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David Basden0ac81ae2006-03-20 22:21:10 -08001/*********************************************************************
2 *
3 * Filename: toim3232-sir.c
4 * Version: 1.0
5 * Description: Implementation of dongles based on the Vishay/Temic
6 * TOIM3232 SIR Endec chipset. Currently only the
7 * IRWave IR320ST-2 is tested, although it should work
8 * with any TOIM3232 or TOIM4232 chipset based RS232
9 * dongle with minimal modification.
10 * Based heavily on the Tekram driver (tekram.c),
11 * with thanks to Dag Brattli and Martin Diehl.
12 * Status: Experimental.
13 * Author: David Basden <davidb-irda@rcpt.to>
14 * Created at: Thu Feb 09 23:47:32 2006
15 *
16 * Copyright (c) 2006 David Basden.
17 * Copyright (c) 1998-1999 Dag Brattli,
18 * Copyright (c) 2002 Martin Diehl,
19 * All Rights Reserved.
20 *
21 * This program is free software; you can redistribute it and/or
22 * modify it under the terms of the GNU General Public License as
23 * published by the Free Software Foundation; either version 2 of
24 * the License, or (at your option) any later version.
25 *
26 * Neither Dag Brattli nor University of Tromsø admit liability nor
27 * provide warranty for any of this software. This material is
28 * provided "AS-IS" and at no charge.
29 *
30 ********************************************************************/
31
32/*
33 * This driver has currently only been tested on the IRWave IR320ST-2
34 *
35 * PROTOCOL:
36 *
37 * The protocol for talking to the TOIM3232 is quite easy, and is
38 * designed to interface with RS232 with only level convertors. The
39 * BR/~D line on the chip is brought high to signal 'command mode',
40 * where a command byte is sent to select the baudrate of the RS232
41 * interface and the pulse length of the IRDA output. When BR/~D
42 * is brought low, the dongle then changes to the selected baudrate,
43 * and the RS232 interface is used for data until BR/~D is brought
44 * high again. The initial speed for the TOIMx323 after RESET is
45 * 9600 baud. The baudrate for command-mode is the last selected
46 * baud-rate, or 9600 after a RESET.
47 *
48 * The dongle I have (below) adds some extra hardware on the front end,
49 * but this is mostly directed towards pariasitic power from the RS232
50 * line rather than changing very much about how to communicate with
51 * the TOIM3232.
52 *
53 * The protocol to talk to the TOIM4232 chipset seems to be almost
54 * identical to the TOIM3232 (and the 4232 datasheet is more detailed)
55 * so this code will probably work on that as well, although I haven't
56 * tested it on that hardware.
57 *
58 * Target dongle variations that might be common:
59 *
60 * DTR and RTS function:
61 * The data sheet for the 4232 has a sample implementation that hooks the
62 * DTR and RTS lines to the RESET and BaudRate/~Data lines of the
63 * chip (through line-converters). Given both DTR and RTS would have to
64 * be held low in normal operation, and the TOIMx232 requires +5V to
65 * signal ground, most dongle designers would almost certainly choose
66 * an implementation that kept at least one of DTR or RTS high in
67 * normal operation to provide power to the dongle, but will likely
68 * vary between designs.
69 *
70 * User specified command bits:
71 * There are two user-controllable output lines from the TOIMx232 that
72 * can be set low or high by setting the appropriate bits in the
73 * high-nibble of the command byte (when setting speed and pulse length).
74 * These might be used to switch on and off added hardware or extra
75 * dongle features.
76 *
77 *
78 * Target hardware: IRWave IR320ST-2
79 *
80 * The IRWave IR320ST-2 is a simple dongle based on the Vishay/Temic
81 * TOIM3232 SIR Endec and the Vishay/Temic TFDS4500 SIR IRDA transciever.
82 * It uses a hex inverter and some discrete components to buffer and
83 * line convert the RS232 down to 5V.
84 *
85 * The dongle is powered through a voltage regulator, fed by a large
86 * capacitor. To switch the dongle on, DTR is brought high to charge
87 * the capacitor and drive the voltage regulator. DTR isn't associated
88 * with any control lines on the TOIM3232. Parisitic power is also taken
89 * from the RTS, TD and RD lines when brought high, but through resistors.
90 * When DTR is low, the circuit might lose power even with RTS high.
91 *
92 * RTS is inverted and attached to the BR/~D input pin. When RTS
93 * is high, BR/~D is low, and the TOIM3232 is in the normal 'data' mode.
94 * RTS is brought low, BR/~D is high, and the TOIM3232 is in 'command
95 * mode'.
96 *
97 * For some unknown reason, the RESET line isn't actually connected
98 * to anything. This means to reset the dongle to get it to a known
99 * state (9600 baud) you must drop DTR and RTS low, wait for the power
100 * capacitor to discharge, and then bring DTR (and RTS for data mode)
101 * high again, and wait for the capacitor to charge, the power supply
102 * to stabilise, and the oscillator clock to stabilise.
103 *
104 * Fortunately, if the current baudrate is known, the chipset can
105 * easily change speed by entering command mode without having to
106 * reset the dongle first.
107 *
108 * Major Components:
109 *
110 * - Vishay/Temic TOIM3232 SIR Endec to change RS232 pulse timings
111 * to IRDA pulse timings
112 * - 3.6864MHz crystal to drive TOIM3232 clock oscillator
113 * - DM74lS04M Inverting Hex line buffer for RS232 input buffering
114 * and level conversion
115 * - PJ2951AC 150mA voltage regulator
116 * - Vishay/Temic TFDS4500 SIR IRDA front-end transceiver
117 *
118 */
119
120#include <linux/module.h>
121#include <linux/delay.h>
122#include <linux/init.h>
123
124#include <net/irda/irda.h>
125
126#include "sir-dev.h"
127
David Basden0ac81ae2006-03-20 22:21:10 -0800128static int toim3232delay = 150; /* default is 150 ms */
Andrew Morton73a6c632006-03-20 22:33:41 -0800129module_param(toim3232delay, int, 0);
130MODULE_PARM_DESC(toim3232delay, "toim3232 dongle write complete delay");
David Basden0ac81ae2006-03-20 22:21:10 -0800131
132#if 0
David Basden0ac81ae2006-03-20 22:21:10 -0800133static int toim3232flipdtr = 0; /* default is DTR high to reset */
Andrew Morton73a6c632006-03-20 22:33:41 -0800134module_param(toim3232flipdtr, int, 0);
135MODULE_PARM_DESC(toim3232flipdtr, "toim3232 dongle invert DTR (Reset)");
David Basden0ac81ae2006-03-20 22:21:10 -0800136
David Basden0ac81ae2006-03-20 22:21:10 -0800137static int toim3232fliprts = 0; /* default is RTS high for baud change */
Andrew Morton73a6c632006-03-20 22:33:41 -0800138module_param(toim3232fliptrs, int, 0);
139MODULE_PARM_DESC(toim3232fliprts, "toim3232 dongle invert RTS (BR/D)");
David Basden0ac81ae2006-03-20 22:21:10 -0800140#endif
141
142static int toim3232_open(struct sir_dev *);
143static int toim3232_close(struct sir_dev *);
144static int toim3232_change_speed(struct sir_dev *, unsigned);
145static int toim3232_reset(struct sir_dev *);
146
147#define TOIM3232_115200 0x00
148#define TOIM3232_57600 0x01
149#define TOIM3232_38400 0x02
150#define TOIM3232_19200 0x03
151#define TOIM3232_9600 0x06
152#define TOIM3232_2400 0x0A
153
154#define TOIM3232_PW 0x10 /* Pulse select bit */
155
156static struct dongle_driver toim3232 = {
157 .owner = THIS_MODULE,
158 .driver_name = "Vishay TOIM3232",
159 .type = IRDA_TOIM3232_DONGLE,
160 .open = toim3232_open,
161 .close = toim3232_close,
162 .reset = toim3232_reset,
163 .set_speed = toim3232_change_speed,
164};
165
166static int __init toim3232_sir_init(void)
167{
168 if (toim3232delay < 1 || toim3232delay > 500)
169 toim3232delay = 200;
170 IRDA_DEBUG(1, "%s - using %d ms delay\n",
171 toim3232.driver_name, toim3232delay);
172 return irda_register_dongle(&toim3232);
173}
174
175static void __exit toim3232_sir_cleanup(void)
176{
177 irda_unregister_dongle(&toim3232);
178}
179
180static int toim3232_open(struct sir_dev *dev)
181{
182 struct qos_info *qos = &dev->qos;
183
184 IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
185
186 /* Pull the lines high to start with.
187 *
188 * For the IR320ST-2, we need to charge the main supply capacitor to
189 * switch the device on. We keep DTR high throughout to do this.
190 * When RTS, TD and RD are high, they will also trickle-charge the
191 * cap. RTS is high for data transmission, and low for baud rate select.
192 * -- DGB
193 */
194 sirdev_set_dtr_rts(dev, TRUE, TRUE);
195
196 /* The TOI3232 supports many speeds between 1200bps and 115000bps.
197 * We really only care about those supported by the IRDA spec, but
198 * 38400 seems to be implemented in many places */
199 qos->baud_rate.bits &= IR_2400|IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
200
201 /* From the tekram driver. Not sure what a reasonable value is -- DGB */
202 qos->min_turn_time.bits = 0x01; /* Needs at least 10 ms */
203 irda_qos_bits_to_value(qos);
204
205 /* irda thread waits 50 msec for power settling */
206
207 return 0;
208}
209
210static int toim3232_close(struct sir_dev *dev)
211{
212 IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
213
214 /* Power off dongle */
215 sirdev_set_dtr_rts(dev, FALSE, FALSE);
216
217 return 0;
218}
219
220/*
221 * Function toim3232change_speed (dev, state, speed)
222 *
223 * Set the speed for the TOIM3232 based dongle. Warning, this
224 * function must be called with a process context!
225 *
226 * Algorithm
227 * 1. keep DTR high but clear RTS to bring into baud programming mode
228 * 2. wait at least 7us to enter programming mode
229 * 3. send control word to set baud rate and timing
230 * 4. wait at least 1us
231 * 5. bring RTS high to enter DATA mode (RS232 is passed through to transceiver)
232 * 6. should take effect immediately (although probably worth waiting)
233 */
234
235#define TOIM3232_STATE_WAIT_SPEED (SIRDEV_STATE_DONGLE_SPEED + 1)
236
237static int toim3232_change_speed(struct sir_dev *dev, unsigned speed)
238{
239 unsigned state = dev->fsm.substate;
240 unsigned delay = 0;
241 u8 byte;
242 static int ret = 0;
243
244 IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
245
246 switch(state) {
247 case SIRDEV_STATE_DONGLE_SPEED:
248
249 /* Figure out what we are going to send as a control byte */
250 switch (speed) {
251 case 2400:
252 byte = TOIM3232_PW|TOIM3232_2400;
253 break;
254 default:
255 speed = 9600;
256 ret = -EINVAL;
257 /* fall thru */
258 case 9600:
259 byte = TOIM3232_PW|TOIM3232_9600;
260 break;
261 case 19200:
262 byte = TOIM3232_PW|TOIM3232_19200;
263 break;
264 case 38400:
265 byte = TOIM3232_PW|TOIM3232_38400;
266 break;
267 case 57600:
268 byte = TOIM3232_PW|TOIM3232_57600;
269 break;
270 case 115200:
271 byte = TOIM3232_115200;
272 break;
273 }
274
275 /* Set DTR, Clear RTS: Go into baud programming mode */
276 sirdev_set_dtr_rts(dev, TRUE, FALSE);
277
278 /* Wait at least 7us */
279 udelay(14);
280
281 /* Write control byte */
282 sirdev_raw_write(dev, &byte, 1);
283
284 dev->speed = speed;
285
286 state = TOIM3232_STATE_WAIT_SPEED;
287 delay = toim3232delay;
288 break;
289
290 case TOIM3232_STATE_WAIT_SPEED:
291 /* Have transmitted control byte * Wait for 'at least 1us' */
292 udelay(14);
293
294 /* Set DTR, Set RTS: Go into normal data mode */
295 sirdev_set_dtr_rts(dev, TRUE, TRUE);
296
297 /* Wait (TODO: check this is needed) */
298 udelay(50);
299 break;
300
301 default:
302 printk(KERN_ERR "%s - undefined state %d\n", __FUNCTION__, state);
303 ret = -EINVAL;
304 break;
305 }
306
307 dev->fsm.substate = state;
308 return (delay > 0) ? delay : ret;
309}
310
311/*
312 * Function toim3232reset (driver)
313 *
314 * This function resets the toim3232 dongle. Warning, this function
315 * must be called with a process context!!
316 *
317 * What we should do is:
318 * 0. Pull RESET high
319 * 1. Wait for at least 7us
320 * 2. Pull RESET low
321 * 3. Wait for at least 7us
322 * 4. Pull BR/~D high
323 * 5. Wait for at least 7us
324 * 6. Send control byte to set baud rate
325 * 7. Wait at least 1us after stop bit
326 * 8. Pull BR/~D low
327 * 9. Should then be in data mode
328 *
329 * Because the IR320ST-2 doesn't have the RESET line connected for some reason,
330 * we'll have to do something else.
331 *
332 * The default speed after a RESET is 9600, so lets try just bringing it up in
333 * data mode after switching it off, waiting for the supply capacitor to
334 * discharge, and then switch it back on. This isn't actually pulling RESET
335 * high, but it seems to have the same effect.
336 *
337 * This behaviour will probably work on dongles that have the RESET line connected,
338 * but if not, add a flag for the IR320ST-2, and implment the above-listed proper
339 * behaviour.
340 *
341 * RTS is inverted and then fed to BR/~D, so to put it in programming mode, we
342 * need to have pull RTS low
343 */
344
345static int toim3232_reset(struct sir_dev *dev)
346{
347 IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
348
349 /* Switch off both DTR and RTS to switch off dongle */
350 sirdev_set_dtr_rts(dev, FALSE, FALSE);
351
352 /* Should sleep a while. This might be evil doing it this way.*/
353 set_current_state(TASK_UNINTERRUPTIBLE);
354 schedule_timeout(msecs_to_jiffies(50));
355
356 /* Set DTR, Set RTS (data mode) */
357 sirdev_set_dtr_rts(dev, TRUE, TRUE);
358
359 /* Wait at least 10 ms for power to stabilize again */
360 set_current_state(TASK_UNINTERRUPTIBLE);
361 schedule_timeout(msecs_to_jiffies(10));
362
363 /* Speed should now be 9600 */
364 dev->speed = 9600;
365
366 return 0;
367}
368
369MODULE_AUTHOR("David Basden <davidb-linux@rcpt.to>");
370MODULE_DESCRIPTION("Vishay/Temic TOIM3232 based dongle driver");
371MODULE_LICENSE("GPL");
372MODULE_ALIAS("irda-dongle-12"); /* IRDA_TOIM3232_DONGLE */
373
374module_init(toim3232_sir_init);
375module_exit(toim3232_sir_cleanup);