cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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serial_ir.c (20637B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * serial_ir.c
      4 *
      5 * serial_ir - Device driver that records pulse- and pause-lengths
      6 *	       (space-lengths) between DDCD event on a serial port.
      7 *
      8 * Copyright (C) 1996,97 Ralph Metzler <rjkm@thp.uni-koeln.de>
      9 * Copyright (C) 1998 Trent Piepho <xyzzy@u.washington.edu>
     10 * Copyright (C) 1998 Ben Pfaff <blp@gnu.org>
     11 * Copyright (C) 1999 Christoph Bartelmus <lirc@bartelmus.de>
     12 * Copyright (C) 2007 Andrei Tanas <andrei@tanas.ca> (suspend/resume support)
     13 * Copyright (C) 2016 Sean Young <sean@mess.org> (port to rc-core)
     14 */
     15
     16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
     17
     18#include <linux/module.h>
     19#include <linux/errno.h>
     20#include <linux/interrupt.h>
     21#include <linux/kernel.h>
     22#include <linux/serial_reg.h>
     23#include <linux/types.h>
     24#include <linux/delay.h>
     25#include <linux/platform_device.h>
     26#include <linux/spinlock.h>
     27#include <media/rc-core.h>
     28
     29struct serial_ir_hw {
     30	int signal_pin;
     31	int signal_pin_change;
     32	u8 on;
     33	u8 off;
     34	unsigned set_send_carrier:1;
     35	unsigned set_duty_cycle:1;
     36	void (*send_pulse)(unsigned int length, ktime_t edge);
     37	void (*send_space)(void);
     38	spinlock_t lock;
     39};
     40
     41#define IR_HOMEBREW	0
     42#define IR_IRDEO	1
     43#define IR_IRDEO_REMOTE	2
     44#define IR_ANIMAX	3
     45#define IR_IGOR		4
     46
     47/* module parameters */
     48static int type;
     49static int io;
     50static int irq;
     51static ulong iommap;
     52static int ioshift;
     53static bool softcarrier = true;
     54static bool share_irq;
     55static int sense = -1;	/* -1 = auto, 0 = active high, 1 = active low */
     56static bool txsense;	/* 0 = active high, 1 = active low */
     57
     58/* forward declarations */
     59static void send_pulse_irdeo(unsigned int length, ktime_t edge);
     60static void send_space_irdeo(void);
     61#ifdef CONFIG_IR_SERIAL_TRANSMITTER
     62static void send_pulse_homebrew(unsigned int length, ktime_t edge);
     63static void send_space_homebrew(void);
     64#endif
     65
     66static struct serial_ir_hw hardware[] = {
     67	[IR_HOMEBREW] = {
     68		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_HOMEBREW].lock),
     69		.signal_pin	   = UART_MSR_DCD,
     70		.signal_pin_change = UART_MSR_DDCD,
     71		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
     72		.off = (UART_MCR_RTS | UART_MCR_OUT2),
     73#ifdef CONFIG_IR_SERIAL_TRANSMITTER
     74		.send_pulse = send_pulse_homebrew,
     75		.send_space = send_space_homebrew,
     76		.set_send_carrier = true,
     77		.set_duty_cycle = true,
     78#endif
     79	},
     80
     81	[IR_IRDEO] = {
     82		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO].lock),
     83		.signal_pin	   = UART_MSR_DSR,
     84		.signal_pin_change = UART_MSR_DDSR,
     85		.on  = UART_MCR_OUT2,
     86		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
     87		.send_pulse = send_pulse_irdeo,
     88		.send_space = send_space_irdeo,
     89		.set_duty_cycle = true,
     90	},
     91
     92	[IR_IRDEO_REMOTE] = {
     93		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO_REMOTE].lock),
     94		.signal_pin	   = UART_MSR_DSR,
     95		.signal_pin_change = UART_MSR_DDSR,
     96		.on  = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
     97		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
     98		.send_pulse = send_pulse_irdeo,
     99		.send_space = send_space_irdeo,
    100		.set_duty_cycle = true,
    101	},
    102
    103	[IR_ANIMAX] = {
    104		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_ANIMAX].lock),
    105		.signal_pin	   = UART_MSR_DCD,
    106		.signal_pin_change = UART_MSR_DDCD,
    107		.on  = 0,
    108		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
    109	},
    110
    111	[IR_IGOR] = {
    112		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IGOR].lock),
    113		.signal_pin	   = UART_MSR_DSR,
    114		.signal_pin_change = UART_MSR_DDSR,
    115		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
    116		.off = (UART_MCR_RTS | UART_MCR_OUT2),
    117#ifdef CONFIG_IR_SERIAL_TRANSMITTER
    118		.send_pulse = send_pulse_homebrew,
    119		.send_space = send_space_homebrew,
    120		.set_send_carrier = true,
    121		.set_duty_cycle = true,
    122#endif
    123	},
    124};
    125
    126#define RS_ISR_PASS_LIMIT 256
    127
    128struct serial_ir {
    129	ktime_t lastkt;
    130	struct rc_dev *rcdev;
    131	struct platform_device *pdev;
    132	struct timer_list timeout_timer;
    133
    134	unsigned int carrier;
    135	unsigned int duty_cycle;
    136};
    137
    138static struct serial_ir serial_ir;
    139
    140/* fetch serial input packet (1 byte) from register offset */
    141static u8 sinp(int offset)
    142{
    143	if (iommap)
    144		/* the register is memory-mapped */
    145		offset <<= ioshift;
    146
    147	return inb(io + offset);
    148}
    149
    150/* write serial output packet (1 byte) of value to register offset */
    151static void soutp(int offset, u8 value)
    152{
    153	if (iommap)
    154		/* the register is memory-mapped */
    155		offset <<= ioshift;
    156
    157	outb(value, io + offset);
    158}
    159
    160static void on(void)
    161{
    162	if (txsense)
    163		soutp(UART_MCR, hardware[type].off);
    164	else
    165		soutp(UART_MCR, hardware[type].on);
    166}
    167
    168static void off(void)
    169{
    170	if (txsense)
    171		soutp(UART_MCR, hardware[type].on);
    172	else
    173		soutp(UART_MCR, hardware[type].off);
    174}
    175
    176static void send_pulse_irdeo(unsigned int length, ktime_t target)
    177{
    178	long rawbits;
    179	int i;
    180	unsigned char output;
    181	unsigned char chunk, shifted;
    182
    183	/* how many bits have to be sent ? */
    184	rawbits = length * 1152 / 10000;
    185	if (serial_ir.duty_cycle > 50)
    186		chunk = 3;
    187	else
    188		chunk = 1;
    189	for (i = 0, output = 0x7f; rawbits > 0; rawbits -= 3) {
    190		shifted = chunk << (i * 3);
    191		shifted >>= 1;
    192		output &= (~shifted);
    193		i++;
    194		if (i == 3) {
    195			soutp(UART_TX, output);
    196			while (!(sinp(UART_LSR) & UART_LSR_THRE))
    197				;
    198			output = 0x7f;
    199			i = 0;
    200		}
    201	}
    202	if (i != 0) {
    203		soutp(UART_TX, output);
    204		while (!(sinp(UART_LSR) & UART_LSR_TEMT))
    205			;
    206	}
    207}
    208
    209static void send_space_irdeo(void)
    210{
    211}
    212
    213#ifdef CONFIG_IR_SERIAL_TRANSMITTER
    214static void send_pulse_homebrew_softcarrier(unsigned int length, ktime_t edge)
    215{
    216	ktime_t now, target = ktime_add_us(edge, length);
    217	/*
    218	 * delta should never exceed 4 seconds and on m68k
    219	 * ndelay(s64) does not compile; so use s32 rather than s64.
    220	 */
    221	s32 delta;
    222	unsigned int pulse, space;
    223
    224	/* Ensure the dividend fits into 32 bit */
    225	pulse = DIV_ROUND_CLOSEST(serial_ir.duty_cycle * (NSEC_PER_SEC / 100),
    226				  serial_ir.carrier);
    227	space = DIV_ROUND_CLOSEST((100 - serial_ir.duty_cycle) *
    228				  (NSEC_PER_SEC / 100), serial_ir.carrier);
    229
    230	for (;;) {
    231		now = ktime_get();
    232		if (ktime_compare(now, target) >= 0)
    233			break;
    234		on();
    235		edge = ktime_add_ns(edge, pulse);
    236		delta = ktime_to_ns(ktime_sub(edge, now));
    237		if (delta > 0)
    238			ndelay(delta);
    239		now = ktime_get();
    240		off();
    241		if (ktime_compare(now, target) >= 0)
    242			break;
    243		edge = ktime_add_ns(edge, space);
    244		delta = ktime_to_ns(ktime_sub(edge, now));
    245		if (delta > 0)
    246			ndelay(delta);
    247	}
    248}
    249
    250static void send_pulse_homebrew(unsigned int length, ktime_t edge)
    251{
    252	if (softcarrier)
    253		send_pulse_homebrew_softcarrier(length, edge);
    254	else
    255		on();
    256}
    257
    258static void send_space_homebrew(void)
    259{
    260	off();
    261}
    262#endif
    263
    264static void frbwrite(unsigned int l, bool is_pulse)
    265{
    266	/* simple noise filter */
    267	static unsigned int ptr, pulse, space;
    268	struct ir_raw_event ev = {};
    269
    270	if (ptr > 0 && is_pulse) {
    271		pulse += l;
    272		if (pulse > 250) {
    273			ev.duration = space;
    274			ev.pulse = false;
    275			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
    276			ev.duration = pulse;
    277			ev.pulse = true;
    278			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
    279			ptr = 0;
    280			pulse = 0;
    281		}
    282		return;
    283	}
    284	if (!is_pulse) {
    285		if (ptr == 0) {
    286			if (l > 20000) {
    287				space = l;
    288				ptr++;
    289				return;
    290			}
    291		} else {
    292			if (l > 20000) {
    293				space += pulse;
    294				if (space > IR_MAX_DURATION)
    295					space = IR_MAX_DURATION;
    296				space += l;
    297				if (space > IR_MAX_DURATION)
    298					space = IR_MAX_DURATION;
    299				pulse = 0;
    300				return;
    301			}
    302
    303			ev.duration = space;
    304			ev.pulse = false;
    305			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
    306			ev.duration = pulse;
    307			ev.pulse = true;
    308			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
    309			ptr = 0;
    310			pulse = 0;
    311		}
    312	}
    313
    314	ev.duration = l;
    315	ev.pulse = is_pulse;
    316	ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
    317}
    318
    319static irqreturn_t serial_ir_irq_handler(int i, void *blah)
    320{
    321	ktime_t kt;
    322	int counter, dcd;
    323	u8 status;
    324	ktime_t delkt;
    325	unsigned int data;
    326	static int last_dcd = -1;
    327
    328	if ((sinp(UART_IIR) & UART_IIR_NO_INT)) {
    329		/* not our interrupt */
    330		return IRQ_NONE;
    331	}
    332
    333	counter = 0;
    334	do {
    335		counter++;
    336		status = sinp(UART_MSR);
    337		if (counter > RS_ISR_PASS_LIMIT) {
    338			dev_err(&serial_ir.pdev->dev, "Trapped in interrupt");
    339			break;
    340		}
    341		if ((status & hardware[type].signal_pin_change) &&
    342		    sense != -1) {
    343			/* get current time */
    344			kt = ktime_get();
    345
    346			/*
    347			 * The driver needs to know if your receiver is
    348			 * active high or active low, or the space/pulse
    349			 * sense could be inverted.
    350			 */
    351
    352			/* calc time since last interrupt in nanoseconds */
    353			dcd = (status & hardware[type].signal_pin) ? 1 : 0;
    354
    355			if (dcd == last_dcd) {
    356				dev_dbg(&serial_ir.pdev->dev,
    357					"ignoring spike: %d %d %lldns %lldns\n",
    358					dcd, sense, ktime_to_ns(kt),
    359					ktime_to_ns(serial_ir.lastkt));
    360				continue;
    361			}
    362
    363			delkt = ktime_sub(kt, serial_ir.lastkt);
    364			if (ktime_compare(delkt, ktime_set(15, 0)) > 0) {
    365				data = IR_MAX_DURATION; /* really long time */
    366				if (!(dcd ^ sense)) {
    367					/* sanity check */
    368					dev_err(&serial_ir.pdev->dev,
    369						"dcd unexpected: %d %d %lldns %lldns\n",
    370						dcd, sense, ktime_to_ns(kt),
    371						ktime_to_ns(serial_ir.lastkt));
    372					/*
    373					 * detecting pulse while this
    374					 * MUST be a space!
    375					 */
    376					sense = sense ? 0 : 1;
    377				}
    378			} else {
    379				data = ktime_to_us(delkt);
    380			}
    381			frbwrite(data, !(dcd ^ sense));
    382			serial_ir.lastkt = kt;
    383			last_dcd = dcd;
    384		}
    385	} while (!(sinp(UART_IIR) & UART_IIR_NO_INT)); /* still pending ? */
    386
    387	mod_timer(&serial_ir.timeout_timer,
    388		  jiffies + usecs_to_jiffies(serial_ir.rcdev->timeout));
    389
    390	ir_raw_event_handle(serial_ir.rcdev);
    391
    392	return IRQ_HANDLED;
    393}
    394
    395static int hardware_init_port(void)
    396{
    397	u8 scratch, scratch2, scratch3;
    398
    399	/*
    400	 * This is a simple port existence test, borrowed from the autoconfig
    401	 * function in drivers/tty/serial/8250/8250_port.c
    402	 */
    403	scratch = sinp(UART_IER);
    404	soutp(UART_IER, 0);
    405#ifdef __i386__
    406	outb(0xff, 0x080);
    407#endif
    408	scratch2 = sinp(UART_IER) & 0x0f;
    409	soutp(UART_IER, 0x0f);
    410#ifdef __i386__
    411	outb(0x00, 0x080);
    412#endif
    413	scratch3 = sinp(UART_IER) & 0x0f;
    414	soutp(UART_IER, scratch);
    415	if (scratch2 != 0 || scratch3 != 0x0f) {
    416		/* we fail, there's nothing here */
    417		pr_err("port existence test failed, cannot continue\n");
    418		return -ENODEV;
    419	}
    420
    421	/* Set DLAB 0. */
    422	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
    423
    424	/* First of all, disable all interrupts */
    425	soutp(UART_IER, sinp(UART_IER) &
    426	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
    427
    428	/* Clear registers. */
    429	sinp(UART_LSR);
    430	sinp(UART_RX);
    431	sinp(UART_IIR);
    432	sinp(UART_MSR);
    433
    434	/* Set line for power source */
    435	off();
    436
    437	/* Clear registers again to be sure. */
    438	sinp(UART_LSR);
    439	sinp(UART_RX);
    440	sinp(UART_IIR);
    441	sinp(UART_MSR);
    442
    443	switch (type) {
    444	case IR_IRDEO:
    445	case IR_IRDEO_REMOTE:
    446		/* setup port to 7N1 @ 115200 Baud */
    447		/* 7N1+start = 9 bits at 115200 ~ 3 bits at 38kHz */
    448
    449		/* Set DLAB 1. */
    450		soutp(UART_LCR, sinp(UART_LCR) | UART_LCR_DLAB);
    451		/* Set divisor to 1 => 115200 Baud */
    452		soutp(UART_DLM, 0);
    453		soutp(UART_DLL, 1);
    454		/* Set DLAB 0 +  7N1 */
    455		soutp(UART_LCR, UART_LCR_WLEN7);
    456		/* THR interrupt already disabled at this point */
    457		break;
    458	default:
    459		break;
    460	}
    461
    462	return 0;
    463}
    464
    465static void serial_ir_timeout(struct timer_list *unused)
    466{
    467	struct ir_raw_event ev = {
    468		.timeout = true,
    469		.duration = serial_ir.rcdev->timeout
    470	};
    471	ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
    472	ir_raw_event_handle(serial_ir.rcdev);
    473}
    474
    475/* Needed by serial_ir_probe() */
    476static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
    477			unsigned int count);
    478static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle);
    479static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier);
    480static int serial_ir_open(struct rc_dev *rcdev);
    481static void serial_ir_close(struct rc_dev *rcdev);
    482
    483static int serial_ir_probe(struct platform_device *dev)
    484{
    485	struct rc_dev *rcdev;
    486	int i, nlow, nhigh, result;
    487
    488	rcdev = devm_rc_allocate_device(&dev->dev, RC_DRIVER_IR_RAW);
    489	if (!rcdev)
    490		return -ENOMEM;
    491
    492	if (hardware[type].send_pulse && hardware[type].send_space)
    493		rcdev->tx_ir = serial_ir_tx;
    494	if (hardware[type].set_send_carrier)
    495		rcdev->s_tx_carrier = serial_ir_tx_carrier;
    496	if (hardware[type].set_duty_cycle)
    497		rcdev->s_tx_duty_cycle = serial_ir_tx_duty_cycle;
    498
    499	switch (type) {
    500	case IR_HOMEBREW:
    501		rcdev->device_name = "Serial IR type home-brew";
    502		break;
    503	case IR_IRDEO:
    504		rcdev->device_name = "Serial IR type IRdeo";
    505		break;
    506	case IR_IRDEO_REMOTE:
    507		rcdev->device_name = "Serial IR type IRdeo remote";
    508		break;
    509	case IR_ANIMAX:
    510		rcdev->device_name = "Serial IR type AnimaX";
    511		break;
    512	case IR_IGOR:
    513		rcdev->device_name = "Serial IR type IgorPlug";
    514		break;
    515	}
    516
    517	rcdev->input_phys = KBUILD_MODNAME "/input0";
    518	rcdev->input_id.bustype = BUS_HOST;
    519	rcdev->input_id.vendor = 0x0001;
    520	rcdev->input_id.product = 0x0001;
    521	rcdev->input_id.version = 0x0100;
    522	rcdev->open = serial_ir_open;
    523	rcdev->close = serial_ir_close;
    524	rcdev->dev.parent = &serial_ir.pdev->dev;
    525	rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
    526	rcdev->driver_name = KBUILD_MODNAME;
    527	rcdev->map_name = RC_MAP_RC6_MCE;
    528	rcdev->min_timeout = 1;
    529	rcdev->timeout = IR_DEFAULT_TIMEOUT;
    530	rcdev->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
    531	rcdev->rx_resolution = 250;
    532
    533	serial_ir.rcdev = rcdev;
    534
    535	timer_setup(&serial_ir.timeout_timer, serial_ir_timeout, 0);
    536
    537	result = devm_request_irq(&dev->dev, irq, serial_ir_irq_handler,
    538				  share_irq ? IRQF_SHARED : 0,
    539				  KBUILD_MODNAME, &hardware);
    540	if (result < 0) {
    541		if (result == -EBUSY)
    542			dev_err(&dev->dev, "IRQ %d busy\n", irq);
    543		else if (result == -EINVAL)
    544			dev_err(&dev->dev, "Bad irq number or handler\n");
    545		return result;
    546	}
    547
    548	/* Reserve io region. */
    549	if ((iommap &&
    550	     (devm_request_mem_region(&dev->dev, iommap, 8UL << ioshift,
    551				      KBUILD_MODNAME) == NULL)) ||
    552	     (!iommap && (devm_request_region(&dev->dev, io, 8,
    553			  KBUILD_MODNAME) == NULL))) {
    554		dev_err(&dev->dev, "port %04x already in use\n", io);
    555		dev_warn(&dev->dev, "use 'setserial /dev/ttySX uart none'\n");
    556		dev_warn(&dev->dev,
    557			 "or compile the serial port driver as module and\n");
    558		dev_warn(&dev->dev, "make sure this module is loaded first\n");
    559		return -EBUSY;
    560	}
    561
    562	result = hardware_init_port();
    563	if (result < 0)
    564		return result;
    565
    566	/* Initialize pulse/space widths */
    567	serial_ir.duty_cycle = 50;
    568	serial_ir.carrier = 38000;
    569
    570	/* If pin is high, then this must be an active low receiver. */
    571	if (sense == -1) {
    572		/* wait 1/2 sec for the power supply */
    573		msleep(500);
    574
    575		/*
    576		 * probe 9 times every 0.04s, collect "votes" for
    577		 * active high/low
    578		 */
    579		nlow = 0;
    580		nhigh = 0;
    581		for (i = 0; i < 9; i++) {
    582			if (sinp(UART_MSR) & hardware[type].signal_pin)
    583				nlow++;
    584			else
    585				nhigh++;
    586			msleep(40);
    587		}
    588		sense = nlow >= nhigh ? 1 : 0;
    589		dev_info(&dev->dev, "auto-detected active %s receiver\n",
    590			 sense ? "low" : "high");
    591	} else
    592		dev_info(&dev->dev, "Manually using active %s receiver\n",
    593			 sense ? "low" : "high");
    594
    595	dev_dbg(&dev->dev, "Interrupt %d, port %04x obtained\n", irq, io);
    596
    597	return devm_rc_register_device(&dev->dev, rcdev);
    598}
    599
    600static int serial_ir_open(struct rc_dev *rcdev)
    601{
    602	unsigned long flags;
    603
    604	/* initialize timestamp */
    605	serial_ir.lastkt = ktime_get();
    606
    607	spin_lock_irqsave(&hardware[type].lock, flags);
    608
    609	/* Set DLAB 0. */
    610	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
    611
    612	soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);
    613
    614	spin_unlock_irqrestore(&hardware[type].lock, flags);
    615
    616	return 0;
    617}
    618
    619static void serial_ir_close(struct rc_dev *rcdev)
    620{
    621	unsigned long flags;
    622
    623	spin_lock_irqsave(&hardware[type].lock, flags);
    624
    625	/* Set DLAB 0. */
    626	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
    627
    628	/* First of all, disable all interrupts */
    629	soutp(UART_IER, sinp(UART_IER) &
    630	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
    631	spin_unlock_irqrestore(&hardware[type].lock, flags);
    632}
    633
    634static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
    635			unsigned int count)
    636{
    637	unsigned long flags;
    638	ktime_t edge;
    639	s64 delta;
    640	int i;
    641
    642	spin_lock_irqsave(&hardware[type].lock, flags);
    643	if (type == IR_IRDEO) {
    644		/* DTR, RTS down */
    645		on();
    646	}
    647
    648	edge = ktime_get();
    649	for (i = 0; i < count; i++) {
    650		if (i % 2)
    651			hardware[type].send_space();
    652		else
    653			hardware[type].send_pulse(txbuf[i], edge);
    654
    655		edge = ktime_add_us(edge, txbuf[i]);
    656		delta = ktime_us_delta(edge, ktime_get());
    657		if (delta > 25) {
    658			spin_unlock_irqrestore(&hardware[type].lock, flags);
    659			usleep_range(delta - 25, delta + 25);
    660			spin_lock_irqsave(&hardware[type].lock, flags);
    661		} else if (delta > 0) {
    662			udelay(delta);
    663		}
    664	}
    665	off();
    666	spin_unlock_irqrestore(&hardware[type].lock, flags);
    667	return count;
    668}
    669
    670static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle)
    671{
    672	serial_ir.duty_cycle = cycle;
    673	return 0;
    674}
    675
    676static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier)
    677{
    678	if (carrier > 500000 || carrier < 20000)
    679		return -EINVAL;
    680
    681	serial_ir.carrier = carrier;
    682	return 0;
    683}
    684
    685static int serial_ir_suspend(struct platform_device *dev,
    686			     pm_message_t state)
    687{
    688	/* Set DLAB 0. */
    689	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
    690
    691	/* Disable all interrupts */
    692	soutp(UART_IER, sinp(UART_IER) &
    693	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
    694
    695	/* Clear registers. */
    696	sinp(UART_LSR);
    697	sinp(UART_RX);
    698	sinp(UART_IIR);
    699	sinp(UART_MSR);
    700
    701	return 0;
    702}
    703
    704static int serial_ir_resume(struct platform_device *dev)
    705{
    706	unsigned long flags;
    707	int result;
    708
    709	result = hardware_init_port();
    710	if (result < 0)
    711		return result;
    712
    713	spin_lock_irqsave(&hardware[type].lock, flags);
    714	/* Enable Interrupt */
    715	serial_ir.lastkt = ktime_get();
    716	soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);
    717	off();
    718
    719	spin_unlock_irqrestore(&hardware[type].lock, flags);
    720
    721	return 0;
    722}
    723
    724static struct platform_driver serial_ir_driver = {
    725	.probe		= serial_ir_probe,
    726	.suspend	= serial_ir_suspend,
    727	.resume		= serial_ir_resume,
    728	.driver		= {
    729		.name	= "serial_ir",
    730	},
    731};
    732
    733static int __init serial_ir_init(void)
    734{
    735	int result;
    736
    737	result = platform_driver_register(&serial_ir_driver);
    738	if (result)
    739		return result;
    740
    741	serial_ir.pdev = platform_device_alloc("serial_ir", 0);
    742	if (!serial_ir.pdev) {
    743		result = -ENOMEM;
    744		goto exit_driver_unregister;
    745	}
    746
    747	result = platform_device_add(serial_ir.pdev);
    748	if (result)
    749		goto exit_device_put;
    750
    751	return 0;
    752
    753exit_device_put:
    754	platform_device_put(serial_ir.pdev);
    755exit_driver_unregister:
    756	platform_driver_unregister(&serial_ir_driver);
    757	return result;
    758}
    759
    760static void serial_ir_exit(void)
    761{
    762	platform_device_unregister(serial_ir.pdev);
    763	platform_driver_unregister(&serial_ir_driver);
    764}
    765
    766static int __init serial_ir_init_module(void)
    767{
    768	switch (type) {
    769	case IR_HOMEBREW:
    770	case IR_IRDEO:
    771	case IR_IRDEO_REMOTE:
    772	case IR_ANIMAX:
    773	case IR_IGOR:
    774		/* if nothing specified, use ttyS0/com1 and irq 4 */
    775		io = io ? io : 0x3f8;
    776		irq = irq ? irq : 4;
    777		break;
    778	default:
    779		return -EINVAL;
    780	}
    781	if (!softcarrier) {
    782		switch (type) {
    783		case IR_HOMEBREW:
    784		case IR_IGOR:
    785			hardware[type].set_send_carrier = false;
    786			hardware[type].set_duty_cycle = false;
    787			break;
    788		}
    789	}
    790
    791	/* make sure sense is either -1, 0, or 1 */
    792	if (sense != -1)
    793		sense = !!sense;
    794
    795	return serial_ir_init();
    796}
    797
    798static void __exit serial_ir_exit_module(void)
    799{
    800	del_timer_sync(&serial_ir.timeout_timer);
    801	serial_ir_exit();
    802}
    803
    804module_init(serial_ir_init_module);
    805module_exit(serial_ir_exit_module);
    806
    807MODULE_DESCRIPTION("Infra-red receiver driver for serial ports.");
    808MODULE_AUTHOR("Ralph Metzler, Trent Piepho, Ben Pfaff, Christoph Bartelmus, Andrei Tanas");
    809MODULE_LICENSE("GPL");
    810
    811module_param(type, int, 0444);
    812MODULE_PARM_DESC(type, "Hardware type (0 = home-brew, 1 = IRdeo, 2 = IRdeo Remote, 3 = AnimaX, 4 = IgorPlug");
    813
    814module_param_hw(io, int, ioport, 0444);
    815MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
    816
    817/* some architectures (e.g. intel xscale) have memory mapped registers */
    818module_param_hw(iommap, ulong, other, 0444);
    819MODULE_PARM_DESC(iommap, "physical base for memory mapped I/O (0 = no memory mapped io)");
    820
    821/*
    822 * some architectures (e.g. intel xscale) align the 8bit serial registers
    823 * on 32bit word boundaries.
    824 * See linux-kernel/drivers/tty/serial/8250/8250.c serial_in()/out()
    825 */
    826module_param_hw(ioshift, int, other, 0444);
    827MODULE_PARM_DESC(ioshift, "shift I/O register offset (0 = no shift)");
    828
    829module_param_hw(irq, int, irq, 0444);
    830MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
    831
    832module_param_hw(share_irq, bool, other, 0444);
    833MODULE_PARM_DESC(share_irq, "Share interrupts (0 = off, 1 = on)");
    834
    835module_param(sense, int, 0444);
    836MODULE_PARM_DESC(sense, "Override autodetection of IR receiver circuit (0 = active high, 1 = active low )");
    837
    838#ifdef CONFIG_IR_SERIAL_TRANSMITTER
    839module_param(txsense, bool, 0444);
    840MODULE_PARM_DESC(txsense, "Sense of transmitter circuit (0 = active high, 1 = active low )");
    841#endif
    842
    843module_param(softcarrier, bool, 0444);
    844MODULE_PARM_DESC(softcarrier, "Software carrier (0 = off, 1 = on, default on)");