1 /*
2 * IR SIR driver, (C) 2000 Milan Pikula <www@fornax.sk>
3 *
4 * sir_ir - Device driver for use with SIR (serial infra red)
5 * mode of IrDA on many notebooks.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <linux/module.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel.h>
18 #include <linux/serial_reg.h>
19 #include <linux/ktime.h>
20 #include <linux/delay.h>
21 #include <linux/platform_device.h>
22
23 #include <media/rc-core.h>
24
25 /* SECTION: Definitions */
26 #define PULSE '['
27
28 /* 9bit * 1s/115200bit in milli seconds = 78.125ms*/
29 #define TIME_CONST (9000000ul / 115200ul)
30
31 /* timeout for sequences in jiffies (=5/100s), must be longer than TIME_CONST */
32 #define SIR_TIMEOUT (HZ * 5 / 100)
33
34 /* onboard sir ports are typically com3 */
35 static int io = 0x3e8;
36 static int irq = 4;
37 static int threshold = 3;
38
39 static DEFINE_SPINLOCK(timer_lock);
40 static struct timer_list timerlist;
41 /* time of last signal change detected */
42 static ktime_t last;
43 /* time of last UART data ready interrupt */
44 static ktime_t last_intr_time;
45 static int last_value;
46 static struct rc_dev *rcdev;
47
48 static struct platform_device *sir_ir_dev;
49
50 static DEFINE_SPINLOCK(hardware_lock);
51
52 /* SECTION: Prototypes */
53
54 /* Communication with user-space */
55 static void add_read_queue(int flag, unsigned long val);
56 /* Hardware */
57 static irqreturn_t sir_interrupt(int irq, void *dev_id);
58 static void send_space(unsigned long len);
59 static void send_pulse(unsigned long len);
60 static int init_hardware(void);
61 static void drop_hardware(void);
62 /* Initialisation */
63
sinp(int offset)64 static inline unsigned int sinp(int offset)
65 {
66 return inb(io + offset);
67 }
68
soutp(int offset,int value)69 static inline void soutp(int offset, int value)
70 {
71 outb(value, io + offset);
72 }
73
74 /* SECTION: Communication with user-space */
sir_tx_ir(struct rc_dev * dev,unsigned int * tx_buf,unsigned int count)75 static int sir_tx_ir(struct rc_dev *dev, unsigned int *tx_buf,
76 unsigned int count)
77 {
78 unsigned long flags;
79 int i;
80
81 local_irq_save(flags);
82 for (i = 0; i < count;) {
83 if (tx_buf[i])
84 send_pulse(tx_buf[i]);
85 i++;
86 if (i >= count)
87 break;
88 if (tx_buf[i])
89 send_space(tx_buf[i]);
90 i++;
91 }
92 local_irq_restore(flags);
93
94 return count;
95 }
96
add_read_queue(int flag,unsigned long val)97 static void add_read_queue(int flag, unsigned long val)
98 {
99 DEFINE_IR_RAW_EVENT(ev);
100
101 pr_debug("add flag %d with val %lu\n", flag, val);
102
103 /*
104 * statistically, pulses are ~TIME_CONST/2 too long. we could
105 * maybe make this more exact, but this is good enough
106 */
107 if (flag) {
108 /* pulse */
109 if (val > TIME_CONST / 2)
110 val -= TIME_CONST / 2;
111 else /* should not ever happen */
112 val = 1;
113 ev.pulse = true;
114 } else {
115 val += TIME_CONST / 2;
116 }
117 ev.duration = US_TO_NS(val);
118
119 ir_raw_event_store_with_filter(rcdev, &ev);
120 }
121
122 /* SECTION: Hardware */
sir_timeout(unsigned long data)123 static void sir_timeout(unsigned long data)
124 {
125 /*
126 * if last received signal was a pulse, but receiving stopped
127 * within the 9 bit frame, we need to finish this pulse and
128 * simulate a signal change to from pulse to space. Otherwise
129 * upper layers will receive two sequences next time.
130 */
131
132 unsigned long flags;
133 unsigned long pulse_end;
134
135 /* avoid interference with interrupt */
136 spin_lock_irqsave(&timer_lock, flags);
137 if (last_value) {
138 /* clear unread bits in UART and restart */
139 outb(UART_FCR_CLEAR_RCVR, io + UART_FCR);
140 /* determine 'virtual' pulse end: */
141 pulse_end = min_t(unsigned long,
142 ktime_us_delta(last, last_intr_time),
143 IR_MAX_DURATION);
144 dev_dbg(&sir_ir_dev->dev, "timeout add %d for %lu usec\n",
145 last_value, pulse_end);
146 add_read_queue(last_value, pulse_end);
147 last_value = 0;
148 last = last_intr_time;
149 }
150 spin_unlock_irqrestore(&timer_lock, flags);
151 ir_raw_event_handle(rcdev);
152 }
153
sir_interrupt(int irq,void * dev_id)154 static irqreturn_t sir_interrupt(int irq, void *dev_id)
155 {
156 unsigned char data;
157 ktime_t curr_time;
158 unsigned long delt;
159 unsigned long deltintr;
160 unsigned long flags;
161 int counter = 0;
162 int iir, lsr;
163
164 while ((iir = inb(io + UART_IIR) & UART_IIR_ID)) {
165 if (++counter > 256) {
166 dev_err(&sir_ir_dev->dev, "Trapped in interrupt");
167 break;
168 }
169
170 switch (iir & UART_IIR_ID) { /* FIXME toto treba preriedit */
171 case UART_IIR_MSI:
172 (void)inb(io + UART_MSR);
173 break;
174 case UART_IIR_RLSI:
175 case UART_IIR_THRI:
176 (void)inb(io + UART_LSR);
177 break;
178 case UART_IIR_RDI:
179 /* avoid interference with timer */
180 spin_lock_irqsave(&timer_lock, flags);
181 do {
182 del_timer(&timerlist);
183 data = inb(io + UART_RX);
184 curr_time = ktime_get();
185 delt = min_t(unsigned long,
186 ktime_us_delta(last, curr_time),
187 IR_MAX_DURATION);
188 deltintr = min_t(unsigned long,
189 ktime_us_delta(last_intr_time,
190 curr_time),
191 IR_MAX_DURATION);
192 dev_dbg(&sir_ir_dev->dev, "t %lu, d %d\n",
193 deltintr, (int)data);
194 /*
195 * if nothing came in last X cycles,
196 * it was gap
197 */
198 if (deltintr > TIME_CONST * threshold) {
199 if (last_value) {
200 dev_dbg(&sir_ir_dev->dev, "GAP\n");
201 /* simulate signal change */
202 add_read_queue(last_value,
203 delt -
204 deltintr);
205 last_value = 0;
206 last = last_intr_time;
207 delt = deltintr;
208 }
209 }
210 data = 1;
211 if (data ^ last_value) {
212 /*
213 * deltintr > 2*TIME_CONST, remember?
214 * the other case is timeout
215 */
216 add_read_queue(last_value,
217 delt - TIME_CONST);
218 last_value = data;
219 last = curr_time;
220 last = ktime_sub_us(last,
221 TIME_CONST);
222 }
223 last_intr_time = curr_time;
224 if (data) {
225 /*
226 * start timer for end of
227 * sequence detection
228 */
229 timerlist.expires = jiffies +
230 SIR_TIMEOUT;
231 add_timer(&timerlist);
232 }
233
234 lsr = inb(io + UART_LSR);
235 } while (lsr & UART_LSR_DR); /* data ready */
236 spin_unlock_irqrestore(&timer_lock, flags);
237 break;
238 default:
239 break;
240 }
241 }
242 ir_raw_event_handle(rcdev);
243 return IRQ_RETVAL(IRQ_HANDLED);
244 }
245
send_space(unsigned long len)246 static void send_space(unsigned long len)
247 {
248 usleep_range(len, len + 25);
249 }
250
send_pulse(unsigned long len)251 static void send_pulse(unsigned long len)
252 {
253 long bytes_out = len / TIME_CONST;
254
255 if (bytes_out == 0)
256 bytes_out++;
257
258 while (bytes_out--) {
259 outb(PULSE, io + UART_TX);
260 /* FIXME treba seriozne cakanie z char/serial.c */
261 while (!(inb(io + UART_LSR) & UART_LSR_THRE))
262 ;
263 }
264 }
265
init_hardware(void)266 static int init_hardware(void)
267 {
268 u8 scratch, scratch2, scratch3;
269 unsigned long flags;
270
271 spin_lock_irqsave(&hardware_lock, flags);
272
273 /*
274 * This is a simple port existence test, borrowed from the autoconfig
275 * function in drivers/tty/serial/8250/8250_port.c
276 */
277 scratch = sinp(UART_IER);
278 soutp(UART_IER, 0);
279 #ifdef __i386__
280 outb(0xff, 0x080);
281 #endif
282 scratch2 = sinp(UART_IER) & 0x0f;
283 soutp(UART_IER, 0x0f);
284 #ifdef __i386__
285 outb(0x00, 0x080);
286 #endif
287 scratch3 = sinp(UART_IER) & 0x0f;
288 soutp(UART_IER, scratch);
289 if (scratch2 != 0 || scratch3 != 0x0f) {
290 /* we fail, there's nothing here */
291 spin_unlock_irqrestore(&hardware_lock, flags);
292 pr_err("port existence test failed, cannot continue\n");
293 return -ENODEV;
294 }
295
296 /* reset UART */
297 outb(0, io + UART_MCR);
298 outb(0, io + UART_IER);
299 /* init UART */
300 /* set DLAB, speed = 115200 */
301 outb(UART_LCR_DLAB | UART_LCR_WLEN7, io + UART_LCR);
302 outb(1, io + UART_DLL); outb(0, io + UART_DLM);
303 /* 7N1+start = 9 bits at 115200 ~ 3 bits at 44000 */
304 outb(UART_LCR_WLEN7, io + UART_LCR);
305 /* FIFO operation */
306 outb(UART_FCR_ENABLE_FIFO, io + UART_FCR);
307 /* interrupts */
308 /* outb(UART_IER_RLSI|UART_IER_RDI|UART_IER_THRI, io + UART_IER); */
309 outb(UART_IER_RDI, io + UART_IER);
310 /* turn on UART */
311 outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2, io + UART_MCR);
312 spin_unlock_irqrestore(&hardware_lock, flags);
313
314 return 0;
315 }
316
drop_hardware(void)317 static void drop_hardware(void)
318 {
319 unsigned long flags;
320
321 spin_lock_irqsave(&hardware_lock, flags);
322
323 /* turn off interrupts */
324 outb(0, io + UART_IER);
325
326 spin_unlock_irqrestore(&hardware_lock, flags);
327 }
328
329 /* SECTION: Initialisation */
sir_ir_probe(struct platform_device * dev)330 static int sir_ir_probe(struct platform_device *dev)
331 {
332 int retval;
333
334 rcdev = devm_rc_allocate_device(&sir_ir_dev->dev, RC_DRIVER_IR_RAW);
335 if (!rcdev)
336 return -ENOMEM;
337
338 rcdev->device_name = "SIR IrDA port";
339 rcdev->input_phys = KBUILD_MODNAME "/input0";
340 rcdev->input_id.bustype = BUS_HOST;
341 rcdev->input_id.vendor = 0x0001;
342 rcdev->input_id.product = 0x0001;
343 rcdev->input_id.version = 0x0100;
344 rcdev->tx_ir = sir_tx_ir;
345 rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
346 rcdev->driver_name = KBUILD_MODNAME;
347 rcdev->map_name = RC_MAP_RC6_MCE;
348 rcdev->timeout = IR_DEFAULT_TIMEOUT;
349 rcdev->dev.parent = &sir_ir_dev->dev;
350
351 setup_timer(&timerlist, sir_timeout, 0);
352
353 /* get I/O port access and IRQ line */
354 if (!devm_request_region(&sir_ir_dev->dev, io, 8, KBUILD_MODNAME)) {
355 pr_err("i/o port 0x%.4x already in use.\n", io);
356 return -EBUSY;
357 }
358 retval = devm_request_irq(&sir_ir_dev->dev, irq, sir_interrupt, 0,
359 KBUILD_MODNAME, NULL);
360 if (retval < 0) {
361 pr_err("IRQ %d already in use.\n", irq);
362 return retval;
363 }
364
365 retval = init_hardware();
366 if (retval) {
367 del_timer_sync(&timerlist);
368 return retval;
369 }
370
371 pr_info("I/O port 0x%.4x, IRQ %d.\n", io, irq);
372
373 retval = devm_rc_register_device(&sir_ir_dev->dev, rcdev);
374 if (retval < 0)
375 return retval;
376
377 return 0;
378 }
379
sir_ir_remove(struct platform_device * dev)380 static int sir_ir_remove(struct platform_device *dev)
381 {
382 drop_hardware();
383 del_timer_sync(&timerlist);
384 return 0;
385 }
386
387 static struct platform_driver sir_ir_driver = {
388 .probe = sir_ir_probe,
389 .remove = sir_ir_remove,
390 .driver = {
391 .name = "sir_ir",
392 },
393 };
394
sir_ir_init(void)395 static int __init sir_ir_init(void)
396 {
397 int retval;
398
399 retval = platform_driver_register(&sir_ir_driver);
400 if (retval)
401 return retval;
402
403 sir_ir_dev = platform_device_alloc("sir_ir", 0);
404 if (!sir_ir_dev) {
405 retval = -ENOMEM;
406 goto pdev_alloc_fail;
407 }
408
409 retval = platform_device_add(sir_ir_dev);
410 if (retval)
411 goto pdev_add_fail;
412
413 return 0;
414
415 pdev_add_fail:
416 platform_device_put(sir_ir_dev);
417 pdev_alloc_fail:
418 platform_driver_unregister(&sir_ir_driver);
419 return retval;
420 }
421
sir_ir_exit(void)422 static void __exit sir_ir_exit(void)
423 {
424 platform_device_unregister(sir_ir_dev);
425 platform_driver_unregister(&sir_ir_driver);
426 }
427
428 module_init(sir_ir_init);
429 module_exit(sir_ir_exit);
430
431 MODULE_DESCRIPTION("Infrared receiver driver for SIR type serial ports");
432 MODULE_AUTHOR("Milan Pikula");
433 MODULE_LICENSE("GPL");
434
435 module_param_hw(io, int, ioport, 0444);
436 MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
437
438 module_param_hw(irq, int, irq, 0444);
439 MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
440
441 module_param(threshold, int, 0444);
442 MODULE_PARM_DESC(threshold, "space detection threshold (3)");
443