summaryrefslogtreecommitdiffstats
path: root/drivers/net/irda/actisys.c
blob: b2e31f4a384c96153cadeb9a6be48b35577a58b4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
/*********************************************************************
 *                
 * Filename:      actisys.c
 * Version:       1.0
 * Description:   Implementation for the ACTiSYS IR-220L and IR-220L+ 
 *                dongles
 * Status:        Beta.
 * Authors:       Dag Brattli <dagb@cs.uit.no> (initially)
 *		  Jean Tourrilhes <jt@hpl.hp.com> (new version)
 * Created at:    Wed Oct 21 20:02:35 1998
 * Modified at:   Fri Dec 17 09:10:43 1999
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 * 
 *     Copyright (c) 1998-1999 Dag Brattli, All Rights Reserved.
 *     Copyright (c) 1999 Jean Tourrilhes
 *      
 *     This program is free software; you can redistribute it and/or 
 *     modify it under the terms of the GNU General Public License as 
 *     published by the Free Software Foundation; either version 2 of 
 *     the License, or (at your option) any later version.
 *  
 *     Neither Dag Brattli nor University of Tromsø admit liability nor
 *     provide warranty for any of this software. This material is 
 *     provided "AS-IS" and at no charge.
 *     
 ********************************************************************/

/*
 * Changelog
 *
 * 0.8 -> 0.9999 - Jean
 *	o New initialisation procedure : much safer and correct
 *	o New procedure the change speed : much faster and simpler
 *	o Other cleanups & comments
 *	Thanks to Lichen Wang @ Actisys for his excellent help...
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/tty.h>
#include <linux/init.h>

#include <net/irda/irda.h>
#include <net/irda/irda_device.h>

/* 
 * Define the timing of the pulses we send to the dongle (to reset it, and
 * to toggle speeds). Basically, the limit here is the propagation speed of
 * the signals through the serial port, the dongle being much faster.  Any
 * serial port support 115 kb/s, so we are sure that pulses 8.5 us wide can
 * go through cleanly . If you are on the wild side, you can try to lower
 * this value (Actisys recommended me 2 us, and 0 us work for me on a P233!)
 */
#define MIN_DELAY 10	/* 10 us to be on the conservative side */

static int  actisys_change_speed(struct irda_task *task);
static int  actisys_reset(struct irda_task *task);
static void actisys_open(dongle_t *self, struct qos_info *qos);
static void actisys_close(dongle_t *self);

/* These are the baudrates supported, in the order available */
/* Note : the 220L doesn't support 38400, but we will fix that below */
static __u32 baud_rates[] = { 9600, 19200, 57600, 115200, 38400 };
#define MAX_SPEEDS 5

static struct dongle_reg dongle = {
	.type = IRDA_ACTISYS_DONGLE,
	.open = actisys_open,
	.close = actisys_close,
	.reset = actisys_reset,
	.change_speed = actisys_change_speed,
	.owner = THIS_MODULE,
};

static struct dongle_reg dongle_plus = {
	.type = IRDA_ACTISYS_PLUS_DONGLE,
	.open = actisys_open,
	.close = actisys_close,
	.reset = actisys_reset,
	.change_speed = actisys_change_speed,
	.owner = THIS_MODULE,
};

/*
 * Function actisys_change_speed (task)
 *
 *	There is two model of Actisys dongle we are dealing with,
 * the 220L and 220L+. At this point, only irattach knows with
 * kind the user has requested (it was an argument on irattach
 * command line).
 *	So, we register a dongle of each sort and let irattach
 * pick the right one...
 */
static int __init actisys_init(void)
{
	int ret;

	/* First, register an Actisys 220L dongle */
	ret = irda_device_register_dongle(&dongle);
	if (ret < 0)
		return ret;
	/* Now, register an Actisys 220L+ dongle */
	ret = irda_device_register_dongle(&dongle_plus);
	if (ret < 0) {
		irda_device_unregister_dongle(&dongle);
		return ret;
	}	
	return 0;
}

static void __exit actisys_cleanup(void)
{
	/* We have to remove both dongles */
	irda_device_unregister_dongle(&dongle);
	irda_device_unregister_dongle(&dongle_plus);
}

static void actisys_open(dongle_t *self, struct qos_info *qos)
{
	/* Power on the dongle */
	self->set_dtr_rts(self->dev, TRUE, TRUE);

	/* Set the speeds we can accept */
	qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;

	/* Remove support for 38400 if this is not a 220L+ dongle */
	if (self->issue->type == IRDA_ACTISYS_DONGLE)
		qos->baud_rate.bits &= ~IR_38400;
	
	qos->min_turn_time.bits = 0x7f; /* Needs 0.01 ms */
}

static void actisys_close(dongle_t *self)
{
	/* Power off the dongle */
	self->set_dtr_rts(self->dev, FALSE, FALSE);
}

/*
 * Function actisys_change_speed (task)
 *
 *    Change speed of the ACTiSYS IR-220L and IR-220L+ type IrDA dongles.
 *    To cycle through the available baud rates, pulse RTS low for a few us.
 *
 *	First, we reset the dongle to always start from a known state.
 *	Then, we cycle through the speeds by pulsing RTS low and then up.
 *	The dongle allow us to pulse quite fast, se we can set speed in one go,
 * which is must faster ( < 100 us) and less complex than what is found
 * in some other dongle drivers...
 *	Note that even if the new speed is the same as the current speed,
 * we reassert the speed. This make sure that things are all right,
 * and it's fast anyway...
 *	By the way, this function will work for both type of dongles,
 * because the additional speed is at the end of the sequence...
 */
static int actisys_change_speed(struct irda_task *task)
{
	dongle_t *self = (dongle_t *) task->instance;
	__u32 speed = (__u32) task->param;	/* Target speed */
	int ret = 0;
	int i = 0;

        IRDA_DEBUG(4, "%s(), speed=%d (was %d)\n", __FUNCTION__, speed, 
		   self->speed);

	/* Go to a known state by reseting the dongle */

	/* Reset the dongle : set DTR low for 10 us */
	self->set_dtr_rts(self->dev, FALSE, TRUE);
	udelay(MIN_DELAY);

	/* Go back to normal mode (we are now at 9600 b/s) */
	self->set_dtr_rts(self->dev, TRUE, TRUE);
 
	/* 
	 * Now, we can set the speed requested. Send RTS pulses until we
         * reach the target speed 
	 */
	for (i=0; i<MAX_SPEEDS; i++) {
		if (speed == baud_rates[i]) {
			self->speed = baud_rates[i];
			break;
		}
		/* Make sure previous pulse is finished */
		udelay(MIN_DELAY);

		/* Set RTS low for 10 us */
		self->set_dtr_rts(self->dev, TRUE, FALSE);
		udelay(MIN_DELAY);

		/* Set RTS high for 10 us */
		self->set_dtr_rts(self->dev, TRUE, TRUE);
	}

	/* Check if life is sweet... */
	if (i >= MAX_SPEEDS)
		ret = -1;  /* This should not happen */

	/* Basta lavoro, on se casse d'ici... */
	irda_task_next_state(task, IRDA_TASK_DONE);

	return ret;
}

/*
 * Function actisys_reset (task)
 *
 *      Reset the Actisys type dongle. Warning, this function must only be
 *      called with a process context!
 *
 * We need to do two things in this function :
 *	o first make sure that the dongle is in a state where it can operate
 *	o second put the dongle in a know state
 *
 *	The dongle is powered of the RTS and DTR lines. In the dongle, there
 * is a big capacitor to accommodate the current spikes. This capacitor
 * takes a least 50 ms to be charged. In theory, the Bios set those lines
 * up, so by the time we arrive here we should be set. It doesn't hurt
 * to be on the conservative side, so we will wait...
 *	Then, we set the speed to 9600 b/s to get in a known state (see in
 * change_speed for details). It is needed because the IrDA stack
 * has tried to set the speed immediately after our first return,
 * so before we can be sure the dongle is up and running.
 */
static int actisys_reset(struct irda_task *task)
{
	dongle_t *self = (dongle_t *) task->instance;
	int ret = 0;

	IRDA_ASSERT(task != NULL, return -1;);

	self->reset_task = task;

	switch (task->state) {
	case IRDA_TASK_INIT:
		/* Set both DTR & RTS to power up the dongle */
		/* In theory redundant with power up in actisys_open() */
		self->set_dtr_rts(self->dev, TRUE, TRUE);
		
		/* Sleep 50 ms to make sure capacitor is charged */
		ret = msecs_to_jiffies(50);
		irda_task_next_state(task, IRDA_TASK_WAIT);
		break;
	case IRDA_TASK_WAIT:			
		/* Reset the dongle : set DTR low for 10 us */
		self->set_dtr_rts(self->dev, FALSE, TRUE);
		udelay(MIN_DELAY);

		/* Go back to normal mode */
		self->set_dtr_rts(self->dev, TRUE, TRUE);
	
		irda_task_next_state(task, IRDA_TASK_DONE);
		self->reset_task = NULL;
		self->speed = 9600;	/* That's the default */
		break;
	default:
		IRDA_ERROR("%s(), unknown state %d\n",
			   __FUNCTION__, task->state);
		irda_task_next_state(task, IRDA_TASK_DONE);
		self->reset_task = NULL;
		ret = -1;
		break;
	}
	return ret;
}

MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no> - Jean Tourrilhes <jt@hpl.hp.com>");
MODULE_DESCRIPTION("ACTiSYS IR-220L and IR-220L+ dongle driver");	
MODULE_LICENSE("GPL");
MODULE_ALIAS("irda-dongle-2"); /* IRDA_ACTISYS_DONGLE */
MODULE_ALIAS("irda-dongle-3"); /* IRDA_ACTISYS_PLUS_DONGLE */

		
/*
 * Function init_module (void)
 *
 *    Initialize Actisys module
 *
 */
module_init(actisys_init);

/*
 * Function cleanup_module (void)
 *
 *    Cleanup Actisys module
 *
 */
module_exit(actisys_cleanup);