2 * IR SIR driver, (C) 2000 Milan Pikula <www@fornax.sk>
4 * sir_ir - Device driver for use with SIR (serial infra red)
5 * mode of IrDA on many notebooks.
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.
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
23 #include <media/rc-core.h>
25 /* SECTION: Definitions */
28 /* 9bit * 1s/115200bit in milli seconds = 78.125ms*/
29 #define TIME_CONST (9000000ul / 115200ul)
31 /* timeout for sequences in jiffies (=5/100s), must be longer than TIME_CONST */
32 #define SIR_TIMEOUT (HZ * 5 / 100)
34 /* onboard sir ports are typically com3 */
35 static int io = 0x3e8;
37 static int threshold = 3;
39 static DEFINE_SPINLOCK(timer_lock);
40 static struct timer_list timerlist;
41 /* time of last signal change detected */
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;
48 static struct platform_device *sir_ir_dev;
50 static DEFINE_SPINLOCK(hardware_lock);
52 /* SECTION: Prototypes */
54 /* Communication with user-space */
55 static void add_read_queue(int flag, unsigned long val);
56 static int init_chrdev(void);
58 static irqreturn_t sir_interrupt(int irq, void *dev_id);
59 static void send_space(unsigned long len);
60 static void send_pulse(unsigned long len);
61 static int init_hardware(void);
62 static void drop_hardware(void);
64 static int init_port(void);
65 static void drop_port(void);
67 static inline unsigned int sinp(int offset)
69 return inb(io + offset);
72 static inline void soutp(int offset, int value)
74 outb(value, io + offset);
77 /* SECTION: Communication with user-space */
78 static int sir_tx_ir(struct rc_dev *dev, unsigned int *tx_buf,
84 local_irq_save(flags);
85 for (i = 0; i < count;) {
87 send_pulse(tx_buf[i]);
92 send_space(tx_buf[i]);
95 local_irq_restore(flags);
100 static void add_read_queue(int flag, unsigned long val)
102 DEFINE_IR_RAW_EVENT(ev);
104 pr_debug("add flag %d with val %lu\n", flag, val);
107 * statistically, pulses are ~TIME_CONST/2 too long. we could
108 * maybe make this more exact, but this is good enough
112 if (val > TIME_CONST / 2)
113 val -= TIME_CONST / 2;
114 else /* should not ever happen */
118 val += TIME_CONST / 2;
120 ev.duration = US_TO_NS(val);
122 ir_raw_event_store_with_filter(rcdev, &ev);
125 static int init_chrdev(void)
127 rcdev = devm_rc_allocate_device(&sir_ir_dev->dev, RC_DRIVER_IR_RAW);
131 rcdev->input_name = "SIR IrDA port";
132 rcdev->input_phys = KBUILD_MODNAME "/input0";
133 rcdev->input_id.bustype = BUS_HOST;
134 rcdev->input_id.vendor = 0x0001;
135 rcdev->input_id.product = 0x0001;
136 rcdev->input_id.version = 0x0100;
137 rcdev->tx_ir = sir_tx_ir;
138 rcdev->allowed_protocols = RC_BIT_ALL_IR_DECODER;
139 rcdev->driver_name = KBUILD_MODNAME;
140 rcdev->map_name = RC_MAP_RC6_MCE;
141 rcdev->timeout = IR_DEFAULT_TIMEOUT;
142 rcdev->dev.parent = &sir_ir_dev->dev;
144 return devm_rc_register_device(&sir_ir_dev->dev, rcdev);
147 /* SECTION: Hardware */
148 static void sir_timeout(unsigned long data)
151 * if last received signal was a pulse, but receiving stopped
152 * within the 9 bit frame, we need to finish this pulse and
153 * simulate a signal change to from pulse to space. Otherwise
154 * upper layers will receive two sequences next time.
158 unsigned long pulse_end;
160 /* avoid interference with interrupt */
161 spin_lock_irqsave(&timer_lock, flags);
163 /* clear unread bits in UART and restart */
164 outb(UART_FCR_CLEAR_RCVR, io + UART_FCR);
165 /* determine 'virtual' pulse end: */
166 pulse_end = min_t(unsigned long,
167 ktime_us_delta(last, last_intr_time),
169 dev_dbg(&sir_ir_dev->dev, "timeout add %d for %lu usec\n",
170 last_value, pulse_end);
171 add_read_queue(last_value, pulse_end);
173 last = last_intr_time;
175 spin_unlock_irqrestore(&timer_lock, flags);
176 ir_raw_event_handle(rcdev);
179 static irqreturn_t sir_interrupt(int irq, void *dev_id)
183 static unsigned long delt;
184 unsigned long deltintr;
188 while ((iir = inb(io + UART_IIR) & UART_IIR_ID)) {
189 switch (iir & UART_IIR_ID) { /* FIXME toto treba preriedit */
191 (void)inb(io + UART_MSR);
195 (void)inb(io + UART_LSR);
198 /* avoid interference with timer */
199 spin_lock_irqsave(&timer_lock, flags);
201 del_timer(&timerlist);
202 data = inb(io + UART_RX);
203 curr_time = ktime_get();
204 delt = min_t(unsigned long,
205 ktime_us_delta(last, curr_time),
207 deltintr = min_t(unsigned long,
208 ktime_us_delta(last_intr_time,
211 dev_dbg(&sir_ir_dev->dev, "t %lu, d %d\n",
212 deltintr, (int)data);
214 * if nothing came in last X cycles,
217 if (deltintr > TIME_CONST * threshold) {
219 dev_dbg(&sir_ir_dev->dev, "GAP\n");
220 /* simulate signal change */
221 add_read_queue(last_value,
225 last = last_intr_time;
230 if (data ^ last_value) {
232 * deltintr > 2*TIME_CONST, remember?
233 * the other case is timeout
235 add_read_queue(last_value,
239 last = ktime_sub_us(last,
242 last_intr_time = curr_time;
245 * start timer for end of
248 timerlist.expires = jiffies +
250 add_timer(&timerlist);
253 lsr = inb(io + UART_LSR);
254 } while (lsr & UART_LSR_DR); /* data ready */
255 spin_unlock_irqrestore(&timer_lock, flags);
261 ir_raw_event_handle(rcdev);
262 return IRQ_RETVAL(IRQ_HANDLED);
265 static void send_space(unsigned long len)
267 usleep_range(len, len + 25);
270 static void send_pulse(unsigned long len)
272 long bytes_out = len / TIME_CONST;
277 while (bytes_out--) {
278 outb(PULSE, io + UART_TX);
279 /* FIXME treba seriozne cakanie z char/serial.c */
280 while (!(inb(io + UART_LSR) & UART_LSR_THRE))
285 static int init_hardware(void)
289 spin_lock_irqsave(&hardware_lock, flags);
291 outb(0, io + UART_MCR);
292 outb(0, io + UART_IER);
294 /* set DLAB, speed = 115200 */
295 outb(UART_LCR_DLAB | UART_LCR_WLEN7, io + UART_LCR);
296 outb(1, io + UART_DLL); outb(0, io + UART_DLM);
297 /* 7N1+start = 9 bits at 115200 ~ 3 bits at 44000 */
298 outb(UART_LCR_WLEN7, io + UART_LCR);
300 outb(UART_FCR_ENABLE_FIFO, io + UART_FCR);
302 /* outb(UART_IER_RLSI|UART_IER_RDI|UART_IER_THRI, io + UART_IER); */
303 outb(UART_IER_RDI, io + UART_IER);
305 outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2, io + UART_MCR);
306 spin_unlock_irqrestore(&hardware_lock, flags);
310 static void drop_hardware(void)
314 spin_lock_irqsave(&hardware_lock, flags);
316 /* turn off interrupts */
317 outb(0, io + UART_IER);
319 spin_unlock_irqrestore(&hardware_lock, flags);
322 /* SECTION: Initialisation */
324 static int init_port(void)
328 setup_timer(&timerlist, sir_timeout, 0);
330 /* get I/O port access and IRQ line */
331 if (!request_region(io, 8, KBUILD_MODNAME)) {
332 pr_err("i/o port 0x%.4x already in use.\n", io);
335 retval = request_irq(irq, sir_interrupt, 0,
336 KBUILD_MODNAME, NULL);
338 release_region(io, 8);
339 pr_err("IRQ %d already in use.\n", irq);
342 pr_info("I/O port 0x%.4x, IRQ %d.\n", io, irq);
347 static void drop_port(void)
350 del_timer_sync(&timerlist);
351 release_region(io, 8);
354 static int init_sir_ir(void)
358 retval = init_port();
365 static int sir_ir_probe(struct platform_device *dev)
369 retval = init_chrdev();
373 return init_sir_ir();
376 static int sir_ir_remove(struct platform_device *dev)
381 static struct platform_driver sir_ir_driver = {
382 .probe = sir_ir_probe,
383 .remove = sir_ir_remove,
389 static int __init sir_ir_init(void)
393 retval = platform_driver_register(&sir_ir_driver);
397 sir_ir_dev = platform_device_alloc("sir_ir", 0);
400 goto pdev_alloc_fail;
403 retval = platform_device_add(sir_ir_dev);
410 platform_device_put(sir_ir_dev);
412 platform_driver_unregister(&sir_ir_driver);
416 static void __exit sir_ir_exit(void)
420 platform_device_unregister(sir_ir_dev);
421 platform_driver_unregister(&sir_ir_driver);
424 module_init(sir_ir_init);
425 module_exit(sir_ir_exit);
427 MODULE_DESCRIPTION("Infrared receiver driver for SIR type serial ports");
428 MODULE_AUTHOR("Milan Pikula");
429 MODULE_LICENSE("GPL");
431 module_param(io, int, 0444);
432 MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
434 module_param(irq, int, 0444);
435 MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
437 module_param(threshold, int, 0444);
438 MODULE_PARM_DESC(threshold, "space detection threshold (3)");