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				https://github.com/torvalds/linux.git
				synced 2025-11-04 10:40:15 +02:00 
			
		
		
		
	This can be done with c99 initializers, which makes the code cleaner
and more transparent. It does require gcc 4.6, because of this bug
in earlier versions:
	https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10676
Since commit cafa0010cd ("Raise the minimum required gcc version to
4.6"), this is the case.
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
		
	
			
		
			
				
	
	
		
			442 lines
		
	
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			442 lines
		
	
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * IR SIR driver, (C) 2000 Milan Pikula <www@fornax.sk>
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 *
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 * sir_ir - Device driver for use with SIR (serial infra red)
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 * mode of IrDA on many notebooks.
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 *
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 *  This program is free software; you can redistribute it and/or modify
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 *  it under the terms of the GNU General Public License as published by
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 *  the Free Software Foundation; either version 2 of the License, or
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 *  (at your option) any later version.
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 */
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/serial_reg.h>
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#include <linux/ktime.h>
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#include <linux/delay.h>
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#include <linux/platform_device.h>
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#include <media/rc-core.h>
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/* SECTION: Definitions */
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#define PULSE '['
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/* 9bit * 1s/115200bit in milli seconds = 78.125ms*/
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#define TIME_CONST (9000000ul / 115200ul)
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/* timeout for sequences in jiffies (=5/100s), must be longer than TIME_CONST */
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#define SIR_TIMEOUT	(HZ * 5 / 100)
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/* onboard sir ports are typically com3 */
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static int io = 0x3e8;
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static int irq = 4;
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static int threshold = 3;
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static DEFINE_SPINLOCK(timer_lock);
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static struct timer_list timerlist;
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/* time of last signal change detected */
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static ktime_t last;
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/* time of last UART data ready interrupt */
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static ktime_t last_intr_time;
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static int last_value;
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static struct rc_dev *rcdev;
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static struct platform_device *sir_ir_dev;
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static DEFINE_SPINLOCK(hardware_lock);
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/* SECTION: Prototypes */
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/* Communication with user-space */
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static void add_read_queue(int flag, unsigned long val);
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/* Hardware */
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static irqreturn_t sir_interrupt(int irq, void *dev_id);
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static void send_space(unsigned long len);
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static void send_pulse(unsigned long len);
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static int init_hardware(void);
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static void drop_hardware(void);
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/* Initialisation */
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static inline unsigned int sinp(int offset)
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{
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	return inb(io + offset);
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}
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static inline void soutp(int offset, int value)
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{
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	outb(value, io + offset);
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}
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/* SECTION: Communication with user-space */
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static int sir_tx_ir(struct rc_dev *dev, unsigned int *tx_buf,
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		     unsigned int count)
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{
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	unsigned long flags;
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	int i;
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	local_irq_save(flags);
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	for (i = 0; i < count;) {
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		if (tx_buf[i])
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			send_pulse(tx_buf[i]);
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		i++;
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		if (i >= count)
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			break;
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		if (tx_buf[i])
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			send_space(tx_buf[i]);
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		i++;
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	}
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	local_irq_restore(flags);
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	return count;
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}
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static void add_read_queue(int flag, unsigned long val)
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{
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	struct ir_raw_event ev = {};
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	pr_debug("add flag %d with val %lu\n", flag, val);
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	/*
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	 * statistically, pulses are ~TIME_CONST/2 too long. we could
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	 * maybe make this more exact, but this is good enough
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	 */
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	if (flag) {
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		/* pulse */
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		if (val > TIME_CONST / 2)
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			val -= TIME_CONST / 2;
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		else /* should not ever happen */
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			val = 1;
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		ev.pulse = true;
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	} else {
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		val += TIME_CONST / 2;
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	}
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	ev.duration = US_TO_NS(val);
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	ir_raw_event_store_with_filter(rcdev, &ev);
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}
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/* SECTION: Hardware */
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static void sir_timeout(struct timer_list *unused)
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{
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	/*
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	 * if last received signal was a pulse, but receiving stopped
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	 * within the 9 bit frame, we need to finish this pulse and
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	 * simulate a signal change to from pulse to space. Otherwise
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	 * upper layers will receive two sequences next time.
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	 */
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	unsigned long flags;
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	unsigned long pulse_end;
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	/* avoid interference with interrupt */
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	spin_lock_irqsave(&timer_lock, flags);
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	if (last_value) {
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		/* clear unread bits in UART and restart */
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		outb(UART_FCR_CLEAR_RCVR, io + UART_FCR);
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		/* determine 'virtual' pulse end: */
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		pulse_end = min_t(unsigned long,
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				  ktime_us_delta(last, last_intr_time),
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				  IR_MAX_DURATION);
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		dev_dbg(&sir_ir_dev->dev, "timeout add %d for %lu usec\n",
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			last_value, pulse_end);
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		add_read_queue(last_value, pulse_end);
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		last_value = 0;
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		last = last_intr_time;
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	}
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	spin_unlock_irqrestore(&timer_lock, flags);
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	ir_raw_event_handle(rcdev);
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}
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static irqreturn_t sir_interrupt(int irq, void *dev_id)
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{
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	unsigned char data;
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	ktime_t curr_time;
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	unsigned long delt;
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	unsigned long deltintr;
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	unsigned long flags;
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	int counter = 0;
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	int iir, lsr;
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	while ((iir = inb(io + UART_IIR) & UART_IIR_ID)) {
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		if (++counter > 256) {
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			dev_err(&sir_ir_dev->dev, "Trapped in interrupt");
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			break;
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		}
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		switch (iir & UART_IIR_ID) { /* FIXME toto treba preriedit */
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		case UART_IIR_MSI:
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			(void)inb(io + UART_MSR);
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			break;
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		case UART_IIR_RLSI:
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		case UART_IIR_THRI:
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			(void)inb(io + UART_LSR);
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			break;
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		case UART_IIR_RDI:
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			/* avoid interference with timer */
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			spin_lock_irqsave(&timer_lock, flags);
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			do {
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				del_timer(&timerlist);
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				data = inb(io + UART_RX);
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				curr_time = ktime_get();
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				delt = min_t(unsigned long,
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					     ktime_us_delta(last, curr_time),
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					     IR_MAX_DURATION);
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				deltintr = min_t(unsigned long,
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						 ktime_us_delta(last_intr_time,
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								curr_time),
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						 IR_MAX_DURATION);
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				dev_dbg(&sir_ir_dev->dev, "t %lu, d %d\n",
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					deltintr, (int)data);
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				/*
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				 * if nothing came in last X cycles,
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				 * it was gap
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				 */
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				if (deltintr > TIME_CONST * threshold) {
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					if (last_value) {
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						dev_dbg(&sir_ir_dev->dev, "GAP\n");
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						/* simulate signal change */
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						add_read_queue(last_value,
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							       delt -
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							       deltintr);
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						last_value = 0;
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						last = last_intr_time;
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						delt = deltintr;
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					}
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				}
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				data = 1;
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				if (data ^ last_value) {
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					/*
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					 * deltintr > 2*TIME_CONST, remember?
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					 * the other case is timeout
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					 */
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					add_read_queue(last_value,
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						       delt - TIME_CONST);
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					last_value = data;
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					last = curr_time;
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					last = ktime_sub_us(last,
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							    TIME_CONST);
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				}
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				last_intr_time = curr_time;
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				if (data) {
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					/*
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					 * start timer for end of
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					 * sequence detection
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					 */
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					timerlist.expires = jiffies +
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								SIR_TIMEOUT;
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					add_timer(&timerlist);
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				}
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				lsr = inb(io + UART_LSR);
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			} while (lsr & UART_LSR_DR); /* data ready */
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			spin_unlock_irqrestore(&timer_lock, flags);
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			break;
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		default:
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			break;
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		}
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	}
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	ir_raw_event_handle(rcdev);
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	return IRQ_RETVAL(IRQ_HANDLED);
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}
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static void send_space(unsigned long len)
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{
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	usleep_range(len, len + 25);
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}
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static void send_pulse(unsigned long len)
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{
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	long bytes_out = len / TIME_CONST;
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	if (bytes_out == 0)
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		bytes_out++;
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	while (bytes_out--) {
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		outb(PULSE, io + UART_TX);
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		/* FIXME treba seriozne cakanie z char/serial.c */
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		while (!(inb(io + UART_LSR) & UART_LSR_THRE))
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			;
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	}
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}
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static int init_hardware(void)
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{
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	u8 scratch, scratch2, scratch3;
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	unsigned long flags;
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	spin_lock_irqsave(&hardware_lock, flags);
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	/*
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	 * This is a simple port existence test, borrowed from the autoconfig
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	 * function in drivers/tty/serial/8250/8250_port.c
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	 */
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	scratch = sinp(UART_IER);
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	soutp(UART_IER, 0);
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#ifdef __i386__
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	outb(0xff, 0x080);
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#endif
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	scratch2 = sinp(UART_IER) & 0x0f;
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	soutp(UART_IER, 0x0f);
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#ifdef __i386__
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	outb(0x00, 0x080);
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#endif
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	scratch3 = sinp(UART_IER) & 0x0f;
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	soutp(UART_IER, scratch);
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	if (scratch2 != 0 || scratch3 != 0x0f) {
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		/* we fail, there's nothing here */
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		spin_unlock_irqrestore(&hardware_lock, flags);
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		pr_err("port existence test failed, cannot continue\n");
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		return -ENODEV;
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	}
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	/* reset UART */
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	outb(0, io + UART_MCR);
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	outb(0, io + UART_IER);
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	/* init UART */
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	/* set DLAB, speed = 115200 */
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	outb(UART_LCR_DLAB | UART_LCR_WLEN7, io + UART_LCR);
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	outb(1, io + UART_DLL); outb(0, io + UART_DLM);
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	/* 7N1+start = 9 bits at 115200 ~ 3 bits at 44000 */
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	outb(UART_LCR_WLEN7, io + UART_LCR);
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	/* FIFO operation */
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	outb(UART_FCR_ENABLE_FIFO, io + UART_FCR);
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	/* interrupts */
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	/* outb(UART_IER_RLSI|UART_IER_RDI|UART_IER_THRI, io + UART_IER); */
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	outb(UART_IER_RDI, io + UART_IER);
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	/* turn on UART */
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	outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2, io + UART_MCR);
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	spin_unlock_irqrestore(&hardware_lock, flags);
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	return 0;
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}
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static void drop_hardware(void)
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{
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	unsigned long flags;
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	spin_lock_irqsave(&hardware_lock, flags);
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	/* turn off interrupts */
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	outb(0, io + UART_IER);
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	spin_unlock_irqrestore(&hardware_lock, flags);
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}
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/* SECTION: Initialisation */
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static int sir_ir_probe(struct platform_device *dev)
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{
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	int retval;
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	rcdev = devm_rc_allocate_device(&sir_ir_dev->dev, RC_DRIVER_IR_RAW);
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	if (!rcdev)
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		return -ENOMEM;
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	rcdev->device_name = "SIR IrDA port";
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	rcdev->input_phys = KBUILD_MODNAME "/input0";
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	rcdev->input_id.bustype = BUS_HOST;
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	rcdev->input_id.vendor = 0x0001;
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	rcdev->input_id.product = 0x0001;
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	rcdev->input_id.version = 0x0100;
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	rcdev->tx_ir = sir_tx_ir;
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	rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
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	rcdev->driver_name = KBUILD_MODNAME;
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	rcdev->map_name = RC_MAP_RC6_MCE;
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	rcdev->timeout = IR_DEFAULT_TIMEOUT;
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	rcdev->dev.parent = &sir_ir_dev->dev;
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	timer_setup(&timerlist, sir_timeout, 0);
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	/* get I/O port access and IRQ line */
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	if (!devm_request_region(&sir_ir_dev->dev, io, 8, KBUILD_MODNAME)) {
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		pr_err("i/o port 0x%.4x already in use.\n", io);
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		return -EBUSY;
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	}
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	retval = devm_request_irq(&sir_ir_dev->dev, irq, sir_interrupt, 0,
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				  KBUILD_MODNAME, NULL);
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	if (retval < 0) {
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		pr_err("IRQ %d already in use.\n", irq);
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		return retval;
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	}
 | 
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	retval = init_hardware();
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	if (retval) {
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		del_timer_sync(&timerlist);
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		return retval;
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	}
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	pr_info("I/O port 0x%.4x, IRQ %d.\n", io, irq);
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	retval = devm_rc_register_device(&sir_ir_dev->dev, rcdev);
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	if (retval < 0)
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		return retval;
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 | 
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	return 0;
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}
 | 
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 | 
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static int sir_ir_remove(struct platform_device *dev)
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{
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	drop_hardware();
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	del_timer_sync(&timerlist);
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	return 0;
 | 
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}
 | 
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 | 
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static struct platform_driver sir_ir_driver = {
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	.probe		= sir_ir_probe,
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	.remove		= sir_ir_remove,
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	.driver		= {
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		.name	= "sir_ir",
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	},
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};
 | 
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 | 
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static int __init sir_ir_init(void)
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{
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	int retval;
 | 
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 | 
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	retval = platform_driver_register(&sir_ir_driver);
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	if (retval)
 | 
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		return retval;
 | 
						|
 | 
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	sir_ir_dev = platform_device_alloc("sir_ir", 0);
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						|
	if (!sir_ir_dev) {
 | 
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		retval = -ENOMEM;
 | 
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		goto pdev_alloc_fail;
 | 
						|
	}
 | 
						|
 | 
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	retval = platform_device_add(sir_ir_dev);
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	if (retval)
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		goto pdev_add_fail;
 | 
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 | 
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	return 0;
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 | 
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pdev_add_fail:
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	platform_device_put(sir_ir_dev);
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pdev_alloc_fail:
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	platform_driver_unregister(&sir_ir_driver);
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	return retval;
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}
 | 
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 | 
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static void __exit sir_ir_exit(void)
 | 
						|
{
 | 
						|
	platform_device_unregister(sir_ir_dev);
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	platform_driver_unregister(&sir_ir_driver);
 | 
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}
 | 
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 | 
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module_init(sir_ir_init);
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module_exit(sir_ir_exit);
 | 
						|
 | 
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MODULE_DESCRIPTION("Infrared receiver driver for SIR type serial ports");
 | 
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MODULE_AUTHOR("Milan Pikula");
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MODULE_LICENSE("GPL");
 | 
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module_param_hw(io, int, ioport, 0444);
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						|
MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
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						|
module_param_hw(irq, int, irq, 0444);
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						|
MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
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						|
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						|
module_param(threshold, int, 0444);
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						|
MODULE_PARM_DESC(threshold, "space detection threshold (3)");
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