drivers/media/rc/serial_ir.c

/*
 * serial_ir.c
 *
 * serial_ir - Device driver that records pulse- and pause-lengths
 *	       (space-lengths) between DDCD event on a serial port.
 *
 * Copyright (C) 1996,97 Ralph Metzler <rjkm@thp.uni-koeln.de>
 * Copyright (C) 1998 Trent Piepho <xyzzy@u.washington.edu>
 * Copyright (C) 1998 Ben Pfaff <blp@gnu.org>
 * Copyright (C) 1999 Christoph Bartelmus <lirc@bartelmus.de>
 * Copyright (C) 2007 Andrei Tanas <andrei@tanas.ca> (suspend/resume support)
 * Copyright (C) 2016 Sean Young <sean@mess.org> (port to rc-core)
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/serial_reg.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <media/rc-core.h>

struct serial_ir_hw {
	int signal_pin;
	int signal_pin_change;
	u8 on;
	u8 off;
	unsigned set_send_carrier:1;
	unsigned set_duty_cycle:1;
	void (*send_pulse)(unsigned int length, ktime_t edge);
	void (*send_space)(void);
	spinlock_t lock;
};

#define IR_HOMEBREW	0
#define IR_IRDEO	1
#define IR_IRDEO_REMOTE	2
#define IR_ANIMAX	3
#define IR_IGOR		4

/* module parameters */
static int type;
static int io;
static int irq;
static ulong iommap;
static int ioshift;
static bool softcarrier = true;
static bool share_irq;
static int sense = -1;	/* -1 = auto, 0 = active high, 1 = active low */
static bool txsense;	/* 0 = active high, 1 = active low */

/* forward declarations */
static void send_pulse_irdeo(unsigned int length, ktime_t edge);
static void send_space_irdeo(void);
#ifdef CONFIG_IR_SERIAL_TRANSMITTER
static void send_pulse_homebrew(unsigned int length, ktime_t edge);
static void send_space_homebrew(void);
#endif

static struct serial_ir_hw hardware[] = {
	[IR_HOMEBREW] = {
		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_HOMEBREW].lock),
		.signal_pin	   = UART_MSR_DCD,
		.signal_pin_change = UART_MSR_DDCD,
		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
		.off = (UART_MCR_RTS | UART_MCR_OUT2),
#ifdef CONFIG_IR_SERIAL_TRANSMITTER
		.send_pulse = send_pulse_homebrew,
		.send_space = send_space_homebrew,
		.set_send_carrier = true,
		.set_duty_cycle = true,
#endif
	},

	[IR_IRDEO] = {
		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO].lock),
		.signal_pin	   = UART_MSR_DSR,
		.signal_pin_change = UART_MSR_DDSR,
		.on  = UART_MCR_OUT2,
		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
		.send_pulse = send_pulse_irdeo,
		.send_space = send_space_irdeo,
		.set_duty_cycle = true,
	},

	[IR_IRDEO_REMOTE] = {
		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO_REMOTE].lock),
		.signal_pin	   = UART_MSR_DSR,
		.signal_pin_change = UART_MSR_DDSR,
		.on  = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
		.send_pulse = send_pulse_irdeo,
		.send_space = send_space_irdeo,
		.set_duty_cycle = true,
	},

	[IR_ANIMAX] = {
		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_ANIMAX].lock),
		.signal_pin	   = UART_MSR_DCD,
		.signal_pin_change = UART_MSR_DDCD,
		.on  = 0,
		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
	},

	[IR_IGOR] = {
		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IGOR].lock),
		.signal_pin	   = UART_MSR_DSR,
		.signal_pin_change = UART_MSR_DDSR,
		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
		.off = (UART_MCR_RTS | UART_MCR_OUT2),
#ifdef CONFIG_IR_SERIAL_TRANSMITTER
		.send_pulse = send_pulse_homebrew,
		.send_space = send_space_homebrew,
		.set_send_carrier = true,
		.set_duty_cycle = true,
#endif
	},
};

#define RS_ISR_PASS_LIMIT 256

struct serial_ir {
	ktime_t lastkt;
	struct rc_dev *rcdev;
	struct platform_device *pdev;
	struct timer_list timeout_timer;

	unsigned int carrier;
	unsigned int duty_cycle;
};

static struct serial_ir serial_ir;

/* fetch serial input packet (1 byte) from register offset */
static u8 sinp(int offset)
{
	if (iommap)
		/* the register is memory-mapped */
		offset <<= ioshift;

	return inb(io + offset);
}

/* write serial output packet (1 byte) of value to register offset */
static void soutp(int offset, u8 value)
{
	if (iommap)
		/* the register is memory-mapped */
		offset <<= ioshift;

	outb(value, io + offset);
}

static void on(void)
{
	if (txsense)
		soutp(UART_MCR, hardware[type].off);
	else
		soutp(UART_MCR, hardware[type].on);
}

static void off(void)
{
	if (txsense)
		soutp(UART_MCR, hardware[type].on);
	else
		soutp(UART_MCR, hardware[type].off);
}

static void send_pulse_irdeo(unsigned int length, ktime_t target)
{
	long rawbits;
	int i;
	unsigned char output;
	unsigned char chunk, shifted;

	/* how many bits have to be sent ? */
	rawbits = length * 1152 / 10000;
	if (serial_ir.duty_cycle > 50)
		chunk = 3;
	else
		chunk = 1;
	for (i = 0, output = 0x7f; rawbits > 0; rawbits -= 3) {
		shifted = chunk << (i * 3);
		shifted >>= 1;
		output &= (~shifted);
		i++;
		if (i == 3) {
			soutp(UART_TX, output);
			while (!(sinp(UART_LSR) & UART_LSR_THRE))
				;
			output = 0x7f;
			i = 0;
		}
	}
	if (i != 0) {
		soutp(UART_TX, output);
		while (!(sinp(UART_LSR) & UART_LSR_TEMT))
			;
	}
}

static void send_space_irdeo(void)
{
}

#ifdef CONFIG_IR_SERIAL_TRANSMITTER
static void send_pulse_homebrew_softcarrier(unsigned int length, ktime_t edge)
{
	ktime_t now, target = ktime_add_us(edge, length);
	/*
	 * delta should never exceed 4 seconds and on m68k
	 * ndelay(s64) does not compile; so use s32 rather than s64.
	 */
	s32 delta;
	unsigned int pulse, space;

	/* Ensure the dividend fits into 32 bit */
	pulse = DIV_ROUND_CLOSEST(serial_ir.duty_cycle * (NSEC_PER_SEC / 100),
				  serial_ir.carrier);
	space = DIV_ROUND_CLOSEST((100 - serial_ir.duty_cycle) *
				  (NSEC_PER_SEC / 100), serial_ir.carrier);

	for (;;) {
		now = ktime_get();
		if (ktime_compare(now, target) >= 0)
			break;
		on();
		edge = ktime_add_ns(edge, pulse);
		delta = ktime_to_ns(ktime_sub(edge, now));
		if (delta > 0)
			ndelay(delta);
		now = ktime_get();
		off();
		if (ktime_compare(now, target) >= 0)
			break;
		edge = ktime_add_ns(edge, space);
		delta = ktime_to_ns(ktime_sub(edge, now));
		if (delta > 0)
			ndelay(delta);
	}
}

static void send_pulse_homebrew(unsigned int length, ktime_t edge)
{
	if (softcarrier)
		send_pulse_homebrew_softcarrier(length, edge);
	else
		on();
}

static void send_space_homebrew(void)
{
	off();
}
#endif

static void frbwrite(unsigned int l, bool is_pulse)
{
	/* simple noise filter */
	static unsigned int ptr, pulse, space;
	DEFINE_IR_RAW_EVENT(ev);

	if (ptr > 0 && is_pulse) {
		pulse += l;
		if (pulse > 250000) {
			ev.duration = space;
			ev.pulse = false;
			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
			ev.duration = pulse;
			ev.pulse = true;
			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
			ptr = 0;
			pulse = 0;
		}
		return;
	}
	if (!is_pulse) {
		if (ptr == 0) {
			if (l > 20000000) {
				space = l;
				ptr++;
				return;
			}
		} else {
			if (l > 20000000) {
				space += pulse;
				if (space > IR_MAX_DURATION)
					space = IR_MAX_DURATION;
				space += l;
				if (space > IR_MAX_DURATION)
					space = IR_MAX_DURATION;
				pulse = 0;
				return;
			}

			ev.duration = space;
			ev.pulse = false;
			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
			ev.duration = pulse;
			ev.pulse = true;
			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
			ptr = 0;
			pulse = 0;
		}
	}

	ev.duration = l;
	ev.pulse = is_pulse;
	ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
}

static irqreturn_t serial_ir_irq_handler(int i, void *blah)
{
	ktime_t kt;
	int counter, dcd;
	u8 status;
	ktime_t delkt;
	unsigned int data;
	static int last_dcd = -1;

	if ((sinp(UART_IIR) & UART_IIR_NO_INT)) {
		/* not our interrupt */
		return IRQ_NONE;
	}

	counter = 0;
	do {
		counter++;
		status = sinp(UART_MSR);
		if (counter > RS_ISR_PASS_LIMIT) {
			dev_err(&serial_ir.pdev->dev, "Trapped in interrupt");
			break;
		}
		if ((status & hardware[type].signal_pin_change) &&
		    sense != -1) {
			/* get current time */
			kt = ktime_get();

			/*
			 * The driver needs to know if your receiver is
			 * active high or active low, or the space/pulse
			 * sense could be inverted.
			 */

			/* calc time since last interrupt in nanoseconds */
			dcd = (status & hardware[type].signal_pin) ? 1 : 0;

			if (dcd == last_dcd) {
				dev_err(&serial_ir.pdev->dev,
					"ignoring spike: %d %d %lldns %lldns\n",
					dcd, sense, ktime_to_ns(kt),
					ktime_to_ns(serial_ir.lastkt));
				continue;
			}

			delkt = ktime_sub(kt, serial_ir.lastkt);
			if (ktime_compare(delkt, ktime_set(15, 0)) > 0) {
				data = IR_MAX_DURATION; /* really long time */
				if (!(dcd ^ sense)) {
					/* sanity check */
					dev_err(&serial_ir.pdev->dev,
						"dcd unexpected: %d %d %lldns %lldns\n",
						dcd, sense, ktime_to_ns(kt),
						ktime_to_ns(serial_ir.lastkt));
					/*
					 * detecting pulse while this
					 * MUST be a space!
					 */
					sense = sense ? 0 : 1;
				}
			} else {
				data = ktime_to_ns(delkt);
			}
			frbwrite(data, !(dcd ^ sense));
			serial_ir.lastkt = kt;
			last_dcd = dcd;
		}
	} while (!(sinp(UART_IIR) & UART_IIR_NO_INT)); /* still pending ? */

	mod_timer(&serial_ir.timeout_timer,
		  jiffies + nsecs_to_jiffies(serial_ir.rcdev->timeout));

	ir_raw_event_handle(serial_ir.rcdev);

	return IRQ_HANDLED;
}

static int hardware_init_port(void)
{
	u8 scratch, scratch2, scratch3;

	/*
	 * 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 */
		pr_err("port existence test failed, cannot continue\n");
		return -ENODEV;
	}

	/* Set DLAB 0. */
	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));

	/* First of all, disable all interrupts */
	soutp(UART_IER, sinp(UART_IER) &
	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));

	/* Clear registers. */
	sinp(UART_LSR);
	sinp(UART_RX);
	sinp(UART_IIR);
	sinp(UART_MSR);

	/* Set line for power source */
	off();

	/* Clear registers again to be sure. */
	sinp(UART_LSR);
	sinp(UART_RX);
	sinp(UART_IIR);
	sinp(UART_MSR);

	switch (type) {
	case IR_IRDEO:
	case IR_IRDEO_REMOTE:
		/* setup port to 7N1 @ 115200 Baud */
		/* 7N1+start = 9 bits at 115200 ~ 3 bits at 38kHz */

		/* Set DLAB 1. */
		soutp(UART_LCR, sinp(UART_LCR) | UART_LCR_DLAB);
		/* Set divisor to 1 => 115200 Baud */
		soutp(UART_DLM, 0);
		soutp(UART_DLL, 1);
		/* Set DLAB 0 +  7N1 */
		soutp(UART_LCR, UART_LCR_WLEN7);
		/* THR interrupt already disabled at this point */
		break;
	default:
		break;
	}

	return 0;
}

static void serial_ir_timeout(unsigned long arg)
{
	DEFINE_IR_RAW_EVENT(ev);

	ev.timeout = true;
	ev.duration = serial_ir.rcdev->timeout;
	ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
	ir_raw_event_handle(serial_ir.rcdev);
}

/* Needed by serial_ir_probe() */
static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
			unsigned int count);
static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle);
static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier);
static int serial_ir_open(struct rc_dev *rcdev);
static void serial_ir_close(struct rc_dev *rcdev);

static int serial_ir_probe(struct platform_device *dev)
{
	struct rc_dev *rcdev;
	int i, nlow, nhigh, result;

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

	if (hardware[type].send_pulse && hardware[type].send_space)
		rcdev->tx_ir = serial_ir_tx;
	if (hardware[type].set_send_carrier)
		rcdev->s_tx_carrier = serial_ir_tx_carrier;
	if (hardware[type].set_duty_cycle)
		rcdev->s_tx_duty_cycle = serial_ir_tx_duty_cycle;

	switch (type) {
	case IR_HOMEBREW:
		rcdev->device_name = "Serial IR type home-brew";
		break;
	case IR_IRDEO:
		rcdev->device_name = "Serial IR type IRdeo";
		break;
	case IR_IRDEO_REMOTE:
		rcdev->device_name = "Serial IR type IRdeo remote";
		break;
	case IR_ANIMAX:
		rcdev->device_name = "Serial IR type AnimaX";
		break;
	case IR_IGOR:
		rcdev->device_name = "Serial IR type IgorPlug";
		break;
	}

	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->open = serial_ir_open;
	rcdev->close = serial_ir_close;
	rcdev->dev.parent = &serial_ir.pdev->dev;
	rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
	rcdev->driver_name = KBUILD_MODNAME;
	rcdev->map_name = RC_MAP_RC6_MCE;
	rcdev->min_timeout = 1;
	rcdev->timeout = IR_DEFAULT_TIMEOUT;
	rcdev->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
	rcdev->rx_resolution = 250000;

	serial_ir.rcdev = rcdev;

	setup_timer(&serial_ir.timeout_timer, serial_ir_timeout,
		    (unsigned long)&serial_ir);

	result = devm_request_irq(&dev->dev, irq, serial_ir_irq_handler,
				  share_irq ? IRQF_SHARED : 0,
				  KBUILD_MODNAME, &hardware);
	if (result < 0) {
		if (result == -EBUSY)
			dev_err(&dev->dev, "IRQ %d busy\n", irq);
		else if (result == -EINVAL)
			dev_err(&dev->dev, "Bad irq number or handler\n");
		return result;
	}

	/* Reserve io region. */
	if ((iommap &&
	     (devm_request_mem_region(&dev->dev, iommap, 8 << ioshift,
				      KBUILD_MODNAME) == NULL)) ||
	     (!iommap && (devm_request_region(&dev->dev, io, 8,
			  KBUILD_MODNAME) == NULL))) {
		dev_err(&dev->dev, "port %04x already in use\n", io);
		dev_warn(&dev->dev, "use 'setserial /dev/ttySX uart none'\n");
		dev_warn(&dev->dev,
			 "or compile the serial port driver as module and\n");
		dev_warn(&dev->dev, "make sure this module is loaded first\n");
		return -EBUSY;
	}

	result = hardware_init_port();
	if (result < 0)
		return result;

	/* Initialize pulse/space widths */
	serial_ir.duty_cycle = 50;
	serial_ir.carrier = 38000;

	/* If pin is high, then this must be an active low receiver. */
	if (sense == -1) {
		/* wait 1/2 sec for the power supply */
		msleep(500);

		/*
		 * probe 9 times every 0.04s, collect "votes" for
		 * active high/low
		 */
		nlow = 0;
		nhigh = 0;
		for (i = 0; i < 9; i++) {
			if (sinp(UART_MSR) & hardware[type].signal_pin)
				nlow++;
			else
				nhigh++;
			msleep(40);
		}
		sense = nlow >= nhigh ? 1 : 0;
		dev_info(&dev->dev, "auto-detected active %s receiver\n",
			 sense ? "low" : "high");
	} else
		dev_info(&dev->dev, "Manually using active %s receiver\n",
			 sense ? "low" : "high");

	dev_dbg(&dev->dev, "Interrupt %d, port %04x obtained\n", irq, io);

	return devm_rc_register_device(&dev->dev, rcdev);
}

static int serial_ir_open(struct rc_dev *rcdev)
{
	unsigned long flags;

	/* initialize timestamp */
	serial_ir.lastkt = ktime_get();

	spin_lock_irqsave(&hardware[type].lock, flags);

	/* Set DLAB 0. */
	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));

	soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);

	spin_unlock_irqrestore(&hardware[type].lock, flags);

	return 0;
}

static void serial_ir_close(struct rc_dev *rcdev)
{
	unsigned long flags;

	spin_lock_irqsave(&hardware[type].lock, flags);

	/* Set DLAB 0. */
	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));

	/* First of all, disable all interrupts */
	soutp(UART_IER, sinp(UART_IER) &
	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
	spin_unlock_irqrestore(&hardware[type].lock, flags);
}

static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
			unsigned int count)
{
	unsigned long flags;
	ktime_t edge;
	s64 delta;
	int i;

	spin_lock_irqsave(&hardware[type].lock, flags);
	if (type == IR_IRDEO) {
		/* DTR, RTS down */
		on();
	}

	edge = ktime_get();
	for (i = 0; i < count; i++) {
		if (i % 2)
			hardware[type].send_space();
		else
			hardware[type].send_pulse(txbuf[i], edge);

		edge = ktime_add_us(edge, txbuf[i]);
		delta = ktime_us_delta(edge, ktime_get());
		if (delta > 25) {
			spin_unlock_irqrestore(&hardware[type].lock, flags);
			usleep_range(delta - 25, delta + 25);
			spin_lock_irqsave(&hardware[type].lock, flags);
		} else if (delta > 0) {
			udelay(delta);
		}
	}
	off();
	spin_unlock_irqrestore(&hardware[type].lock, flags);
	return count;
}

static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle)
{
	serial_ir.duty_cycle = cycle;
	return 0;
}

static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier)
{
	if (carrier > 500000 || carrier < 20000)
		return -EINVAL;

	serial_ir.carrier = carrier;
	return 0;
}

static int serial_ir_suspend(struct platform_device *dev,
			     pm_message_t state)
{
	/* Set DLAB 0. */
	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));

	/* Disable all interrupts */
	soutp(UART_IER, sinp(UART_IER) &
	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));

	/* Clear registers. */
	sinp(UART_LSR);
	sinp(UART_RX);
	sinp(UART_IIR);
	sinp(UART_MSR);

	return 0;
}

static int serial_ir_resume(struct platform_device *dev)
{
	unsigned long flags;
	int result;

	result = hardware_init_port();
	if (result < 0)
		return result;

	spin_lock_irqsave(&hardware[type].lock, flags);
	/* Enable Interrupt */
	serial_ir.lastkt = ktime_get();
	soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);
	off();

	spin_unlock_irqrestore(&hardware[type].lock, flags);

	return 0;
}

static struct platform_driver serial_ir_driver = {
	.probe		= serial_ir_probe,
	.suspend	= serial_ir_suspend,
	.resume		= serial_ir_resume,
	.driver		= {
		.name	= "serial_ir",
	},
};

static int __init serial_ir_init(void)
{
	int result;

	result = platform_driver_register(&serial_ir_driver);
	if (result)
		return result;

	serial_ir.pdev = platform_device_alloc("serial_ir", 0);
	if (!serial_ir.pdev) {
		result = -ENOMEM;
		goto exit_driver_unregister;
	}

	result = platform_device_add(serial_ir.pdev);
	if (result)
		goto exit_device_put;

	return 0;

exit_device_put:
	platform_device_put(serial_ir.pdev);
exit_driver_unregister:
	platform_driver_unregister(&serial_ir_driver);
	return result;
}

static void serial_ir_exit(void)
{
	platform_device_unregister(serial_ir.pdev);
	platform_driver_unregister(&serial_ir_driver);
}

static int __init serial_ir_init_module(void)
{
	int result;

	switch (type) {
	case IR_HOMEBREW:
	case IR_IRDEO:
	case IR_IRDEO_REMOTE:
	case IR_ANIMAX:
	case IR_IGOR:
		/* if nothing specified, use ttyS0/com1 and irq 4 */
		io = io ? io : 0x3f8;
		irq = irq ? irq : 4;
		break;
	default:
		return -EINVAL;
	}
	if (!softcarrier) {
		switch (type) {
		case IR_HOMEBREW:
		case IR_IGOR:
			hardware[type].set_send_carrier = false;
			hardware[type].set_duty_cycle = false;
			break;
		}
	}

	/* make sure sense is either -1, 0, or 1 */
	if (sense != -1)
		sense = !!sense;

	result = serial_ir_init();
	if (!result)
		return 0;

	serial_ir_exit();
	return result;
}

static void __exit serial_ir_exit_module(void)
{
	del_timer_sync(&serial_ir.timeout_timer);
	serial_ir_exit();
}

module_init(serial_ir_init_module);
module_exit(serial_ir_exit_module);

MODULE_DESCRIPTION("Infra-red receiver driver for serial ports.");
MODULE_AUTHOR("Ralph Metzler, Trent Piepho, Ben Pfaff, Christoph Bartelmus, Andrei Tanas");
MODULE_LICENSE("GPL");

module_param(type, int, 0444);
MODULE_PARM_DESC(type, "Hardware type (0 = home-brew, 1 = IRdeo, 2 = IRdeo Remote, 3 = AnimaX, 4 = IgorPlug");

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

/* some architectures (e.g. intel xscale) have memory mapped registers */
module_param_hw(iommap, ulong, other, 0444);
MODULE_PARM_DESC(iommap, "physical base for memory mapped I/O (0 = no memory mapped io)");

/*
 * some architectures (e.g. intel xscale) align the 8bit serial registers
 * on 32bit word boundaries.
 * See linux-kernel/drivers/tty/serial/8250/8250.c serial_in()/out()
 */
module_param_hw(ioshift, int, other, 0444);
MODULE_PARM_DESC(ioshift, "shift I/O register offset (0 = no shift)");

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

module_param_hw(share_irq, bool, other, 0444);
MODULE_PARM_DESC(share_irq, "Share interrupts (0 = off, 1 = on)");

module_param(sense, int, 0444);
MODULE_PARM_DESC(sense, "Override autodetection of IR receiver circuit (0 = active high, 1 = active low )");

#ifdef CONFIG_IR_SERIAL_TRANSMITTER
module_param(txsense, bool, 0444);
MODULE_PARM_DESC(txsense, "Sense of transmitter circuit (0 = active high, 1 = active low )");
#endif

module_param(softcarrier, bool, 0444);
MODULE_PARM_DESC(softcarrier, "Software carrier (0 = off, 1 = on, default on)");