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 #include <linux/module.h>
32 #include <linux/delay.h>
33 #include <linux/tty.h>
34 #include <linux/sched.h>
35 #include <linux/init.h>
36
37 #include <net/irda/irda.h>
38 #include <net/irda/irmod.h>
39 #include <net/irda/irda_device.h>
40
41 #define MIN_DELAY 25 /* 15 us, but wait a little more to be sure */
42 #define MAX_DELAY 10000 /* 1 ms */
43
44 static void litelink_open(dongle_t *self, struct qos_info *qos);
45 static void litelink_close(dongle_t *self);
46 static int litelink_change_speed(struct irda_task *task);
47 static int litelink_reset(struct irda_task *task);
48
49 /* These are the baudrates supported */
50 static __u32 baud_rates[] = { 115200, 57600, 38400, 19200, 9600 };
51
52 static struct dongle_reg dongle = {
53 Q_NULL,
54 IRDA_LITELINK_DONGLE,
55 litelink_open,
56 litelink_close,
57 litelink_reset,
58 litelink_change_speed,
59 };
60
litelink_init(void)61 int __init litelink_init(void)
62 {
63 return irda_device_register_dongle(&dongle);
64 }
65
litelink_cleanup(void)66 void litelink_cleanup(void)
67 {
68 irda_device_unregister_dongle(&dongle);
69 }
70
litelink_open(dongle_t * self,struct qos_info * qos)71 static void litelink_open(dongle_t *self, struct qos_info *qos)
72 {
73 qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
74 qos->min_turn_time.bits = 0x7f; /* Needs 0.01 ms */
75
76 MOD_INC_USE_COUNT;
77 }
78
litelink_close(dongle_t * self)79 static void litelink_close(dongle_t *self)
80 {
81 /* Power off dongle */
82 self->set_dtr_rts(self->dev, FALSE, FALSE);
83
84 MOD_DEC_USE_COUNT;
85 }
86
87 /*
88 * Function litelink_change_speed (task)
89 *
90 * Change speed of the Litelink dongle. To cycle through the available
91 * baud rates, pulse RTS low for a few ms.
92 */
litelink_change_speed(struct irda_task * task)93 static int litelink_change_speed(struct irda_task *task)
94 {
95 dongle_t *self = (dongle_t *) task->instance;
96 __u32 speed = (__u32) task->param;
97 int i;
98
99 /* Clear RTS to reset dongle */
100 self->set_dtr_rts(self->dev, TRUE, FALSE);
101
102 /* Sleep a minimum of 15 us */
103 udelay(MIN_DELAY);
104
105 /* Go back to normal mode */
106 self->set_dtr_rts(self->dev, TRUE, TRUE);
107
108 /* Sleep a minimum of 15 us */
109 udelay(MIN_DELAY);
110
111 /* Cycle through avaiable baudrates until we reach the correct one */
112 for (i=0; i<5 && baud_rates[i] != speed; i++) {
113 /* Set DTR, clear RTS */
114 self->set_dtr_rts(self->dev, FALSE, TRUE);
115
116 /* Sleep a minimum of 15 us */
117 udelay(MIN_DELAY);
118
119 /* Set DTR, Set RTS */
120 self->set_dtr_rts(self->dev, TRUE, TRUE);
121
122 /* Sleep a minimum of 15 us */
123 udelay(MIN_DELAY);
124 }
125 irda_task_next_state(task, IRDA_TASK_DONE);
126
127 return 0;
128 }
129
130 /*
131 * Function litelink_reset (task)
132 *
133 * Reset the Litelink type dongle.
134 *
135 */
litelink_reset(struct irda_task * task)136 static int litelink_reset(struct irda_task *task)
137 {
138 dongle_t *self = (dongle_t *) task->instance;
139
140 /* Power on dongle */
141 self->set_dtr_rts(self->dev, TRUE, TRUE);
142
143 /* Sleep a minimum of 15 us */
144 udelay(MIN_DELAY);
145
146 /* Clear RTS to reset dongle */
147 self->set_dtr_rts(self->dev, TRUE, FALSE);
148
149 /* Sleep a minimum of 15 us */
150 udelay(MIN_DELAY);
151
152 /* Go back to normal mode */
153 self->set_dtr_rts(self->dev, TRUE, TRUE);
154
155 /* Sleep a minimum of 15 us */
156 udelay(MIN_DELAY);
157
158 /* This dongles speed defaults to 115200 bps */
159 self->speed = 115200;
160
161 irda_task_next_state(task, IRDA_TASK_DONE);
162
163 return 0;
164 }
165
166 #ifdef MODULE
167 MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
168 MODULE_DESCRIPTION("Parallax Litelink dongle driver");
169 MODULE_LICENSE("GPL");
170
171
172 /*
173 * Function init_module (void)
174 *
175 * Initialize Litelink module
176 *
177 */
init_module(void)178 int init_module(void)
179 {
180 return litelink_init();
181 }
182
183 /*
184 * Function cleanup_module (void)
185 *
186 * Cleanup Litelink module
187 *
188 */
cleanup_module(void)189 void cleanup_module(void)
190 {
191 litelink_cleanup();
192 }
193 #endif /* MODULE */
194