[deliverable/linux.git] / drivers / isdn / hardware / eicon / dqueue.c

/* $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;
		}
	}
}
Commit	Line	Data
1da177e4 LT	1	/* $Id: dqueue.c,v 1.5 2003/04/12 21:40:49 schindler Exp $
	2	*
	3	* Driver for Eicon DIVA Server ISDN cards.
	4	* User Mode IDI Interface
	5	*
	6	* Copyright 2000-2003 by Armin Schindler (mac@melware.de)
	7	* Copyright 2000-2003 Cytronics & Melware (info@melware.de)
	8	*
	9	* This software may be used and distributed according to the terms
	10	* of the GNU General Public License, incorporated herein by reference.
	11	*/
	12
	13	#include "platform.h"
	14	#include "dqueue.h"
	15
	16	int
475be4d8	17	diva_data_q_init(diva_um_idi_data_queue_t *q,
1da177e4 LT	18	int max_length, int max_segments)
	19	{
	20	int i;
	21
	22	q->max_length = max_length;
	23	q->segments = max_segments;
	24
	25	for (i = 0; i < q->segments; i++) {
	26	q->data[i] = NULL;
	27	q->length[i] = 0;
	28	}
	29	q->read = q->write = q->count = q->segment_pending = 0;
	30
	31	for (i = 0; i < q->segments; i++) {
	32	if (!(q->data[i] = diva_os_malloc(0, q->max_length))) {
	33	diva_data_q_finit(q);
	34	return (-1);
	35	}
	36	}
	37
	38	return (0);
	39	}
	40
475be4d8	41	int diva_data_q_finit(diva_um_idi_data_queue_t *q)
1da177e4 LT	42	{
	43	int i;
	44
	45	for (i = 0; i < q->segments; i++) {
	46	if (q->data[i]) {
	47	diva_os_free(0, q->data[i]);
	48	}
	49	q->data[i] = NULL;
	50	q->length[i] = 0;
	51	}
	52	q->read = q->write = q->count = q->segment_pending = 0;
	53
	54	return (0);
	55	}
	56
475be4d8	57	int diva_data_q_get_max_length(const diva_um_idi_data_queue_t *q)
1da177e4 LT	58	{
	59	return (q->max_length);
	60	}
	61
475be4d8	62	void diva_data_q_get_segment4write(diva_um_idi_data_queue_t q)
1da177e4 LT	63	{
	64	if ((!q->segment_pending) && (q->count < q->segments)) {
	65	q->segment_pending = 1;
	66	return (q->data[q->write]);
	67	}
	68
	69	return NULL;
	70	}
	71
	72	void
475be4d8	73	diva_data_q_ack_segment4write(diva_um_idi_data_queue_t *q, int length)
1da177e4 LT	74	{
	75	if (q->segment_pending) {
	76	q->length[q->write] = length;
	77	q->count++;
	78	q->write++;
	79	if (q->write >= q->segments) {
	80	q->write = 0;
	81	}
	82	q->segment_pending = 0;
	83	}
	84	}
	85
	86	const void diva_data_q_get_segment4read(const diva_um_idi_data_queue_t
	87	q)
	88	{
	89	if (q->count) {
	90	return (q->data[q->read]);
	91	}
	92	return NULL;
	93	}
	94
475be4d8	95	int diva_data_q_get_segment_length(const diva_um_idi_data_queue_t *q)
1da177e4 LT	96	{
	97	return (q->length[q->read]);
	98	}
	99
475be4d8	100	void diva_data_q_ack_segment4read(diva_um_idi_data_queue_t *q)
1da177e4 LT	101	{
	102	if (q->count) {
	103	q->length[q->read] = 0;
	104	q->count--;
	105	q->read++;
	106	if (q->read >= q->segments) {
	107	q->read = 0;
	108	}
	109	}
	110	}