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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 
49 static int litelink_open(struct sir_dev *dev);
50 static int litelink_close(struct sir_dev *dev);
51 static int litelink_change_speed(struct sir_dev *dev, unsigned speed);
52 static int litelink_reset(struct sir_dev *dev);
53 
54 /* These are the baudrates supported - 9600 must be last one! */
55 static unsigned baud_rates[] = { 115200, 57600, 38400, 19200, 9600 };
56 
57 static 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 
litelink_sir_init(void)67 static int __init litelink_sir_init(void)
68 {
69 	return irda_register_dongle(&litelink);
70 }
71 
litelink_sir_cleanup(void)72 static void __exit litelink_sir_cleanup(void)
73 {
74 	irda_unregister_dongle(&litelink);
75 }
76 
litelink_open(struct sir_dev * dev)77 static 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 
litelink_close(struct sir_dev * dev)96 static 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  */
litelink_change_speed(struct sir_dev * dev,unsigned speed)112 static 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  */
litelink_reset(struct sir_dev * dev)157 static 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 
190 MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
191 MODULE_DESCRIPTION("Parallax Litelink dongle driver");
192 MODULE_LICENSE("GPL");
193 MODULE_ALIAS("irda-dongle-5"); /* IRDA_LITELINK_DONGLE */
194 
195 /*
196  * Function init_module (void)
197  *
198  *    Initialize Litelink module
199  *
200  */
201 module_init(litelink_sir_init);
202 
203 /*
204  * Function cleanup_module (void)
205  *
206  *    Cleanup Litelink module
207  *
208  */
209 module_exit(litelink_sir_cleanup);
210