1/*********************************************************************
  2 *                
  3 * Filename:      litelink.c
  4 * Version:       1.1
  5 * Description:   Driver for the Parallax LiteLink dongle
  6 * Status:        Stable
  7 * Author:        Dag Brattli <dagb@cs.uit.no>
  8 * Created at:    Fri May  7 12:50:33 1999
  9 * Modified at:   Fri Dec 17 09:14:23 1999
 10 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 11 * 
 12 *     Copyright (c) 1999 Dag Brattli, All Rights Reserved.
 13 *     
 14 *     This program is free software; you can redistribute it and/or 
 15 *     modify it under the terms of the GNU General Public License as 
 16 *     published by the Free Software Foundation; either version 2 of 
 17 *     the License, or (at your option) any later version.
 18 * 
 19 *     This program is distributed in the hope that it will be useful,
 20 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 21 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 22 *     GNU General Public License for more details.
 23 * 
 24 *     You should have received a copy of the GNU General Public License 
 25 *     along with this program; if not, write to the Free Software 
 26 *     Foundation, Inc., 59 Temple Place, Suite 330, Boston, 
 27 *     MA 02111-1307 USA
 28 *     
 29 ********************************************************************/
 30
 31/*
 32 * Modified at:   Thu Jan 15 2003
 33 * Modified by:   Eugene Crosser <crosser@average.org>
 34 *
 35 * Convert to "new" IRDA infrastructure for kernel 2.6
 36 */
 37
 38#include <linux/module.h>
 39#include <linux/delay.h>
 40#include <linux/init.h>
 41
 42#include <net/irda/irda.h>
 43
 44#include "sir-dev.h"
 45
 46#define MIN_DELAY 25      /* 15 us, but wait a little more to be sure */
 47#define MAX_DELAY 10000   /* 1 ms */
 48
 49static int litelink_open(struct sir_dev *dev);
 50static int litelink_close(struct sir_dev *dev);
 51static int litelink_change_speed(struct sir_dev *dev, unsigned speed);
 52static int litelink_reset(struct sir_dev *dev);
 53
 54/* These are the baudrates supported - 9600 must be last one! */
 55static unsigned baud_rates[] = { 115200, 57600, 38400, 19200, 9600 };
 56
 57static struct dongle_driver litelink = {
 58	.owner		= THIS_MODULE,
 59	.driver_name	= "Parallax LiteLink",
 60	.type		= IRDA_LITELINK_DONGLE,
 61	.open		= litelink_open,
 62	.close		= litelink_close,
 63	.reset		= litelink_reset,
 64	.set_speed	= litelink_change_speed,
 65};
 66
 67static int __init litelink_sir_init(void)
 68{
 69	return irda_register_dongle(&litelink);
 70}
 71
 72static void __exit litelink_sir_cleanup(void)
 73{
 74	irda_unregister_dongle(&litelink);
 75}
 76
 77static int litelink_open(struct sir_dev *dev)
 78{
 79	struct qos_info *qos = &dev->qos;
 80
 81	IRDA_DEBUG(2, "%s()\n", __func__);
 82
 83	/* Power up dongle */
 84	sirdev_set_dtr_rts(dev, TRUE, TRUE);
 85
 86	/* Set the speeds we can accept */
 87	qos->baud_rate.bits &= IR_115200|IR_57600|IR_38400|IR_19200|IR_9600;
 88	qos->min_turn_time.bits = 0x7f; /* Needs 0.01 ms */
 89	irda_qos_bits_to_value(qos);
 90
 91	/* irda thread waits 50 msec for power settling */
 92
 93	return 0;
 94}
 95
 96static int litelink_close(struct sir_dev *dev)
 97{
 98	IRDA_DEBUG(2, "%s()\n", __func__);
 99
100	/* Power off dongle */
101	sirdev_set_dtr_rts(dev, FALSE, FALSE);
102
103	return 0;
104}
105
106/*
107 * Function litelink_change_speed (task)
108 *
109 *    Change speed of the Litelink dongle. To cycle through the available 
110 *    baud rates, pulse RTS low for a few ms.  
111 */
112static int litelink_change_speed(struct sir_dev *dev, unsigned speed)
113{
114        int i;
115
116	IRDA_DEBUG(2, "%s()\n", __func__);
117
118	/* dongle already reset by irda-thread - current speed (dongle and
119	 * port) is the default speed (115200 for litelink!)
120	 */
121
122	/* Cycle through avaiable baudrates until we reach the correct one */
123	for (i = 0; baud_rates[i] != speed; i++) {
124
125		/* end-of-list reached due to invalid speed request */
126		if (baud_rates[i] == 9600)
127			break;
128
129		/* Set DTR, clear RTS */
130		sirdev_set_dtr_rts(dev, FALSE, TRUE);
131
132		/* Sleep a minimum of 15 us */
133		udelay(MIN_DELAY);
134
135		/* Set DTR, Set RTS */
136		sirdev_set_dtr_rts(dev, TRUE, TRUE);
137
138		/* Sleep a minimum of 15 us */
139		udelay(MIN_DELAY);
140        }
141
142	dev->speed = baud_rates[i];
143
144	/* invalid baudrate should not happen - but if, we return -EINVAL and
145	 * the dongle configured for 9600 so the stack has a chance to recover
146	 */
147
148	return (dev->speed == speed) ? 0 : -EINVAL;
149}
150
151/*
152 * Function litelink_reset (task)
153 *
154 *      Reset the Litelink type dongle.
155 *
156 */
157static int litelink_reset(struct sir_dev *dev)
158{
159	IRDA_DEBUG(2, "%s()\n", __func__);
160
161	/* probably the power-up can be dropped here, but with only
162	 * 15 usec delay it's not worth the risk unless somebody with
163	 * the hardware confirms it doesn't break anything...
164	 */
165
166	/* Power on dongle */
167	sirdev_set_dtr_rts(dev, TRUE, TRUE);
168
169	/* Sleep a minimum of 15 us */
170	udelay(MIN_DELAY);
171
172	/* Clear RTS to reset dongle */
173	sirdev_set_dtr_rts(dev, TRUE, FALSE);
174
175	/* Sleep a minimum of 15 us */
176	udelay(MIN_DELAY);
177
178	/* Go back to normal mode */
179	sirdev_set_dtr_rts(dev, TRUE, TRUE);
180
181	/* Sleep a minimum of 15 us */
182	udelay(MIN_DELAY);
183
184	/* This dongles speed defaults to 115200 bps */
185	dev->speed = 115200;
186
187	return 0;
188}
189
190MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
191MODULE_DESCRIPTION("Parallax Litelink dongle driver");	
192MODULE_LICENSE("GPL");
193MODULE_ALIAS("irda-dongle-5"); /* IRDA_LITELINK_DONGLE */
194
195/*
196 * Function init_module (void)
197 *
198 *    Initialize Litelink module
199 *
200 */
201module_init(litelink_sir_init);
202
203/*
204 * Function cleanup_module (void)
205 *
206 *    Cleanup Litelink module
207 *
208 */
209module_exit(litelink_sir_cleanup);