V4L/DVB: staging/lirc: add lirc_serial driver

Signed-off-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/staging/lirc/lirc_serial.c

+/*
+ * lirc_serial.c
+ *
+ * lirc_serial - 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)
+ *  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.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+/*
+ * Steve's changes to improve transmission fidelity:
+ *   - for systems with the rdtsc instruction and the clock counter, a
+ *     send_pule that times the pulses directly using the counter.
+ *     This means that the LIRC_SERIAL_TRANSMITTER_LATENCY fudge is
+ *     not needed. Measurement shows very stable waveform, even where
+ *     PCI activity slows the access to the UART, which trips up other
+ *     versions.
+ *   - For other system, non-integer-microsecond pulse/space lengths,
+ *     done using fixed point binary. So, much more accurate carrier
+ *     frequency.
+ *   - fine tuned transmitter latency, taking advantage of fractional
+ *     microseconds in previous change
+ *   - Fixed bug in the way transmitter latency was accounted for by
+ *     tuning the pulse lengths down - the send_pulse routine ignored
+ *     this overhead as it timed the overall pulse length - so the
+ *     pulse frequency was right but overall pulse length was too
+ *     long. Fixed by accounting for latency on each pulse/space
+ *     iteration.
+ *
+ * Steve Davies <steve@daviesfam.org>  July 2001
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/serial_reg.h>
+#include <linux/time.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/poll.h>
+#include <linux/platform_device.h>
+
+#include <asm/system.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/fcntl.h>
+#include <linux/spinlock.h>
+
+#ifdef CONFIG_LIRC_SERIAL_NSLU2
+#include <asm/hardware.h>
+#endif
+/* From Intel IXP42X Developer's Manual (#252480-005): */
+/* ftp://download.intel.com/design/network/manuals/25248005.pdf */
+#define UART_IE_IXP42X_UUE   0x40 /* IXP42X UART Unit enable */
+#define UART_IE_IXP42X_RTOIE 0x10 /* IXP42X Receiver Data Timeout int.enable */
+
+#include <media/lirc.h>
+#include <media/lirc_dev.h>
+
+#define LIRC_DRIVER_NAME "lirc_serial"
+
+struct lirc_serial {
+	int signal_pin;
+	int signal_pin_change;
+	u8 on;
+	u8 off;
+	long (*send_pulse)(unsigned long length);
+	void (*send_space)(long length);
+	int features;
+	spinlock_t lock;
+};
+
+#define LIRC_HOMEBREW		0
+#define LIRC_IRDEO		1
+#define LIRC_IRDEO_REMOTE	2
+#define LIRC_ANIMAX		3
+#define LIRC_IGOR		4
+#define LIRC_NSLU2		5
+
+/*** module parameters ***/
+static int type;
+static int io;
+static int irq;
+static int iommap;
+static int ioshift;
+static int softcarrier = 1;
+static int share_irq;
+static int debug;
+static int sense = -1;	/* -1 = auto, 0 = active high, 1 = active low */
+static int txsense;	/* 0 = active high, 1 = active low */
+
+#define dprintk(fmt, args...)					\
+	do {							\
+		if (debug)					\
+			printk(KERN_DEBUG LIRC_DRIVER_NAME ": "	\
+			       fmt, ## args);			\
+	} while (0)
+
+/* forward declarations */
+static long send_pulse_irdeo(unsigned long length);
+static long send_pulse_homebrew(unsigned long length);
+static void send_space_irdeo(long length);
+static void send_space_homebrew(long length);
+
+static struct lirc_serial hardware[] = {
+	[LIRC_HOMEBREW] = {
+		.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),
+		.send_pulse = send_pulse_homebrew,
+		.send_space = send_space_homebrew,
+#ifdef CONFIG_LIRC_SERIAL_TRANSMITTER
+		.features    = (LIRC_CAN_SET_SEND_DUTY_CYCLE |
+				LIRC_CAN_SET_SEND_CARRIER |
+				LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2)
+#else
+		.features    = LIRC_CAN_REC_MODE2
+#endif
+	},
+
+	[LIRC_IRDEO] = {
+		.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,
+		.features    = (LIRC_CAN_SET_SEND_DUTY_CYCLE |
+				LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2)
+	},
+
+	[LIRC_IRDEO_REMOTE] = {
+		.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,
+		.features    = (LIRC_CAN_SET_SEND_DUTY_CYCLE |
+				LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2)
+	},
+
+	[LIRC_ANIMAX] = {
+		.signal_pin        = UART_MSR_DCD,
+		.signal_pin_change = UART_MSR_DDCD,
+		.on  = 0,
+		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
+		.send_pulse = NULL,
+		.send_space = NULL,
+		.features   = LIRC_CAN_REC_MODE2
+	},
+
+	[LIRC_IGOR] = {
+		.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),
+		.send_pulse = send_pulse_homebrew,
+		.send_space = send_space_homebrew,
+#ifdef CONFIG_LIRC_SERIAL_TRANSMITTER
+		.features    = (LIRC_CAN_SET_SEND_DUTY_CYCLE |
+				LIRC_CAN_SET_SEND_CARRIER |
+				LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2)
+#else
+		.features    = LIRC_CAN_REC_MODE2
+#endif
+	},
+
+#ifdef CONFIG_LIRC_SERIAL_NSLU2
+	/*
+	 * Modified Linksys Network Storage Link USB 2.0 (NSLU2):
+	 * We receive on CTS of the 2nd serial port (R142,LHS), we
+	 * transmit with a IR diode between GPIO[1] (green status LED),
+	 * and ground (Matthias Goebl <matthias.goebl@goebl.net>).
+	 * See also http://www.nslu2-linux.org for this device
+	 */
+	[LIRC_NSLU2] = {
+		.signal_pin        = UART_MSR_CTS,
+		.signal_pin_change = UART_MSR_DCTS,
+		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
+		.off = (UART_MCR_RTS | UART_MCR_OUT2),
+		.send_pulse = send_pulse_homebrew,
+		.send_space = send_space_homebrew,
+#ifdef CONFIG_LIRC_SERIAL_TRANSMITTER
+		.features    = (LIRC_CAN_SET_SEND_DUTY_CYCLE |
+				LIRC_CAN_SET_SEND_CARRIER |
+				LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2)
+#else
+		.features    = LIRC_CAN_REC_MODE2
+#endif
+	},
+#endif
+
+};
+
+#define RS_ISR_PASS_LIMIT 256
+
+/*
+ * A long pulse code from a remote might take up to 300 bytes.  The
+ * daemon should read the bytes as soon as they are generated, so take
+ * the number of keys you think you can push before the daemon runs
+ * and multiply by 300.  The driver will warn you if you overrun this
+ * buffer.  If you have a slow computer or non-busmastering IDE disks,
+ * maybe you will need to increase this.
+ */
+
+/* This MUST be a power of two!  It has to be larger than 1 as well. */
+
+#define RBUF_LEN 256
+
+static struct timeval lasttv = {0, 0};
+
+static struct lirc_buffer rbuf;
+
+static unsigned int freq = 38000;
+static unsigned int duty_cycle = 50;
+
+/* Initialized in init_timing_params() */
+static unsigned long period;
+static unsigned long pulse_width;
+static unsigned long space_width;
+
+#if defined(__i386__)
+/*
+ * From:
+ * Linux I/O port programming mini-HOWTO
+ * Author: Riku Saikkonen <Riku.Saikkonen@hut.fi>
+ * v, 28 December 1997
+ *
+ * [...]
+ * Actually, a port I/O instruction on most ports in the 0-0x3ff range
+ * takes almost exactly 1 microsecond, so if you're, for example, using
+ * the parallel port directly, just do additional inb()s from that port
+ * to delay.
+ * [...]
+ */
+/* transmitter latency 1.5625us 0x1.90 - this figure arrived at from
+ * comment above plus trimming to match actual measured frequency.
+ * This will be sensitive to cpu speed, though hopefully most of the 1.5us
+ * is spent in the uart access.  Still - for reference test machine was a
+ * 1.13GHz Athlon system - Steve
+ */
+
+/*
+ * changed from 400 to 450 as this works better on slower machines;
+ * faster machines will use the rdtsc code anyway
+ */
+#define LIRC_SERIAL_TRANSMITTER_LATENCY 450
+
+#else
+
+/* does anybody have information on other platforms ? */
+/* 256 = 1<<8 */
+#define LIRC_SERIAL_TRANSMITTER_LATENCY 256
+
+#endif  /* __i386__ */
+/*
+ * FIXME: should we be using hrtimers instead of this
+ * LIRC_SERIAL_TRANSMITTER_LATENCY nonsense?
+ */
+
+/* fetch serial input packet (1 byte) from register offset */
+static u8 sinp(int offset)
+{
+	if (iommap != 0)
+		/* 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 != 0)
+		/* the register is memory-mapped */
+		offset <<= ioshift;
+
+	outb(value, io + offset);
+}
+
+static void on(void)
+{
+#ifdef CONFIG_LIRC_SERIAL_NSLU2
+	/*
+	 * On NSLU2, we put the transmit diode between the output of the green
+	 * status LED and ground
+	 */
+	if (type == LIRC_NSLU2) {
+		gpio_line_set(NSLU2_LED_GRN, IXP4XX_GPIO_LOW);
+		return;
+	}
+#endif
+	if (txsense)
+		soutp(UART_MCR, hardware[type].off);
+	else
+		soutp(UART_MCR, hardware[type].on);
+}
+
+static void off(void)
+{
+#ifdef CONFIG_LIRC_SERIAL_NSLU2
+	if (type == LIRC_NSLU2) {
+		gpio_line_set(NSLU2_LED_GRN, IXP4XX_GPIO_HIGH);
+		return;
+	}
+#endif
+	if (txsense)
+		soutp(UART_MCR, hardware[type].on);
+	else
+		soutp(UART_MCR, hardware[type].off);
+}
+
+#ifndef MAX_UDELAY_MS
+#define MAX_UDELAY_US 5000
+#else
+#define MAX_UDELAY_US (MAX_UDELAY_MS*1000)
+#endif
+
+static void safe_udelay(unsigned long usecs)
+{
+	while (usecs > MAX_UDELAY_US) {
+		udelay(MAX_UDELAY_US);
+		usecs -= MAX_UDELAY_US;
+	}
+	udelay(usecs);
+}
+
+#ifdef USE_RDTSC
+/*
+ * This is an overflow/precision juggle, complicated in that we can't
+ * do long long divide in the kernel
+ */
+
+/*
+ * When we use the rdtsc instruction to measure clocks, we keep the
+ * pulse and space widths as clock cycles.  As this is CPU speed
+ * dependent, the widths must be calculated in init_port and ioctl
+ * time
+ */
+
+/* So send_pulse can quickly convert microseconds to clocks */
+static unsigned long conv_us_to_clocks;
+
+static int init_timing_params(unsigned int new_duty_cycle,
+		unsigned int new_freq)
+{
+	unsigned long long loops_per_sec, work;
+
+	duty_cycle = new_duty_cycle;
+	freq = new_freq;
+
+	loops_per_sec = current_cpu_data.loops_per_jiffy;
+	loops_per_sec *= HZ;
+
+	/* How many clocks in a microsecond?, avoiding long long divide */
+	work = loops_per_sec;
+	work *= 4295;  /* 4295 = 2^32 / 1e6 */
+	conv_us_to_clocks = (work >> 32);
+
+	/*
+	 * Carrier period in clocks, approach good up to 32GHz clock,
+	 * gets carrier frequency within 8Hz
+	 */
+	period = loops_per_sec >> 3;
+	period /= (freq >> 3);
+
+	/* Derive pulse and space from the period */
+	pulse_width = period * duty_cycle / 100;
+	space_width = period - pulse_width;
+	dprintk("in init_timing_params, freq=%d, duty_cycle=%d, "
+		"clk/jiffy=%ld, pulse=%ld, space=%ld, "
+		"conv_us_to_clocks=%ld\n",
+		freq, duty_cycle, current_cpu_data.loops_per_jiffy,
+		pulse_width, space_width, conv_us_to_clocks);
+	return 0;
+}
+#else /* ! USE_RDTSC */
+static int init_timing_params(unsigned int new_duty_cycle,
+		unsigned int new_freq)
+{
+/*
+ * period, pulse/space width are kept with 8 binary places -
+ * IE multiplied by 256.
+ */
+	if (256 * 1000000L / new_freq * new_duty_cycle / 100 <=
+	    LIRC_SERIAL_TRANSMITTER_LATENCY)
+		return -EINVAL;
+	if (256 * 1000000L / new_freq * (100 - new_duty_cycle) / 100 <=
+	    LIRC_SERIAL_TRANSMITTER_LATENCY)
+		return -EINVAL;
+	duty_cycle = new_duty_cycle;
+	freq = new_freq;
+	period = 256 * 1000000L / freq;
+	pulse_width = period * duty_cycle / 100;
+	space_width = period - pulse_width;
+	dprintk("in init_timing_params, freq=%d pulse=%ld, "
+		"space=%ld\n", freq, pulse_width, space_width);
+	return 0;
+}
+#endif /* USE_RDTSC */
+
+
+/* return value: space length delta */
+
+static long send_pulse_irdeo(unsigned long length)
+{
+	long rawbits, ret;
+	int i;
+	unsigned char output;
+	unsigned char chunk, shifted;
+
+	/* how many bits have to be sent ? */
+	rawbits = length * 1152 / 10000;
+	if (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))
+			;
+	}
+
+	if (i == 0)
+		ret = (-rawbits) * 10000 / 1152;
+	else
+		ret = (3 - i) * 3 * 10000 / 1152 + (-rawbits) * 10000 / 1152;
+
+	return ret;
+}
+
+#ifdef USE_RDTSC
+/* Version that uses Pentium rdtsc instruction to measure clocks */
+
+/*
+ * This version does sub-microsecond timing using rdtsc instruction,
+ * and does away with the fudged LIRC_SERIAL_TRANSMITTER_LATENCY
+ * Implicitly i586 architecture...  - Steve
+ */
+
+static long send_pulse_homebrew_softcarrier(unsigned long length)
+{
+	int flag;
+	unsigned long target, start, now;
+
+	/* Get going quick as we can */
+	rdtscl(start);
+	on();
+	/* Convert length from microseconds to clocks */
+	length *= conv_us_to_clocks;
+	/* And loop till time is up - flipping at right intervals */
+	now = start;
+	target = pulse_width;
+	flag = 1;
+	/*
+	 * FIXME: This looks like a hard busy wait, without even an occasional,
+	 * polite, cpu_relax() call.  There's got to be a better way?
+	 *
+	 * The i2c code has the result of a lot of bit-banging work, I wonder if
+	 * there's something there which could be helpful here.
+	 */
+	while ((now - start) < length) {
+		/* Delay till flip time */
+		do {
+			rdtscl(now);
+		} while ((now - start) < target);
+
+		/* flip */
+		if (flag) {
+			rdtscl(now);
+			off();
+			target += space_width;
+		} else {
+			rdtscl(now); on();
+			target += pulse_width;
+		}
+		flag = !flag;
+	}
+	rdtscl(now);
+	return ((now - start) - length) / conv_us_to_clocks;
+}
+#else /* ! USE_RDTSC */
+/* Version using udelay() */
+
+/*
+ * here we use fixed point arithmetic, with 8
+ * fractional bits.  that gets us within 0.1% or so of the right average
+ * frequency, albeit with some jitter in pulse length - Steve
+ */
+
+/* To match 8 fractional bits used for pulse/space length */
+
+static long send_pulse_homebrew_softcarrier(unsigned long length)
+{
+	int flag;
+	unsigned long actual, target, d;
+	length <<= 8;
+
+	actual = 0; target = 0; flag = 0;
+	while (actual < length) {
+		if (flag) {
+			off();
+			target += space_width;
+		} else {
+			on();
+			target += pulse_width;
+		}
+		d = (target - actual -
+		     LIRC_SERIAL_TRANSMITTER_LATENCY + 128) >> 8;
+		/*
+		 * Note - we've checked in ioctl that the pulse/space
+		 * widths are big enough so that d is > 0
+		 */
+		udelay(d);
+		actual += (d << 8) + LIRC_SERIAL_TRANSMITTER_LATENCY;
+		flag = !flag;
+	}
+	return (actual-length) >> 8;
+}
+#endif /* USE_RDTSC */
+
+static long send_pulse_homebrew(unsigned long length)
+{
+	if (length <= 0)
+		return 0;
+
+	if (softcarrier)
+		return send_pulse_homebrew_softcarrier(length);
+	else {
+		on();
+		safe_udelay(length);
+		return 0;
+	}
+}
+
+static void send_space_irdeo(long length)
+{
+	if (length <= 0)
+		return;
+
+	safe_udelay(length);
+}
+
+static void send_space_homebrew(long length)
+{
+	off();
+	if (length <= 0)
+		return;
+	safe_udelay(length);
+}
+
+static void rbwrite(int l)
+{
+	if (lirc_buffer_full(&rbuf)) {
+		/* no new signals will be accepted */
+		dprintk("Buffer overrun\n");
+		return;
+	}
+	lirc_buffer_write(&rbuf, (void *)&l);
+}
+
+static void frbwrite(int l)
+{
+	/* simple noise filter */
+	static int pulse, space;
+	static unsigned int ptr;
+
+	if (ptr > 0 && (l & PULSE_BIT)) {
+		pulse += l & PULSE_MASK;
+		if (pulse > 250) {
+			rbwrite(space);
+			rbwrite(pulse | PULSE_BIT);
+			ptr = 0;
+			pulse = 0;
+		}
+		return;
+	}
+	if (!(l & PULSE_BIT)) {
+		if (ptr == 0) {
+			if (l > 20000) {
+				space = l;
+				ptr++;
+				return;
+			}
+		} else {
+			if (l > 20000) {
+				space += pulse;
+				if (space > PULSE_MASK)
+					space = PULSE_MASK;
+				space += l;
+				if (space > PULSE_MASK)
+					space = PULSE_MASK;
+				pulse = 0;
+				return;
+			}
+			rbwrite(space);
+			rbwrite(pulse | PULSE_BIT);
+			ptr = 0;
+			pulse = 0;
+		}
+	}
+	rbwrite(l);
+}
+
+static irqreturn_t irq_handler(int i, void *blah)
+{
+	struct timeval tv;
+	int counter, dcd;
+	u8 status;
+	long deltv;
+	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) {
+			printk(KERN_WARNING LIRC_DRIVER_NAME ": AIEEEE: "
+			       "We're caught!\n");
+			break;
+		}
+		if ((status & hardware[type].signal_pin_change)
+		    && sense != -1) {
+			/* get current time */
+			do_gettimeofday(&tv);
+
+			/* New mode, written by Trent Piepho
+			   <xyzzy@u.washington.edu>. */
+
+			/*
+			 * The old format was not very portable.
+			 * We now use an int to pass pulses
+			 * and spaces to user space.
+			 *
+			 * If PULSE_BIT is set a pulse has been
+			 * received, otherwise a space has been
+			 * received.  The driver needs to know if your
+			 * receiver is active high or active low, or
+			 * the space/pulse sense could be
+			 * inverted. The bits denoted by PULSE_MASK are
+			 * the length in microseconds. Lengths greater
+			 * than or equal to 16 seconds are clamped to
+			 * PULSE_MASK.  All other bits are unused.
+			 * This is a much simpler interface for user
+			 * programs, as well as eliminating "out of
+			 * phase" errors with space/pulse
+			 * autodetection.
+			 */
+
+			/* calc time since last interrupt in microseconds */
+			dcd = (status & hardware[type].signal_pin) ? 1 : 0;
+
+			if (dcd == last_dcd) {
+				printk(KERN_WARNING LIRC_DRIVER_NAME
+				": ignoring spike: %d %d %lx %lx %lx %lx\n",
+				dcd, sense,
+				tv.tv_sec, lasttv.tv_sec,
+				tv.tv_usec, lasttv.tv_usec);
+				continue;
+			}
+
+			deltv = tv.tv_sec-lasttv.tv_sec;
+			if (tv.tv_sec < lasttv.tv_sec ||
+			    (tv.tv_sec == lasttv.tv_sec &&
+			     tv.tv_usec < lasttv.tv_usec)) {
+				printk(KERN_WARNING LIRC_DRIVER_NAME
+				       ": AIEEEE: your clock just jumped "
+				       "backwards\n");
+				printk(KERN_WARNING LIRC_DRIVER_NAME
+				       ": %d %d %lx %lx %lx %lx\n",
+				       dcd, sense,
+				       tv.tv_sec, lasttv.tv_sec,
+				       tv.tv_usec, lasttv.tv_usec);
+				data = PULSE_MASK;
+			} else if (deltv > 15) {
+				data = PULSE_MASK; /* really long time */
+				if (!(dcd^sense)) {
+					/* sanity check */
+					printk(KERN_WARNING LIRC_DRIVER_NAME
+					       ": AIEEEE: "
+					       "%d %d %lx %lx %lx %lx\n",
+					       dcd, sense,
+					       tv.tv_sec, lasttv.tv_sec,
+					       tv.tv_usec, lasttv.tv_usec);
+					/*
+					 * detecting pulse while this
+					 * MUST be a space!
+					 */
+					sense = sense ? 0 : 1;
+				}
+			} else
+				data = (int) (deltv*1000000 +
+					       tv.tv_usec -
+					       lasttv.tv_usec);
+			frbwrite(dcd^sense ? data : (data|PULSE_BIT));
+			lasttv = tv;
+			last_dcd = dcd;
+			wake_up_interruptible(&rbuf.wait_poll);
+		}
+	} while (!(sinp(UART_IIR) & UART_IIR_NO_INT)); /* still pending ? */
+	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/serial/8250.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 */
+		printk(KERN_ERR LIRC_DRIVER_NAME ": port existence test "
+		       "failed, cannot continue\n");
+		return -EINVAL;
+	}
+
+
+
+	/* 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);
+
+#ifdef CONFIG_LIRC_SERIAL_NSLU2
+	if (type == LIRC_NSLU2) {
+		/* Setup NSLU2 UART */
+
+		/* Enable UART */
+		soutp(UART_IER, sinp(UART_IER) | UART_IE_IXP42X_UUE);
+		/* Disable Receiver data Time out interrupt */
+		soutp(UART_IER, sinp(UART_IER) & ~UART_IE_IXP42X_RTOIE);
+		/* set out2 = interrupt unmask; off() doesn't set MCR
+		   on NSLU2 */
+		soutp(UART_MCR, UART_MCR_RTS|UART_MCR_OUT2);
+	}
+#endif
+
+	/* 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 LIRC_IRDEO:
+	case LIRC_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 int init_port(void)
+{
+	int i, nlow, nhigh;
+
+	/* Reserve io region. */
+	/*
+	 * Future MMAP-Developers: Attention!
+	 * For memory mapped I/O you *might* need to use ioremap() first,
+	 * for the NSLU2 it's done in boot code.
+	 */
+	if (((iommap != 0)
+	     && (request_mem_region(iommap, 8 << ioshift,
+				    LIRC_DRIVER_NAME) == NULL))
+	   || ((iommap == 0)
+	       && (request_region(io, 8, LIRC_DRIVER_NAME) == NULL))) {
+		printk(KERN_ERR  LIRC_DRIVER_NAME
+		       ": port %04x already in use\n", io);
+		printk(KERN_WARNING LIRC_DRIVER_NAME
+		       ": use 'setserial /dev/ttySX uart none'\n");
+		printk(KERN_WARNING LIRC_DRIVER_NAME
+		       ": or compile the serial port driver as module and\n");
+		printk(KERN_WARNING LIRC_DRIVER_NAME
+		       ": make sure this module is loaded first\n");
+		return -EBUSY;
+	}
+
+	if (hardware_init_port() < 0)
+		return -EINVAL;
+
+	/* Initialize pulse/space widths */
+	init_timing_params(duty_cycle, freq);
+
+	/* 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);
+		printk(KERN_INFO LIRC_DRIVER_NAME  ": auto-detected active "
+		       "%s receiver\n", sense ? "low" : "high");
+	} else
+		printk(KERN_INFO LIRC_DRIVER_NAME  ": Manually using active "
+		       "%s receiver\n", sense ? "low" : "high");
+
+	return 0;
+}
+
+static int set_use_inc(void *data)
+{
+	int result;
+	unsigned long flags;
+
+	/* initialize timestamp */
+	do_gettimeofday(&lasttv);
+
+	result = request_irq(irq, irq_handler,
+			     IRQF_DISABLED | (share_irq ? IRQF_SHARED : 0),
+			     LIRC_DRIVER_NAME, (void *)&hardware);
+
+	switch (result) {
+	case -EBUSY:
+		printk(KERN_ERR LIRC_DRIVER_NAME ": IRQ %d busy\n", irq);
+		return -EBUSY;
+	case -EINVAL:
+		printk(KERN_ERR LIRC_DRIVER_NAME
+		       ": Bad irq number or handler\n");
+		return -EINVAL;
+	default:
+		dprintk("Interrupt %d, port %04x obtained\n", irq, io);
+		break;
+	};
+
+	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 set_use_dec(void *data)
+{	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);
+
+	free_irq(irq, (void *)&hardware);
+
+	dprintk("freed IRQ %d\n", irq);
+}
+
+static ssize_t lirc_write(struct file *file, const char *buf,
+			 size_t n, loff_t *ppos)
+{
+	int i, count;
+	unsigned long flags;
+	long delta = 0;
+	int *wbuf;
+
+	if (!(hardware[type].features & LIRC_CAN_SEND_PULSE))
+		return -EBADF;
+
+	count = n / sizeof(int);
+	if (n % sizeof(int) || count % 2 == 0)
+		return -EINVAL;
+	wbuf = memdup_user(buf, n);
+	if (PTR_ERR(wbuf))
+		return PTR_ERR(wbuf);
+	spin_lock_irqsave(&hardware[type].lock, flags);
+	if (type == LIRC_IRDEO) {
+		/* DTR, RTS down */
+		on();
+	}
+	for (i = 0; i < count; i++) {
+		if (i%2)
+			hardware[type].send_space(wbuf[i] - delta);
+		else
+			delta = hardware[type].send_pulse(wbuf[i]);
+	}
+	off();
+	spin_unlock_irqrestore(&hardware[type].lock, flags);
+	return n;
+}
+
+static long lirc_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
+{
+	int result;
+	unsigned long value;
+	unsigned int ivalue;
+
+	switch (cmd) {
+	case LIRC_GET_SEND_MODE:
+		if (!(hardware[type].features&LIRC_CAN_SEND_MASK))
+			return -ENOIOCTLCMD;
+
+		result = put_user(LIRC_SEND2MODE
+				  (hardware[type].features&LIRC_CAN_SEND_MASK),
+				  (unsigned long *) arg);
+		if (result)
+			return result;
+		break;
+
+	case LIRC_SET_SEND_MODE:
+		if (!(hardware[type].features&LIRC_CAN_SEND_MASK))
+			return -ENOIOCTLCMD;
+
+		result = get_user(value, (unsigned long *) arg);
+		if (result)
+			return result;
+		/* only LIRC_MODE_PULSE supported */
+		if (value != LIRC_MODE_PULSE)
+			return -ENOSYS;
+		break;
+
+	case LIRC_GET_LENGTH:
+		return -ENOSYS;
+		break;
+
+	case LIRC_SET_SEND_DUTY_CYCLE:
+		dprintk("SET_SEND_DUTY_CYCLE\n");
+		if (!(hardware[type].features&LIRC_CAN_SET_SEND_DUTY_CYCLE))
+			return -ENOIOCTLCMD;
+
+		result = get_user(ivalue, (unsigned int *) arg);
+		if (result)
+			return result;
+		if (ivalue <= 0 || ivalue > 100)
+			return -EINVAL;
+		return init_timing_params(ivalue, freq);
+		break;
+
+	case LIRC_SET_SEND_CARRIER:
+		dprintk("SET_SEND_CARRIER\n");
+		if (!(hardware[type].features&LIRC_CAN_SET_SEND_CARRIER))
+			return -ENOIOCTLCMD;
+
+		result = get_user(ivalue, (unsigned int *) arg);
+		if (result)
+			return result;
+		if (ivalue > 500000 || ivalue < 20000)
+			return -EINVAL;
+		return init_timing_params(duty_cycle, ivalue);
+		break;
+
+	default:
+		return lirc_dev_fop_ioctl(filep, cmd, arg);
+	}
+	return 0;
+}
+
+static struct file_operations lirc_fops = {
+	.owner		= THIS_MODULE,
+	.write		= lirc_write,
+	.unlocked_ioctl	= lirc_ioctl,
+	.read		= lirc_dev_fop_read,
+	.poll		= lirc_dev_fop_poll,
+	.open		= lirc_dev_fop_open,
+	.release	= lirc_dev_fop_close,
+};
+
+static struct lirc_driver driver = {
+	.name		= LIRC_DRIVER_NAME,
+	.minor		= -1,
+	.code_length	= 1,
+	.sample_rate	= 0,
+	.data		= NULL,
+	.add_to_buf	= NULL,
+	.rbuf		= &rbuf,
+	.set_use_inc	= set_use_inc,
+	.set_use_dec	= set_use_dec,
+	.fops		= &lirc_fops,
+	.dev		= NULL,
+	.owner		= THIS_MODULE,
+};
+
+static struct platform_device *lirc_serial_dev;
+
+static int __devinit lirc_serial_probe(struct platform_device *dev)
+{
+	return 0;
+}
+
+static int __devexit lirc_serial_remove(struct platform_device *dev)
+{
+	return 0;
+}
+
+static int lirc_serial_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;
+}
+
+/* twisty maze... need a forward-declaration here... */
+static void lirc_serial_exit(void);
+
+static int lirc_serial_resume(struct platform_device *dev)
+{
+	unsigned long flags;
+
+	if (hardware_init_port() < 0) {
+		lirc_serial_exit();
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&hardware[type].lock, flags);
+	/* Enable Interrupt */
+	do_gettimeofday(&lasttv);
+	soutp(UART_IER, sinp(UART_IER)|UART_IER_MSI);
+	off();
+
+	lirc_buffer_clear(&rbuf);
+
+	spin_unlock_irqrestore(&hardware[type].lock, flags);
+
+	return 0;
+}
+
+static struct platform_driver lirc_serial_driver = {
+	.probe		= lirc_serial_probe,
+	.remove		= __devexit_p(lirc_serial_remove),
+	.suspend	= lirc_serial_suspend,
+	.resume		= lirc_serial_resume,
+	.driver		= {
+		.name	= "lirc_serial",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init lirc_serial_init(void)
+{
+	int result;
+
+	/* Init read buffer. */
+	result = lirc_buffer_init(&rbuf, sizeof(int), RBUF_LEN);
+	if (result < 0)
+		return -ENOMEM;
+
+	result = platform_driver_register(&lirc_serial_driver);
+	if (result) {
+		printk("lirc register returned %d\n", result);
+		goto exit_buffer_free;
+	}
+
+	lirc_serial_dev = platform_device_alloc("lirc_serial", 0);
+	if (!lirc_serial_dev) {
+		result = -ENOMEM;
+		goto exit_driver_unregister;
+	}
+
+	result = platform_device_add(lirc_serial_dev);
+	if (result)
+		goto exit_device_put;
+
+	return 0;
+
+exit_device_put:
+	platform_device_put(lirc_serial_dev);
+exit_driver_unregister:
+	platform_driver_unregister(&lirc_serial_driver);
+exit_buffer_free:
+	lirc_buffer_free(&rbuf);
+	return result;
+}
+
+static void lirc_serial_exit(void)
+{
+	platform_device_unregister(lirc_serial_dev);
+	platform_driver_unregister(&lirc_serial_driver);
+	lirc_buffer_free(&rbuf);
+}
+
+static int __init lirc_serial_init_module(void)
+{
+	int result;
+
+	result = lirc_serial_init();
+	if (result)
+		return result;
+
+	switch (type) {
+	case LIRC_HOMEBREW:
+	case LIRC_IRDEO:
+	case LIRC_IRDEO_REMOTE:
+	case LIRC_ANIMAX:
+	case LIRC_IGOR:
+		/* if nothing specified, use ttyS0/com1 and irq 4 */
+		io = io ? io : 0x3f8;
+		irq = irq ? irq : 4;
+		break;
+#ifdef CONFIG_LIRC_SERIAL_NSLU2
+	case LIRC_NSLU2:
+		io = io ? io : IRQ_IXP4XX_UART2;
+		irq = irq ? irq : (IXP4XX_UART2_BASE_VIRT + REG_OFFSET);
+		iommap = iommap ? iommap : IXP4XX_UART2_BASE_PHYS;
+		ioshift = ioshift ? ioshift : 2;
+		break;
+#endif
+	default:
+		result = -EINVAL;
+		goto exit_serial_exit;
+	}
+	if (!softcarrier) {
+		switch (type) {
+		case LIRC_HOMEBREW:
+		case LIRC_IGOR:
+#ifdef CONFIG_LIRC_SERIAL_NSLU2
+		case LIRC_NSLU2:
+#endif
+			hardware[type].features &=
+				~(LIRC_CAN_SET_SEND_DUTY_CYCLE|
+				  LIRC_CAN_SET_SEND_CARRIER);
+			break;
+		}
+	}
+
+	result = init_port();
+	if (result < 0)
+		goto exit_serial_exit;
+	driver.features = hardware[type].features;
+	driver.dev = &lirc_serial_dev->dev;
+	driver.minor = lirc_register_driver(&driver);
+	if (driver.minor < 0) {
+		printk(KERN_ERR  LIRC_DRIVER_NAME
+		       ": register_chrdev failed!\n");
+		result = -EIO;
+		goto exit_release;
+	}
+	return 0;
+exit_release:
+	release_region(io, 8);
+exit_serial_exit:
+	lirc_serial_exit();
+	return result;
+}
+
+static void __exit lirc_serial_exit_module(void)
+{
+	lirc_serial_exit();
+	if (iommap != 0)
+		release_mem_region(iommap, 8 << ioshift);
+	else
+		release_region(io, 8);
+	lirc_unregister_driver(driver.minor);
+	dprintk("cleaned up module\n");
+}
+
+
+module_init(lirc_serial_init_module);
+module_exit(lirc_serial_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, S_IRUGO);
+MODULE_PARM_DESC(type, "Hardware type (0 = home-brew, 1 = IRdeo,"
+		 " 2 = IRdeo Remote, 3 = AnimaX, 4 = IgorPlug,"
+		 " 5 = NSLU2 RX:CTS2/TX:GreenLED)");
+
+module_param(io, int, S_IRUGO);
+MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
+
+/* some architectures (e.g. intel xscale) have memory mapped registers */
+module_param(iommap, bool, S_IRUGO);
+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/serial/8250.c serial_in()/out()
+ */
+module_param(ioshift, int, S_IRUGO);
+MODULE_PARM_DESC(ioshift, "shift I/O register offset (0 = no shift)");
+
+module_param(irq, int, S_IRUGO);
+MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
+
+module_param(share_irq, bool, S_IRUGO);
+MODULE_PARM_DESC(share_irq, "Share interrupts (0 = off, 1 = on)");
+
+module_param(sense, bool, S_IRUGO);
+MODULE_PARM_DESC(sense, "Override autodetection of IR receiver circuit"
+		 " (0 = active high, 1 = active low )");
+
+#ifdef CONFIG_LIRC_SERIAL_TRANSMITTER
+module_param(txsense, bool, S_IRUGO);
+MODULE_PARM_DESC(txsense, "Sense of transmitter circuit"
+		 " (0 = active high, 1 = active low )");
+#endif
+
+module_param(softcarrier, bool, S_IRUGO);
+MODULE_PARM_DESC(softcarrier, "Software carrier (0 = off, 1 = on, default on)");
+
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Enable debugging messages");