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0ac81ae3 DB |
1 | /********************************************************************* |
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 | |
7c9d440e | 81 | * TOIM3232 SIR Endec and the Vishay/Temic TFDS4500 SIR IRDA transceiver. |
0ac81ae3 DB |
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> | |
d43c36dc | 123 | #include <linux/sched.h> |
0ac81ae3 DB |
124 | |
125 | #include <net/irda/irda.h> | |
126 | ||
127 | #include "sir-dev.h" | |
128 | ||
0ac81ae3 | 129 | static int toim3232delay = 150; /* default is 150 ms */ |
73a6c630 AM |
130 | module_param(toim3232delay, int, 0); |
131 | MODULE_PARM_DESC(toim3232delay, "toim3232 dongle write complete delay"); | |
0ac81ae3 | 132 | |
0ac81ae3 DB |
133 | static int toim3232_open(struct sir_dev *); |
134 | static int toim3232_close(struct sir_dev *); | |
135 | static int toim3232_change_speed(struct sir_dev *, unsigned); | |
136 | static int toim3232_reset(struct sir_dev *); | |
137 | ||
138 | #define TOIM3232_115200 0x00 | |
139 | #define TOIM3232_57600 0x01 | |
140 | #define TOIM3232_38400 0x02 | |
141 | #define TOIM3232_19200 0x03 | |
142 | #define TOIM3232_9600 0x06 | |
143 | #define TOIM3232_2400 0x0A | |
144 | ||
145 | #define TOIM3232_PW 0x10 /* Pulse select bit */ | |
146 | ||
147 | static struct dongle_driver toim3232 = { | |
148 | .owner = THIS_MODULE, | |
149 | .driver_name = "Vishay TOIM3232", | |
150 | .type = IRDA_TOIM3232_DONGLE, | |
151 | .open = toim3232_open, | |
152 | .close = toim3232_close, | |
153 | .reset = toim3232_reset, | |
154 | .set_speed = toim3232_change_speed, | |
155 | }; | |
156 | ||
157 | static int __init toim3232_sir_init(void) | |
158 | { | |
159 | if (toim3232delay < 1 || toim3232delay > 500) | |
160 | toim3232delay = 200; | |
955a9d20 JP |
161 | pr_debug("%s - using %d ms delay\n", |
162 | toim3232.driver_name, toim3232delay); | |
0ac81ae3 DB |
163 | return irda_register_dongle(&toim3232); |
164 | } | |
165 | ||
166 | static void __exit toim3232_sir_cleanup(void) | |
167 | { | |
168 | irda_unregister_dongle(&toim3232); | |
169 | } | |
170 | ||
171 | static int toim3232_open(struct sir_dev *dev) | |
172 | { | |
173 | struct qos_info *qos = &dev->qos; | |
174 | ||
0ac81ae3 DB |
175 | /* Pull the lines high to start with. |
176 | * | |
177 | * For the IR320ST-2, we need to charge the main supply capacitor to | |
178 | * switch the device on. We keep DTR high throughout to do this. | |
179 | * When RTS, TD and RD are high, they will also trickle-charge the | |
180 | * cap. RTS is high for data transmission, and low for baud rate select. | |
181 | * -- DGB | |
182 | */ | |
183 | sirdev_set_dtr_rts(dev, TRUE, TRUE); | |
184 | ||
185 | /* The TOI3232 supports many speeds between 1200bps and 115000bps. | |
186 | * We really only care about those supported by the IRDA spec, but | |
187 | * 38400 seems to be implemented in many places */ | |
188 | qos->baud_rate.bits &= IR_2400|IR_9600|IR_19200|IR_38400|IR_57600|IR_115200; | |
189 | ||
190 | /* From the tekram driver. Not sure what a reasonable value is -- DGB */ | |
191 | qos->min_turn_time.bits = 0x01; /* Needs at least 10 ms */ | |
192 | irda_qos_bits_to_value(qos); | |
193 | ||
194 | /* irda thread waits 50 msec for power settling */ | |
195 | ||
196 | return 0; | |
197 | } | |
198 | ||
199 | static int toim3232_close(struct sir_dev *dev) | |
200 | { | |
0ac81ae3 DB |
201 | /* Power off dongle */ |
202 | sirdev_set_dtr_rts(dev, FALSE, FALSE); | |
203 | ||
204 | return 0; | |
205 | } | |
206 | ||
207 | /* | |
208 | * Function toim3232change_speed (dev, state, speed) | |
209 | * | |
210 | * Set the speed for the TOIM3232 based dongle. Warning, this | |
211 | * function must be called with a process context! | |
212 | * | |
213 | * Algorithm | |
214 | * 1. keep DTR high but clear RTS to bring into baud programming mode | |
215 | * 2. wait at least 7us to enter programming mode | |
216 | * 3. send control word to set baud rate and timing | |
217 | * 4. wait at least 1us | |
218 | * 5. bring RTS high to enter DATA mode (RS232 is passed through to transceiver) | |
219 | * 6. should take effect immediately (although probably worth waiting) | |
220 | */ | |
221 | ||
222 | #define TOIM3232_STATE_WAIT_SPEED (SIRDEV_STATE_DONGLE_SPEED + 1) | |
223 | ||
224 | static int toim3232_change_speed(struct sir_dev *dev, unsigned speed) | |
225 | { | |
226 | unsigned state = dev->fsm.substate; | |
227 | unsigned delay = 0; | |
228 | u8 byte; | |
229 | static int ret = 0; | |
230 | ||
0ac81ae3 DB |
231 | switch(state) { |
232 | case SIRDEV_STATE_DONGLE_SPEED: | |
233 | ||
234 | /* Figure out what we are going to send as a control byte */ | |
235 | switch (speed) { | |
236 | case 2400: | |
237 | byte = TOIM3232_PW|TOIM3232_2400; | |
238 | break; | |
239 | default: | |
240 | speed = 9600; | |
241 | ret = -EINVAL; | |
242 | /* fall thru */ | |
243 | case 9600: | |
244 | byte = TOIM3232_PW|TOIM3232_9600; | |
245 | break; | |
246 | case 19200: | |
247 | byte = TOIM3232_PW|TOIM3232_19200; | |
248 | break; | |
249 | case 38400: | |
250 | byte = TOIM3232_PW|TOIM3232_38400; | |
251 | break; | |
252 | case 57600: | |
253 | byte = TOIM3232_PW|TOIM3232_57600; | |
254 | break; | |
255 | case 115200: | |
256 | byte = TOIM3232_115200; | |
257 | break; | |
258 | } | |
259 | ||
260 | /* Set DTR, Clear RTS: Go into baud programming mode */ | |
261 | sirdev_set_dtr_rts(dev, TRUE, FALSE); | |
262 | ||
263 | /* Wait at least 7us */ | |
264 | udelay(14); | |
265 | ||
266 | /* Write control byte */ | |
267 | sirdev_raw_write(dev, &byte, 1); | |
268 | ||
269 | dev->speed = speed; | |
270 | ||
271 | state = TOIM3232_STATE_WAIT_SPEED; | |
272 | delay = toim3232delay; | |
273 | break; | |
274 | ||
275 | case TOIM3232_STATE_WAIT_SPEED: | |
276 | /* Have transmitted control byte * Wait for 'at least 1us' */ | |
277 | udelay(14); | |
278 | ||
279 | /* Set DTR, Set RTS: Go into normal data mode */ | |
280 | sirdev_set_dtr_rts(dev, TRUE, TRUE); | |
281 | ||
282 | /* Wait (TODO: check this is needed) */ | |
283 | udelay(50); | |
284 | break; | |
285 | ||
286 | default: | |
a97a6f10 | 287 | printk(KERN_ERR "%s - undefined state %d\n", __func__, state); |
0ac81ae3 DB |
288 | ret = -EINVAL; |
289 | break; | |
290 | } | |
291 | ||
292 | dev->fsm.substate = state; | |
293 | return (delay > 0) ? delay : ret; | |
294 | } | |
295 | ||
296 | /* | |
297 | * Function toim3232reset (driver) | |
298 | * | |
299 | * This function resets the toim3232 dongle. Warning, this function | |
300 | * must be called with a process context!! | |
301 | * | |
302 | * What we should do is: | |
303 | * 0. Pull RESET high | |
304 | * 1. Wait for at least 7us | |
305 | * 2. Pull RESET low | |
306 | * 3. Wait for at least 7us | |
307 | * 4. Pull BR/~D high | |
308 | * 5. Wait for at least 7us | |
309 | * 6. Send control byte to set baud rate | |
310 | * 7. Wait at least 1us after stop bit | |
311 | * 8. Pull BR/~D low | |
312 | * 9. Should then be in data mode | |
313 | * | |
314 | * Because the IR320ST-2 doesn't have the RESET line connected for some reason, | |
315 | * we'll have to do something else. | |
316 | * | |
317 | * The default speed after a RESET is 9600, so lets try just bringing it up in | |
318 | * data mode after switching it off, waiting for the supply capacitor to | |
319 | * discharge, and then switch it back on. This isn't actually pulling RESET | |
320 | * high, but it seems to have the same effect. | |
321 | * | |
322 | * This behaviour will probably work on dongles that have the RESET line connected, | |
323 | * but if not, add a flag for the IR320ST-2, and implment the above-listed proper | |
324 | * behaviour. | |
325 | * | |
326 | * RTS is inverted and then fed to BR/~D, so to put it in programming mode, we | |
327 | * need to have pull RTS low | |
328 | */ | |
329 | ||
330 | static int toim3232_reset(struct sir_dev *dev) | |
331 | { | |
0ac81ae3 DB |
332 | /* Switch off both DTR and RTS to switch off dongle */ |
333 | sirdev_set_dtr_rts(dev, FALSE, FALSE); | |
334 | ||
335 | /* Should sleep a while. This might be evil doing it this way.*/ | |
336 | set_current_state(TASK_UNINTERRUPTIBLE); | |
337 | schedule_timeout(msecs_to_jiffies(50)); | |
338 | ||
339 | /* Set DTR, Set RTS (data mode) */ | |
340 | sirdev_set_dtr_rts(dev, TRUE, TRUE); | |
341 | ||
342 | /* Wait at least 10 ms for power to stabilize again */ | |
343 | set_current_state(TASK_UNINTERRUPTIBLE); | |
344 | schedule_timeout(msecs_to_jiffies(10)); | |
345 | ||
346 | /* Speed should now be 9600 */ | |
347 | dev->speed = 9600; | |
348 | ||
349 | return 0; | |
350 | } | |
351 | ||
352 | MODULE_AUTHOR("David Basden <davidb-linux@rcpt.to>"); | |
353 | MODULE_DESCRIPTION("Vishay/Temic TOIM3232 based dongle driver"); | |
354 | MODULE_LICENSE("GPL"); | |
355 | MODULE_ALIAS("irda-dongle-12"); /* IRDA_TOIM3232_DONGLE */ | |
356 | ||
357 | module_init(toim3232_sir_init); | |
358 | module_exit(toim3232_sir_cleanup); |