1 files changed, 170 insertions, 0 deletions

diff --git a/drivers/telephony/phonedev.c b/drivers/telephony/phonedev.c
new file mode 100644
index 000000000000..3c987f49f6b4
--- /dev/null
+++ b/drivers/telephony/phonedev.c
@@ -0,0 +1,170 @@
+/*
+ *            Telephony registration for Linux
+ *
+ *              (c) Copyright 1999 Red Hat Software Inc.
+ *
+ *              This program is free software; you can redistribute it and/or
+ *              modify it under the terms of the GNU General Public License
+ *              as published by the Free Software Foundation; either version
+ *              2 of the License, or (at your option) any later version.
+ *
+ * Author:      Alan Cox, <alan@redhat.com>
+ *
+ * Fixes:       Mar 01 2000 Thomas Sparr, <thomas.l.sparr@telia.com>
+ *              phone_register_device now works with unit!=PHONE_UNIT_ANY
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/phonedev.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#include <linux/kmod.h>
+#include <linux/sem.h>
+#include <linux/devfs_fs_kernel.h>
+
+#define PHONE_NUM_DEVICES       256
+
+/*
+ *    Active devices 
+ */
+
+static struct phone_device *phone_device[PHONE_NUM_DEVICES];
+static DECLARE_MUTEX(phone_lock);
+
+/*
+ *    Open a phone device.
+ */
+
+static int phone_open(struct inode *inode, struct file *file)
+{
+        unsigned int minor = iminor(inode);
+        int err = 0;
+        struct phone_device *p;
+        struct file_operations *old_fops, *new_fops = NULL;
+
+        if (minor >= PHONE_NUM_DEVICES)
+                return -ENODEV;
+
+        down(&phone_lock);
+        p = phone_device[minor];
+        if (p)
+                new_fops = fops_get(p->f_op);
+        if (!new_fops) {
+                up(&phone_lock);
+                request_module("char-major-%d-%d", PHONE_MAJOR, minor);
+                down(&phone_lock);
+                p = phone_device[minor];
+                if (p == NULL || (new_fops = fops_get(p->f_op)) == NULL)
+                {
+                        err=-ENODEV;
+                        goto end;
+                }
+        }
+        old_fops = file->f_op;
+        file->f_op = new_fops;
+        if (p->open)
+                err = p->open(p, file); /* Tell the device it is open */
+        if (err) {
+                fops_put(file->f_op);
+                file->f_op = fops_get(old_fops);
+        }
+        fops_put(old_fops);
+end:
+        up(&phone_lock);
+        return err;
+}
+
+/*
+ *    Telephony For Linux device drivers request registration here.
+ */
+
+int phone_register_device(struct phone_device *p, int unit)
+{
+        int base;
+        int end;
+        int i;
+
+        base = 0;
+        end = PHONE_NUM_DEVICES - 1;
+
+        if (unit != PHONE_UNIT_ANY) {
+                base = unit;
+                end = unit + 1;  /* enter the loop at least one time */
+        }
+        
+        down(&phone_lock);
+        for (i = base; i < end; i++) {
+                if (phone_device[i] == NULL) {
+                        phone_device[i] = p;
+                        p->minor = i;
+                        devfs_mk_cdev(MKDEV(PHONE_MAJOR,i),
+                                S_IFCHR|S_IRUSR|S_IWUSR, "phone/%d", i);
+                        up(&phone_lock);
+                        return 0;
+                }
+        }
+        up(&phone_lock);
+        return -ENFILE;
+}
+
+/*
+ *    Unregister an unused Telephony for linux device
+ */
+
+void phone_unregister_device(struct phone_device *pfd)
+{
+        down(&phone_lock);
+        if (phone_device[pfd->minor] != pfd)
+                panic("phone: bad unregister");
+        devfs_remove("phone/%d", pfd->minor);
+        phone_device[pfd->minor] = NULL;
+        up(&phone_lock);
+}
+
+
+static struct file_operations phone_fops =
+{
+        .owner          = THIS_MODULE,
+        .open           = phone_open,
+};
+
+/*
+ *      Board init functions
+ */
+ 
+
+/*
+ *    Initialise Telephony for linux
+ */
+
+static int __init telephony_init(void)
+{
+        printk(KERN_INFO "Linux telephony interface: v1.00\n");
+        if (register_chrdev(PHONE_MAJOR, "telephony", &phone_fops)) {
+                printk("phonedev: unable to get major %d\n", PHONE_MAJOR);
+                return -EIO;
+        }
+
+        return 0;
+}
+
+static void __exit telephony_exit(void)
+{
+        unregister_chrdev(PHONE_MAJOR, "telephony");
+}
+
+module_init(telephony_init);
+module_exit(telephony_exit);
+
+MODULE_LICENSE("GPL");
+
+EXPORT_SYMBOL(phone_register_device);
+EXPORT_SYMBOL(phone_unregister_device);