V4L/DVB: staging/lirc: add lirc_it87 driver

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

drivers/staging/lirc/lirc_it87.c

+/*
+ * LIRC driver for ITE IT8712/IT8705 CIR port
+ *
+ * Copyright (C) 2001 Hans-Gunter Lutke Uphues <hg_lu@web.de>
+ *
+ * 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
+ *
+ * ITE IT8705 and IT8712(not tested) and IT8720 CIR-port support for lirc based
+ * via cut and paste from lirc_sir.c (C) 2000 Milan Pikula
+ *
+ * Attention: Sendmode only tested with debugging logs
+ *
+ * 2001/02/27 Christoph Bartelmus <lirc@bartelmus.de> :
+ *   reimplemented read function
+ * 2005/06/05 Andrew Calkin implemented support for Asus Digimatrix,
+ *   based on work of the following member of the Outertrack Digimatrix
+ *   Forum: Art103 <r_tay@hotmail.com>
+ * 2009/12/24 James Edwards <jimbo-lirc@edwardsclan.net> implemeted support
+ *   for ITE8704/ITE8718, on my machine, the DSDT reports 8704, but the
+ *   chip identifies as 18.
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/kernel.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 <asm/system.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/fcntl.h>
+
+#include <linux/timer.h>
+#include <linux/pnp.h>
+
+#include <media/lirc.h>
+#include <media/lirc_dev.h>
+
+#include "lirc_it87.h"
+
+#ifdef LIRC_IT87_DIGIMATRIX
+static int digimatrix = 1;
+static int it87_freq = 36; /* kHz */
+static int irq = 9;
+#else
+static int digimatrix;
+static int it87_freq = 38; /* kHz */
+static int irq = IT87_CIR_DEFAULT_IRQ;
+#endif
+
+static unsigned long it87_bits_in_byte_out;
+static unsigned long it87_send_counter;
+static unsigned char it87_RXEN_mask = IT87_CIR_RCR_RXEN;
+
+#define RBUF_LEN 1024
+
+#define LIRC_DRIVER_NAME "lirc_it87"
+
+/* timeout for sequences in jiffies (=5/100s) */
+/* must be longer than TIME_CONST */
+#define IT87_TIMEOUT	(HZ*5/100)
+
+/* module parameters */
+static int debug;
+#define dprintk(fmt, args...)					\
+	do {							\
+		if (debug)					\
+			printk(KERN_DEBUG LIRC_DRIVER_NAME ": "	\
+			       fmt, ## args);			\
+	} while (0)
+
+static int io = IT87_CIR_DEFAULT_IOBASE;
+/* receiver demodulator default: off */
+static int it87_enable_demodulator;
+
+static int timer_enabled;
+static DEFINE_SPINLOCK(timer_lock);
+static struct timer_list timerlist;
+/* time of last signal change detected */
+static struct timeval last_tv = {0, 0};
+/* time of last UART data ready interrupt */
+static struct timeval last_intr_tv = {0, 0};
+static int last_value;
+
+static DECLARE_WAIT_QUEUE_HEAD(lirc_read_queue);
+
+static DEFINE_SPINLOCK(hardware_lock);
+static DEFINE_SPINLOCK(dev_lock);
+
+static int rx_buf[RBUF_LEN];
+unsigned int rx_tail, rx_head;
+
+static struct pnp_driver it87_pnp_driver;
+
+/* SECTION: Prototypes */
+
+/* Communication with user-space */
+static int lirc_open(struct inode *inode, struct file *file);
+static int lirc_close(struct inode *inode, struct file *file);
+static unsigned int lirc_poll(struct file *file, poll_table *wait);
+static ssize_t lirc_read(struct file *file, char *buf,
+			 size_t count, loff_t *ppos);
+static ssize_t lirc_write(struct file *file, const char *buf,
+			  size_t n, loff_t *pos);
+static long lirc_ioctl(struct file *filep, unsigned int cmd, unsigned long arg);
+static void add_read_queue(int flag, unsigned long val);
+static int init_chrdev(void);
+static void drop_chrdev(void);
+/* Hardware */
+static irqreturn_t it87_interrupt(int irq, void *dev_id);
+static void send_space(unsigned long len);
+static void send_pulse(unsigned long len);
+static void init_send(void);
+static void terminate_send(unsigned long len);
+static int init_hardware(void);
+static void drop_hardware(void);
+/* Initialisation */
+static int init_port(void);
+static void drop_port(void);
+
+
+/* SECTION: Communication with user-space */
+
+static int lirc_open(struct inode *inode, struct file *file)
+{
+	spin_lock(&dev_lock);
+	if (module_refcount(THIS_MODULE)) {
+		spin_unlock(&dev_lock);
+		return -EBUSY;
+	}
+	spin_unlock(&dev_lock);
+	return 0;
+}
+
+
+static int lirc_close(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+
+static unsigned int lirc_poll(struct file *file, poll_table *wait)
+{
+	poll_wait(file, &lirc_read_queue, wait);
+	if (rx_head != rx_tail)
+		return POLLIN | POLLRDNORM;
+	return 0;
+}
+
+
+static ssize_t lirc_read(struct file *file, char *buf,
+			 size_t count, loff_t *ppos)
+{
+	int n = 0;
+	int retval = 0;
+
+	while (n < count) {
+		if (file->f_flags & O_NONBLOCK && rx_head == rx_tail) {
+			retval = -EAGAIN;
+			break;
+		}
+		retval = wait_event_interruptible(lirc_read_queue,
+						  rx_head != rx_tail);
+		if (retval)
+			break;
+
+		if (copy_to_user((void *) buf + n, (void *) (rx_buf + rx_head),
+				 sizeof(int))) {
+			retval = -EFAULT;
+			break;
+		}
+		rx_head = (rx_head + 1) & (RBUF_LEN - 1);
+		n += sizeof(int);
+	}
+	if (n)
+		return n;
+	return retval;
+}
+
+
+static ssize_t lirc_write(struct file *file, const char *buf,
+			  size_t n, loff_t *pos)
+{
+	int i = 0;
+	int *tx_buf;
+
+	if (n % sizeof(int))
+		return -EINVAL;
+	tx_buf = memdup_user(buf, n);
+	if (IS_ERR(tx_buf))
+		return PTR_ERR(tx_buf);
+	n /= sizeof(int);
+	init_send();
+	while (1) {
+		if (i >= n)
+			break;
+		if (tx_buf[i])
+			send_pulse(tx_buf[i]);
+		i++;
+		if (i >= n)
+			break;
+		if (tx_buf[i])
+			send_space(tx_buf[i]);
+		i++;
+	}
+	terminate_send(tx_buf[i - 1]);
+	return n;
+}
+
+
+static long lirc_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
+{
+	int retval = 0;
+	unsigned long value = 0;
+	unsigned int ivalue;
+	unsigned long hw_flags;
+
+	if (cmd == LIRC_GET_FEATURES)
+		value = LIRC_CAN_SEND_PULSE |
+			LIRC_CAN_SET_SEND_CARRIER |
+			LIRC_CAN_REC_MODE2;
+	else if (cmd == LIRC_GET_SEND_MODE)
+		value = LIRC_MODE_PULSE;
+	else if (cmd == LIRC_GET_REC_MODE)
+		value = LIRC_MODE_MODE2;
+
+	switch (cmd) {
+	case LIRC_GET_FEATURES:
+	case LIRC_GET_SEND_MODE:
+	case LIRC_GET_REC_MODE:
+		retval = put_user(value, (unsigned long *) arg);
+		break;
+
+	case LIRC_SET_SEND_MODE:
+	case LIRC_SET_REC_MODE:
+		retval = get_user(value, (unsigned long *) arg);
+		break;
+
+	case LIRC_SET_SEND_CARRIER:
+		retval = get_user(ivalue, (unsigned int *) arg);
+		if (retval)
+			return retval;
+		ivalue /= 1000;
+		if (ivalue > IT87_CIR_FREQ_MAX ||
+		    ivalue < IT87_CIR_FREQ_MIN)
+			return -EINVAL;
+
+		it87_freq = ivalue;
+
+		spin_lock_irqsave(&hardware_lock, hw_flags);
+		outb(((inb(io + IT87_CIR_TCR2) & IT87_CIR_TCR2_TXMPW) |
+		      (it87_freq - IT87_CIR_FREQ_MIN) << 3),
+		      io + IT87_CIR_TCR2);
+		spin_unlock_irqrestore(&hardware_lock, hw_flags);
+		dprintk("demodulation frequency: %d kHz\n", it87_freq);
+
+		break;
+
+	default:
+		retval = -EINVAL;
+	}
+
+	if (retval)
+		return retval;
+
+	if (cmd == LIRC_SET_REC_MODE) {
+		if (value != LIRC_MODE_MODE2)
+			retval = -ENOSYS;
+	} else if (cmd == LIRC_SET_SEND_MODE) {
+		if (value != LIRC_MODE_PULSE)
+			retval = -ENOSYS;
+	}
+	return retval;
+}
+
+static void add_read_queue(int flag, unsigned long val)
+{
+	unsigned int new_rx_tail;
+	int newval;
+
+	dprintk("add flag %d with val %lu\n", flag, val);
+
+	newval = val & PULSE_MASK;
+
+	/*
+	 * statistically, pulses are ~TIME_CONST/2 too long. we could
+	 * maybe make this more exact, but this is good enough
+	 */
+	if (flag) {
+		/* pulse */
+		if (newval > TIME_CONST / 2)
+			newval -= TIME_CONST / 2;
+		else /* should not ever happen */
+			newval = 1;
+		newval |= PULSE_BIT;
+	} else
+		newval += TIME_CONST / 2;
+	new_rx_tail = (rx_tail + 1) & (RBUF_LEN - 1);
+	if (new_rx_tail == rx_head) {
+		dprintk("Buffer overrun.\n");
+		return;
+	}
+	rx_buf[rx_tail] = newval;
+	rx_tail = new_rx_tail;
+	wake_up_interruptible(&lirc_read_queue);
+}
+
+
+static struct file_operations lirc_fops = {
+	.owner		= THIS_MODULE,
+	.read		= lirc_read,
+	.write		= lirc_write,
+	.poll		= lirc_poll,
+	.unlocked_ioctl	= lirc_ioctl,
+	.open		= lirc_open,
+	.release	= lirc_close,
+};
+
+static int set_use_inc(void *data)
+{
+       return 0;
+}
+
+static void set_use_dec(void *data)
+{
+}
+
+static struct lirc_driver driver = {
+       .name		= LIRC_DRIVER_NAME,
+       .minor		= -1,
+       .code_length	= 1,
+       .sample_rate	= 0,
+       .data		= NULL,
+       .add_to_buf	= NULL,
+       .set_use_inc	= set_use_inc,
+       .set_use_dec	= set_use_dec,
+       .fops		= &lirc_fops,
+       .dev		= NULL,
+       .owner		= THIS_MODULE,
+};
+
+
+#ifdef MODULE
+static int init_chrdev(void)
+{
+	driver.minor = lirc_register_driver(&driver);
+
+	if (driver.minor < 0) {
+		printk(KERN_ERR LIRC_DRIVER_NAME ": init_chrdev() failed.\n");
+		return -EIO;
+	}
+	return 0;
+}
+
+
+static void drop_chrdev(void)
+{
+	lirc_unregister_driver(driver.minor);
+}
+#endif
+
+
+/* SECTION: Hardware */
+static long delta(struct timeval *tv1, struct timeval *tv2)
+{
+	unsigned long deltv;
+
+	deltv = tv2->tv_sec - tv1->tv_sec;
+	if (deltv > 15)
+		deltv = 0xFFFFFF;
+	else
+		deltv = deltv*1000000 + tv2->tv_usec - tv1->tv_usec;
+	return deltv;
+}
+
+static void it87_timeout(unsigned long data)
+{
+	unsigned long flags;
+
+	/* avoid interference with interrupt */
+	spin_lock_irqsave(&timer_lock, flags);
+
+	if (digimatrix) {
+		/* We have timed out. Disable the RX mechanism. */
+
+		outb((inb(io + IT87_CIR_RCR) & ~IT87_CIR_RCR_RXEN) |
+		     IT87_CIR_RCR_RXACT, io + IT87_CIR_RCR);
+		if (it87_RXEN_mask)
+			outb(inb(io + IT87_CIR_RCR) | IT87_CIR_RCR_RXEN,
+			     io + IT87_CIR_RCR);
+		dprintk(" TIMEOUT\n");
+		timer_enabled = 0;
+
+		/* fifo clear */
+		outb(inb(io + IT87_CIR_TCR1) | IT87_CIR_TCR1_FIFOCLR,
+		     io+IT87_CIR_TCR1);
+
+	} else {
+		/*
+		 * 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.
+		 */
+
+		if (last_value) {
+			unsigned long pulse_end;
+
+			/* determine 'virtual' pulse end: */
+			pulse_end = delta(&last_tv, &last_intr_tv);
+			dprintk("timeout add %d for %lu usec\n",
+				last_value, pulse_end);
+			add_read_queue(last_value, pulse_end);
+			last_value = 0;
+			last_tv = last_intr_tv;
+		}
+	}
+	spin_unlock_irqrestore(&timer_lock, flags);
+}
+
+static irqreturn_t it87_interrupt(int irq, void *dev_id)
+{
+	unsigned char data;
+	struct timeval curr_tv;
+	static unsigned long deltv;
+	unsigned long deltintrtv;
+	unsigned long flags, hw_flags;
+	int iir, lsr;
+	int fifo = 0;
+	static char lastbit;
+	char bit;
+
+	/* Bit duration in microseconds */
+	const unsigned long bit_duration = 1000000ul /
+		(115200 / IT87_CIR_BAUDRATE_DIVISOR);
+
+
+	iir = inb(io + IT87_CIR_IIR);
+
+	switch (iir & IT87_CIR_IIR_IID) {
+	case 0x4:
+	case 0x6:
+		lsr = inb(io + IT87_CIR_RSR) & (IT87_CIR_RSR_RXFTO |
+						IT87_CIR_RSR_RXFBC);
+		fifo = lsr & IT87_CIR_RSR_RXFBC;
+		dprintk("iir: 0x%x fifo: 0x%x\n", iir, lsr);
+
+		/* avoid interference with timer */
+		spin_lock_irqsave(&timer_lock, flags);
+		spin_lock_irqsave(&hardware_lock, hw_flags);
+		if (digimatrix) {
+			static unsigned long acc_pulse;
+			static unsigned long acc_space;
+
+			do {
+				data = inb(io + IT87_CIR_DR);
+				data = ~data;
+				fifo--;
+				if (data != 0x00) {
+					if (timer_enabled)
+						del_timer(&timerlist);
+					/*
+					 * start timer for end of
+					 * sequence detection
+					 */
+					timerlist.expires = jiffies +
+							    IT87_TIMEOUT;
+					add_timer(&timerlist);
+					timer_enabled = 1;
+				}
+				/* Loop through */
+				for (bit = 0; bit < 8; ++bit) {
+					if ((data >> bit) & 1) {
+						++acc_pulse;
+						if (lastbit == 0) {
+							add_read_queue(0,
+								acc_space *
+								 bit_duration);
+							acc_space = 0;
+						}
+					} else {
+						++acc_space;
+						if (lastbit == 1) {
+							add_read_queue(1,
+								acc_pulse *
+								 bit_duration);
+							acc_pulse = 0;
+						}
+					}
+					lastbit = (data >> bit) & 1;
+				}
+
+			} while (fifo != 0);
+		} else { /* Normal Operation */
+			do {
+				del_timer(&timerlist);
+				data = inb(io + IT87_CIR_DR);
+
+				dprintk("data=%02x\n", data);
+				do_gettimeofday(&curr_tv);
+				deltv = delta(&last_tv, &curr_tv);
+				deltintrtv = delta(&last_intr_tv, &curr_tv);
+
+				dprintk("t %lu , d %d\n",
+					deltintrtv, (int)data);
+
+				/*
+				 * if nothing came in last 2 cycles,
+				 * it was gap
+				 */
+				if (deltintrtv > TIME_CONST * 2) {
+					if (last_value) {
+						dprintk("GAP\n");
+
+						/* simulate signal change */
+						add_read_queue(last_value,
+							       deltv -
+							       deltintrtv);
+						last_value = 0;
+						last_tv.tv_sec =
+							last_intr_tv.tv_sec;
+						last_tv.tv_usec =
+							last_intr_tv.tv_usec;
+						deltv = deltintrtv;
+					}
+				}
+				data = 1;
+				if (data ^ last_value) {
+					/*
+					 * deltintrtv > 2*TIME_CONST,
+					 * remember ? the other case is
+					 * timeout
+					 */
+					add_read_queue(last_value,
+						       deltv-TIME_CONST);
+					last_value = data;
+					last_tv = curr_tv;
+					if (last_tv.tv_usec >= TIME_CONST)
+						last_tv.tv_usec -= TIME_CONST;
+					else {
+						last_tv.tv_sec--;
+						last_tv.tv_usec += 1000000 -
+							TIME_CONST;
+					}
+				}
+				last_intr_tv = curr_tv;
+				if (data) {
+					/*
+					 * start timer for end of
+					 * sequence detection
+					 */
+					timerlist.expires =
+						jiffies + IT87_TIMEOUT;
+					add_timer(&timerlist);
+				}
+				outb((inb(io + IT87_CIR_RCR) &
+				     ~IT87_CIR_RCR_RXEN) |
+				     IT87_CIR_RCR_RXACT,
+				     io + IT87_CIR_RCR);
+				if (it87_RXEN_mask)
+					outb(inb(io + IT87_CIR_RCR) |
+					     IT87_CIR_RCR_RXEN,
+					     io + IT87_CIR_RCR);
+				fifo--;
+			} while (fifo != 0);
+		}
+		spin_unlock_irqrestore(&hardware_lock, hw_flags);
+		spin_unlock_irqrestore(&timer_lock, flags);
+
+		return IRQ_RETVAL(IRQ_HANDLED);
+
+	default:
+		/* not our irq */
+		dprintk("unknown IRQ (shouldn't happen) !!\n");
+		return IRQ_RETVAL(IRQ_NONE);
+	}
+}
+
+
+static void send_it87(unsigned long len, unsigned long stime,
+		      unsigned char send_byte, unsigned int count_bits)
+{
+	long count = len / stime;
+	long time_left = 0;
+	static unsigned char byte_out;
+	unsigned long hw_flags;
+
+	dprintk("%s: len=%ld, sb=%d\n", __func__, len, send_byte);
+
+	time_left = (long)len - (long)count * (long)stime;
+	count += ((2 * time_left) / stime);
+	while (count) {
+		long i = 0;
+		for (i = 0; i < count_bits; i++) {
+			byte_out = (byte_out << 1) | (send_byte & 1);
+			it87_bits_in_byte_out++;
+		}
+		if (it87_bits_in_byte_out == 8) {
+			dprintk("out=0x%x, tsr_txfbc: 0x%x\n",
+				byte_out,
+				inb(io + IT87_CIR_TSR) &
+				IT87_CIR_TSR_TXFBC);
+
+			while ((inb(io + IT87_CIR_TSR) &
+				IT87_CIR_TSR_TXFBC) >= IT87_CIR_FIFO_SIZE)
+				;
+
+			spin_lock_irqsave(&hardware_lock, hw_flags);
+			outb(byte_out, io + IT87_CIR_DR);
+			spin_unlock_irqrestore(&hardware_lock, hw_flags);
+
+			it87_bits_in_byte_out = 0;
+			it87_send_counter++;
+			byte_out = 0;
+		}
+		count--;
+	}
+}
+
+
+/*TODO: maybe exchange space and pulse because it8705 only modulates 0-bits */
+
+static void send_space(unsigned long len)
+{
+	send_it87(len, TIME_CONST, IT87_CIR_SPACE, IT87_CIR_BAUDRATE_DIVISOR);
+}
+
+static void send_pulse(unsigned long len)
+{
+	send_it87(len, TIME_CONST, IT87_CIR_PULSE, IT87_CIR_BAUDRATE_DIVISOR);
+}
+
+
+static void init_send()
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&hardware_lock, flags);
+	/* RXEN=0: receiver disable */
+	it87_RXEN_mask = 0;
+	outb(inb(io + IT87_CIR_RCR) & ~IT87_CIR_RCR_RXEN,
+	     io + IT87_CIR_RCR);
+	spin_unlock_irqrestore(&hardware_lock, flags);
+	it87_bits_in_byte_out = 0;
+	it87_send_counter = 0;
+}
+
+
+static void terminate_send(unsigned long len)
+{
+	unsigned long flags;
+	unsigned long last = 0;
+
+	last = it87_send_counter;
+	/* make sure all necessary data has been sent */
+	while (last == it87_send_counter)
+		send_space(len);
+	/* wait until all data sent */
+	while ((inb(io + IT87_CIR_TSR) & IT87_CIR_TSR_TXFBC) != 0)
+		;
+	/* then re-enable receiver */
+	spin_lock_irqsave(&hardware_lock, flags);
+	it87_RXEN_mask = IT87_CIR_RCR_RXEN;
+	outb(inb(io + IT87_CIR_RCR) | IT87_CIR_RCR_RXEN,
+	     io + IT87_CIR_RCR);
+	spin_unlock_irqrestore(&hardware_lock, flags);
+}
+
+
+static int init_hardware(void)
+{
+	unsigned long flags;
+	unsigned char it87_rcr = 0;
+
+	spin_lock_irqsave(&hardware_lock, flags);
+	/* init cir-port */
+	/* enable r/w-access to Baudrate-Register */
+	outb(IT87_CIR_IER_BR, io + IT87_CIR_IER);
+	outb(IT87_CIR_BAUDRATE_DIVISOR % 0x100, io+IT87_CIR_BDLR);
+	outb(IT87_CIR_BAUDRATE_DIVISOR / 0x100, io+IT87_CIR_BDHR);
+	/* Baudrate Register off, define IRQs: Input only */
+	if (digimatrix) {
+		outb(IT87_CIR_IER_IEC | IT87_CIR_IER_RFOIE, io + IT87_CIR_IER);
+		/* RX: HCFS=0, RXDCR = 001b (33,75..38,25 kHz), RXEN=1 */
+	} else {
+		outb(IT87_CIR_IER_IEC | IT87_CIR_IER_RDAIE, io + IT87_CIR_IER);
+		/* RX: HCFS=0, RXDCR = 001b (35,6..40,3 kHz), RXEN=1 */
+	}
+	it87_rcr = (IT87_CIR_RCR_RXEN & it87_RXEN_mask) | 0x1;
+	if (it87_enable_demodulator)
+		it87_rcr |= IT87_CIR_RCR_RXEND;
+	outb(it87_rcr, io + IT87_CIR_RCR);
+	if (digimatrix) {
+		/* Set FIFO depth to 1 byte, and disable TX */
+		outb(inb(io + IT87_CIR_TCR1) |  0x00,
+		     io + IT87_CIR_TCR1);
+
+		/*
+		 * TX: it87_freq (36kHz), 'reserved' sensitivity
+		 * setting (0x00)
+		 */
+		outb(((it87_freq - IT87_CIR_FREQ_MIN) << 3) | 0x00,
+		     io + IT87_CIR_TCR2);
+	} else {
+		/* TX: 38kHz, 13,3us (pulse-width) */
+		outb(((it87_freq - IT87_CIR_FREQ_MIN) << 3) | 0x06,
+		     io + IT87_CIR_TCR2);
+	}
+	spin_unlock_irqrestore(&hardware_lock, flags);
+	return 0;
+}
+
+
+static void drop_hardware(void)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&hardware_lock, flags);
+	disable_irq(irq);
+	/* receiver disable */
+	it87_RXEN_mask = 0;
+	outb(0x1, io + IT87_CIR_RCR);
+	/* turn off irqs */
+	outb(0, io + IT87_CIR_IER);
+	/* fifo clear */
+	outb(IT87_CIR_TCR1_FIFOCLR, io+IT87_CIR_TCR1);
+	/* reset */
+	outb(IT87_CIR_IER_RESET, io+IT87_CIR_IER);
+	enable_irq(irq);
+	spin_unlock_irqrestore(&hardware_lock, flags);
+}
+
+
+static unsigned char it87_read(unsigned char port)
+{
+	outb(port, IT87_ADRPORT);
+	return inb(IT87_DATAPORT);
+}
+
+
+static void it87_write(unsigned char port, unsigned char data)
+{
+	outb(port, IT87_ADRPORT);
+	outb(data, IT87_DATAPORT);
+}
+
+
+/* SECTION: Initialisation */
+
+static int init_port(void)
+{
+	unsigned long hw_flags;
+	int retval = 0;
+
+	unsigned char init_bytes[4] = IT87_INIT;
+	unsigned char it87_chipid = 0;
+	unsigned char ldn = 0;
+	unsigned int  it87_io = 0;
+	unsigned int  it87_irq = 0;
+
+	/* Enter MB PnP Mode */
+	outb(init_bytes[0], IT87_ADRPORT);
+	outb(init_bytes[1], IT87_ADRPORT);
+	outb(init_bytes[2], IT87_ADRPORT);
+	outb(init_bytes[3], IT87_ADRPORT);
+
+	/* 8712 or 8705 ? */
+	it87_chipid = it87_read(IT87_CHIP_ID1);
+	if (it87_chipid != 0x87) {
+		retval = -ENXIO;
+		return retval;
+	}
+	it87_chipid = it87_read(IT87_CHIP_ID2);
+	if ((it87_chipid != 0x05) &&
+		(it87_chipid != 0x12) &&
+		(it87_chipid != 0x18) &&
+		(it87_chipid != 0x20)) {
+		printk(KERN_INFO LIRC_DRIVER_NAME
+		       ": no IT8704/05/12/18/20 found (claimed IT87%02x), "
+		       "exiting..\n", it87_chipid);
+		retval = -ENXIO;
+		return retval;
+	}
+	printk(KERN_INFO LIRC_DRIVER_NAME
+	       ": found IT87%02x.\n",
+	       it87_chipid);
+
+	/* get I/O-Port and IRQ */
+	if (it87_chipid == 0x12 || it87_chipid == 0x18)
+		ldn = IT8712_CIR_LDN;
+	else
+		ldn = IT8705_CIR_LDN;
+	it87_write(IT87_LDN, ldn);
+
+	it87_io = it87_read(IT87_CIR_BASE_MSB) * 256 +
+		  it87_read(IT87_CIR_BASE_LSB);
+	if (it87_io == 0) {
+		if (io == 0)
+			io = IT87_CIR_DEFAULT_IOBASE;
+		printk(KERN_INFO LIRC_DRIVER_NAME
+		       ": set default io 0x%x\n",
+		       io);
+		it87_write(IT87_CIR_BASE_MSB, io / 0x100);
+		it87_write(IT87_CIR_BASE_LSB, io % 0x100);
+	} else
+		io = it87_io;
+
+	it87_irq = it87_read(IT87_CIR_IRQ);
+	if (digimatrix || it87_irq == 0) {
+		if (irq == 0)
+			irq = IT87_CIR_DEFAULT_IRQ;
+		printk(KERN_INFO LIRC_DRIVER_NAME
+		       ": set default irq 0x%x\n",
+		       irq);
+		it87_write(IT87_CIR_IRQ, irq);
+	} else
+		irq = it87_irq;
+
+	spin_lock_irqsave(&hardware_lock, hw_flags);
+	/* reset */
+	outb(IT87_CIR_IER_RESET, io+IT87_CIR_IER);
+	/* fifo clear */
+	outb(IT87_CIR_TCR1_FIFOCLR |
+	     /*	     IT87_CIR_TCR1_ILE | */
+	     IT87_CIR_TCR1_TXRLE |
+	     IT87_CIR_TCR1_TXENDF, io+IT87_CIR_TCR1);
+	spin_unlock_irqrestore(&hardware_lock, hw_flags);
+
+	/* get I/O port access and IRQ line */
+	if (request_region(io, 8, LIRC_DRIVER_NAME) == NULL) {
+		printk(KERN_ERR LIRC_DRIVER_NAME
+		       ": i/o port 0x%.4x already in use.\n", io);
+		/* Leaving MB PnP Mode */
+		it87_write(IT87_CFGCTRL, 0x2);
+		return -EBUSY;
+	}
+
+	/* activate CIR-Device */
+	it87_write(IT87_CIR_ACT, 0x1);
+
+	/* Leaving MB PnP Mode */
+	it87_write(IT87_CFGCTRL, 0x2);
+
+	retval = request_irq(irq, it87_interrupt, 0 /*IRQF_DISABLED*/,
+			     LIRC_DRIVER_NAME, NULL);
+	if (retval < 0) {
+		printk(KERN_ERR LIRC_DRIVER_NAME
+		       ": IRQ %d already in use.\n",
+		       irq);
+		release_region(io, 8);
+		return retval;
+	}
+
+	printk(KERN_INFO LIRC_DRIVER_NAME
+	       ": I/O port 0x%.4x, IRQ %d.\n", io, irq);
+
+	init_timer(&timerlist);
+	timerlist.function = it87_timeout;
+	timerlist.data = 0xabadcafe;
+
+	return 0;
+}
+
+
+static void drop_port(void)
+{
+#if 0
+	unsigned char init_bytes[4] = IT87_INIT;
+
+	/* Enter MB PnP Mode */
+	outb(init_bytes[0], IT87_ADRPORT);
+	outb(init_bytes[1], IT87_ADRPORT);
+	outb(init_bytes[2], IT87_ADRPORT);
+	outb(init_bytes[3], IT87_ADRPORT);
+
+	/* deactivate CIR-Device */
+	it87_write(IT87_CIR_ACT, 0x0);
+
+	/* Leaving MB PnP Mode */
+	it87_write(IT87_CFGCTRL, 0x2);
+#endif
+
+	del_timer_sync(&timerlist);
+	free_irq(irq, NULL);
+	release_region(io, 8);
+}
+
+
+static int init_lirc_it87(void)
+{
+	int retval;
+
+	init_waitqueue_head(&lirc_read_queue);
+	retval = init_port();
+	if (retval < 0)
+		return retval;
+	init_hardware();
+	printk(KERN_INFO LIRC_DRIVER_NAME ": Installed.\n");
+	return 0;
+}
+
+static int it87_probe(struct pnp_dev *pnp_dev,
+		      const struct pnp_device_id *dev_id)
+{
+	int retval;
+
+	driver.dev = &pnp_dev->dev;
+
+	retval = init_chrdev();
+	if (retval < 0)
+		return retval;
+
+	retval = init_lirc_it87();
+	if (retval)
+		goto init_lirc_it87_failed;
+
+	return 0;
+
+init_lirc_it87_failed:
+	drop_chrdev();
+
+	return retval;
+}
+
+static int __init lirc_it87_init(void)
+{
+	return pnp_register_driver(&it87_pnp_driver);
+}
+
+
+static void __exit lirc_it87_exit(void)
+{
+	drop_hardware();
+	drop_chrdev();
+	drop_port();
+	pnp_unregister_driver(&it87_pnp_driver);
+	printk(KERN_INFO LIRC_DRIVER_NAME ": Uninstalled.\n");
+}
+
+/* SECTION: PNP for ITE8704/18 */
+
+static const struct pnp_device_id pnp_dev_table[] = {
+	{"ITE8704", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(pnp, pnp_dev_table);
+
+static struct pnp_driver it87_pnp_driver = {
+	.name           = LIRC_DRIVER_NAME,
+	.id_table       = pnp_dev_table,
+	.probe		= it87_probe,
+};
+
+module_init(lirc_it87_init);
+module_exit(lirc_it87_exit);
+
+MODULE_DESCRIPTION("LIRC driver for ITE IT8704/05/12/18/20 CIR port");
+MODULE_AUTHOR("Hans-Gunter Lutke Uphues");
+MODULE_LICENSE("GPL");
+
+module_param(io, int, S_IRUGO);
+MODULE_PARM_DESC(io, "I/O base address (default: 0x310)");
+
+module_param(irq, int, S_IRUGO);
+#ifdef LIRC_IT87_DIGIMATRIX
+MODULE_PARM_DESC(irq, "Interrupt (1,3-12) (default: 9)");
+#else
+MODULE_PARM_DESC(irq, "Interrupt (1,3-12) (default: 7)");
+#endif
+
+module_param(it87_enable_demodulator, bool, S_IRUGO);
+MODULE_PARM_DESC(it87_enable_demodulator,
+		 "Receiver demodulator enable/disable (1/0), default: 0");
+
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Enable debugging messages");
+
+module_param(digimatrix, bool, S_IRUGO | S_IWUSR);
+#ifdef LIRC_IT87_DIGIMATRIX
+MODULE_PARM_DESC(digimatrix,
+	"Asus Digimatrix it87 compat. enable/disable (1/0), default: 1");
+#else
+MODULE_PARM_DESC(digimatrix,
+	"Asus Digimatrix it87 compat. enable/disable (1/0), default: 0");
+#endif
+
+
+module_param(it87_freq, int, S_IRUGO);
+#ifdef LIRC_IT87_DIGIMATRIX
+MODULE_PARM_DESC(it87_freq,
+    "Carrier demodulator frequency (kHz), (default: 36)");
+#else
+MODULE_PARM_DESC(it87_freq,
+    "Carrier demodulator frequency (kHz), (default: 38)");
+#endif

drivers/staging/lirc/lirc_it87.h

+/* lirc_it87.h */
+/* SECTION: Definitions */
+
+/********************************* ITE IT87xx ************************/
+
+/* based on the following documentation from ITE:
+   a) IT8712F Preliminary CIR Programming Guide V0.1
+   b) IT8705F Simple LPC I/O Preliminary Specification V0.3
+   c) IT8712F EC-LPC I/O Preliminary Specification V0.5
+*/
+
+/* IT8712/05 Ports: */
+#define IT87_ADRPORT      0x2e
+#define IT87_DATAPORT     0x2f
+#define IT87_INIT         {0x87, 0x01, 0x55, 0x55}
+
+/* alternate Ports: */
+/*
+#define IT87_ADRPORT      0x4e
+#define IT87_DATAPORT     0x4f
+#define IT87_INIT         {0x87, 0x01, 0x55, 0xaa}
+ */
+
+/* IT8712/05 Registers */
+#define IT87_CFGCTRL      0x2
+#define IT87_LDN          0x7
+#define IT87_CHIP_ID1     0x20
+#define IT87_CHIP_ID2     0x21
+#define IT87_CFG_VERSION  0x22
+#define IT87_SWSUSPEND    0x23
+
+#define IT8712_CIR_LDN    0xa
+#define IT8705_CIR_LDN    0x7
+
+/* CIR Configuration Registers: */
+#define IT87_CIR_ACT      0x30
+#define IT87_CIR_BASE_MSB 0x60
+#define IT87_CIR_BASE_LSB 0x61
+#define IT87_CIR_IRQ      0x70
+#define IT87_CIR_CONFIG   0xf0
+
+/* List of IT87_CIR registers: offset to BaseAddr */
+#define IT87_CIR_DR   0
+#define IT87_CIR_IER  1
+#define IT87_CIR_RCR  2
+#define IT87_CIR_TCR1 3
+#define IT87_CIR_TCR2 4
+#define IT87_CIR_TSR  5
+#define IT87_CIR_RSR  6
+#define IT87_CIR_BDLR 5
+#define IT87_CIR_BDHR 6
+#define IT87_CIR_IIR  7
+
+/* Bit Definition */
+/* IER: */
+#define IT87_CIR_IER_TM_EN   0x80
+#define IT87_CIR_IER_RESEVED 0x40
+#define IT87_CIR_IER_RESET   0x20
+#define IT87_CIR_IER_BR      0x10
+#define IT87_CIR_IER_IEC     0x8
+#define IT87_CIR_IER_RFOIE   0x4
+#define IT87_CIR_IER_RDAIE   0x2
+#define IT87_CIR_IER_TLDLIE  0x1
+
+/* RCR: */
+#define IT87_CIR_RCR_RDWOS  0x80
+#define IT87_CIR_RCR_HCFS   0x40
+#define IT87_CIR_RCR_RXEN   0x20
+#define IT87_CIR_RCR_RXEND  0x10
+#define IT87_CIR_RCR_RXACT  0x8
+#define IT87_CIR_RCR_RXDCR  0x7
+
+/* TCR1: */
+#define IT87_CIR_TCR1_FIFOCLR 0x80
+#define IT87_CIR_TCR1_ILE     0x40
+#define IT87_CIR_TCR1_FIFOTL  0x30
+#define IT87_CIR_TCR1_TXRLE   0x8
+#define IT87_CIR_TCR1_TXENDF  0x4
+#define IT87_CIR_TCR1_TXMPM   0x3
+
+/* TCR2: */
+#define IT87_CIR_TCR2_CFQ   0xf8
+#define IT87_CIR_TCR2_TXMPW 0x7
+
+/* TSR: */
+#define IT87_CIR_TSR_RESERVED 0xc0
+#define IT87_CIR_TSR_TXFBC    0x3f
+
+/* RSR: */
+#define IT87_CIR_RSR_RXFTO    0x80
+#define IT87_CIR_RSR_RESERVED 0x40
+#define IT87_CIR_RSR_RXFBC    0x3f
+
+/* IIR: */
+#define IT87_CIR_IIR_RESERVED 0xf8
+#define IT87_CIR_IIR_IID      0x6
+#define IT87_CIR_IIR_IIP      0x1
+
+/* TM: */
+#define IT87_CIR_TM_IL_SEL    0x80
+#define IT87_CIR_TM_RESERVED  0x40
+#define IT87_CIR_TM_TM_REG    0x3f
+
+#define IT87_CIR_FIFO_SIZE 32
+
+/* Baudratedivisor for IT87: power of 2: only 1,2,4 or 8) */
+#define IT87_CIR_BAUDRATE_DIVISOR 0x1
+#define IT87_CIR_DEFAULT_IOBASE 0x310
+#define IT87_CIR_DEFAULT_IRQ    0x7
+#define IT87_CIR_SPACE 0x00
+#define IT87_CIR_PULSE 0xff
+#define IT87_CIR_FREQ_MIN 27
+#define IT87_CIR_FREQ_MAX 58
+#define TIME_CONST (IT87_CIR_BAUDRATE_DIVISOR * 8000000ul / 115200ul)
+
+/********************************* ITE IT87xx ************************/