/*
* IR SIR driver, (C) 2000 Milan Pikula <www@fornax.sk>
*
* sir_ir - Device driver for use with SIR (serial infra red)
* mode of IrDA on many notebooks.
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/serial_reg.h>
#include <linux/ktime.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <media/rc-core.h>
/* SECTION: Definitions */
#define PULSE '['
/* 9bit * 1s/115200bit in milli seconds = 78.125ms*/
#define TIME_CONST (9000000ul / 115200ul)
/* timeout for sequences in jiffies (=5/100s), must be longer than TIME_CONST */
#define SIR_TIMEOUT (HZ * 5 / 100)
/* onboard sir ports are typically com3 */
static int io = 0x3e8;
static int irq = 4;
static int threshold = 3;
static DEFINE_SPINLOCK(timer_lock);
static struct timer_list timerlist;
/* time of last signal change detected */
static ktime_t last;
/* time of last UART data ready interrupt */
static ktime_t last_intr_time;
static int last_value;
static struct rc_dev *rcdev;
static struct platform_device *sir_ir_dev;
static DEFINE_SPINLOCK(hardware_lock);
/* SECTION: Prototypes */
/* Communication with user-space */
static void add_read_queue(int flag, unsigned long val);
/* Hardware */
static irqreturn_t sir_interrupt(int irq, void *dev_id);
static void send_space(unsigned long len);
static void send_pulse(unsigned long len);
static int init_hardware(void);
static void drop_hardware(void);
/* Initialisation */
static inline unsigned int sinp(int offset)
{
return inb(io + offset);
}
static inline void soutp(int offset, int value)
{
outb(value, io + offset);
}
/* SECTION: Communication with user-space */
static int sir_tx_ir(struct rc_dev *dev, unsigned int *tx_buf,
unsigned int count)
{
unsigned long flags;
int i;
local_irq_save(flags);
for (i = 0; i < count;) {
if (tx_buf[i])
send_pulse(tx_buf[i]);
i++;
if (i >= count)
break;
if (tx_buf[i])
send_space(tx_buf[i]);
i++;
}
local_irq_restore(flags);
return count;
}
static void add_read_queue(int flag, unsigned long val)
{
DEFINE_IR_RAW_EVENT(ev);
pr_debug("add flag %d with val %lu\n", flag, val);
/*
* statistically, pulses are ~TIME_CONST/2 too long. we could
* maybe make this more exact, but this is good enough
*/
if (flag) {
/* pulse */
if (val > TIME_CONST / 2)
val -= TIME_CONST / 2;
else /* should not ever happen */
val = 1;
ev.pulse = true;
} else {
val += TIME_CONST / 2;
}
ev.duration = US_TO_NS(val);
ir_raw_event_store_with_filter(rcdev, &ev);
}
/* SECTION: Hardware */
static void sir_timeout(struct timer_list *unused)
{
/*
* 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.
*/
unsigned long flags;
unsigned long pulse_end;
/* avoid interference with interrupt */
spin_lock_irqsave(&timer_lock, flags);
if (last_value) {
/* clear unread bits in UART and restart */
outb(UART_FCR_CLEAR_RCVR, io + UART_FCR);
/* determine 'virtual' pulse end: */
pulse_end = min_t(unsigned long,
ktime_us_delta(last, last_intr_time),
IR_MAX_DURATION);
dev_dbg(&sir_ir_dev->dev, "timeout add %d for %lu usec\n",
last_value, pulse_end);
add_read_queue(last_value, pulse_end);
last_value = 0;
last = last_intr_time;
}
spin_unlock_irqrestore(&timer_lock, flags);
ir_raw_event_handle(rcdev);
}
static irqreturn_t sir_interrupt(int irq, void *dev_id)
{
unsigned char data;
ktime_t curr_time;
unsigned long delt;
unsigned long deltintr;
unsigned long flags;
int counter = 0;
int iir, lsr;
while ((iir = inb(io + UART_IIR) & UART_IIR_ID)) {
if (++counter > 256) {
dev_err(&sir_ir_dev->dev, "Trapped in interrupt");
break;
}
switch (iir & UART_IIR_ID) { /* FIXME toto treba preriedit */
case UART_IIR_MSI:
(void)inb(io + UART_MSR);
break;
case UART_IIR_RLSI:
case UART_IIR_THRI:
(void)inb(io + UART_LSR);
break;
case UART_IIR_RDI:
/* avoid interference with timer */
spin_lock_irqsave(&timer_lock, flags);
do {
del_timer(&timerlist);
data = inb(io + UART_RX);
curr_time = ktime_get();
delt = min_t(unsigned long,
ktime_us_delta(last, curr_time),
IR_MAX_DURATION);
deltintr = min_t(unsigned long,
ktime_us_delta(last_intr_time,
curr_time),
IR_MAX_DURATION);
dev_dbg(&sir_ir_dev->dev, "t %lu, d %d\n",
deltintr, (int)data);
/*
* if nothing came in last X cycles,
* it was gap
*/
if (deltintr > TIME_CONST * threshold) {
if (last_value) {
dev_dbg(&sir_ir_dev->dev, "GAP\n");
/* simulate signal change */
add_read_queue(last_value,
delt -
deltintr);
last_value = 0;
last = last_intr_time;
delt = deltintr;
}
}
data = 1;
if (data ^ last_value) {
/*
* deltintr > 2*TIME_CONST, remember?
* the other case is timeout
*/
add_read_queue(last_value,
delt - TIME_CONST);
last_value = data;
last = curr_time;
last = ktime_sub_us(last,
TIME_CONST);
}
last_intr_time = curr_time;
if (data) {
/*
* start timer for end of
* sequence detection
*/
timerlist.expires = jiffies +
SIR_TIMEOUT;
add_timer(&timerlist);
}
lsr = inb(io + UART_LSR);
} while (lsr & UART_LSR_DR); /* data ready */
spin_unlock_irqrestore(&timer_lock, flags);
break;
default:
break;
}
}
ir_raw_event_handle(rcdev);
return IRQ_RETVAL(IRQ_HANDLED);
}
static void send_space(unsigned long len)
{
usleep_range(len, len + 25);
}
static void send_pulse(unsigned long len)
{
long bytes_out = len / TIME_CONST;
if (bytes_out == 0)
bytes_out++;
while (bytes_out--) {
outb(PULSE, io + UART_TX);
/* FIXME treba seriozne cakanie z char/serial.c */
while (!(inb(io + UART_LSR) & UART_LSR_THRE))
;
}
}
static int init_hardware(void)
{
u8 scratch, scratch2, scratch3;
unsigned long flags;
spin_lock_irqsave(&hardware_lock, flags);
/*
* 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 */
spin_unlock_irqrestore(&hardware_lock, flags);
pr_err("port existence test failed, cannot continue\n");
return -ENODEV;
}
/* reset UART */
outb(0, io + UART_MCR);
outb(0, io + UART_IER);
/* init UART */
/* set DLAB, speed = 115200 */
outb(UART_LCR_DLAB | UART_LCR_WLEN7, io + UART_LCR);
outb(1, io + UART_DLL); outb(0, io + UART_DLM);
/* 7N1+start = 9 bits at 115200 ~ 3 bits at 44000 */
outb(UART_LCR_WLEN7, io + UART_LCR);
/* FIFO operation */
outb(UART_FCR_ENABLE_FIFO, io + UART_FCR);
/* interrupts */
/* outb(UART_IER_RLSI|UART_IER_RDI|UART_IER_THRI, io + UART_IER); */
outb(UART_IER_RDI, io + UART_IER);
/* turn on UART */
outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2, io + UART_MCR);
spin_unlock_irqrestore(&hardware_lock, flags);
return 0;
}
static void drop_hardware(void)
{
unsigned long flags;
spin_lock_irqsave(&hardware_lock, flags);
/* turn off interrupts */
outb(0, io + UART_IER);
spin_unlock_irqrestore(&hardware_lock, flags);
}
/* SECTION: Initialisation */
static int sir_ir_probe(struct platform_device *dev)
{
int retval;
rcdev = devm_rc_allocate_device(&sir_ir_dev->dev, RC_DRIVER_IR_RAW);
if (!rcdev)
return -ENOMEM;
rcdev->device_name = "SIR IrDA port";
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->tx_ir = sir_tx_ir;
rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
rcdev->driver_name = KBUILD_MODNAME;
rcdev->map_name = RC_MAP_RC6_MCE;
rcdev->timeout = IR_DEFAULT_TIMEOUT;
rcdev->dev.parent = &sir_ir_dev->dev;
timer_setup(&timerlist, sir_timeout, 0);
/* get I/O port access and IRQ line */
if (!devm_request_region(&sir_ir_dev->dev, io, 8, KBUILD_MODNAME)) {
pr_err("i/o port 0x%.4x already in use.\n", io);
return -EBUSY;
}
retval = devm_request_irq(&sir_ir_dev->dev, irq, sir_interrupt, 0,
KBUILD_MODNAME, NULL);
if (retval < 0) {
pr_err("IRQ %d already in use.\n", irq);
return retval;
}
retval = init_hardware();
if (retval) {
del_timer_sync(&timerlist);
return retval;
}
pr_info("I/O port 0x%.4x, IRQ %d.\n", io, irq);
retval = devm_rc_register_device(&sir_ir_dev->dev, rcdev);
if (retval < 0)
return retval;
return 0;
}
static int sir_ir_remove(struct platform_device *dev)
{
drop_hardware();
del_timer_sync(&timerlist);
return 0;
}
static struct platform_driver sir_ir_driver = {
.probe = sir_ir_probe,
.remove = sir_ir_remove,
.driver = {
.name = "sir_ir",
},
};
static int __init sir_ir_init(void)
{
int retval;
retval = platform_driver_register(&sir_ir_driver);
if (retval)
return retval;
sir_ir_dev = platform_device_alloc("sir_ir", 0);
if (!sir_ir_dev) {
retval = -ENOMEM;
goto pdev_alloc_fail;
}
retval = platform_device_add(sir_ir_dev);
if (retval)
goto pdev_add_fail;
return 0;
pdev_add_fail:
platform_device_put(sir_ir_dev);
pdev_alloc_fail:
platform_driver_unregister(&sir_ir_driver);
return retval;
}
static void __exit sir_ir_exit(void)
{
platform_device_unregister(sir_ir_dev);
platform_driver_unregister(&sir_ir_driver);
}
module_init(sir_ir_init);
module_exit(sir_ir_exit);
MODULE_DESCRIPTION("Infrared receiver driver for SIR type serial ports");
MODULE_AUTHOR("Milan Pikula");
MODULE_LICENSE("GPL");
module_param_hw(io, int, ioport, 0444);
MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
module_param_hw(irq, int, irq, 0444);
MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
module_param(threshold, int, 0444);
MODULE_PARM_DESC(threshold, "space detection threshold (3)");
