Re: [PATCH v3 1/2] [media] serial_ir: port lirc_serial to rc-core

[Sean Young <sean@mess.org>]

On Mon, Nov 21, 2016 at 02:28:08PM -0200, Mauro Carvalho Chehab wrote:
> Em Fri, 11 Nov 2016 23:13:06 +0000
> Sean Young <sean@mess.org> escreveu:
> 
> > Tested with a homebrew serial ir. Remove last remmants of the nslu2
> > which could not be enabled.
> 
> Thanks for this! It is really nice to see any efforts on moving the drivers
> under staging. 

Unfortunately some of the hardware is hard to track down. I've got my eyes
on ebay, but if anyone can help me out with:

- Sasem OnAir VFD/IR (Dign HV5 or D.Vine 5 HTPC IR/VFD) (lirc_sasem)
- lirc parallel (lirc_parallel)
- Original iMon SoundGraph IR receiver/display (lirc_imon)

I would appreciate it and I can work on getting the drivers out of staging.

> IMHO, it is almost ready for upstream merge, but I would prefer if you
> could do all changes, in incremental patches, on the driver at
> drivers/staging/media/lirc/lirc_serial.c, doing the module rename
> (together with Kconfig/Makefile/MAINTAINERS change) on the last one. 

That is better, I've reworked it.

> That makes my life a way easier, as I'll only need to review the final
> patch, not caring about the intermediate ones (except for compilation test).

New patch series ready to be sent and tested at each commit.

> I have a few nitpicks here, plus one more serious issue: don't use
> udelay() for very long times. See below.

Thanks!
> 
> > 
> > Signed-off-by: Sean Young <sean@mess.org>
> > ---
> >  MAINTAINERS                              |    6 +
> >  drivers/media/rc/Kconfig                 |   17 +
> >  drivers/media/rc/Makefile                |    1 +
> >  drivers/media/rc/serial_ir.c             | 1003 ++++++++++++++++++++++++++
> >  drivers/staging/media/lirc/Kconfig       |   13 -
> >  drivers/staging/media/lirc/Makefile      |    1 -
> >  drivers/staging/media/lirc/lirc_serial.c | 1130 ------------------------------
> >  7 files changed, 1027 insertions(+), 1144 deletions(-)
> >  create mode 100644 drivers/media/rc/serial_ir.c
> >  delete mode 100644 drivers/staging/media/lirc/lirc_serial.c
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 93e9f42..cd8fd50 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -10604,6 +10604,12 @@ S:	Maintained
> >  F:	Documentation/devicetree/bindings/serial/
> >  F:	drivers/tty/serial/
> >  
> > +SERIAL IR RECEIVER
> > +M:	Sean Young <sean@mess.org>
> > +L:	linux-media@vger.kernel.org
> > +S:	Maintained
> > +F:	drivers/media/rc/serial_ir.c
> > +
> >  STI CEC DRIVER
> >  M:	Benjamin Gaignard <benjamin.gaignard@linaro.org>
> >  L:	kernel@stlinux.com
> > diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
> > index 370e16e..629e8ca 100644
> > --- a/drivers/media/rc/Kconfig
> > +++ b/drivers/media/rc/Kconfig
> > @@ -389,4 +389,21 @@ config IR_SUNXI
> >  	   To compile this driver as a module, choose M here: the module will
> >  	   be called sunxi-ir.
> >  
> > +config IR_SERIAL
> > +	tristate "Homebrew Serial Port Receiver"
> > +	depends on RC_CORE
> > +	---help---
> > +	   Say Y if you want to use Homebrew Serial Port Receivers and
> > +	   Transceivers.
> > +
> > +	   To compile this driver as a module, choose M here: the module will
> > +	   be called serial-ir.
> > +
> > +config IR_SERIAL_TRANSMITTER
> > +	bool "Serial Port Transmitter"
> > +	default y
> > +	depends on IR_SERIAL
> > +	---help---
> > +	   Serial Port Transmitter support
> > +
> >  endif #RC_DEVICES
> > diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
> > index 379a5c0..3a984ee 100644
> > --- a/drivers/media/rc/Makefile
> > +++ b/drivers/media/rc/Makefile
> > @@ -37,3 +37,4 @@ obj-$(CONFIG_IR_TTUSBIR) += ttusbir.o
> >  obj-$(CONFIG_RC_ST) += st_rc.o
> >  obj-$(CONFIG_IR_SUNXI) += sunxi-cir.o
> >  obj-$(CONFIG_IR_IMG) += img-ir/
> > +obj-$(CONFIG_IR_SERIAL) += serial_ir.o
> > diff --git a/drivers/media/rc/serial_ir.c b/drivers/media/rc/serial_ir.c
> > new file mode 100644
> > index 0000000..378ae09
> > --- /dev/null
> > +++ b/drivers/media/rc/serial_ir.c
> > @@ -0,0 +1,1003 @@
> > +/*
> > + * 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.
> > + */
> > +
> > +/*
> > + * 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 IR_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
> > + */
> > +
> > +#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>
> > +
> > +#define DRIVER_NAME "serial_ir"
> 
> Why not use KBUILD_MODNAME instead?

Good point.
> 
> > +
> > +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;
> > +	long (*send_pulse)(unsigned long length);
> > +	void (*send_space)(long length);
> > +	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 ***/
> 
> Nitpick: please use:
> 	/* module parameters */
> 
> too fit at the Kernel's coding style.
> 
> Also, this could cause kernel-doc to do something wrong, if we ever
> add this file to Documentation.

I'll fix it.

> > +static int type;
> > +static int io;
> > +static int irq;
> > +static bool 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 long send_pulse_irdeo(unsigned long length);
> > +static void send_space_irdeo(long length);
> > +#ifdef CONFIG_IR_SERIAL_TRANSMITTER
> > +static long send_pulse_homebrew(unsigned long length);
> > +static void send_space_homebrew(long length);
> > +#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),
> > +		.send_pulse = NULL,
> > +		.send_space = NULL,
> > +	},
> > +
> > +	[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;
> > +
> > +	unsigned int freq;
> > +	unsigned int duty_cycle;
> > +
> > +	unsigned long period;
> > +	unsigned long pulse_width, space_width;
> > +};
> > +
> > +static struct serial_ir serial_ir;
> > +
> > +#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 IR_SERIAL_TRANSMITTER_LATENCY 450
> > +
> > +#else
> > +
> > +/* does anybody have information on other platforms ? */
> > +/* 256 = 1<<8 */
> > +#define IR_SERIAL_TRANSMITTER_LATENCY 256
> > +
> > +#endif	/* __i386__ */
> > +/*
> > + * FIXME: should we be using hrtimers instead of this
> > + * IR_SERIAL_TRANSMITTER_LATENCY nonsense?
> > + */
> 
> This all above is hacky, but you fixed on patch 2, so, I'm OK.

In the next series this will be patched in staging as you suggested.

> > +
> > +/* 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);
> > +}
> > +
> > +#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);
> > +}
> 
> That seems a hack to avoid warnings. Instead, use usleep_range()
> when you need to wait for more than MAX_UDELAY_US, as the high
> precision clock is OK when the delay is bigger than 5 ms.
> 
> Actually, it could make sense to use usleep_range() when the
> delay is bigger than 10 us, according with:
> 
> 	Documentation/timers/timers-howto.txt

Aha! I thought about using hrtimers, and kept that as "something to do in
the future". Using usleep_range() is much nicer and simpler indeed.

> 
> > +
> > +#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
> > + */
> > +
> > +static int init_timing_params(unsigned int new_duty_cycle,
> > +		unsigned int new_freq)
> > +{
> > +	__u64 loops_per_sec, work;
> > +
> > +	serial_ir.duty_cycle = new_duty_cycle;
> > +	serial_ir.freq = new_freq;
> > +
> > +	loops_per_sec = __this_cpu_read(cpu.info.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 */
> > +
> > +	/*
> > +	 * Carrier period in clocks, approach good up to 32GHz clock,
> > +	 * gets carrier frequency within 8Hz
> > +	 */
> > +	serial_ir.period = loops_per_sec >> 3;
> > +	serial_ir.pperiod /= (freq >> 3);
> > +
> > +	/* Derive pulse and space from the period */
> > +	serial_ir.ppulse_width = serial_ir.period * serial.ir.duty_cycle / 100;
> > +	serial_ir.pspace_width = serial_ir.period - serial_ir.pulse_width;
> > +	pr_debug("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, __this_cpu_read(cpu_info.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 <=
> > +	    IR_SERIAL_TRANSMITTER_LATENCY)
> > +		return -EINVAL;
> > +	if (256 * 1000000L / new_freq * (100 - new_duty_cycle) / 100 <=
> > +	    IR_SERIAL_TRANSMITTER_LATENCY)
> > +		return -EINVAL;
> > +	serial_ir.duty_cycle = new_duty_cycle;
> > +	serial_ir.freq = new_freq;
> > +	serial_ir.period = 256 * 1000000L / serial_ir.freq;
> > +	serial_ir.pulse_width = serial_ir.period * serial_ir.duty_cycle / 100;
> > +	serial_ir.space_width = serial_ir.period - serial_ir.pulse_width;
> > +	pr_debug("in init_timing_params, freq=%d pulse=%ld, space=%ld\n",
> > +				serial_ir.freq, serial_ir.pulse_width,
> > +				serial_ir.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 (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))
> > +			;
> > +	}
> > +
> > +	if (i == 0)
> > +		ret = (-rawbits) * 10000 / 1152;
> > +	else
> > +		ret = (3 - i) * 3 * 10000 / 1152 + (-rawbits) * 10000 / 1152;
> > +
> > +	return ret;
> > +}
> > +
> > +/* 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
> > + *
> > + * This should use ndelay instead.
> > + */
> > +
> > +/* To match 8 fractional bits used for pulse/space length */
> > +
> > +static void send_space_irdeo(long length)
> > +{
> > +	if (length <= 0)
> > +		return;
> > +
> > +	safe_udelay(length);
> > +}
> > +
> > +#ifdef CONFIG_IR_SERIAL_TRANSMITTER
> > +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 += serial_ir.space_width;
> > +		} else {
> > +			on();
> > +			target += serial_ir.pulse_width;
> > +		}
> > +		d = (target - actual -
> > +		     IR_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) + IR_SERIAL_TRANSMITTER_LATENCY;
> > +		flag = !flag;
> > +	}
> > +	return (actual-length) >> 8;
> > +}
> > +
> > +static long send_pulse_homebrew(unsigned long length)
> > +{
> > +	if (length <= 0)
> > +		return 0;
> > +
> > +	if (softcarrier)
> > +		return send_pulse_homebrew_softcarrier(length);
> > +
> > +	on();
> > +	safe_udelay(length);
> > +	return 0;
> > +}
> > +
> > +static void send_space_homebrew(long length)
> > +{
> > +	off();
> > +	if (length <= 0)
> > +		return;
> > +	safe_udelay(length);
> > +}
> > +#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;
> > +			ir_raw_event_handle(serial_ir.rcdev);
> > +		}
> > +	} 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 */
> > +		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 int serial_ir_probe(struct platform_device *dev)
> > +{
> > +	int i, nlow, nhigh, result;
> > +
> > +	result = devm_request_irq(&dev->dev, irq, serial_ir_irq_handler,
> > +			     (share_irq ? IRQF_SHARED : 0),
> > +			     DRIVER_NAME, &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,
> > +					 DRIVER_NAME) == NULL))
> > +	   || ((!iommap)
> > +	       && (devm_request_region(&dev->dev, io, 8,
> > +				       DRIVER_NAME) == 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 */
> > +	init_timing_params(50, 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 0;
> > +}
> > +
> > +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;
> > +	long delta = 0;
> > +	int i;
> > +
> > +	spin_lock_irqsave(&hardware[type].lock, flags);
> > +	if (type == IR_IRDEO) {
> > +		/* DTR, RTS down */
> > +		on();
> > +	}
> > +	for (i = 0; i < count; i++) {
> > +		if (i%2)
> > +			hardware[type].send_space(txbuf[i] - delta);
> > +		else
> > +			delta = hardware[type].send_pulse(txbuf[i]);
> > +	}
> > +	off();
> > +	spin_unlock_irqrestore(&hardware[type].lock, flags);
> > +	return count;
> > +}
> > +
> > +static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle)
> > +{
> > +	return init_timing_params(cycle, serial_ir.freq);
> > +}
> > +
> > +static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier)
> > +{
> > +	if (carrier > 500000 || carrier < 20000)
> > +		return -EINVAL;
> > +
> > +	return init_timing_params(serial_ir.duty_cycle, carrier);
> > +}
> > +
> > +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)
> > +{
> > +	struct rc_dev *rcdev;
> > +	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 result;
> > +
> > +	rcdev = devm_rc_allocate_device(&serial_ir.pdev->dev);
> > +	if (!rcdev) {
> > +		result = -ENOMEM;
> > +		goto serial_cleanup;
> > +	}
> > +
> > +	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->input_name = "Serial IR type home-brew";
> > +		break;
> > +	case IR_IRDEO:
> > +		rcdev->input_name = "Serial IR type IRdeo";
> > +		break;
> > +	case IR_IRDEO_REMOTE:
> > +		rcdev->input_name = "Serial IR type IRdeo remote";
> > +		break;
> > +	case IR_ANIMAX:
> > +		rcdev->input_name = "Serial IR type AnimaX";
> > +		break;
> > +	case IR_IGOR:
> > +		rcdev->input_name = "Serial IR type IgorPlug";
> > +		break;
> > +	}
> > +
> > +	rcdev->input_phys = DRIVER_NAME "/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->driver_type = RC_DRIVER_IR_RAW;
> > +	rcdev->allowed_protocols = RC_BIT_ALL;
> > +	rcdev->driver_name = DRIVER_NAME;
> > +	rcdev->map_name = RC_MAP_RC6_MCE;
> > +	rcdev->timeout = IR_DEFAULT_TIMEOUT;
> > +	rcdev->rx_resolution = 250000;
> > +
> > +	serial_ir.rcdev = rcdev;
> > +
> > +	result = rc_register_device(rcdev);
> > +
> > +	if (!result)
> > +		return 0;
> > +serial_cleanup:
> > +	serial_ir_exit();
> > +	return result;
> > +}
> > +
> > +static void __exit serial_ir_exit_module(void)
> > +{
> > +	rc_unregister_device(serial_ir.rcdev);
> > +	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(io, int, 0444);
> > +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, 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(ioshift, int, 0444);
> > +MODULE_PARM_DESC(ioshift, "shift I/O register offset (0 = no shift)");
> > +
> > +module_param(irq, int, 0444);
> > +MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
> > +
> > +module_param(share_irq, bool, 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)");
> > diff --git a/drivers/staging/media/lirc/Kconfig b/drivers/staging/media/lirc/Kconfig
> > index 6879c46..25b7e7c 100644
> > --- a/drivers/staging/media/lirc/Kconfig
> > +++ b/drivers/staging/media/lirc/Kconfig
> > @@ -38,19 +38,6 @@ config LIRC_SASEM
> >  	help
> >  	  Driver for the Sasem OnAir Remocon-V or Dign HV5 HTPC IR/VFD Module
> >  
> > -config LIRC_SERIAL
> > -	tristate "Homebrew Serial Port Receiver"
> > -	depends on LIRC
> > -	help
> > -	  Driver for Homebrew Serial Port Receivers
> > -
> > -config LIRC_SERIAL_TRANSMITTER
> > -	bool "Serial Port Transmitter"
> > -	default y
> > -	depends on LIRC_SERIAL
> > -	help
> > -	  Serial Port Transmitter support
> > -
> >  config LIRC_SIR
> >  	tristate "Built-in SIR IrDA port"
> >  	depends on LIRC
> > diff --git a/drivers/staging/media/lirc/Makefile b/drivers/staging/media/lirc/Makefile
> > index 5430adf..7f919ea 100644
> > --- a/drivers/staging/media/lirc/Makefile
> > +++ b/drivers/staging/media/lirc/Makefile
> > @@ -7,6 +7,5 @@ obj-$(CONFIG_LIRC_BT829)	+= lirc_bt829.o
> >  obj-$(CONFIG_LIRC_IMON)		+= lirc_imon.o
> >  obj-$(CONFIG_LIRC_PARALLEL)	+= lirc_parallel.o
> >  obj-$(CONFIG_LIRC_SASEM)	+= lirc_sasem.o
> > -obj-$(CONFIG_LIRC_SERIAL)	+= lirc_serial.o
> >  obj-$(CONFIG_LIRC_SIR)		+= lirc_sir.o
> >  obj-$(CONFIG_LIRC_ZILOG)	+= lirc_zilog.o
> > diff --git a/drivers/staging/media/lirc/lirc_serial.c b/drivers/staging/media/lirc/lirc_serial.c
> > deleted file mode 100644
> > index b798b31..0000000
> > --- a/drivers/staging/media/lirc/lirc_serial.c
> > +++ /dev/null
> > @@ -1,1130 +0,0 @@
> > -/*
> > - * 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
> > - */
> > -
> > -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> > -
> > -#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/ktime.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 <linux/gpio.h>
> > -#include <linux/io.h>
> > -#include <linux/irq.h>
> > -#include <linux/fcntl.h>
> > -#include <linux/spinlock.h>
> > -
> > -/* 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 bool 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 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] = {
> > -		.lock = __SPIN_LOCK_UNLOCKED(hardware[LIRC_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),
> > -		.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] = {
> > -		.lock = __SPIN_LOCK_UNLOCKED(hardware[LIRC_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,
> > -		.features    = (LIRC_CAN_SET_SEND_DUTY_CYCLE |
> > -				LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2)
> > -	},
> > -
> > -	[LIRC_IRDEO_REMOTE] = {
> > -		.lock = __SPIN_LOCK_UNLOCKED(hardware[LIRC_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,
> > -		.features    = (LIRC_CAN_SET_SEND_DUTY_CYCLE |
> > -				LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2)
> > -	},
> > -
> > -	[LIRC_ANIMAX] = {
> > -		.lock = __SPIN_LOCK_UNLOCKED(hardware[LIRC_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),
> > -		.send_pulse = NULL,
> > -		.send_space = NULL,
> > -		.features   = LIRC_CAN_REC_MODE2
> > -	},
> > -
> > -	[LIRC_IGOR] = {
> > -		.lock = __SPIN_LOCK_UNLOCKED(hardware[LIRC_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),
> > -		.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
> > -	},
> > -};
> > -
> > -#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 ktime_t lastkt;
> > -
> > -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)
> > -		/* 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);
> > -}
> > -
> > -#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
> > - */
> > -
> > -static int init_timing_params(unsigned int new_duty_cycle,
> > -		unsigned int new_freq)
> > -{
> > -	__u64 loops_per_sec, work;
> > -
> > -	duty_cycle = new_duty_cycle;
> > -	freq = new_freq;
> > -
> > -	loops_per_sec = __this_cpu_read(cpu.info.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 */
> > -
> > -	/*
> > -	 * 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;
> > -	pr_debug("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, __this_cpu_read(cpu_info.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;
> > -	pr_debug("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;
> > -}
> > -
> > -/* 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
> > - *
> > - * This should use ndelay instead.
> > - */
> > -
> > -/* 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;
> > -}
> > -
> > -static long send_pulse_homebrew(unsigned long length)
> > -{
> > -	if (length <= 0)
> > -		return 0;
> > -
> > -	if (softcarrier)
> > -		return send_pulse_homebrew_softcarrier(length);
> > -
> > -	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 */
> > -		pr_debug("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 lirc_irq_handler(int i, void *blah)
> > -{
> > -	ktime_t kt;
> > -	int counter, dcd;
> > -	u8 status;
> > -	ktime_t delkt;
> > -	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) {
> > -			pr_warn("AIEEEE: We're caught!\n");
> > -			break;
> > -		}
> > -		if ((status & hardware[type].signal_pin_change)
> > -		    && sense != -1) {
> > -			/* get current time */
> > -			kt = ktime_get();
> > -
> > -			/* 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) {
> > -				pr_warn("ignoring spike: %d %d %llx %llx\n",
> > -					dcd, sense, ktime_to_us(kt),
> > -					ktime_to_us(lastkt));
> > -				continue;
> > -			}
> > -
> > -			delkt = ktime_sub(kt, lastkt);
> > -			if (ktime_compare(delkt, ktime_set(15, 0)) > 0) {
> > -				data = PULSE_MASK; /* really long time */
> > -				if (!(dcd^sense)) {
> > -					/* sanity check */
> > -					pr_warn("AIEEEE: %d %d %llx %llx\n",
> > -						dcd, sense, ktime_to_us(kt),
> > -						ktime_to_us(lastkt));
> > -					/*
> > -					 * detecting pulse while this
> > -					 * MUST be a space!
> > -					 */
> > -					sense = sense ? 0 : 1;
> > -				}
> > -			} else
> > -				data = (int) ktime_to_us(delkt);
> > -			frbwrite(dcd^sense ? data : (data|PULSE_BIT));
> > -			lastkt = kt;
> > -			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 */
> > -		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 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 lirc_serial_probe(struct platform_device *dev)
> > -{
> > -	int i, nlow, nhigh, result;
> > -
> > -	result = devm_request_irq(&dev->dev, irq, lirc_irq_handler,
> > -			     (share_irq ? IRQF_SHARED : 0),
> > -			     LIRC_DRIVER_NAME, &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. */
> > -	/*
> > -	 * 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)
> > -	     && (devm_request_mem_region(&dev->dev, iommap, 8 << ioshift,
> > -					 LIRC_DRIVER_NAME) == NULL))
> > -	   || ((!iommap)
> > -	       && (devm_request_region(&dev->dev, io, 8,
> > -				       LIRC_DRIVER_NAME) == 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 */
> > -	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;
> > -		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 0;
> > -}
> > -
> > -static int set_use_inc(void *data)
> > -{
> > -	unsigned long flags;
> > -
> > -	/* initialize timestamp */
> > -	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 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);
> > -}
> > -
> > -static ssize_t lirc_write(struct file *file, const char __user *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 -EPERM;
> > -
> > -	count = n / sizeof(int);
> > -	if (n % sizeof(int) || count % 2 == 0)
> > -		return -EINVAL;
> > -	wbuf = memdup_user(buf, n);
> > -	if (IS_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);
> > -	kfree(wbuf);
> > -	return n;
> > -}
> > -
> > -static long lirc_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
> > -{
> > -	int result;
> > -	u32 __user *uptr = (u32 __user *)arg;
> > -	u32 value;
> > -
> > -	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),
> > -				  uptr);
> > -		if (result)
> > -			return result;
> > -		break;
> > -
> > -	case LIRC_SET_SEND_MODE:
> > -		if (!(hardware[type].features&LIRC_CAN_SEND_MASK))
> > -			return -ENOIOCTLCMD;
> > -
> > -		result = get_user(value, uptr);
> > -		if (result)
> > -			return result;
> > -		/* only LIRC_MODE_PULSE supported */
> > -		if (value != LIRC_MODE_PULSE)
> > -			return -EINVAL;
> > -		break;
> > -
> > -	case LIRC_GET_LENGTH:
> > -		return -ENOIOCTLCMD;
> > -
> > -	case LIRC_SET_SEND_DUTY_CYCLE:
> > -		pr_debug("SET_SEND_DUTY_CYCLE\n");
> > -		if (!(hardware[type].features&LIRC_CAN_SET_SEND_DUTY_CYCLE))
> > -			return -ENOIOCTLCMD;
> > -
> > -		result = get_user(value, uptr);
> > -		if (result)
> > -			return result;
> > -		if (value <= 0 || value > 100)
> > -			return -EINVAL;
> > -		return init_timing_params(value, freq);
> > -
> > -	case LIRC_SET_SEND_CARRIER:
> > -		pr_debug("SET_SEND_CARRIER\n");
> > -		if (!(hardware[type].features&LIRC_CAN_SET_SEND_CARRIER))
> > -			return -ENOIOCTLCMD;
> > -
> > -		result = get_user(value, uptr);
> > -		if (result)
> > -			return result;
> > -		if (value > 500000 || value < 20000)
> > -			return -EINVAL;
> > -		return init_timing_params(duty_cycle, value);
> > -
> > -	default:
> > -		return lirc_dev_fop_ioctl(filep, cmd, arg);
> > -	}
> > -	return 0;
> > -}
> > -
> > -static const struct file_operations lirc_fops = {
> > -	.owner		= THIS_MODULE,
> > -	.write		= lirc_write,
> > -	.unlocked_ioctl	= lirc_ioctl,
> > -#ifdef CONFIG_COMPAT
> > -	.compat_ioctl	= lirc_ioctl,
> > -#endif
> > -	.read		= lirc_dev_fop_read,
> > -	.poll		= lirc_dev_fop_poll,
> > -	.open		= lirc_dev_fop_open,
> > -	.release	= lirc_dev_fop_close,
> > -	.llseek		= no_llseek,
> > -};
> > -
> > -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 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;
> > -	int result;
> > -
> > -	result = hardware_init_port();
> > -	if (result < 0)
> > -		return result;
> > -
> > -	spin_lock_irqsave(&hardware[type].lock, flags);
> > -	/* Enable Interrupt */
> > -	lastkt = ktime_get();
> > -	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,
> > -	.suspend	= lirc_serial_suspend,
> > -	.resume		= lirc_serial_resume,
> > -	.driver		= {
> > -		.name	= "lirc_serial",
> > -	},
> > -};
> > -
> > -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 result;
> > -
> > -	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;
> > -
> > -	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;
> > -	default:
> > -		return -EINVAL;
> > -	}
> > -	if (!softcarrier) {
> > -		switch (type) {
> > -		case LIRC_HOMEBREW:
> > -		case LIRC_IGOR:
> > -			hardware[type].features &=
> > -				~(LIRC_CAN_SET_SEND_DUTY_CYCLE|
> > -				  LIRC_CAN_SET_SEND_CARRIER);
> > -			break;
> > -		}
> > -	}
> > -
> > -	/* make sure sense is either -1, 0, or 1 */
> > -	if (sense != -1)
> > -		sense = !!sense;
> > -
> > -	result = lirc_serial_init();
> > -	if (result)
> > -		return result;
> > -
> > -	driver.features = hardware[type].features;
> > -	driver.dev = &lirc_serial_dev->dev;
> > -	driver.minor = lirc_register_driver(&driver);
> > -	if (driver.minor < 0) {
> > -		pr_err("register_chrdev failed!\n");
> > -		lirc_serial_exit();
> > -		return driver.minor;
> > -	}
> > -	return 0;
> > -}
> > -
> > -static void __exit lirc_serial_exit_module(void)
> > -{
> > -	lirc_unregister_driver(driver.minor);
> > -	lirc_serial_exit();
> > -	pr_debug("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/drivers/tty/serial/8250/8250.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, int, 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)");

Thanks

Sean