Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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.
 */
 
#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)
{
<------>struct 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 = 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)");