		+= kcapi_proc.o

ccflags-y += -I$(srctree)/$(src)/../include -I$(srctree)/$(src)/../include/uapi

obj-$(CONFIG_BT_CMTP)			+= kernelcapi.o

kernelcapi-y				:= kcapi.o capiutil.o capi.o kcapi_proc.o

#include <linux/isdn/capiutil.h>

#include <linux/isdn/capicmd.h>

MODULE_DESCRIPTION("CAPI4Linux: Userspace /dev/capi20 interface");

#include "kcapi.h"

MODULE_DESCRIPTION("CAPI4Linux: kernel CAPI layer and /dev/capi20 interface");

MODULE_AUTHOR("Carsten Paeth");

MODULE_LICENSE("GPL");

{

	const char *compileinfo;

	int major_ret;

	int ret;

	ret = kcapi_init();

	if (ret)

		return ret;

	major_ret = register_chrdev(capi_major, "capi20", &capi_fops);

	if (major_ret < 0) {

		printk(KERN_ERR "capi20: unable to get major %d\n", capi_major);

		kcapi_exit();

		return major_ret;

	}

	capi_class = class_create(THIS_MODULE, "capi");

	if (IS_ERR(capi_class)) {

		unregister_chrdev(capi_major, "capi20");

		kcapi_exit();

		return PTR_ERR(capi_class);

	}

		device_destroy(capi_class, MKDEV(capi_major, 0));

		class_destroy(capi_class);

		unregister_chrdev(capi_major, "capi20");

		kcapi_exit();

		return -ENOMEM;

	}

	unregister_chrdev(capi_major, "capi20");

	capinc_tty_exit();

	kcapi_exit();

}

module_init(capi_init);