File: /usr/src/linux/drivers/net/irda/actisys.c
1 /*********************************************************************
2 *
3 * Filename: actisys.c
4 * Version: 1.0
5 * Description: Implementation for the ACTiSYS IR-220L and IR-220L+
6 * dongles
7 * Status: Beta.
8 * Authors: Dag Brattli <dagb@cs.uit.no> (initially)
9 * Jean Tourrilhes <jt@hpl.hp.com> (new version)
10 * Created at: Wed Oct 21 20:02:35 1998
11 * Modified at: Fri Dec 17 09:10:43 1999
12 * Modified by: Dag Brattli <dagb@cs.uit.no>
13 *
14 * Copyright (c) 1998-1999 Dag Brattli, All Rights Reserved.
15 * Copyright (c) 1999 Jean Tourrilhes
16 *
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License as
19 * published by the Free Software Foundation; either version 2 of
20 * the License, or (at your option) any later version.
21 *
22 * Neither Dag Brattli nor University of Tromsų admit liability nor
23 * provide warranty for any of this software. This material is
24 * provided "AS-IS" and at no charge.
25 *
26 ********************************************************************/
27
28 /*
29 * Changelog
30 *
31 * 0.8 -> 0.9999 - Jean
32 * o New initialisation procedure : much safer and correct
33 * o New procedure the change speed : much faster and simpler
34 * o Other cleanups & comments
35 * Thanks to Lichen Wang @ Actisys for his excellent help...
36 */
37
38 #include <linux/module.h>
39 #include <linux/delay.h>
40 #include <linux/tty.h>
41 #include <linux/sched.h>
42 #include <linux/init.h>
43
44 #include <net/irda/irda.h>
45 #include <net/irda/irmod.h>
46 #include <net/irda/irda_device.h>
47
48 /*
49 * Define the timing of the pulses we send to the dongle (to reset it, and
50 * to toggle speeds). Basically, the limit here is the propagation speed of
51 * the signals through the serial port, the dongle being much faster. Any
52 * serial port support 115 kb/s, so we are sure that pulses 8.5 us wide can
53 * go through cleanly . If you are on the wild side, you can try to lower
54 * this value (Actisys recommended me 2 us, and 0 us work for me on a P233!)
55 */
56 #define MIN_DELAY 10 /* 10 us to be on the conservative side */
57
58 static int actisys_change_speed(struct irda_task *task);
59 static int actisys_reset(struct irda_task *task);
60 static void actisys_open(dongle_t *self, struct qos_info *qos);
61 static void actisys_close(dongle_t *self);
62
63 /* These are the baudrates supported, in the order available */
64 /* Note : the 220L doesn't support 38400, but we will fix that below */
65 static __u32 baud_rates[] = { 9600, 19200, 57600, 115200, 38400 };
66 #define MAX_SPEEDS 5
67
68 static struct dongle_reg dongle = {
69 Q_NULL,
70 IRDA_ACTISYS_DONGLE,
71 actisys_open,
72 actisys_close,
73 actisys_reset,
74 actisys_change_speed,
75 };
76
77 static struct dongle_reg dongle_plus = {
78 Q_NULL,
79 IRDA_ACTISYS_PLUS_DONGLE,
80 actisys_open,
81 actisys_close,
82 actisys_reset,
83 actisys_change_speed,
84 };
85
86 /*
87 * Function actisys_change_speed (task)
88 *
89 * There is two model of Actisys dongle we are dealing with,
90 * the 220L and 220L+. At this point, only irattach knows with
91 * kind the user has requested (it was an argument on irattach
92 * command line).
93 * So, we register a dongle of each sort and let irattach
94 * pick the right one...
95 */
96 int __init actisys_init(void)
97 {
98 int ret;
99
100 /* First, register an Actisys 220L dongle */
101 ret = irda_device_register_dongle(&dongle);
102 if (ret < 0)
103 return ret;
104 /* Now, register an Actisys 220L+ dongle */
105 ret = irda_device_register_dongle(&dongle_plus);
106 if (ret < 0) {
107 irda_device_unregister_dongle(&dongle);
108 return ret;
109 }
110 return 0;
111 }
112
113 void actisys_cleanup(void)
114 {
115 /* We have to remove both dongles */
116 irda_device_unregister_dongle(&dongle);
117 irda_device_unregister_dongle(&dongle_plus);
118 }
119
120 static void actisys_open(dongle_t *self, struct qos_info *qos)
121 {
122 /* Power on the dongle */
123 self->set_dtr_rts(self->dev, TRUE, TRUE);
124
125 /* Set the speeds we can accept */
126 qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
127
128 /* Remove support for 38400 if this is not a 220L+ dongle */
129 if (self->issue->type == IRDA_ACTISYS_DONGLE)
130 qos->baud_rate.bits &= ~IR_38400;
131
132 qos->min_turn_time.bits = 0x7f; /* Needs 0.01 ms */
133
134 MOD_INC_USE_COUNT;
135 }
136
137 static void actisys_close(dongle_t *self)
138 {
139 /* Power off the dongle */
140 self->set_dtr_rts(self->dev, FALSE, FALSE);
141
142 MOD_DEC_USE_COUNT;
143 }
144
145 /*
146 * Function actisys_change_speed (task)
147 *
148 * Change speed of the ACTiSYS IR-220L and IR-220L+ type IrDA dongles.
149 * To cycle through the available baud rates, pulse RTS low for a few us.
150 *
151 * First, we reset the dongle to always start from a known state.
152 * Then, we cycle through the speeds by pulsing RTS low and then up.
153 * The dongle allow us to pulse quite fast, se we can set speed in one go,
154 * which is must faster ( < 100 us) and less complex than what is found
155 * in some other dongle drivers...
156 * Note that even if the new speed is the same as the current speed,
157 * we reassert the speed. This make sure that things are all right,
158 * and it's fast anyway...
159 * By the way, this function will work for both type of dongles,
160 * because the additional speed is at the end of the sequence...
161 */
162 static int actisys_change_speed(struct irda_task *task)
163 {
164 dongle_t *self = (dongle_t *) task->instance;
165 __u32 speed = (__u32) task->param; /* Target speed */
166 int ret = 0;
167 int i = 0;
168
169 IRDA_DEBUG(4, __FUNCTION__ "(), speed=%d (was %d)\n", speed,
170 self->speed);
171
172 /* Go to a known state by reseting the dongle */
173
174 /* Reset the dongle : set DTR low for 10 us */
175 self->set_dtr_rts(self->dev, FALSE, TRUE);
176 udelay(MIN_DELAY);
177
178 /* Go back to normal mode (we are now at 9600 b/s) */
179 self->set_dtr_rts(self->dev, TRUE, TRUE);
180
181 /*
182 * Now, we can set the speed requested. Send RTS pulses until we
183 * reach the target speed
184 */
185 for (i=0; i<MAX_SPEEDS; i++) {
186 if (speed == baud_rates[i]) {
187 self->speed = baud_rates[i];
188 break;
189 }
190 /* Make sure previous pulse is finished */
191 udelay(MIN_DELAY);
192
193 /* Set RTS low for 10 us */
194 self->set_dtr_rts(self->dev, TRUE, FALSE);
195 udelay(MIN_DELAY);
196
197 /* Set RTS high for 10 us */
198 self->set_dtr_rts(self->dev, TRUE, TRUE);
199 }
200
201 /* Check if life is sweet... */
202 if (i >= MAX_SPEEDS)
203 ret = -1; /* This should not happen */
204
205 /* Basta lavoro, on se casse d'ici... */
206 irda_task_next_state(task, IRDA_TASK_DONE);
207
208 return ret;
209 }
210
211 /*
212 * Function actisys_reset (task)
213 *
214 * Reset the Actisys type dongle. Warning, this function must only be
215 * called with a process context!
216 *
217 * We need to do two things in this function :
218 * o first make sure that the dongle is in a state where it can operate
219 * o second put the dongle in a know state
220 *
221 * The dongle is powered of the RTS and DTR lines. In the dongle, there
222 * is a big capacitor to accomodate the current spikes. This capacitor
223 * takes a least 50 ms to be charged. In theory, the Bios set those lines
224 * up, so by the time we arrive here we should be set. It doesn't hurt
225 * to be on the conservative side, so we will wait...
226 * Then, we set the speed to 9600 b/s to get in a known state (see in
227 * change_speed for details). It is needed because the IrDA stack
228 * has tried to set the speed immediately after our first return,
229 * so before we can be sure the dongle is up and running.
230 */
231 static int actisys_reset(struct irda_task *task)
232 {
233 dongle_t *self = (dongle_t *) task->instance;
234 int ret = 0;
235
236 ASSERT(task != NULL, return -1;);
237
238 self->reset_task = task;
239
240 switch (task->state) {
241 case IRDA_TASK_INIT:
242 /* Set both DTR & RTS to power up the dongle */
243 /* In theory redundant with power up in actisys_open() */
244 self->set_dtr_rts(self->dev, TRUE, TRUE);
245
246 /* Sleep 50 ms to make sure capacitor is charged */
247 ret = MSECS_TO_JIFFIES(50);
248 irda_task_next_state(task, IRDA_TASK_WAIT);
249 break;
250 case IRDA_TASK_WAIT:
251 /* Reset the dongle : set DTR low for 10 us */
252 self->set_dtr_rts(self->dev, FALSE, TRUE);
253 udelay(MIN_DELAY);
254
255 /* Go back to normal mode */
256 self->set_dtr_rts(self->dev, TRUE, TRUE);
257
258 irda_task_next_state(task, IRDA_TASK_DONE);
259 self->reset_task = NULL;
260 self->speed = 9600; /* That's the default */
261 break;
262 default:
263 ERROR(__FUNCTION__ "(), unknown state %d\n", task->state);
264 irda_task_next_state(task, IRDA_TASK_DONE);
265 self->reset_task = NULL;
266 ret = -1;
267 break;
268 }
269 return ret;
270 }
271
272 #ifdef MODULE
273 MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no> - Jean Tourrilhes <jt@hpl.hp.com>");
274 MODULE_DESCRIPTION("ACTiSYS IR-220L and IR-220L+ dongle driver");
275
276 /*
277 * Function init_module (void)
278 *
279 * Initialize Actisys module
280 *
281 */
282 int init_module(void)
283 {
284 return actisys_init();
285 }
286
287 /*
288 * Function cleanup_module (void)
289 *
290 * Cleanup Actisys module
291 *
292 */
293 void cleanup_module(void)
294 {
295 actisys_cleanup();
296 }
297 #endif /* MODULE */
298