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, see <http://www.gnu.org/licenses/>.
26 *
27 ********************************************************************/
28
29/*
30 * Modified at:   Thu Jan 15 2003
31 * Modified by:   Eugene Crosser <crosser@average.org>
32 *
33 * Convert to "new" IRDA infrastructure for kernel 2.6
34 */
35
36#include <linux/module.h>
37#include <linux/delay.h>
38#include <linux/init.h>
39
40#include <net/irda/irda.h>
41
42#include "sir-dev.h"
43
44#define MIN_DELAY 25      /* 15 us, but wait a little more to be sure */
45#define MAX_DELAY 10000   /* 1 ms */
46
47static int litelink_open(struct sir_dev *dev);
48static int litelink_close(struct sir_dev *dev);
49static int litelink_change_speed(struct sir_dev *dev, unsigned speed);
50static int litelink_reset(struct sir_dev *dev);
51
52/* These are the baudrates supported - 9600 must be last one! */
53static unsigned baud_rates[] = { 115200, 57600, 38400, 19200, 9600 };
54
55static struct dongle_driver litelink = {
56	.owner		= THIS_MODULE,
57	.driver_name	= "Parallax LiteLink",
58	.type		= IRDA_LITELINK_DONGLE,
59	.open		= litelink_open,
60	.close		= litelink_close,
61	.reset		= litelink_reset,
62	.set_speed	= litelink_change_speed,
63};
64
65static int __init litelink_sir_init(void)
66{
67	return irda_register_dongle(&litelink);
68}
69
70static void __exit litelink_sir_cleanup(void)
71{
72	irda_unregister_dongle(&litelink);
73}
74
75static int litelink_open(struct sir_dev *dev)
76{
77	struct qos_info *qos = &dev->qos;
78
79	/* Power up dongle */
80	sirdev_set_dtr_rts(dev, TRUE, TRUE);
81
82	/* Set the speeds we can accept */
83	qos->baud_rate.bits &= IR_115200|IR_57600|IR_38400|IR_19200|IR_9600;
84	qos->min_turn_time.bits = 0x7f; /* Needs 0.01 ms */
85	irda_qos_bits_to_value(qos);
86
87	/* irda thread waits 50 msec for power settling */
88
89	return 0;
90}
91
92static int litelink_close(struct sir_dev *dev)
93{
94	/* Power off dongle */
95	sirdev_set_dtr_rts(dev, FALSE, FALSE);
96
97	return 0;
98}
99
100/*
101 * Function litelink_change_speed (task)
102 *
103 *    Change speed of the Litelink dongle. To cycle through the available
104 *    baud rates, pulse RTS low for a few ms.
105 */
106static int litelink_change_speed(struct sir_dev *dev, unsigned speed)
107{
108        int i;
109
110	/* dongle already reset by irda-thread - current speed (dongle and
111	 * port) is the default speed (115200 for litelink!)
112	 */
113
114	/* Cycle through avaiable baudrates until we reach the correct one */
115	for (i = 0; baud_rates[i] != speed; i++) {
116
117		/* end-of-list reached due to invalid speed request */
118		if (baud_rates[i] == 9600)
119			break;
120
121		/* Set DTR, clear RTS */
122		sirdev_set_dtr_rts(dev, FALSE, TRUE);
123
124		/* Sleep a minimum of 15 us */
125		udelay(MIN_DELAY);
126
127		/* Set DTR, Set RTS */
128		sirdev_set_dtr_rts(dev, TRUE, TRUE);
129
130		/* Sleep a minimum of 15 us */
131		udelay(MIN_DELAY);
132        }
133
134	dev->speed = baud_rates[i];
135
136	/* invalid baudrate should not happen - but if, we return -EINVAL and
137	 * the dongle configured for 9600 so the stack has a chance to recover
138	 */
139
140	return (dev->speed == speed) ? 0 : -EINVAL;
141}
142
143/*
144 * Function litelink_reset (task)
145 *
146 *      Reset the Litelink type dongle.
147 *
148 */
149static int litelink_reset(struct sir_dev *dev)
150{
151	/* probably the power-up can be dropped here, but with only
152	 * 15 usec delay it's not worth the risk unless somebody with
153	 * the hardware confirms it doesn't break anything...
154	 */
155
156	/* Power on dongle */
157	sirdev_set_dtr_rts(dev, TRUE, TRUE);
158
159	/* Sleep a minimum of 15 us */
160	udelay(MIN_DELAY);
161
162	/* Clear RTS to reset dongle */
163	sirdev_set_dtr_rts(dev, TRUE, FALSE);
164
165	/* Sleep a minimum of 15 us */
166	udelay(MIN_DELAY);
167
168	/* Go back to normal mode */
169	sirdev_set_dtr_rts(dev, TRUE, TRUE);
170
171	/* Sleep a minimum of 15 us */
172	udelay(MIN_DELAY);
173
174	/* This dongles speed defaults to 115200 bps */
175	dev->speed = 115200;
176
177	return 0;
178}
179
180MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
181MODULE_DESCRIPTION("Parallax Litelink dongle driver");
182MODULE_LICENSE("GPL");
183MODULE_ALIAS("irda-dongle-5"); /* IRDA_LITELINK_DONGLE */
184
185/*
186 * Function init_module (void)
187 *
188 *    Initialize Litelink module
189 *
190 */
191module_init(litelink_sir_init);
192
193/*
194 * Function cleanup_module (void)
195 *
196 *    Cleanup Litelink module
197 *
198 */
199module_exit(litelink_sir_cleanup);
200