drivers/media/rc/sir_ir.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * IR SIR driver, (C) 2000 Milan Pikula <www@fornax.sk>
  *
  * sir_ir - Device driver for use with SIR (serial infra red)
  * mode of IrDA on many notebooks.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/serial_reg.h>
 #include <linux/ktime.h>
 #include <linux/delay.h>
 #include <linux/platform_device.h>

 #include <media/rc-core.h>

 /* SECTION: Definitions */
 #define PULSE '['

 /* 9bit * 1s/115200bit in milli seconds = 78.125ms*/
 #define TIME_CONST (9000000ul / 115200ul)

 /* timeout for sequences in jiffies (=5/100s), must be longer than TIME_CONST */
 #define SIR_TIMEOUT	(HZ * 5 / 100)

 /* onboard sir ports are typically com3 */
 static int io = 0x3e8;
 static int irq = 4;
 static int threshold = 3;

 static DEFINE_SPINLOCK(timer_lock);
 static struct timer_list timerlist;
 /* time of last signal change detected */
 static ktime_t last;
 /* time of last UART data ready interrupt */
 static ktime_t last_intr_time;
 static int last_value;
 static struct rc_dev *rcdev;

 static struct platform_device *sir_ir_dev;

 static DEFINE_SPINLOCK(hardware_lock);

 /* SECTION: Prototypes */

 /* Communication with user-space */
 static void add_read_queue(int flag, unsigned long val);
 /* Hardware */
 static irqreturn_t sir_interrupt(int irq, void *dev_id);
 static void send_space(unsigned long len);
 static void send_pulse(unsigned long len);
 static int init_hardware(void);
 static void drop_hardware(void);
 /* Initialisation */

 static inline unsigned int sinp(int offset)
 {
 	return inb(io + offset);
 }

 static inline void soutp(int offset, int value)
 {
 	outb(value, io + offset);
 }

 /* SECTION: Communication with user-space */
 static int sir_tx_ir(struct rc_dev *dev, unsigned int *tx_buf,
 		     unsigned int count)
 {
 	unsigned long flags;
 	int i;

 	local_irq_save(flags);
 	for (i = 0; i < count;) {
 		if (tx_buf[i])
 			send_pulse(tx_buf[i]);
 		i++;
 		if (i >= count)
 			break;
 		if (tx_buf[i])
 			send_space(tx_buf[i]);
 		i++;
 	}
 	local_irq_restore(flags);

 	return count;
 }

 static void add_read_queue(int flag, unsigned long val)
 {
 	struct ir_raw_event ev = {};

 	pr_debug("add flag %d with val %lu\n", flag, val);

 	/*
 	 * statistically, pulses are ~TIME_CONST/2 too long. we could
 	 * maybe make this more exact, but this is good enough
 	 */
 	if (flag) {
 		/* pulse */
 		if (val > TIME_CONST / 2)
 			val -= TIME_CONST / 2;
 		else /* should not ever happen */
 			val = 1;
 		ev.pulse = true;
 	} else {
 		val += TIME_CONST / 2;
 	}
 	ev.duration = US_TO_NS(val);

 	ir_raw_event_store_with_filter(rcdev, &ev);
 }

 /* SECTION: Hardware */
 static void sir_timeout(struct timer_list *unused)
 {
 	/*
 	 * if last received signal was a pulse, but receiving stopped
 	 * within the 9 bit frame, we need to finish this pulse and
 	 * simulate a signal change to from pulse to space. Otherwise
 	 * upper layers will receive two sequences next time.
 	 */

 	unsigned long flags;
 	unsigned long pulse_end;

 	/* avoid interference with interrupt */
 	spin_lock_irqsave(&timer_lock, flags);
 	if (last_value) {
 		/* clear unread bits in UART and restart */
 		outb(UART_FCR_CLEAR_RCVR, io + UART_FCR);
 		/* determine 'virtual' pulse end: */
 		pulse_end = min_t(unsigned long,
 				  ktime_us_delta(last, last_intr_time),
 				  IR_MAX_DURATION);
 		dev_dbg(&sir_ir_dev->dev, "timeout add %d for %lu usec\n",
 			last_value, pulse_end);
 		add_read_queue(last_value, pulse_end);
 		last_value = 0;
 		last = last_intr_time;
 	}
 	spin_unlock_irqrestore(&timer_lock, flags);
 	ir_raw_event_handle(rcdev);
 }

 static irqreturn_t sir_interrupt(int irq, void *dev_id)
 {
 	unsigned char data;
 	ktime_t curr_time;
 	unsigned long delt;
 	unsigned long deltintr;
 	unsigned long flags;
 	int counter = 0;
 	int iir, lsr;

 	while ((iir = inb(io + UART_IIR) & UART_IIR_ID)) {
 		if (++counter > 256) {
 			dev_err(&sir_ir_dev->dev, "Trapped in interrupt");
 			break;
 		}

 		switch (iir & UART_IIR_ID) { /* FIXME toto treba preriedit */
 		case UART_IIR_MSI:
 			(void)inb(io + UART_MSR);
 			break;
 		case UART_IIR_RLSI:
 		case UART_IIR_THRI:
 			(void)inb(io + UART_LSR);
 			break;
 		case UART_IIR_RDI:
 			/* avoid interference with timer */
 			spin_lock_irqsave(&timer_lock, flags);
 			do {
 				del_timer(&timerlist);
 				data = inb(io + UART_RX);
 				curr_time = ktime_get();
 				delt = min_t(unsigned long,
 					     ktime_us_delta(last, curr_time),
 					     IR_MAX_DURATION);
 				deltintr = min_t(unsigned long,
 						 ktime_us_delta(last_intr_time,
 								curr_time),
 						 IR_MAX_DURATION);
 				dev_dbg(&sir_ir_dev->dev, "t %lu, d %d\n",
 					deltintr, (int)data);
 				/*
 				 * if nothing came in last X cycles,
 				 * it was gap
 				 */
 				if (deltintr > TIME_CONST * threshold) {
 					if (last_value) {
 						dev_dbg(&sir_ir_dev->dev, "GAP\n");
 						/* simulate signal change */
 						add_read_queue(last_value,
 							       delt -
 							       deltintr);
 						last_value = 0;
 						last = last_intr_time;
 						delt = deltintr;
 					}
 				}
 				data = 1;
 				if (data ^ last_value) {
 					/*
 					 * deltintr > 2*TIME_CONST, remember?
 					 * the other case is timeout
 					 */
 					add_read_queue(last_value,
 						       delt - TIME_CONST);
 					last_value = data;
 					last = curr_time;
 					last = ktime_sub_us(last,
 							    TIME_CONST);
 				}
 				last_intr_time = curr_time;
 				if (data) {
 					/*
 					 * start timer for end of
 					 * sequence detection
 					 */
 					timerlist.expires = jiffies +
 								SIR_TIMEOUT;
 					add_timer(&timerlist);
 				}

 				lsr = inb(io + UART_LSR);
 			} while (lsr & UART_LSR_DR); /* data ready */
 			spin_unlock_irqrestore(&timer_lock, flags);
 			break;
 		default:
 			break;
 		}
 	}
 	ir_raw_event_handle(rcdev);
 	return IRQ_RETVAL(IRQ_HANDLED);
 }

 static void send_space(unsigned long len)
 {
 	usleep_range(len, len + 25);
 }

 static void send_pulse(unsigned long len)
 {
 	long bytes_out = len / TIME_CONST;

 	if (bytes_out == 0)
 		bytes_out++;

 	while (bytes_out--) {
 		outb(PULSE, io + UART_TX);
 		/* FIXME treba seriozne cakanie z char/serial.c */
 		while (!(inb(io + UART_LSR) & UART_LSR_THRE))
 			;
 	}
 }

 static int init_hardware(void)
 {
 	u8 scratch, scratch2, scratch3;
 	unsigned long flags;

 	spin_lock_irqsave(&hardware_lock, flags);

 	/*
 	 * This is a simple port existence test, borrowed from the autoconfig
 	 * function in drivers/tty/serial/8250/8250_port.c
 	 */
 	scratch = sinp(UART_IER);
 	soutp(UART_IER, 0);
 #ifdef __i386__
 	outb(0xff, 0x080);
 #endif
 	scratch2 = sinp(UART_IER) & 0x0f;
 	soutp(UART_IER, 0x0f);
 #ifdef __i386__
 	outb(0x00, 0x080);
 #endif
 	scratch3 = sinp(UART_IER) & 0x0f;
 	soutp(UART_IER, scratch);
 	if (scratch2 != 0 || scratch3 != 0x0f) {
 		/* we fail, there's nothing here */
 		spin_unlock_irqrestore(&hardware_lock, flags);
 		pr_err("port existence test failed, cannot continue\n");
 		return -ENODEV;
 	}

 	/* reset UART */
 	outb(0, io + UART_MCR);
 	outb(0, io + UART_IER);
 	/* init UART */
 	/* set DLAB, speed = 115200 */
 	outb(UART_LCR_DLAB | UART_LCR_WLEN7, io + UART_LCR);
 	outb(1, io + UART_DLL); outb(0, io + UART_DLM);
 	/* 7N1+start = 9 bits at 115200 ~ 3 bits at 44000 */
 	outb(UART_LCR_WLEN7, io + UART_LCR);
 	/* FIFO operation */
 	outb(UART_FCR_ENABLE_FIFO, io + UART_FCR);
 	/* interrupts */
 	/* outb(UART_IER_RLSI|UART_IER_RDI|UART_IER_THRI, io + UART_IER); */
 	outb(UART_IER_RDI, io + UART_IER);
 	/* turn on UART */
 	outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2, io + UART_MCR);
 	spin_unlock_irqrestore(&hardware_lock, flags);

 	return 0;
 }

 static void drop_hardware(void)
 {
 	unsigned long flags;

 	spin_lock_irqsave(&hardware_lock, flags);

 	/* turn off interrupts */
 	outb(0, io + UART_IER);

 	spin_unlock_irqrestore(&hardware_lock, flags);
 }

 /* SECTION: Initialisation */
 static int sir_ir_probe(struct platform_device *dev)
 {
 	int retval;

 	rcdev = devm_rc_allocate_device(&sir_ir_dev->dev, RC_DRIVER_IR_RAW);
 	if (!rcdev)
 		return -ENOMEM;

 	rcdev->device_name = "SIR IrDA port";
 	rcdev->input_phys = KBUILD_MODNAME "/input0";
 	rcdev->input_id.bustype = BUS_HOST;
 	rcdev->input_id.vendor = 0x0001;
 	rcdev->input_id.product = 0x0001;
 	rcdev->input_id.version = 0x0100;
 	rcdev->tx_ir = sir_tx_ir;
 	rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
 	rcdev->driver_name = KBUILD_MODNAME;
 	rcdev->map_name = RC_MAP_RC6_MCE;
 	rcdev->timeout = IR_DEFAULT_TIMEOUT;
 	rcdev->dev.parent = &sir_ir_dev->dev;

 	timer_setup(&timerlist, sir_timeout, 0);

 	/* get I/O port access and IRQ line */
 	if (!devm_request_region(&sir_ir_dev->dev, io, 8, KBUILD_MODNAME)) {
 		pr_err("i/o port 0x%.4x already in use.\n", io);
 		return -EBUSY;
 	}
 	retval = devm_request_irq(&sir_ir_dev->dev, irq, sir_interrupt, 0,
 				  KBUILD_MODNAME, NULL);
 	if (retval < 0) {
 		pr_err("IRQ %d already in use.\n", irq);
 		return retval;
 	}

 	retval = init_hardware();
 	if (retval) {
 		del_timer_sync(&timerlist);
 		return retval;
 	}

 	pr_info("I/O port 0x%.4x, IRQ %d.\n", io, irq);

 	retval = devm_rc_register_device(&sir_ir_dev->dev, rcdev);
 	if (retval < 0)
 		return retval;

 	return 0;
 }

 static int sir_ir_remove(struct platform_device *dev)
 {
 	drop_hardware();
 	del_timer_sync(&timerlist);
 	return 0;
 }

 static struct platform_driver sir_ir_driver = {
 	.probe		= sir_ir_probe,
 	.remove		= sir_ir_remove,
 	.driver		= {
 		.name	= "sir_ir",
 	},
 };

 static int __init sir_ir_init(void)
 {
 	int retval;

 	retval = platform_driver_register(&sir_ir_driver);
 	if (retval)
 		return retval;

 	sir_ir_dev = platform_device_alloc("sir_ir", 0);
 	if (!sir_ir_dev) {
 		retval = -ENOMEM;
 		goto pdev_alloc_fail;
 	}

 	retval = platform_device_add(sir_ir_dev);
 	if (retval)
 		goto pdev_add_fail;

 	return 0;

 pdev_add_fail:
 	platform_device_put(sir_ir_dev);
 pdev_alloc_fail:
 	platform_driver_unregister(&sir_ir_driver);
 	return retval;
 }

 static void __exit sir_ir_exit(void)
 {
 	platform_device_unregister(sir_ir_dev);
 	platform_driver_unregister(&sir_ir_driver);
 }

 module_init(sir_ir_init);
 module_exit(sir_ir_exit);

 MODULE_DESCRIPTION("Infrared receiver driver for SIR type serial ports");
 MODULE_AUTHOR("Milan Pikula");
 MODULE_LICENSE("GPL");

 module_param_hw(io, int, ioport, 0444);
 MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");

 module_param_hw(irq, int, irq, 0444);
 MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");

 module_param(threshold, int, 0444);
 MODULE_PARM_DESC(threshold, "space detection threshold (3)");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* IR SIR driver, (C) 2000 Milan Pikula <www@fornax.sk>
	*
	* sir_ir - Device driver for use with SIR (serial infra red)
	* mode of IrDA on many notebooks.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/module.h>
	#include <linux/interrupt.h>
	#include <linux/kernel.h>
	#include <linux/serial_reg.h>
	#include <linux/ktime.h>
	#include <linux/delay.h>
	#include <linux/platform_device.h>

	#include <media/rc-core.h>

	/* SECTION: Definitions */
	#define PULSE '['

	/* 9bit * 1s/115200bit in milli seconds = 78.125ms*/
	#define TIME_CONST (9000000ul / 115200ul)

	/* timeout for sequences in jiffies (=5/100s), must be longer than TIME_CONST */
	#define SIR_TIMEOUT (HZ * 5 / 100)

	/* onboard sir ports are typically com3 */
	static int io = 0x3e8;
	static int irq = 4;
	static int threshold = 3;

	static DEFINE_SPINLOCK(timer_lock);
	static struct timer_list timerlist;
	/* time of last signal change detected */
	static ktime_t last;
	/* time of last UART data ready interrupt */
	static ktime_t last_intr_time;
	static int last_value;
	static struct rc_dev *rcdev;

	static struct platform_device *sir_ir_dev;

	static DEFINE_SPINLOCK(hardware_lock);

	/* SECTION: Prototypes */

	/* Communication with user-space */
	static void add_read_queue(int flag, unsigned long val);
	/* Hardware */
	static irqreturn_t sir_interrupt(int irq, void *dev_id);
	static void send_space(unsigned long len);
	static void send_pulse(unsigned long len);
	static int init_hardware(void);
	static void drop_hardware(void);
	/* Initialisation */

	static inline unsigned int sinp(int offset)
	{
	return inb(io + offset);
	}

	static inline void soutp(int offset, int value)
	{
	outb(value, io + offset);
	}

	/* SECTION: Communication with user-space */
	static int sir_tx_ir(struct rc_dev dev, unsigned int tx_buf,
	unsigned int count)
	{
	unsigned long flags;
	int i;

	local_irq_save(flags);
	for (i = 0; i < count;) {
	if (tx_buf[i])
	send_pulse(tx_buf[i]);
	i++;
	if (i >= count)
	break;
	if (tx_buf[i])
	send_space(tx_buf[i]);
	i++;
	}
	local_irq_restore(flags);

	return count;
	}

	static void add_read_queue(int flag, unsigned long val)
	{
	struct ir_raw_event ev = {};

	pr_debug("add flag %d with val %lu\n", flag, val);

	/*
	* statistically, pulses are ~TIME_CONST/2 too long. we could
	* maybe make this more exact, but this is good enough
	*/
	if (flag) {
	/* pulse */
	if (val > TIME_CONST / 2)
	val -= TIME_CONST / 2;
	else /* should not ever happen */
	val = 1;
	ev.pulse = true;
	} else {
	val += TIME_CONST / 2;
	}
	ev.duration = US_TO_NS(val);

	ir_raw_event_store_with_filter(rcdev, &ev);
	}

	/* SECTION: Hardware */
	static void sir_timeout(struct timer_list *unused)
	{
	/*
	* if last received signal was a pulse, but receiving stopped
	* within the 9 bit frame, we need to finish this pulse and
	* simulate a signal change to from pulse to space. Otherwise
	* upper layers will receive two sequences next time.
	*/

	unsigned long flags;
	unsigned long pulse_end;

	/* avoid interference with interrupt */
	spin_lock_irqsave(&timer_lock, flags);
	if (last_value) {
	/* clear unread bits in UART and restart */
	outb(UART_FCR_CLEAR_RCVR, io + UART_FCR);
	/* determine 'virtual' pulse end: */
	pulse_end = min_t(unsigned long,
	ktime_us_delta(last, last_intr_time),
	IR_MAX_DURATION);
	dev_dbg(&sir_ir_dev->dev, "timeout add %d for %lu usec\n",
	last_value, pulse_end);
	add_read_queue(last_value, pulse_end);
	last_value = 0;
	last = last_intr_time;
	}
	spin_unlock_irqrestore(&timer_lock, flags);
	ir_raw_event_handle(rcdev);
	}

	static irqreturn_t sir_interrupt(int irq, void *dev_id)
	{
	unsigned char data;
	ktime_t curr_time;
	unsigned long delt;
	unsigned long deltintr;
	unsigned long flags;
	int counter = 0;
	int iir, lsr;

	while ((iir = inb(io + UART_IIR) & UART_IIR_ID)) {
	if (++counter > 256) {
	dev_err(&sir_ir_dev->dev, "Trapped in interrupt");
	break;
	}

	switch (iir & UART_IIR_ID) { /* FIXME toto treba preriedit */
	case UART_IIR_MSI:
	(void)inb(io + UART_MSR);
	break;
	case UART_IIR_RLSI:
	case UART_IIR_THRI:
	(void)inb(io + UART_LSR);
	break;
	case UART_IIR_RDI:
	/* avoid interference with timer */
	spin_lock_irqsave(&timer_lock, flags);
	do {
	del_timer(&timerlist);
	data = inb(io + UART_RX);
	curr_time = ktime_get();
	delt = min_t(unsigned long,
	ktime_us_delta(last, curr_time),
	IR_MAX_DURATION);
	deltintr = min_t(unsigned long,
	ktime_us_delta(last_intr_time,
	curr_time),
	IR_MAX_DURATION);
	dev_dbg(&sir_ir_dev->dev, "t %lu, d %d\n",
	deltintr, (int)data);
	/*
	* if nothing came in last X cycles,
	* it was gap
	*/
	if (deltintr > TIME_CONST * threshold) {
	if (last_value) {
	dev_dbg(&sir_ir_dev->dev, "GAP\n");
	/* simulate signal change */
	add_read_queue(last_value,
	delt -
	deltintr);
	last_value = 0;
	last = last_intr_time;
	delt = deltintr;
	}
	}
	data = 1;
	if (data ^ last_value) {
	/*
	* deltintr > 2*TIME_CONST, remember?
	* the other case is timeout
	*/
	add_read_queue(last_value,
	delt - TIME_CONST);
	last_value = data;
	last = curr_time;
	last = ktime_sub_us(last,
	TIME_CONST);
	}
	last_intr_time = curr_time;
	if (data) {
	/*
	* start timer for end of
	* sequence detection
	*/
	timerlist.expires = jiffies +
	SIR_TIMEOUT;
	add_timer(&timerlist);
	}

	lsr = inb(io + UART_LSR);
	} while (lsr & UART_LSR_DR); /* data ready */
	spin_unlock_irqrestore(&timer_lock, flags);
	break;
	default:
	break;
	}
	}
	ir_raw_event_handle(rcdev);
	return IRQ_RETVAL(IRQ_HANDLED);
	}

	static void send_space(unsigned long len)
	{
	usleep_range(len, len + 25);
	}

	static void send_pulse(unsigned long len)
	{
	long bytes_out = len / TIME_CONST;

	if (bytes_out == 0)
	bytes_out++;

	while (bytes_out--) {
	outb(PULSE, io + UART_TX);
	/* FIXME treba seriozne cakanie z char/serial.c */
	while (!(inb(io + UART_LSR) & UART_LSR_THRE))
	;
	}
	}

	static int init_hardware(void)
	{
	u8 scratch, scratch2, scratch3;
	unsigned long flags;

	spin_lock_irqsave(&hardware_lock, flags);

	/*
	* This is a simple port existence test, borrowed from the autoconfig
	* function in drivers/tty/serial/8250/8250_port.c
	*/
	scratch = sinp(UART_IER);
	soutp(UART_IER, 0);
	#ifdef __i386__
	outb(0xff, 0x080);
	#endif
	scratch2 = sinp(UART_IER) & 0x0f;
	soutp(UART_IER, 0x0f);
	#ifdef __i386__
	outb(0x00, 0x080);
	#endif
	scratch3 = sinp(UART_IER) & 0x0f;
	soutp(UART_IER, scratch);
	if (scratch2 != 0 \|\| scratch3 != 0x0f) {
	/* we fail, there's nothing here */
	spin_unlock_irqrestore(&hardware_lock, flags);
	pr_err("port existence test failed, cannot continue\n");
	return -ENODEV;
	}

	/* reset UART */
	outb(0, io + UART_MCR);
	outb(0, io + UART_IER);
	/* init UART */
	/* set DLAB, speed = 115200 */
	outb(UART_LCR_DLAB \| UART_LCR_WLEN7, io + UART_LCR);
	outb(1, io + UART_DLL); outb(0, io + UART_DLM);
	/* 7N1+start = 9 bits at 115200 ~ 3 bits at 44000 */
	outb(UART_LCR_WLEN7, io + UART_LCR);
	/* FIFO operation */
	outb(UART_FCR_ENABLE_FIFO, io + UART_FCR);
	/* interrupts */
	/* outb(UART_IER_RLSI\|UART_IER_RDI\|UART_IER_THRI, io + UART_IER); */
	outb(UART_IER_RDI, io + UART_IER);
	/* turn on UART */
	outb(UART_MCR_DTR \| UART_MCR_RTS \| UART_MCR_OUT2, io + UART_MCR);
	spin_unlock_irqrestore(&hardware_lock, flags);

	return 0;
	}

	static void drop_hardware(void)
	{
	unsigned long flags;

	spin_lock_irqsave(&hardware_lock, flags);

	/* turn off interrupts */
	outb(0, io + UART_IER);

	spin_unlock_irqrestore(&hardware_lock, flags);
	}

	/* SECTION: Initialisation */
	static int sir_ir_probe(struct platform_device *dev)
	{
	int retval;

	rcdev = devm_rc_allocate_device(&sir_ir_dev->dev, RC_DRIVER_IR_RAW);
	if (!rcdev)
	return -ENOMEM;

	rcdev->device_name = "SIR IrDA port";
	rcdev->input_phys = KBUILD_MODNAME "/input0";
	rcdev->input_id.bustype = BUS_HOST;
	rcdev->input_id.vendor = 0x0001;
	rcdev->input_id.product = 0x0001;
	rcdev->input_id.version = 0x0100;
	rcdev->tx_ir = sir_tx_ir;
	rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
	rcdev->driver_name = KBUILD_MODNAME;
	rcdev->map_name = RC_MAP_RC6_MCE;
	rcdev->timeout = IR_DEFAULT_TIMEOUT;
	rcdev->dev.parent = &sir_ir_dev->dev;

	timer_setup(&timerlist, sir_timeout, 0);

	/* get I/O port access and IRQ line */
	if (!devm_request_region(&sir_ir_dev->dev, io, 8, KBUILD_MODNAME)) {
	pr_err("i/o port 0x%.4x already in use.\n", io);
	return -EBUSY;
	}
	retval = devm_request_irq(&sir_ir_dev->dev, irq, sir_interrupt, 0,
	KBUILD_MODNAME, NULL);
	if (retval < 0) {
	pr_err("IRQ %d already in use.\n", irq);
	return retval;
	}

	retval = init_hardware();
	if (retval) {
	del_timer_sync(&timerlist);
	return retval;
	}

	pr_info("I/O port 0x%.4x, IRQ %d.\n", io, irq);

	retval = devm_rc_register_device(&sir_ir_dev->dev, rcdev);
	if (retval < 0)
	return retval;

	return 0;
	}

	static int sir_ir_remove(struct platform_device *dev)
	{
	drop_hardware();
	del_timer_sync(&timerlist);
	return 0;
	}

	static struct platform_driver sir_ir_driver = {
	.probe = sir_ir_probe,
	.remove = sir_ir_remove,
	.driver = {
	.name = "sir_ir",
	},
	};

	static int __init sir_ir_init(void)
	{
	int retval;

	retval = platform_driver_register(&sir_ir_driver);
	if (retval)
	return retval;

	sir_ir_dev = platform_device_alloc("sir_ir", 0);
	if (!sir_ir_dev) {
	retval = -ENOMEM;
	goto pdev_alloc_fail;
	}

	retval = platform_device_add(sir_ir_dev);
	if (retval)
	goto pdev_add_fail;

	return 0;

	pdev_add_fail:
	platform_device_put(sir_ir_dev);
	pdev_alloc_fail:
	platform_driver_unregister(&sir_ir_driver);
	return retval;
	}

	static void __exit sir_ir_exit(void)
	{
	platform_device_unregister(sir_ir_dev);
	platform_driver_unregister(&sir_ir_driver);
	}

	module_init(sir_ir_init);
	module_exit(sir_ir_exit);

	MODULE_DESCRIPTION("Infrared receiver driver for SIR type serial ports");
	MODULE_AUTHOR("Milan Pikula");
	MODULE_LICENSE("GPL");

	module_param_hw(io, int, ioport, 0444);
	MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");

	module_param_hw(irq, int, irq, 0444);
	MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");

	module_param(threshold, int, 0444);
	MODULE_PARM_DESC(threshold, "space detection threshold (3)");