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kernel/linux-rt-4.4.41/drivers/isdn/hardware/eicon/dqueue.c 2.12 KB
5113f6f70   김현기   kernel add
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  /* $Id: dqueue.c,v 1.5 2003/04/12 21:40:49 schindler Exp $
   *
   * Driver for Eicon DIVA Server ISDN cards.
   * User Mode IDI Interface
   *
   * Copyright 2000-2003 by Armin Schindler (mac@melware.de)
   * Copyright 2000-2003 Cytronics & Melware (info@melware.de)
   *
   * This software may be used and distributed according to the terms
   * of the GNU General Public License, incorporated herein by reference.
   */
  
  #include "platform.h"
  #include "dqueue.h"
  
  int
  diva_data_q_init(diva_um_idi_data_queue_t *q,
  		 int max_length, int max_segments)
  {
  	int i;
  
  	q->max_length = max_length;
  	q->segments = max_segments;
  
  	for (i = 0; i < q->segments; i++) {
  		q->data[i] = NULL;
  		q->length[i] = 0;
  	}
  	q->read = q->write = q->count = q->segment_pending = 0;
  
  	for (i = 0; i < q->segments; i++) {
  		if (!(q->data[i] = diva_os_malloc(0, q->max_length))) {
  			diva_data_q_finit(q);
  			return (-1);
  		}
  	}
  
  	return (0);
  }
  
  int diva_data_q_finit(diva_um_idi_data_queue_t *q)
  {
  	int i;
  
  	for (i = 0; i < q->segments; i++) {
  		if (q->data[i]) {
  			diva_os_free(0, q->data[i]);
  		}
  		q->data[i] = NULL;
  		q->length[i] = 0;
  	}
  	q->read = q->write = q->count = q->segment_pending = 0;
  
  	return (0);
  }
  
  int diva_data_q_get_max_length(const diva_um_idi_data_queue_t *q)
  {
  	return (q->max_length);
  }
  
  void *diva_data_q_get_segment4write(diva_um_idi_data_queue_t *q)
  {
  	if ((!q->segment_pending) && (q->count < q->segments)) {
  		q->segment_pending = 1;
  		return (q->data[q->write]);
  	}
  
  	return NULL;
  }
  
  void
  diva_data_q_ack_segment4write(diva_um_idi_data_queue_t *q, int length)
  {
  	if (q->segment_pending) {
  		q->length[q->write] = length;
  		q->count++;
  		q->write++;
  		if (q->write >= q->segments) {
  			q->write = 0;
  		}
  		q->segment_pending = 0;
  	}
  }
  
  const void *diva_data_q_get_segment4read(const diva_um_idi_data_queue_t *
  					 q)
  {
  	if (q->count) {
  		return (q->data[q->read]);
  	}
  	return NULL;
  }
  
  int diva_data_q_get_segment_length(const diva_um_idi_data_queue_t *q)
  {
  	return (q->length[q->read]);
  }
  
  void diva_data_q_ack_segment4read(diva_um_idi_data_queue_t *q)
  {
  	if (q->count) {
  		q->length[q->read] = 0;
  		q->count--;
  		q->read++;
  		if (q->read >= q->segments) {
  			q->read = 0;
  		}
  	}
  }