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
47 static int litelink_open(struct sir_dev *dev);
48 static int litelink_close(struct sir_dev *dev);
49 static int litelink_change_speed(struct sir_dev *dev, unsigned speed);
50 static int litelink_reset(struct sir_dev *dev);
51
52 /* These are the baudrates supported - 9600 must be last one! */
53 static unsigned baud_rates[] = { 115200, 57600, 38400, 19200, 9600 };
54
55 static 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
litelink_sir_init(void)65 static int __init litelink_sir_init(void)
66 {
67 return irda_register_dongle(&litelink);
68 }
69
litelink_sir_cleanup(void)70 static void __exit litelink_sir_cleanup(void)
71 {
72 irda_unregister_dongle(&litelink);
73 }
74
litelink_open(struct sir_dev * dev)75 static int litelink_open(struct sir_dev *dev)
76 {
77 struct qos_info *qos = &dev->qos;
78
79 IRDA_DEBUG(2, "%s()\n", __func__);
80
81 /* Power up dongle */
82 sirdev_set_dtr_rts(dev, TRUE, TRUE);
83
84 /* Set the speeds we can accept */
85 qos->baud_rate.bits &= IR_115200|IR_57600|IR_38400|IR_19200|IR_9600;
86 qos->min_turn_time.bits = 0x7f; /* Needs 0.01 ms */
87 irda_qos_bits_to_value(qos);
88
89 /* irda thread waits 50 msec for power settling */
90
91 return 0;
92 }
93
litelink_close(struct sir_dev * dev)94 static int litelink_close(struct sir_dev *dev)
95 {
96 IRDA_DEBUG(2, "%s()\n", __func__);
97
98 /* Power off dongle */
99 sirdev_set_dtr_rts(dev, FALSE, FALSE);
100
101 return 0;
102 }
103
104 /*
105 * Function litelink_change_speed (task)
106 *
107 * Change speed of the Litelink dongle. To cycle through the available
108 * baud rates, pulse RTS low for a few ms.
109 */
litelink_change_speed(struct sir_dev * dev,unsigned speed)110 static int litelink_change_speed(struct sir_dev *dev, unsigned speed)
111 {
112 int i;
113
114 IRDA_DEBUG(2, "%s()\n", __func__);
115
116 /* dongle already reset by irda-thread - current speed (dongle and
117 * port) is the default speed (115200 for litelink!)
118 */
119
120 /* Cycle through avaiable baudrates until we reach the correct one */
121 for (i = 0; baud_rates[i] != speed; i++) {
122
123 /* end-of-list reached due to invalid speed request */
124 if (baud_rates[i] == 9600)
125 break;
126
127 /* Set DTR, clear RTS */
128 sirdev_set_dtr_rts(dev, FALSE, TRUE);
129
130 /* Sleep a minimum of 15 us */
131 udelay(MIN_DELAY);
132
133 /* Set DTR, Set RTS */
134 sirdev_set_dtr_rts(dev, TRUE, TRUE);
135
136 /* Sleep a minimum of 15 us */
137 udelay(MIN_DELAY);
138 }
139
140 dev->speed = baud_rates[i];
141
142 /* invalid baudrate should not happen - but if, we return -EINVAL and
143 * the dongle configured for 9600 so the stack has a chance to recover
144 */
145
146 return (dev->speed == speed) ? 0 : -EINVAL;
147 }
148
149 /*
150 * Function litelink_reset (task)
151 *
152 * Reset the Litelink type dongle.
153 *
154 */
litelink_reset(struct sir_dev * dev)155 static int litelink_reset(struct sir_dev *dev)
156 {
157 IRDA_DEBUG(2, "%s()\n", __func__);
158
159 /* probably the power-up can be dropped here, but with only
160 * 15 usec delay it's not worth the risk unless somebody with
161 * the hardware confirms it doesn't break anything...
162 */
163
164 /* Power on dongle */
165 sirdev_set_dtr_rts(dev, TRUE, TRUE);
166
167 /* Sleep a minimum of 15 us */
168 udelay(MIN_DELAY);
169
170 /* Clear RTS to reset dongle */
171 sirdev_set_dtr_rts(dev, TRUE, FALSE);
172
173 /* Sleep a minimum of 15 us */
174 udelay(MIN_DELAY);
175
176 /* Go back to normal mode */
177 sirdev_set_dtr_rts(dev, TRUE, TRUE);
178
179 /* Sleep a minimum of 15 us */
180 udelay(MIN_DELAY);
181
182 /* This dongles speed defaults to 115200 bps */
183 dev->speed = 115200;
184
185 return 0;
186 }
187
188 MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
189 MODULE_DESCRIPTION("Parallax Litelink dongle driver");
190 MODULE_LICENSE("GPL");
191 MODULE_ALIAS("irda-dongle-5"); /* IRDA_LITELINK_DONGLE */
192
193 /*
194 * Function init_module (void)
195 *
196 * Initialize Litelink module
197 *
198 */
199 module_init(litelink_sir_init);
200
201 /*
202 * Function cleanup_module (void)
203 *
204 * Cleanup Litelink module
205 *
206 */
207 module_exit(litelink_sir_cleanup);
208