blob: 96ae0294ac102a9238b5f9453c6185485343ebed [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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)
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/serial_reg.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <media/rc-core.h>
struct serial_ir_hw {
int signal_pin;
int signal_pin_change;
u8 on;
u8 off;
unsigned set_send_carrier:1;
unsigned set_duty_cycle:1;
void (*send_pulse)(unsigned int length, ktime_t edge);
void (*send_space)(void);
spinlock_t lock;
};
#define IR_HOMEBREW 0
#define IR_IRDEO 1
#define IR_IRDEO_REMOTE 2
#define IR_ANIMAX 3
#define IR_IGOR 4
/* module parameters */
static int type;
static int io;
static int irq;
static ulong iommap;
static int ioshift;
static bool softcarrier = true;
static bool share_irq;
static int sense = -1; /* -1 = auto, 0 = active high, 1 = active low */
static bool txsense; /* 0 = active high, 1 = active low */
/* forward declarations */
static void send_pulse_irdeo(unsigned int length, ktime_t edge);
static void send_space_irdeo(void);
#ifdef CONFIG_IR_SERIAL_TRANSMITTER
static void send_pulse_homebrew(unsigned int length, ktime_t edge);
static void send_space_homebrew(void);
#endif
static struct serial_ir_hw hardware[] = {
[IR_HOMEBREW] = {
.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_HOMEBREW].lock),
.signal_pin = UART_MSR_DCD,
.signal_pin_change = UART_MSR_DDCD,
.on = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
.off = (UART_MCR_RTS | UART_MCR_OUT2),
#ifdef CONFIG_IR_SERIAL_TRANSMITTER
.send_pulse = send_pulse_homebrew,
.send_space = send_space_homebrew,
.set_send_carrier = true,
.set_duty_cycle = true,
#endif
},
[IR_IRDEO] = {
.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO].lock),
.signal_pin = UART_MSR_DSR,
.signal_pin_change = UART_MSR_DDSR,
.on = UART_MCR_OUT2,
.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
.send_pulse = send_pulse_irdeo,
.send_space = send_space_irdeo,
.set_duty_cycle = true,
},
[IR_IRDEO_REMOTE] = {
.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO_REMOTE].lock),
.signal_pin = UART_MSR_DSR,
.signal_pin_change = UART_MSR_DDSR,
.on = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
.send_pulse = send_pulse_irdeo,
.send_space = send_space_irdeo,
.set_duty_cycle = true,
},
[IR_ANIMAX] = {
.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_ANIMAX].lock),
.signal_pin = UART_MSR_DCD,
.signal_pin_change = UART_MSR_DDCD,
.on = 0,
.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
},
[IR_IGOR] = {
.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IGOR].lock),
.signal_pin = UART_MSR_DSR,
.signal_pin_change = UART_MSR_DDSR,
.on = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
.off = (UART_MCR_RTS | UART_MCR_OUT2),
#ifdef CONFIG_IR_SERIAL_TRANSMITTER
.send_pulse = send_pulse_homebrew,
.send_space = send_space_homebrew,
.set_send_carrier = true,
.set_duty_cycle = true,
#endif
},
};
#define RS_ISR_PASS_LIMIT 256
struct serial_ir {
ktime_t lastkt;
struct rc_dev *rcdev;
struct platform_device *pdev;
struct timer_list timeout_timer;
unsigned int carrier;
unsigned int duty_cycle;
};
static struct serial_ir serial_ir;
/* fetch serial input packet (1 byte) from register offset */
static u8 sinp(int offset)
{
if (iommap)
/* the register is memory-mapped */
offset <<= ioshift;
return inb(io + offset);
}
/* write serial output packet (1 byte) of value to register offset */
static void soutp(int offset, u8 value)
{
if (iommap)
/* the register is memory-mapped */
offset <<= ioshift;
outb(value, io + offset);
}
static void on(void)
{
if (txsense)
soutp(UART_MCR, hardware[type].off);
else
soutp(UART_MCR, hardware[type].on);
}
static void off(void)
{
if (txsense)
soutp(UART_MCR, hardware[type].on);
else
soutp(UART_MCR, hardware[type].off);
}
static void send_pulse_irdeo(unsigned int length, ktime_t target)
{
long rawbits;
int i;
unsigned char output;
unsigned char chunk, shifted;
/* how many bits have to be sent ? */
rawbits = length * 1152 / 10000;
if (serial_ir.duty_cycle > 50)
chunk = 3;
else
chunk = 1;
for (i = 0, output = 0x7f; rawbits > 0; rawbits -= 3) {
shifted = chunk << (i * 3);
shifted >>= 1;
output &= (~shifted);
i++;
if (i == 3) {
soutp(UART_TX, output);
while (!(sinp(UART_LSR) & UART_LSR_THRE))
;
output = 0x7f;
i = 0;
}
}
if (i != 0) {
soutp(UART_TX, output);
while (!(sinp(UART_LSR) & UART_LSR_TEMT))
;
}
}
static void send_space_irdeo(void)
{
}
#ifdef CONFIG_IR_SERIAL_TRANSMITTER
static void send_pulse_homebrew_softcarrier(unsigned int length, ktime_t edge)
{
ktime_t now, target = ktime_add_us(edge, length);
/*
* delta should never exceed 4 seconds and on m68k
* ndelay(s64) does not compile; so use s32 rather than s64.
*/
s32 delta;
unsigned int pulse, space;
/* Ensure the dividend fits into 32 bit */
pulse = DIV_ROUND_CLOSEST(serial_ir.duty_cycle * (NSEC_PER_SEC / 100),
serial_ir.carrier);
space = DIV_ROUND_CLOSEST((100 - serial_ir.duty_cycle) *
(NSEC_PER_SEC / 100), serial_ir.carrier);
for (;;) {
now = ktime_get();
if (ktime_compare(now, target) >= 0)
break;
on();
edge = ktime_add_ns(edge, pulse);
delta = ktime_to_ns(ktime_sub(edge, now));
if (delta > 0)
ndelay(delta);
now = ktime_get();
off();
if (ktime_compare(now, target) >= 0)
break;
edge = ktime_add_ns(edge, space);
delta = ktime_to_ns(ktime_sub(edge, now));
if (delta > 0)
ndelay(delta);
}
}
static void send_pulse_homebrew(unsigned int length, ktime_t edge)
{
if (softcarrier)
send_pulse_homebrew_softcarrier(length, edge);
else
on();
}
static void send_space_homebrew(void)
{
off();
}
#endif
static void frbwrite(unsigned int l, bool is_pulse)
{
/* simple noise filter */
static unsigned int ptr, pulse, space;
struct ir_raw_event ev = {};
if (ptr > 0 && is_pulse) {
pulse += l;
if (pulse > 250) {
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 > 20000) {
space = l;
ptr++;
return;
}
} else {
if (l > 20000) {
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_dbg(&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_us(delkt);
}
frbwrite(data, !(dcd ^ sense));
serial_ir.lastkt = kt;
last_dcd = dcd;
}
} while (!(sinp(UART_IIR) & UART_IIR_NO_INT)); /* still pending ? */
mod_timer(&serial_ir.timeout_timer,
jiffies + usecs_to_jiffies(serial_ir.rcdev->timeout));
ir_raw_event_handle(serial_ir.rcdev);
return IRQ_HANDLED;
}
static int hardware_init_port(void)
{
u8 scratch, scratch2, scratch3;
/*
* This is a simple port existence test, borrowed from the autoconfig
* function in drivers/tty/serial/8250/8250_port.c
*/
scratch = sinp(UART_IER);
soutp(UART_IER, 0);
#ifdef __i386__
outb(0xff, 0x080);
#endif
scratch2 = sinp(UART_IER) & 0x0f;
soutp(UART_IER, 0x0f);
#ifdef __i386__
outb(0x00, 0x080);
#endif
scratch3 = sinp(UART_IER) & 0x0f;
soutp(UART_IER, scratch);
if (scratch2 != 0 || scratch3 != 0x0f) {
/* we fail, there's nothing here */
pr_err("port existence test failed, cannot continue\n");
return -ENODEV;
}
/* Set DLAB 0. */
soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
/* First of all, disable all interrupts */
soutp(UART_IER, sinp(UART_IER) &
(~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
/* Clear registers. */
sinp(UART_LSR);
sinp(UART_RX);
sinp(UART_IIR);
sinp(UART_MSR);
/* Set line for power source */
off();
/* Clear registers again to be sure. */
sinp(UART_LSR);
sinp(UART_RX);
sinp(UART_IIR);
sinp(UART_MSR);
switch (type) {
case IR_IRDEO:
case IR_IRDEO_REMOTE:
/* setup port to 7N1 @ 115200 Baud */
/* 7N1+start = 9 bits at 115200 ~ 3 bits at 38kHz */
/* Set DLAB 1. */
soutp(UART_LCR, sinp(UART_LCR) | UART_LCR_DLAB);
/* Set divisor to 1 => 115200 Baud */
soutp(UART_DLM, 0);
soutp(UART_DLL, 1);
/* Set DLAB 0 + 7N1 */
soutp(UART_LCR, UART_LCR_WLEN7);
/* THR interrupt already disabled at this point */
break;
default:
break;
}
return 0;
}
static void serial_ir_timeout(struct timer_list *unused)
{
struct ir_raw_event ev = {
.timeout = true,
.duration = serial_ir.rcdev->timeout
};
ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
ir_raw_event_handle(serial_ir.rcdev);
}
/* Needed by serial_ir_probe() */
static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
unsigned int count);
static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle);
static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier);
static int serial_ir_open(struct rc_dev *rcdev);
static void serial_ir_close(struct rc_dev *rcdev);
static int serial_ir_probe(struct platform_device *dev)
{
struct rc_dev *rcdev;
int i, nlow, nhigh, result;
rcdev = devm_rc_allocate_device(&dev->dev, RC_DRIVER_IR_RAW);
if (!rcdev)
return -ENOMEM;
if (hardware[type].send_pulse && hardware[type].send_space)
rcdev->tx_ir = serial_ir_tx;
if (hardware[type].set_send_carrier)
rcdev->s_tx_carrier = serial_ir_tx_carrier;
if (hardware[type].set_duty_cycle)
rcdev->s_tx_duty_cycle = serial_ir_tx_duty_cycle;
switch (type) {
case IR_HOMEBREW:
rcdev->device_name = "Serial IR type home-brew";
break;
case IR_IRDEO:
rcdev->device_name = "Serial IR type IRdeo";
break;
case IR_IRDEO_REMOTE:
rcdev->device_name = "Serial IR type IRdeo remote";
break;
case IR_ANIMAX:
rcdev->device_name = "Serial IR type AnimaX";
break;
case IR_IGOR:
rcdev->device_name = "Serial IR type IgorPlug";
break;
}
rcdev->input_phys = KBUILD_MODNAME "/input0";
rcdev->input_id.bustype = BUS_HOST;
rcdev->input_id.vendor = 0x0001;
rcdev->input_id.product = 0x0001;
rcdev->input_id.version = 0x0100;
rcdev->open = serial_ir_open;
rcdev->close = serial_ir_close;
rcdev->dev.parent = &serial_ir.pdev->dev;
rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
rcdev->driver_name = KBUILD_MODNAME;
rcdev->map_name = RC_MAP_RC6_MCE;
rcdev->min_timeout = 1;
rcdev->timeout = IR_DEFAULT_TIMEOUT;
rcdev->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
rcdev->rx_resolution = 250;
serial_ir.rcdev = rcdev;
timer_setup(&serial_ir.timeout_timer, serial_ir_timeout, 0);
result = devm_request_irq(&dev->dev, irq, serial_ir_irq_handler,
share_irq ? IRQF_SHARED : 0,
KBUILD_MODNAME, &hardware);
if (result < 0) {
if (result == -EBUSY)
dev_err(&dev->dev, "IRQ %d busy\n", irq);
else if (result == -EINVAL)
dev_err(&dev->dev, "Bad irq number or handler\n");
return result;
}
/* Reserve io region. */
if ((iommap &&
(devm_request_mem_region(&dev->dev, iommap, 8UL << ioshift,
KBUILD_MODNAME) == NULL)) ||
(!iommap && (devm_request_region(&dev->dev, io, 8,
KBUILD_MODNAME) == NULL))) {
dev_err(&dev->dev, "port %04x already in use\n", io);
dev_warn(&dev->dev, "use 'setserial /dev/ttySX uart none'\n");
dev_warn(&dev->dev,
"or compile the serial port driver as module and\n");
dev_warn(&dev->dev, "make sure this module is loaded first\n");
return -EBUSY;
}
result = hardware_init_port();
if (result < 0)
return result;
/* Initialize pulse/space widths */
serial_ir.duty_cycle = 50;
serial_ir.carrier = 38000;
/* If pin is high, then this must be an active low receiver. */
if (sense == -1) {
/* wait 1/2 sec for the power supply */
msleep(500);
/*
* probe 9 times every 0.04s, collect "votes" for
* active high/low
*/
nlow = 0;
nhigh = 0;
for (i = 0; i < 9; i++) {
if (sinp(UART_MSR) & hardware[type].signal_pin)
nlow++;
else
nhigh++;
msleep(40);
}
sense = nlow >= nhigh ? 1 : 0;
dev_info(&dev->dev, "auto-detected active %s receiver\n",
sense ? "low" : "high");
} else
dev_info(&dev->dev, "Manually using active %s receiver\n",
sense ? "low" : "high");
dev_dbg(&dev->dev, "Interrupt %d, port %04x obtained\n", irq, io);
return devm_rc_register_device(&dev->dev, rcdev);
}
static int serial_ir_open(struct rc_dev *rcdev)
{
unsigned long flags;
/* initialize timestamp */
serial_ir.lastkt = ktime_get();
spin_lock_irqsave(&hardware[type].lock, flags);
/* Set DLAB 0. */
soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);
spin_unlock_irqrestore(&hardware[type].lock, flags);
return 0;
}
static void serial_ir_close(struct rc_dev *rcdev)
{
unsigned long flags;
spin_lock_irqsave(&hardware[type].lock, flags);
/* Set DLAB 0. */
soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
/* First of all, disable all interrupts */
soutp(UART_IER, sinp(UART_IER) &
(~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
spin_unlock_irqrestore(&hardware[type].lock, flags);
}
static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
unsigned int count)
{
unsigned long flags;
ktime_t edge;
s64 delta;
int i;
spin_lock_irqsave(&hardware[type].lock, flags);
if (type == IR_IRDEO) {
/* DTR, RTS down */
on();
}
edge = ktime_get();
for (i = 0; i < count; i++) {
if (i % 2)
hardware[type].send_space();
else
hardware[type].send_pulse(txbuf[i], edge);
edge = ktime_add_us(edge, txbuf[i]);
delta = ktime_us_delta(edge, ktime_get());
if (delta > 25) {
spin_unlock_irqrestore(&hardware[type].lock, flags);
usleep_range(delta - 25, delta + 25);
spin_lock_irqsave(&hardware[type].lock, flags);
} else if (delta > 0) {
udelay(delta);
}
}
off();
spin_unlock_irqrestore(&hardware[type].lock, flags);
return count;
}
static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle)
{
serial_ir.duty_cycle = cycle;
return 0;
}
static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier)
{
if (carrier > 500000 || carrier < 20000)
return -EINVAL;
serial_ir.carrier = carrier;
return 0;
}
static int serial_ir_suspend(struct platform_device *dev,
pm_message_t state)
{
/* Set DLAB 0. */
soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
/* Disable all interrupts */
soutp(UART_IER, sinp(UART_IER) &
(~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
/* Clear registers. */
sinp(UART_LSR);
sinp(UART_RX);
sinp(UART_IIR);
sinp(UART_MSR);
return 0;
}
static int serial_ir_resume(struct platform_device *dev)
{
unsigned long flags;
int result;
result = hardware_init_port();
if (result < 0)
return result;
spin_lock_irqsave(&hardware[type].lock, flags);
/* Enable Interrupt */
serial_ir.lastkt = ktime_get();
soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);
off();
spin_unlock_irqrestore(&hardware[type].lock, flags);
return 0;
}
static struct platform_driver serial_ir_driver = {
.probe = serial_ir_probe,
.suspend = serial_ir_suspend,
.resume = serial_ir_resume,
.driver = {
.name = "serial_ir",
},
};
static int __init serial_ir_init(void)
{
int result;
result = platform_driver_register(&serial_ir_driver);
if (result)
return result;
serial_ir.pdev = platform_device_alloc("serial_ir", 0);
if (!serial_ir.pdev) {
result = -ENOMEM;
goto exit_driver_unregister;
}
result = platform_device_add(serial_ir.pdev);
if (result)
goto exit_device_put;
return 0;
exit_device_put:
platform_device_put(serial_ir.pdev);
exit_driver_unregister:
platform_driver_unregister(&serial_ir_driver);
return result;
}
static void serial_ir_exit(void)
{
platform_device_unregister(serial_ir.pdev);
platform_driver_unregister(&serial_ir_driver);
}
static int __init serial_ir_init_module(void)
{
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;
return serial_ir_init();
}
static void __exit serial_ir_exit_module(void)
{
del_timer_sync(&serial_ir.timeout_timer);
serial_ir_exit();
}
module_init(serial_ir_init_module);
module_exit(serial_ir_exit_module);
MODULE_DESCRIPTION("Infra-red receiver driver for serial ports.");
MODULE_AUTHOR("Ralph Metzler, Trent Piepho, Ben Pfaff, Christoph Bartelmus, Andrei Tanas");
MODULE_LICENSE("GPL");
module_param(type, int, 0444);
MODULE_PARM_DESC(type, "Hardware type (0 = home-brew, 1 = IRdeo, 2 = IRdeo Remote, 3 = AnimaX, 4 = IgorPlug");
module_param_hw(io, int, ioport, 0444);
MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
/* some architectures (e.g. intel xscale) have memory mapped registers */
module_param_hw(iommap, ulong, other, 0444);
MODULE_PARM_DESC(iommap, "physical base for memory mapped I/O (0 = no memory mapped io)");
/*
* some architectures (e.g. intel xscale) align the 8bit serial registers
* on 32bit word boundaries.
* See linux-kernel/drivers/tty/serial/8250/8250.c serial_in()/out()
*/
module_param_hw(ioshift, int, other, 0444);
MODULE_PARM_DESC(ioshift, "shift I/O register offset (0 = no shift)");
module_param_hw(irq, int, irq, 0444);
MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
module_param_hw(share_irq, bool, other, 0444);
MODULE_PARM_DESC(share_irq, "Share interrupts (0 = off, 1 = on)");
module_param(sense, int, 0444);
MODULE_PARM_DESC(sense, "Override autodetection of IR receiver circuit (0 = active high, 1 = active low )");
#ifdef CONFIG_IR_SERIAL_TRANSMITTER
module_param(txsense, bool, 0444);
MODULE_PARM_DESC(txsense, "Sense of transmitter circuit (0 = active high, 1 = active low )");
#endif
module_param(softcarrier, bool, 0444);
MODULE_PARM_DESC(softcarrier, "Software carrier (0 = off, 1 = on, default on)");